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osmo-bsc/src/osmo-bsc/handover_decision.c

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[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
/* Handover Decision making for Inter-BTS (Intra-BSC) Handover. This
* only implements the handover algorithm/decision, but not execution
* of it */
/* (C) 2009 by Harald Welte <laforge@gnumonks.org>
*
* All Rights Reserved
*
* This program is free software; you can redistribute it and/or modify
License change: We are now AGPLv3+ instead of GPLv2+ The reason for this is quite simple: We want to make sure anyone running a customized version of OpenBSC to operate a network will have to release all custom modifiations to the source code.
2011-01-01 14:25:50 +00:00
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
License change: We are now AGPLv3+ instead of GPLv2+ The reason for this is quite simple: We want to make sure anyone running a customized version of OpenBSC to operate a network will have to release all custom modifiations to the source code.
2011-01-01 14:25:50 +00:00
* GNU Affero General Public License for more details.
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
*
License change: We are now AGPLv3+ instead of GPLv2+ The reason for this is quite simple: We want to make sure anyone running a customized version of OpenBSC to operate a network will have to release all custom modifiations to the source code.
2011-01-01 14:25:50 +00:00
* You should have received a copy of the GNU Affero General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
*
*/
#include <stdlib.h>
#include <errno.h>
src: use new library libosmogsm and new path to headers in libosmocore libosmogsm is a new library that is distributed in the libosmocore. Now, openbsc depends on it. This patch gets openbsc with this change. This patch also rewrites all include path to the new osmocom/[gsm|core] Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
2011-03-22 15:47:59 +00:00
#include <osmocom/core/msgb.h>
move include/openbsc to include/osmocom/bsc Change-Id: I39e7b882caa98334636d19ccd104fd83d07d5055
2017-09-04 13:15:32 +00:00
#include <osmocom/bsc/debug.h>
#include <osmocom/bsc/gsm_data.h>
#include <osmocom/bsc/meas_rep.h>
#include <osmocom/bsc/signal.h>
src: use new library libosmogsm and new path to headers in libosmocore libosmogsm is a new library that is distributed in the libosmocore. Now, openbsc depends on it. This patch gets openbsc with this change. This patch also rewrites all include path to the new osmocom/[gsm|core] Signed-off-by: Pablo Neira Ayuso <pablo@gnumonks.org>
2011-03-22 15:47:59 +00:00
#include <osmocom/core/talloc.h>
#include <osmocom/gsm/gsm_utils.h>
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
large refactoring: use FSMs for lchans; add inter-BSC HO Add FSMs: - timeslot_fsm: handle dynamic timeslots and OML+RSL availability. - lchan_fsm: handle an individual lchan activation, RTP stream and release, signal the appropriate calling FSMs on success, failure, release. - mgw_endpoint_fsm: handle one entire endpoint with several CI. - assignment_fsm: BSSMAP Assignment Request. - handover_fsm: all of intra, inter-MO and inter-MT handover. Above FSMs absorb large parts of the gscon FSM. The gscon FSM was surpassing the maximum amount events (32), and it is more logical to treat assignment, handover and MGW procedures in separate FSMs. - Add logging macros for each FSM type: - LOG_TS() - LOG_LCHAN() - LOG_MGWEP(), LOG_CI() - LOG_ASSIGNMENT() - LOG_HO() These log with the osmo_fsm_inst where present. New style decision: logging without a final newline char is awkward, especially for gsmtap logging and when other logs interleave LOGPC() calls; we have various cases where the final \n goes missing, and also this invokes the log category checking N times instead of once. So I decided to make these macros *always* append a newline, but only if there is no final newline yet. I hope that the compiler optimizes the strlen() of the constant format strings away. Thus I can log with or without typing "\n" and always get an \n termination anyway. General: - replace osmo_timers, state enums and program-wide osmo_signal_dispatch() with dedicated FSM timeouts, states and events. - introduce a common way to handle Tnnn timers: gsm_timers.h/.c: struct T_def. These can be used (with some macro magic) to define a state's timeout once, and not make mistakes for each osmo_fsm_inst_state_chg(). Details: bsc_subscr_conn_fsm.c: - move most states of this FSM to lchan_fsm, assignment_fsm, handover_fsm and mgw_endpoint_fsm. - There is exactly one state for an ongoing Assignment, with all details handled in conn->assignment.fi. The state relies on the assignment_fsm's timeout. - There is one state for an ongoing Handover; except for an incoming Handover from a remote BSS, the gscon remains in ST_INIT until the new lchan and conn are both established. - move bssmap_add_lcls_status() to osmo_bsc_lcls.c abis_rsl.c: - move all dynamic timeslot logic away into timeslot_fsm. Only keep plain send/receive functions in abis_rsl.c - reduce some rsl functions to merely send a message, rename to "_tx_". - rsl_ipacc_mdcx(): add '_tx_' in the name; move parts that change the lchan state out into the lchan_fsm, the lchan->abis_ip.* are now set there prior to invoking this function. - move all timers and error/release handling away into various FSMs. - tweak ipa_smod_s_for_lchan() and ipa_rtp_pt_for_lchan() to not require an lchan passed, but just mode,type that they require. Rename to ipacc_speech_mode*() and ipacc_payload_type(). - add rsl_forward_layer3_info, used for inter-BSC HO MO, to just send the RR message received during BSSMAP Handover Command. - move various logging to LOG_LCHAN() in order to log with the lchan FSM instance. One drawback is that the lchan FSM is limited to one logging category, i.e. this moves some logging from DRR to DRSL. It might actually make sense to combine those categories. - lose LOGP...LOGPC logging cascades: they are bad for gsmtap logging and for performance. - handle_classmark_chg(): change logging, move cm2 len check out of the cm3 condition (I hope that's correct). - gsm48_send_ho_cmd(): split off gsm48_make_ho_cmd() which doesn't send right away, so that during inter-bsc HO we can make an RR Handover Command to send via the MSC to the remote BSS. assignment_fsm.c: - the Chan Mode Modify in case of re-using the same lchan is not implemented yet, because this was also missing in the previous implementation (OS#3357). osmo_bsc_api.c: - simplify bsc_mr_config() and move to lchan_fsm.c, the only caller; rename to lchan_mr_config(). (bsc_mr_config() used to copy the values to mr_bts_lv twice, once by member assignment and then again with a memcpy.) - During handover, we used to copy the MR config from the old lchan. Since we may handover between FR and HR, rather set the MR Config anew every time, so that FR rates are always available on FR lchans, and never on HR lchans. Depends: I03ee7ce840ecfa0b6a33358e7385528aabd4873f (libosmocore), I1f2918418c38918c5ac70acaa51a47adfca12b5e (libosmocore) Change-Id: I82e3f918295daa83274a4cf803f046979f284366
2018-05-14 16:14:15 +00:00
#include <osmocom/bsc/handover_fsm.h>
HO prep: introduce per-BTS handover config, with defaults on net node It is desirable to allow configuring handover for each individual network cell. At the same time, it is desirable to set global defaults. Treat the 'network' node handover parameters as global defaults, add another set of parameters for each individual BTS. This raises questions on how the 'network' node should affect the individual BTS. The simplistic solution would have been: on creating a BTS in the config, just copy the current defaults; with serious drawbacks: - tweaking any parameter in the telnet VTY on network node will never affect any running BTS. - network node defaults *must* be issued before the bts sections in the config file. - when writing a config back to file, we would copy all net node defaults to each BTS node, making the network node configs pointless. Instead, add a handover_cfg API that tracks whether a given node has a value set or not. A bts node ho_cfg gets a pointer to the network node config and returns those values if locally unset. If no value is set on any node, use the "factory" defaults, which are hardcoded in the API. Only write back exactly those config items that were actually issued in a config file / on the telnet VTY. (ho_cfg API wise, we could trivially add another ho_cfg level per TRX if we so desire in the future.) Implement ho parameters as an opaque config struct with getters and setters to ensure the tracking is always heeded. Opaqueness dictates allocating instead of direct embedding in gsm_network and gsm_bts structs, ctx is gsm_net / bts. This is 100% backwards compatible to old configs. - No VTY command syntax changes (only the online help). - If a 'bts' sets nothing, it will use the 'network' defaults. - The 'show network' output only changes in presence of individual BTS configs. On 'show network', say "Handover: On|Off" as before, iff all BTS reflect identical behavior. Otherwise, output BTS counts of handover being enabled or not. Use the same set of VTY commands (same VTY cmd syntax as before) on network and BTS nodes, i.e. don't duplicate VTY code. From the current vty->node, figure out which ho_cfg to modify. For linking, add handover_cfg.c (the value API) in libcommon, while the handover_vty.c is in libbsc. This is mainly because some utility programs use gsm_network and hence suck in the ho stuff, but don't need the VTY commands. Review the VTY online help strings. Add VTY transcript test for handover options, testing config propagation from network to bts nodes, 'show network' output and VTY online help strings. (Needs recent addition of '... !' wildcard to osmo_interact_common.py.) I considered leaving parts of this more readable, but in the end decided for heavy use of macros to define and declare the API, because more values will be added in upcoming patches and I want to prevent myself from messing them up. Inspired-by: jolly/new_handover branch, which moves the config to 'bts' level Depends: I7c1ebb2e7f059047903a53de26a0ec1ce7fa9b98 (osmo-python-tests) Change-Id: I79d35f6d3c0fbee67904378ad7f216df34fde79a
2017-11-27 20:29:33 +00:00
#include <osmocom/bsc/handover_cfg.h>
Move struct gsm_bts: gsm_data.* => bts.* Place all code related to the object into the related file. Having all the data model in one file made sense in early stage of development to make progress quickly, but nowadays it hurts more than helps, due to constantly growing size and more and more bits being added to the model, gaining in complexity. Currently, having lots of different objects mixed up in gsm_data.h is a hole of despair, where nobody can make any sense were to properly put new stuff in, ending up with functions related to same object in different files or with wrong prefixes, declarations of non-existing functions, etc. because people cannot make up their mind on strict relation to objects in the data model. Splitting them in files really helps finding code operating on a specific object and helping with logically splitting in the future. Change-Id: I00c15f5285b5c1a0109279b7ab192d5467a04ece
2020-07-15 18:53:16 +00:00
#include <osmocom/bsc/bts.h>
HO prep: introduce per-BTS handover config, with defaults on net node It is desirable to allow configuring handover for each individual network cell. At the same time, it is desirable to set global defaults. Treat the 'network' node handover parameters as global defaults, add another set of parameters for each individual BTS. This raises questions on how the 'network' node should affect the individual BTS. The simplistic solution would have been: on creating a BTS in the config, just copy the current defaults; with serious drawbacks: - tweaking any parameter in the telnet VTY on network node will never affect any running BTS. - network node defaults *must* be issued before the bts sections in the config file. - when writing a config back to file, we would copy all net node defaults to each BTS node, making the network node configs pointless. Instead, add a handover_cfg API that tracks whether a given node has a value set or not. A bts node ho_cfg gets a pointer to the network node config and returns those values if locally unset. If no value is set on any node, use the "factory" defaults, which are hardcoded in the API. Only write back exactly those config items that were actually issued in a config file / on the telnet VTY. (ho_cfg API wise, we could trivially add another ho_cfg level per TRX if we so desire in the future.) Implement ho parameters as an opaque config struct with getters and setters to ensure the tracking is always heeded. Opaqueness dictates allocating instead of direct embedding in gsm_network and gsm_bts structs, ctx is gsm_net / bts. This is 100% backwards compatible to old configs. - No VTY command syntax changes (only the online help). - If a 'bts' sets nothing, it will use the 'network' defaults. - The 'show network' output only changes in presence of individual BTS configs. On 'show network', say "Handover: On|Off" as before, iff all BTS reflect identical behavior. Otherwise, output BTS counts of handover being enabled or not. Use the same set of VTY commands (same VTY cmd syntax as before) on network and BTS nodes, i.e. don't duplicate VTY code. From the current vty->node, figure out which ho_cfg to modify. For linking, add handover_cfg.c (the value API) in libcommon, while the handover_vty.c is in libbsc. This is mainly because some utility programs use gsm_network and hence suck in the ho stuff, but don't need the VTY commands. Review the VTY online help strings. Add VTY transcript test for handover options, testing config propagation from network to bts nodes, 'show network' output and VTY online help strings. (Needs recent addition of '... !' wildcard to osmo_interact_common.py.) I considered leaving parts of this more readable, but in the end decided for heavy use of macros to define and declare the API, because more values will be added in upcoming patches and I want to prevent myself from messing them up. Inspired-by: jolly/new_handover branch, which moves the config to 'bts' level Depends: I7c1ebb2e7f059047903a53de26a0ec1ce7fa9b98 (osmo-python-tests) Change-Id: I79d35f6d3c0fbee67904378ad7f216df34fde79a
2017-11-27 20:29:33 +00:00
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
/* did we get a RXLEV for a given cell in the given report? */
static int rxlev_for_cell_in_rep(struct gsm_meas_rep *mr,
misc: Move from u_int to uint types of stdint.h This was done with sed on the files.
2011-04-18 15:04:00 +00:00
uint16_t arfcn, uint8_t bsic)
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
{
int i;
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
for (i = 0; i < mr->num_cell; i++) {
struct gsm_meas_rep_cell *mrc = &mr->cell[i];
/* search for matching report */
if (!(mrc->arfcn == arfcn && mrc->bsic == bsic))
continue;
mrc->flags |= MRC_F_PROCESSED;
return mrc->rxlev;
for now we only do handover of TCH channels
2009-12-18 10:49:20 +00:00
}
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
return -ENODEV;
}
for now we only do handover of TCH channels
2009-12-18 10:49:20 +00:00
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
/* obtain averaged rxlev for given neighbor */
static int neigh_meas_avg(struct neigh_meas_proc *nmp, int window)
{
unsigned int i, idx;
int avg = 0;
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
HO: Count neighbor measurements and reduce window of neigh_meas_avg Always start with a counter of 0 for a new measurement report. If the neigh_meas_avg is caluclated over the given window, the window is reduced, if there are less measurement reports received so far. Change-Id: I1c74f27f9663a3083610c985a080fca331c19bd3
2013-06-01 15:00:59 +00:00
/* reduce window to the actual number of existing measurements */
fixup: neigh_meas_avg: fix condition to reduce window size Change-Id: Ia2269be448436d676289c84b9b05da7f51ee4a85
2017-12-05 00:03:39 +00:00
if (window > nmp->rxlev_cnt)
HO: Count neighbor measurements and reduce window of neigh_meas_avg Always start with a counter of 0 for a new measurement report. If the neigh_meas_avg is caluclated over the given window, the window is reduced, if there are less measurement reports received so far. Change-Id: I1c74f27f9663a3083610c985a080fca331c19bd3
2013-06-01 15:00:59 +00:00
window = nmp->rxlev_cnt;
/* this should never happen */
fixup: neigh_meas_avg: detect invalid window size as <=0, log if invalid Change-Id: I8c5d0642aeb4fbee73a035b9f73cf3a09b1bcf90
2017-12-05 00:01:38 +00:00
if (window <= 0) {
HO: Change debug category at handover decision: DHO -> DHODEC Change-Id: I7322b790f647b681bfe3a9c95b04516fbc7cbf88
2013-07-07 07:12:17 +00:00
LOGP(DHODEC, LOGL_ERROR, "Requested Neighbor RxLev for invalid window size of %d\n", window);
HO: Count neighbor measurements and reduce window of neigh_meas_avg Always start with a counter of 0 for a new measurement report. If the neigh_meas_avg is caluclated over the given window, the window is reduced, if there are less measurement reports received so far. Change-Id: I1c74f27f9663a3083610c985a080fca331c19bd3
2013-06-01 15:00:59 +00:00
return 0;
fixup: neigh_meas_avg: detect invalid window size as <=0, log if invalid Change-Id: I8c5d0642aeb4fbee73a035b9f73cf3a09b1bcf90
2017-12-05 00:01:38 +00:00
}
HO: Count neighbor measurements and reduce window of neigh_meas_avg Always start with a counter of 0 for a new measurement report. If the neigh_meas_avg is caluclated over the given window, the window is reduced, if there are less measurement reports received so far. Change-Id: I1c74f27f9663a3083610c985a080fca331c19bd3
2013-06-01 15:00:59 +00:00
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
idx = calc_initial_idx(ARRAY_SIZE(nmp->rxlev),
nmp->rxlev_cnt % ARRAY_SIZE(nmp->rxlev),
window);
for (i = 0; i < window; i++) {
int j = (idx+i) % ARRAY_SIZE(nmp->rxlev);
avg += nmp->rxlev[j];
}
return avg / window;
}
/* find empty or evict bad neighbor */
static struct neigh_meas_proc *find_evict_neigh(struct gsm_lchan *lchan)
{
int j, worst = 999999;
ho: Initialize nmp_worst as it was not initialized The compiler can't know that on the first iteration we will assign nmp_worst as we have used a high average value.
2011-04-18 15:16:56 +00:00
struct neigh_meas_proc *nmp_worst = NULL;
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
/* first try to find an empty/unused slot */
for (j = 0; j < ARRAY_SIZE(lchan->neigh_meas); j++) {
struct neigh_meas_proc *nmp = &lchan->neigh_meas[j];
if (!nmp->arfcn)
return nmp;
}
/* no empty slot found. evict worst neighbor from list */
for (j = 0; j < ARRAY_SIZE(lchan->neigh_meas); j++) {
struct neigh_meas_proc *nmp = &lchan->neigh_meas[j];
int avg = neigh_meas_avg(nmp, MAX_WIN_NEIGH_AVG);
ho: Initialize nmp_worst as it was not initialized The compiler can't know that on the first iteration we will assign nmp_worst as we have used a high average value.
2011-04-18 15:16:56 +00:00
if (!nmp_worst || avg < worst) {
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
worst = avg;
nmp_worst = nmp;
}
}
return nmp_worst;
}
/* process neighbor cell measurement reports */
static void process_meas_neigh(struct gsm_meas_rep *mr)
{
int i, j, idx;
/* for each reported cell, try to update global state */
for (j = 0; j < ARRAY_SIZE(mr->lchan->neigh_meas); j++) {
struct neigh_meas_proc *nmp = &mr->lchan->neigh_meas[j];
unsigned int idx;
int rxlev;
/* skip unused entries */
if (!nmp->arfcn)
continue;
rxlev = rxlev_for_cell_in_rep(mr, nmp->arfcn, nmp->bsic);
idx = nmp->rxlev_cnt % ARRAY_SIZE(nmp->rxlev);
if (rxlev >= 0) {
nmp->rxlev[idx] = rxlev;
nmp->last_seen_nr = mr->nr;
} else
nmp->rxlev[idx] = 0;
nmp->rxlev_cnt++;
}
/* iterate over list of reported cells, check if we did not
* process all of them */
for (i = 0; i < mr->num_cell; i++) {
struct gsm_meas_rep_cell *mrc = &mr->cell[i];
struct neigh_meas_proc *nmp;
if (mrc->flags & MRC_F_PROCESSED)
continue;
nmp = find_evict_neigh(mr->lchan);
nmp->arfcn = mrc->arfcn;
nmp->bsic = mrc->bsic;
HO: Count neighbor measurements and reduce window of neigh_meas_avg Always start with a counter of 0 for a new measurement report. If the neigh_meas_avg is caluclated over the given window, the window is reduced, if there are less measurement reports received so far. Change-Id: I1c74f27f9663a3083610c985a080fca331c19bd3
2013-06-01 15:00:59 +00:00
nmp->rxlev_cnt = 0;
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
idx = nmp->rxlev_cnt % ARRAY_SIZE(nmp->rxlev);
nmp->rxlev[idx] = mrc->rxlev;
nmp->rxlev_cnt++;
nmp->last_seen_nr = mr->nr;
mrc->flags |= MRC_F_PROCESSED;
}
}
/* attempt to do a handover */
large refactoring: use FSMs for lchans; add inter-BSC HO Add FSMs: - timeslot_fsm: handle dynamic timeslots and OML+RSL availability. - lchan_fsm: handle an individual lchan activation, RTP stream and release, signal the appropriate calling FSMs on success, failure, release. - mgw_endpoint_fsm: handle one entire endpoint with several CI. - assignment_fsm: BSSMAP Assignment Request. - handover_fsm: all of intra, inter-MO and inter-MT handover. Above FSMs absorb large parts of the gscon FSM. The gscon FSM was surpassing the maximum amount events (32), and it is more logical to treat assignment, handover and MGW procedures in separate FSMs. - Add logging macros for each FSM type: - LOG_TS() - LOG_LCHAN() - LOG_MGWEP(), LOG_CI() - LOG_ASSIGNMENT() - LOG_HO() These log with the osmo_fsm_inst where present. New style decision: logging without a final newline char is awkward, especially for gsmtap logging and when other logs interleave LOGPC() calls; we have various cases where the final \n goes missing, and also this invokes the log category checking N times instead of once. So I decided to make these macros *always* append a newline, but only if there is no final newline yet. I hope that the compiler optimizes the strlen() of the constant format strings away. Thus I can log with or without typing "\n" and always get an \n termination anyway. General: - replace osmo_timers, state enums and program-wide osmo_signal_dispatch() with dedicated FSM timeouts, states and events. - introduce a common way to handle Tnnn timers: gsm_timers.h/.c: struct T_def. These can be used (with some macro magic) to define a state's timeout once, and not make mistakes for each osmo_fsm_inst_state_chg(). Details: bsc_subscr_conn_fsm.c: - move most states of this FSM to lchan_fsm, assignment_fsm, handover_fsm and mgw_endpoint_fsm. - There is exactly one state for an ongoing Assignment, with all details handled in conn->assignment.fi. The state relies on the assignment_fsm's timeout. - There is one state for an ongoing Handover; except for an incoming Handover from a remote BSS, the gscon remains in ST_INIT until the new lchan and conn are both established. - move bssmap_add_lcls_status() to osmo_bsc_lcls.c abis_rsl.c: - move all dynamic timeslot logic away into timeslot_fsm. Only keep plain send/receive functions in abis_rsl.c - reduce some rsl functions to merely send a message, rename to "_tx_". - rsl_ipacc_mdcx(): add '_tx_' in the name; move parts that change the lchan state out into the lchan_fsm, the lchan->abis_ip.* are now set there prior to invoking this function. - move all timers and error/release handling away into various FSMs. - tweak ipa_smod_s_for_lchan() and ipa_rtp_pt_for_lchan() to not require an lchan passed, but just mode,type that they require. Rename to ipacc_speech_mode*() and ipacc_payload_type(). - add rsl_forward_layer3_info, used for inter-BSC HO MO, to just send the RR message received during BSSMAP Handover Command. - move various logging to LOG_LCHAN() in order to log with the lchan FSM instance. One drawback is that the lchan FSM is limited to one logging category, i.e. this moves some logging from DRR to DRSL. It might actually make sense to combine those categories. - lose LOGP...LOGPC logging cascades: they are bad for gsmtap logging and for performance. - handle_classmark_chg(): change logging, move cm2 len check out of the cm3 condition (I hope that's correct). - gsm48_send_ho_cmd(): split off gsm48_make_ho_cmd() which doesn't send right away, so that during inter-bsc HO we can make an RR Handover Command to send via the MSC to the remote BSS. assignment_fsm.c: - the Chan Mode Modify in case of re-using the same lchan is not implemented yet, because this was also missing in the previous implementation (OS#3357). osmo_bsc_api.c: - simplify bsc_mr_config() and move to lchan_fsm.c, the only caller; rename to lchan_mr_config(). (bsc_mr_config() used to copy the values to mr_bts_lv twice, once by member assignment and then again with a memcpy.) - During handover, we used to copy the MR config from the old lchan. Since we may handover between FR and HR, rather set the MR Config anew every time, so that FR rates are always available on FR lchans, and never on HR lchans. Depends: I03ee7ce840ecfa0b6a33358e7385528aabd4873f (libosmocore), I1f2918418c38918c5ac70acaa51a47adfca12b5e (libosmocore) Change-Id: I82e3f918295daa83274a4cf803f046979f284366
2018-05-14 16:14:15 +00:00
static void attempt_handover(struct gsm_meas_rep *mr)
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
{
large refactoring: use FSMs for lchans; add inter-BSC HO Add FSMs: - timeslot_fsm: handle dynamic timeslots and OML+RSL availability. - lchan_fsm: handle an individual lchan activation, RTP stream and release, signal the appropriate calling FSMs on success, failure, release. - mgw_endpoint_fsm: handle one entire endpoint with several CI. - assignment_fsm: BSSMAP Assignment Request. - handover_fsm: all of intra, inter-MO and inter-MT handover. Above FSMs absorb large parts of the gscon FSM. The gscon FSM was surpassing the maximum amount events (32), and it is more logical to treat assignment, handover and MGW procedures in separate FSMs. - Add logging macros for each FSM type: - LOG_TS() - LOG_LCHAN() - LOG_MGWEP(), LOG_CI() - LOG_ASSIGNMENT() - LOG_HO() These log with the osmo_fsm_inst where present. New style decision: logging without a final newline char is awkward, especially for gsmtap logging and when other logs interleave LOGPC() calls; we have various cases where the final \n goes missing, and also this invokes the log category checking N times instead of once. So I decided to make these macros *always* append a newline, but only if there is no final newline yet. I hope that the compiler optimizes the strlen() of the constant format strings away. Thus I can log with or without typing "\n" and always get an \n termination anyway. General: - replace osmo_timers, state enums and program-wide osmo_signal_dispatch() with dedicated FSM timeouts, states and events. - introduce a common way to handle Tnnn timers: gsm_timers.h/.c: struct T_def. These can be used (with some macro magic) to define a state's timeout once, and not make mistakes for each osmo_fsm_inst_state_chg(). Details: bsc_subscr_conn_fsm.c: - move most states of this FSM to lchan_fsm, assignment_fsm, handover_fsm and mgw_endpoint_fsm. - There is exactly one state for an ongoing Assignment, with all details handled in conn->assignment.fi. The state relies on the assignment_fsm's timeout. - There is one state for an ongoing Handover; except for an incoming Handover from a remote BSS, the gscon remains in ST_INIT until the new lchan and conn are both established. - move bssmap_add_lcls_status() to osmo_bsc_lcls.c abis_rsl.c: - move all dynamic timeslot logic away into timeslot_fsm. Only keep plain send/receive functions in abis_rsl.c - reduce some rsl functions to merely send a message, rename to "_tx_". - rsl_ipacc_mdcx(): add '_tx_' in the name; move parts that change the lchan state out into the lchan_fsm, the lchan->abis_ip.* are now set there prior to invoking this function. - move all timers and error/release handling away into various FSMs. - tweak ipa_smod_s_for_lchan() and ipa_rtp_pt_for_lchan() to not require an lchan passed, but just mode,type that they require. Rename to ipacc_speech_mode*() and ipacc_payload_type(). - add rsl_forward_layer3_info, used for inter-BSC HO MO, to just send the RR message received during BSSMAP Handover Command. - move various logging to LOG_LCHAN() in order to log with the lchan FSM instance. One drawback is that the lchan FSM is limited to one logging category, i.e. this moves some logging from DRR to DRSL. It might actually make sense to combine those categories. - lose LOGP...LOGPC logging cascades: they are bad for gsmtap logging and for performance. - handle_classmark_chg(): change logging, move cm2 len check out of the cm3 condition (I hope that's correct). - gsm48_send_ho_cmd(): split off gsm48_make_ho_cmd() which doesn't send right away, so that during inter-bsc HO we can make an RR Handover Command to send via the MSC to the remote BSS. assignment_fsm.c: - the Chan Mode Modify in case of re-using the same lchan is not implemented yet, because this was also missing in the previous implementation (OS#3357). osmo_bsc_api.c: - simplify bsc_mr_config() and move to lchan_fsm.c, the only caller; rename to lchan_mr_config(). (bsc_mr_config() used to copy the values to mr_bts_lv twice, once by member assignment and then again with a memcpy.) - During handover, we used to copy the MR config from the old lchan. Since we may handover between FR and HR, rather set the MR Config anew every time, so that FR rates are always available on FR lchans, and never on HR lchans. Depends: I03ee7ce840ecfa0b6a33358e7385528aabd4873f (libosmocore), I1f2918418c38918c5ac70acaa51a47adfca12b5e (libosmocore) Change-Id: I82e3f918295daa83274a4cf803f046979f284366
2018-05-14 16:14:15 +00:00
struct handover_out_req req;
HO prep: introduce per-BTS handover config, with defaults on net node It is desirable to allow configuring handover for each individual network cell. At the same time, it is desirable to set global defaults. Treat the 'network' node handover parameters as global defaults, add another set of parameters for each individual BTS. This raises questions on how the 'network' node should affect the individual BTS. The simplistic solution would have been: on creating a BTS in the config, just copy the current defaults; with serious drawbacks: - tweaking any parameter in the telnet VTY on network node will never affect any running BTS. - network node defaults *must* be issued before the bts sections in the config file. - when writing a config back to file, we would copy all net node defaults to each BTS node, making the network node configs pointless. Instead, add a handover_cfg API that tracks whether a given node has a value set or not. A bts node ho_cfg gets a pointer to the network node config and returns those values if locally unset. If no value is set on any node, use the "factory" defaults, which are hardcoded in the API. Only write back exactly those config items that were actually issued in a config file / on the telnet VTY. (ho_cfg API wise, we could trivially add another ho_cfg level per TRX if we so desire in the future.) Implement ho parameters as an opaque config struct with getters and setters to ensure the tracking is always heeded. Opaqueness dictates allocating instead of direct embedding in gsm_network and gsm_bts structs, ctx is gsm_net / bts. This is 100% backwards compatible to old configs. - No VTY command syntax changes (only the online help). - If a 'bts' sets nothing, it will use the 'network' defaults. - The 'show network' output only changes in presence of individual BTS configs. On 'show network', say "Handover: On|Off" as before, iff all BTS reflect identical behavior. Otherwise, output BTS counts of handover being enabled or not. Use the same set of VTY commands (same VTY cmd syntax as before) on network and BTS nodes, i.e. don't duplicate VTY code. From the current vty->node, figure out which ho_cfg to modify. For linking, add handover_cfg.c (the value API) in libcommon, while the handover_vty.c is in libbsc. This is mainly because some utility programs use gsm_network and hence suck in the ho stuff, but don't need the VTY commands. Review the VTY online help strings. Add VTY transcript test for handover options, testing config propagation from network to bts nodes, 'show network' output and VTY online help strings. (Needs recent addition of '... !' wildcard to osmo_interact_common.py.) I considered leaving parts of this more readable, but in the end decided for heavy use of macros to define and declare the API, because more values will be added in upcoming patches and I want to prevent myself from messing them up. Inspired-by: jolly/new_handover branch, which moves the config to 'bts' level Depends: I7c1ebb2e7f059047903a53de26a0ec1ce7fa9b98 (osmo-python-tests) Change-Id: I79d35f6d3c0fbee67904378ad7f216df34fde79a
2017-11-27 20:29:33 +00:00
struct gsm_bts *bts = mr->lchan->ts->trx->bts;
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
struct neigh_meas_proc *best_cell = NULL;
unsigned int best_better_db = 0;
hodec2 log: less verbose, more concise logging Drop numerous log statements that merely bloat the ho decision log. Logging HO candidates: log more compact in a single line, do not use LOGPC and multiline output. The result is more useful information in a quarter of the log lines. LOGPHOLCHAN(), LOGPHOLCHANTOBTS(): - log lchan->type instead of lchan->ts->pchan - always log the speech mode ===== Before ===== DHODEC handover_decision_2.c:1131 (lchan 0.010 TCH/F) (subscr IMSI:000001) MEASUREMENT REPORT (1 neighbors) DHODEC handover_decision_2.c:1136 (lchan 0.010 TCH/F) (subscr IMSI:000001) 0: arfcn=871 bsic=63 neigh_idx=0 rxlev=30 flags=0 DHODEC handover_decision_2.c:261 (lchan 0.010 TCH/F) (subscr IMSI:000001) neigh 871 rxlev=30 last_seen_nr=3 DHODEC handover_decision_2.c:1158 (lchan 0.010 TCH/F) (subscr IMSI:000001) HODEC2: evaluating measurement report DHODEC handover_decision_2.c:1175 (lchan 0.010 TCH/F) (subscr IMSI:000001) Measurement report: average RX level = -110 DHODEC handover_decision_2.c:1190 (lchan 0.010 TCH/F) (subscr IMSI:000001) Virtually improving RX level from -110 to -105, due to AFS bias DHODEC handover_decision_2.c:1220 (lchan 0.010 TCH/F) (subscr IMSI:000001) Attempting handover/assignment due to low rxlev DHODEC handover_decision_2.c:899 (lchan 0.010 TCH/F) (subscr IMSI:000001) Collecting candidates for Assignment and Handover DHODEC handover_decision_2.c:407 (lchan 0.010 TCH/F)->(BTS 0) (subscr IMSI:000001) tch_mode='SPEECH_AMR' type='TCH_F' DHODEC handover_decision_2.c:313 (lchan 0.010 TCH/F) (subscr IMSI:000001) FR3 supported DHODEC handover_decision_2.c:313 (lchan 0.010 TCH/F) (subscr IMSI:000001) HR3 supported DHODEC handover_decision_2.c:489 (lchan 0.010 TCH/F)->(BTS 0) (subscr IMSI:000001) removing TCH/F, already on TCH/F in this cell DHODEC handover_decision_2.c:573 (lchan 0.010 TCH/F)->(BTS 0) (subscr IMSI:000001) TCH/H would not be congested after HO DHODEC handover_decision_2.c:605 (lchan 0.010 TCH/F)->(BTS 0) (subscr IMSI:000001) TCH/H would not be less congested in target than source cell after HO DHODEC handover_decision_2.c:609 (lchan 0.010 TCH/F)->(BTS 0) (subscr IMSI:000001) requirements=0x30 DHODEC handover_decision_2.c:704 - current BTS 0, RX level -110 DHODEC handover_decision_2.c:707 o free TCH/F slots 3, minimum required 0 DHODEC handover_decision_2.c:709 o free TCH/H slots 4, minimum required 0 DHODEC handover_decision_2.c:714 o no requirement fulfilled for TCHF (no assignment possible) DHODEC handover_decision_2.c:737 o requirement A B fulfilled for TCHH (not congested after assignment) DHODEC handover_decision_2.c:407 (lchan 0.010 TCH/F)->(BTS 1) (subscr IMSI:000001) tch_mode='SPEECH_AMR' type='TCH_F' DHODEC handover_decision_2.c:313 (lchan 0.010 TCH/F) (subscr IMSI:000001) FR3 supported DHODEC handover_decision_2.c:313 (lchan 0.010 TCH/F) (subscr IMSI:000001) HR3 supported DHODEC handover_decision_2.c:563 (lchan 0.010 TCH/F)->(BTS 1) (subscr IMSI:000001) TCH/F would not be congested after HO DHODEC handover_decision_2.c:573 (lchan 0.010 TCH/F)->(BTS 1) (subscr IMSI:000001) TCH/H would not be congested after HO DHODEC handover_decision_2.c:595 (lchan 0.010 TCH/F)->(BTS 1) (subscr IMSI:000001) TCH/F would not be less congested in target than source cell after HO DHODEC handover_decision_2.c:605 (lchan 0.010 TCH/F)->(BTS 1) (subscr IMSI:000001) TCH/H would not be less congested in target than source cell after HO DHODEC handover_decision_2.c:609 (lchan 0.010 TCH/F)->(BTS 1) (subscr IMSI:000001) requirements=0x33 DHODEC handover_decision_2.c:701 - neighbor BTS 1, RX level -110 -> -80 DHODEC handover_decision_2.c:707 o free TCH/F slots 4, minimum required 0 DHODEC handover_decision_2.c:709 o free TCH/H slots 4, minimum required 0 DHODEC handover_decision_2.c:712 o requirement A B fulfilled for TCHF (not congested after handover) DHODEC handover_decision_2.c:737 o requirement A B fulfilled for TCHH (not congested after handover) DHODEC handover_decision_2.c:914 (lchan 0.010 TCH/F) (subscr IMSI:000001) adding 2 candidates from 1 neighbors, total 2 DHODEC handover_decision_2.c:1020 (lchan 0.010 TCH/F)->(BTS 1) (subscr IMSI:000001) Best candidate, RX level -80 DHODEC handover_decision_2.c:625 (lchan 0.010 TCH/F)->(BTS 1) (subscr IMSI:000001) Triggering Handover DHODEC handover_decision_2.c:688 (lchan 0.010 TCH/F)->(BTS 1) (subscr IMSI:000001) Triggering handover to TCH/F, due to low rxlevel DHO handover_logic.c:133 (BTS 0 trx 0 ts 1 lchan 0 TCH/F)->(BTS 1 lchan TCH_F) Initiating Handover... DMSC handover_logic.c:135 SUBSCR_CONN[0x612000000520]{ACTIVE}: Received Event HO_START DHODEC handover_logic.c:172 (BTS 0 trx 0 arfcn 870 ts 1 lchan 0 TCH/F)->(BTS 1 trx 0 arfcn 871 ts 1 lchan 0 TCH/F) (subscr IMSI:000001) Triggering Handover ===== After ===== DHODEC handover_decision_2.c:1039 (lchan 0.010 TCH_F SPEECH_AMR) (subscr IMSI:000001) MEASUREMENT REPORT (1 neighbors) DHODEC handover_decision_2.c:1044 (lchan 0.010 TCH_F SPEECH_AMR) (subscr IMSI:000001) 0: arfcn=871 bsic=63 neigh_idx=0 rxlev=30 flags=0 DHODEC handover_decision_2.c:1097 (lchan 0.010 TCH_F SPEECH_AMR) (subscr IMSI:000001) Avg RX level = -110 dBm, +5 dBm AFS bias = -105 dBm; Avg RX quality = -1 (invalid), +0 AFS bias = -1 DHODEC handover_decision_2.c:1122 (lchan 0.010 TCH_F SPEECH_AMR) (subscr IMSI:000001) RX level is TOO LOW: -105 < -100 DHODEC handover_decision_2.c:677 (lchan 0.010 TCH_F SPEECH_AMR)->(BTS 0) (subscr IMSI:000001) RX level -110; TCH/F={free 3 (want 0), [-] not a candidate}; TCH/H={free 4 (want 0), [ABC] good} DHODEC handover_decision_2.c:671 (lchan 0.010 TCH_F SPEECH_AMR)->(BTS 1) (subscr IMSI:000001) RX level -110 -> -80; TCH/F={free 4 (want 0), [ABC] good}; TCH/H={free 4 (want 0), [ABC] good} DHODEC handover_decision_2.c:928 (lchan 0.010 TCH_F SPEECH_AMR)->(BTS 1) (subscr IMSI:000001) Best candidate, RX level -80 DHODEC handover_decision_2.c:641 (lchan 0.010 TCH_F SPEECH_AMR)->(BTS 1) (subscr IMSI:000001) Triggering handover to TCH/F, due to low rxlevel DMSC handover_logic.c:125 SUBSCR_CONN[0x612000000520]{ACTIVE}: Received Event HO_START DHODEC handover_logic.c:169 (BTS 0 trx 0 arfcn 870 ts 1 lchan 0 TCH_F SPEECH_AMR)->(BTS 1 trx 0 arfcn 871 ts 1 lchan 0 TCH/F) (subscr IMSI:000001) Triggering Handover Change-Id: If1add9b57a051d32b67a4a08ab47a9655aa9dd17
2018-07-19 14:14:09 +00:00
int i;
if (!ho_get_ho_active(bts->ho))
large refactoring: use FSMs for lchans; add inter-BSC HO Add FSMs: - timeslot_fsm: handle dynamic timeslots and OML+RSL availability. - lchan_fsm: handle an individual lchan activation, RTP stream and release, signal the appropriate calling FSMs on success, failure, release. - mgw_endpoint_fsm: handle one entire endpoint with several CI. - assignment_fsm: BSSMAP Assignment Request. - handover_fsm: all of intra, inter-MO and inter-MT handover. Above FSMs absorb large parts of the gscon FSM. The gscon FSM was surpassing the maximum amount events (32), and it is more logical to treat assignment, handover and MGW procedures in separate FSMs. - Add logging macros for each FSM type: - LOG_TS() - LOG_LCHAN() - LOG_MGWEP(), LOG_CI() - LOG_ASSIGNMENT() - LOG_HO() These log with the osmo_fsm_inst where present. New style decision: logging without a final newline char is awkward, especially for gsmtap logging and when other logs interleave LOGPC() calls; we have various cases where the final \n goes missing, and also this invokes the log category checking N times instead of once. So I decided to make these macros *always* append a newline, but only if there is no final newline yet. I hope that the compiler optimizes the strlen() of the constant format strings away. Thus I can log with or without typing "\n" and always get an \n termination anyway. General: - replace osmo_timers, state enums and program-wide osmo_signal_dispatch() with dedicated FSM timeouts, states and events. - introduce a common way to handle Tnnn timers: gsm_timers.h/.c: struct T_def. These can be used (with some macro magic) to define a state's timeout once, and not make mistakes for each osmo_fsm_inst_state_chg(). Details: bsc_subscr_conn_fsm.c: - move most states of this FSM to lchan_fsm, assignment_fsm, handover_fsm and mgw_endpoint_fsm. - There is exactly one state for an ongoing Assignment, with all details handled in conn->assignment.fi. The state relies on the assignment_fsm's timeout. - There is one state for an ongoing Handover; except for an incoming Handover from a remote BSS, the gscon remains in ST_INIT until the new lchan and conn are both established. - move bssmap_add_lcls_status() to osmo_bsc_lcls.c abis_rsl.c: - move all dynamic timeslot logic away into timeslot_fsm. Only keep plain send/receive functions in abis_rsl.c - reduce some rsl functions to merely send a message, rename to "_tx_". - rsl_ipacc_mdcx(): add '_tx_' in the name; move parts that change the lchan state out into the lchan_fsm, the lchan->abis_ip.* are now set there prior to invoking this function. - move all timers and error/release handling away into various FSMs. - tweak ipa_smod_s_for_lchan() and ipa_rtp_pt_for_lchan() to not require an lchan passed, but just mode,type that they require. Rename to ipacc_speech_mode*() and ipacc_payload_type(). - add rsl_forward_layer3_info, used for inter-BSC HO MO, to just send the RR message received during BSSMAP Handover Command. - move various logging to LOG_LCHAN() in order to log with the lchan FSM instance. One drawback is that the lchan FSM is limited to one logging category, i.e. this moves some logging from DRR to DRSL. It might actually make sense to combine those categories. - lose LOGP...LOGPC logging cascades: they are bad for gsmtap logging and for performance. - handle_classmark_chg(): change logging, move cm2 len check out of the cm3 condition (I hope that's correct). - gsm48_send_ho_cmd(): split off gsm48_make_ho_cmd() which doesn't send right away, so that during inter-bsc HO we can make an RR Handover Command to send via the MSC to the remote BSS. assignment_fsm.c: - the Chan Mode Modify in case of re-using the same lchan is not implemented yet, because this was also missing in the previous implementation (OS#3357). osmo_bsc_api.c: - simplify bsc_mr_config() and move to lchan_fsm.c, the only caller; rename to lchan_mr_config(). (bsc_mr_config() used to copy the values to mr_bts_lv twice, once by member assignment and then again with a memcpy.) - During handover, we used to copy the MR config from the old lchan. Since we may handover between FR and HR, rather set the MR Config anew every time, so that FR rates are always available on FR lchans, and never on HR lchans. Depends: I03ee7ce840ecfa0b6a33358e7385528aabd4873f (libosmocore), I1f2918418c38918c5ac70acaa51a47adfca12b5e (libosmocore) Change-Id: I82e3f918295daa83274a4cf803f046979f284366
2018-05-14 16:14:15 +00:00
return;
[handover] don't use measurement reports with NCELL=7 NCELL=7 inidicates that there was no neighbor cell info in the SI5 on the SACCH.
2009-12-19 20:29:19 +00:00
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
/* find the best cell in this report that is at least RXLEV_HYST
* better than the current serving cell */
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
for (i = 0; i < ARRAY_SIZE(mr->lchan->neigh_meas); i++) {
struct neigh_meas_proc *nmp = &mr->lchan->neigh_meas[i];
int avg, better;
/* skip empty slots */
if (nmp->arfcn == 0)
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
continue;
Fix some typos Fix typos and common misspellings in code comments and in the manual. Change-Id: I46fc9d424620c77ae9ccf78b58081bd303386d7c
2019-11-13 21:10:41 +00:00
/* calculate average rxlev for this cell over the window */
HO: cfg: separate hodec1 from hodec2 parameters Do not share config items between the current handover decision and the upcoming handover_decision_2. Rename current handover config items to hodec2_* and duplicate the ones relevant to handover decision algorithm 1 with name prefix of hodec1_*. I considered moving hodec2 parameters to an entirely separate .c file and struct, but that causes considerable code bloat. Rather use the nice handover_cfg net/bts level mechanism as-is, and simply prefix the names. In the VTY, the hodec1 parameters are configurable by 'handover foo 23' commands, while the hodec2 parameters are by 'handover2 foo 23'. The generic VTY commands to enable/disable handover and to choose the algorithm are still 'handover (0|1)' and 'handover algorithm (1|2)'. (Note, a subsequent commit will rename the 'handover foo' for hodec1 to 'handover1 foo' and add backwards-compat aliases.) For example, the 'window rxlev averaging 5' command now exists both for handover decision 1 and handover decision 2, and its values are independent. This is valid config: network # set up handover decision algorithm 1 # (pending rename of these items to 'handover1 ...') handover window rxlev averaging 5 handover window rxlev neighbor averaging 5 # set up handover decision algorithm 2 handover2 window rxlev averaging 7 handover2 window rxlev neighbor averaging 7 handover2 penalty-time max-distance 10 # enable handover handover 1 bts 0 handover algorithm 1 bts 1 handover algorithm 2 In this example, bts 0 uses algo 1 with rxlev averaging of 5, while bts 1 uses algorithm 2 where rxlev averaging of 7 is in effect. Change-Id: I6475b2543b18d21710a6d774b214cb484f36ec8e
2018-02-14 18:56:23 +00:00
avg = neigh_meas_avg(nmp, ho_get_hodec1_rxlev_neigh_avg_win(bts->ho));
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
/* check if hysteresis is fulfilled */
HO: cfg: separate hodec1 from hodec2 parameters Do not share config items between the current handover decision and the upcoming handover_decision_2. Rename current handover config items to hodec2_* and duplicate the ones relevant to handover decision algorithm 1 with name prefix of hodec1_*. I considered moving hodec2 parameters to an entirely separate .c file and struct, but that causes considerable code bloat. Rather use the nice handover_cfg net/bts level mechanism as-is, and simply prefix the names. In the VTY, the hodec1 parameters are configurable by 'handover foo 23' commands, while the hodec2 parameters are by 'handover2 foo 23'. The generic VTY commands to enable/disable handover and to choose the algorithm are still 'handover (0|1)' and 'handover algorithm (1|2)'. (Note, a subsequent commit will rename the 'handover foo' for hodec1 to 'handover1 foo' and add backwards-compat aliases.) For example, the 'window rxlev averaging 5' command now exists both for handover decision 1 and handover decision 2, and its values are independent. This is valid config: network # set up handover decision algorithm 1 # (pending rename of these items to 'handover1 ...') handover window rxlev averaging 5 handover window rxlev neighbor averaging 5 # set up handover decision algorithm 2 handover2 window rxlev averaging 7 handover2 window rxlev neighbor averaging 7 handover2 penalty-time max-distance 10 # enable handover handover 1 bts 0 handover algorithm 1 bts 1 handover algorithm 2 In this example, bts 0 uses algo 1 with rxlev averaging of 5, while bts 1 uses algorithm 2 where rxlev averaging of 7 is in effect. Change-Id: I6475b2543b18d21710a6d774b214cb484f36ec8e
2018-02-14 18:56:23 +00:00
if (avg < mr->dl.full.rx_lev + ho_get_hodec1_pwr_hysteresis(bts->ho))
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
continue;
better = avg - mr->dl.full.rx_lev;
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
if (better > best_better_db) {
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
best_cell = nmp;
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
best_better_db = better;
}
}
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
if (!best_cell)
large refactoring: use FSMs for lchans; add inter-BSC HO Add FSMs: - timeslot_fsm: handle dynamic timeslots and OML+RSL availability. - lchan_fsm: handle an individual lchan activation, RTP stream and release, signal the appropriate calling FSMs on success, failure, release. - mgw_endpoint_fsm: handle one entire endpoint with several CI. - assignment_fsm: BSSMAP Assignment Request. - handover_fsm: all of intra, inter-MO and inter-MT handover. Above FSMs absorb large parts of the gscon FSM. The gscon FSM was surpassing the maximum amount events (32), and it is more logical to treat assignment, handover and MGW procedures in separate FSMs. - Add logging macros for each FSM type: - LOG_TS() - LOG_LCHAN() - LOG_MGWEP(), LOG_CI() - LOG_ASSIGNMENT() - LOG_HO() These log with the osmo_fsm_inst where present. New style decision: logging without a final newline char is awkward, especially for gsmtap logging and when other logs interleave LOGPC() calls; we have various cases where the final \n goes missing, and also this invokes the log category checking N times instead of once. So I decided to make these macros *always* append a newline, but only if there is no final newline yet. I hope that the compiler optimizes the strlen() of the constant format strings away. Thus I can log with or without typing "\n" and always get an \n termination anyway. General: - replace osmo_timers, state enums and program-wide osmo_signal_dispatch() with dedicated FSM timeouts, states and events. - introduce a common way to handle Tnnn timers: gsm_timers.h/.c: struct T_def. These can be used (with some macro magic) to define a state's timeout once, and not make mistakes for each osmo_fsm_inst_state_chg(). Details: bsc_subscr_conn_fsm.c: - move most states of this FSM to lchan_fsm, assignment_fsm, handover_fsm and mgw_endpoint_fsm. - There is exactly one state for an ongoing Assignment, with all details handled in conn->assignment.fi. The state relies on the assignment_fsm's timeout. - There is one state for an ongoing Handover; except for an incoming Handover from a remote BSS, the gscon remains in ST_INIT until the new lchan and conn are both established. - move bssmap_add_lcls_status() to osmo_bsc_lcls.c abis_rsl.c: - move all dynamic timeslot logic away into timeslot_fsm. Only keep plain send/receive functions in abis_rsl.c - reduce some rsl functions to merely send a message, rename to "_tx_". - rsl_ipacc_mdcx(): add '_tx_' in the name; move parts that change the lchan state out into the lchan_fsm, the lchan->abis_ip.* are now set there prior to invoking this function. - move all timers and error/release handling away into various FSMs. - tweak ipa_smod_s_for_lchan() and ipa_rtp_pt_for_lchan() to not require an lchan passed, but just mode,type that they require. Rename to ipacc_speech_mode*() and ipacc_payload_type(). - add rsl_forward_layer3_info, used for inter-BSC HO MO, to just send the RR message received during BSSMAP Handover Command. - move various logging to LOG_LCHAN() in order to log with the lchan FSM instance. One drawback is that the lchan FSM is limited to one logging category, i.e. this moves some logging from DRR to DRSL. It might actually make sense to combine those categories. - lose LOGP...LOGPC logging cascades: they are bad for gsmtap logging and for performance. - handle_classmark_chg(): change logging, move cm2 len check out of the cm3 condition (I hope that's correct). - gsm48_send_ho_cmd(): split off gsm48_make_ho_cmd() which doesn't send right away, so that during inter-bsc HO we can make an RR Handover Command to send via the MSC to the remote BSS. assignment_fsm.c: - the Chan Mode Modify in case of re-using the same lchan is not implemented yet, because this was also missing in the previous implementation (OS#3357). osmo_bsc_api.c: - simplify bsc_mr_config() and move to lchan_fsm.c, the only caller; rename to lchan_mr_config(). (bsc_mr_config() used to copy the values to mr_bts_lv twice, once by member assignment and then again with a memcpy.) - During handover, we used to copy the MR config from the old lchan. Since we may handover between FR and HR, rather set the MR Config anew every time, so that FR rates are always available on FR lchans, and never on HR lchans. Depends: I03ee7ce840ecfa0b6a33358e7385528aabd4873f (libosmocore), I1f2918418c38918c5ac70acaa51a47adfca12b5e (libosmocore) Change-Id: I82e3f918295daa83274a4cf803f046979f284366
2018-05-14 16:14:15 +00:00
return;
req = (struct handover_out_req){
.from_hodec_id = HODEC1,
.old_lchan = mr->lchan,
fix/refactor neighbor config The neighbor configuration storage is fundamentally broken: it requires all local cells to be configured before being able to list them as neighbors of each other. Upon config write-back, the neighbor config however is placed back inline with the other config, and hence a written-out neighbor config no longer works on program restart. The cause of this problem is that the config is stored as explicit pointers between local cells (struct gsm_bts), which of course requires the pointer to exist before being able to reference it. Instead, store the actual configuration that the user entered as-is, without pointers or references to objects that need to be ready. Resolve the neighbors every time a neighbor is needed. Hence the user may enter any config at any place in the config file, even non-working config (like a BTS number that doesn't exist), and the relation to actual local or remote neighbor cells is made at runtime. Abort program startup if the initial neighbor configuration contains errors. Related: OS#5018 Change-Id: I9ed992f8bfff888b3933733c0576f92d50f2625b
2021-03-09 16:11:45 +00:00
.target_cell_ab = {
large refactoring: use FSMs for lchans; add inter-BSC HO Add FSMs: - timeslot_fsm: handle dynamic timeslots and OML+RSL availability. - lchan_fsm: handle an individual lchan activation, RTP stream and release, signal the appropriate calling FSMs on success, failure, release. - mgw_endpoint_fsm: handle one entire endpoint with several CI. - assignment_fsm: BSSMAP Assignment Request. - handover_fsm: all of intra, inter-MO and inter-MT handover. Above FSMs absorb large parts of the gscon FSM. The gscon FSM was surpassing the maximum amount events (32), and it is more logical to treat assignment, handover and MGW procedures in separate FSMs. - Add logging macros for each FSM type: - LOG_TS() - LOG_LCHAN() - LOG_MGWEP(), LOG_CI() - LOG_ASSIGNMENT() - LOG_HO() These log with the osmo_fsm_inst where present. New style decision: logging without a final newline char is awkward, especially for gsmtap logging and when other logs interleave LOGPC() calls; we have various cases where the final \n goes missing, and also this invokes the log category checking N times instead of once. So I decided to make these macros *always* append a newline, but only if there is no final newline yet. I hope that the compiler optimizes the strlen() of the constant format strings away. Thus I can log with or without typing "\n" and always get an \n termination anyway. General: - replace osmo_timers, state enums and program-wide osmo_signal_dispatch() with dedicated FSM timeouts, states and events. - introduce a common way to handle Tnnn timers: gsm_timers.h/.c: struct T_def. These can be used (with some macro magic) to define a state's timeout once, and not make mistakes for each osmo_fsm_inst_state_chg(). Details: bsc_subscr_conn_fsm.c: - move most states of this FSM to lchan_fsm, assignment_fsm, handover_fsm and mgw_endpoint_fsm. - There is exactly one state for an ongoing Assignment, with all details handled in conn->assignment.fi. The state relies on the assignment_fsm's timeout. - There is one state for an ongoing Handover; except for an incoming Handover from a remote BSS, the gscon remains in ST_INIT until the new lchan and conn are both established. - move bssmap_add_lcls_status() to osmo_bsc_lcls.c abis_rsl.c: - move all dynamic timeslot logic away into timeslot_fsm. Only keep plain send/receive functions in abis_rsl.c - reduce some rsl functions to merely send a message, rename to "_tx_". - rsl_ipacc_mdcx(): add '_tx_' in the name; move parts that change the lchan state out into the lchan_fsm, the lchan->abis_ip.* are now set there prior to invoking this function. - move all timers and error/release handling away into various FSMs. - tweak ipa_smod_s_for_lchan() and ipa_rtp_pt_for_lchan() to not require an lchan passed, but just mode,type that they require. Rename to ipacc_speech_mode*() and ipacc_payload_type(). - add rsl_forward_layer3_info, used for inter-BSC HO MO, to just send the RR message received during BSSMAP Handover Command. - move various logging to LOG_LCHAN() in order to log with the lchan FSM instance. One drawback is that the lchan FSM is limited to one logging category, i.e. this moves some logging from DRR to DRSL. It might actually make sense to combine those categories. - lose LOGP...LOGPC logging cascades: they are bad for gsmtap logging and for performance. - handle_classmark_chg(): change logging, move cm2 len check out of the cm3 condition (I hope that's correct). - gsm48_send_ho_cmd(): split off gsm48_make_ho_cmd() which doesn't send right away, so that during inter-bsc HO we can make an RR Handover Command to send via the MSC to the remote BSS. assignment_fsm.c: - the Chan Mode Modify in case of re-using the same lchan is not implemented yet, because this was also missing in the previous implementation (OS#3357). osmo_bsc_api.c: - simplify bsc_mr_config() and move to lchan_fsm.c, the only caller; rename to lchan_mr_config(). (bsc_mr_config() used to copy the values to mr_bts_lv twice, once by member assignment and then again with a memcpy.) - During handover, we used to copy the MR config from the old lchan. Since we may handover between FR and HR, rather set the MR Config anew every time, so that FR rates are always available on FR lchans, and never on HR lchans. Depends: I03ee7ce840ecfa0b6a33358e7385528aabd4873f (libosmocore), I1f2918418c38918c5ac70acaa51a47adfca12b5e (libosmocore) Change-Id: I82e3f918295daa83274a4cf803f046979f284366
2018-05-14 16:14:15 +00:00
.arfcn = best_cell->arfcn,
.bsic = best_cell->bsic,
},
};
handover_request(&req);
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
}
/* process an already parsed measurement report and decide if we want to
* attempt a handover */
HO: introduce ho decision callbacks Instead of reacting on S_LCHAN* signals in the handover decision code, introduce callbacks for the handover decision to be invoked by handover_logic.c at the appropriate time. The rationale is explained in a comment to struct handover_decision_callbacks, quoting: " All events that are interesting for handover decision are actually communicated by S_LCHAN_* signals, so theoretically, each handover algorithm could evaluate those. However, handover_logic.c cleans up handover operation state upon receiving some of these signals. To allow a handover decision algorithm to take advantage of e.g. the struct bsc_handover before it is discarded, the handover decision event handler needs to be invoked before handover_logic.c discards the state. For example, if the handover decision wants to place a penalty timer upon a handover failure, it still needs to know which target cell the handover failed for; handover_logic.c erases that knowledge on handover failure, since it needs to clean up the lchan's handover state. The most explicit and safest way to ensure the correct order of event handling is to invoke the handover decision algorithm's actions from handover_logic.c itself, before cleaning up. This struct provides the callback functions for this purpose. For consistency, also handle signals in this way that aren't actually in danger of interference from handover_logic.c (which also saves repeated lookup of handover state for lchans). Thus, handover decision algorithms should not register any signal handler at all. " Also: - Publish struct bsc_handover to use it as argument to above callbacks. - Add enum hodec_id to struct bsc_handover, to be able to signal the appropriate hodec algorithm per event. - Add hodec_id argument to bsc_handover_start*() to be placed in the bsc_handover struct. - Publish the LOGPHO logging macros in handover.h along with struct bsc_handover, convenient for logging in callback implementations. Replace handover_decision.c's signal handler with a registered handover_decision_callbacks instance. (Upcoming handover_decision_2 will use all of the callbacks introduced here.) Change-Id: Id5b64504007fe03e0406a4b395cd0359232b77d2
2018-02-15 13:10:12 +00:00
static void on_measurement_report(struct gsm_meas_rep *mr)
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
{
HO prep: introduce per-BTS handover config, with defaults on net node It is desirable to allow configuring handover for each individual network cell. At the same time, it is desirable to set global defaults. Treat the 'network' node handover parameters as global defaults, add another set of parameters for each individual BTS. This raises questions on how the 'network' node should affect the individual BTS. The simplistic solution would have been: on creating a BTS in the config, just copy the current defaults; with serious drawbacks: - tweaking any parameter in the telnet VTY on network node will never affect any running BTS. - network node defaults *must* be issued before the bts sections in the config file. - when writing a config back to file, we would copy all net node defaults to each BTS node, making the network node configs pointless. Instead, add a handover_cfg API that tracks whether a given node has a value set or not. A bts node ho_cfg gets a pointer to the network node config and returns those values if locally unset. If no value is set on any node, use the "factory" defaults, which are hardcoded in the API. Only write back exactly those config items that were actually issued in a config file / on the telnet VTY. (ho_cfg API wise, we could trivially add another ho_cfg level per TRX if we so desire in the future.) Implement ho parameters as an opaque config struct with getters and setters to ensure the tracking is always heeded. Opaqueness dictates allocating instead of direct embedding in gsm_network and gsm_bts structs, ctx is gsm_net / bts. This is 100% backwards compatible to old configs. - No VTY command syntax changes (only the online help). - If a 'bts' sets nothing, it will use the 'network' defaults. - The 'show network' output only changes in presence of individual BTS configs. On 'show network', say "Handover: On|Off" as before, iff all BTS reflect identical behavior. Otherwise, output BTS counts of handover being enabled or not. Use the same set of VTY commands (same VTY cmd syntax as before) on network and BTS nodes, i.e. don't duplicate VTY code. From the current vty->node, figure out which ho_cfg to modify. For linking, add handover_cfg.c (the value API) in libcommon, while the handover_vty.c is in libbsc. This is mainly because some utility programs use gsm_network and hence suck in the ho stuff, but don't need the VTY commands. Review the VTY online help strings. Add VTY transcript test for handover options, testing config propagation from network to bts nodes, 'show network' output and VTY online help strings. (Needs recent addition of '... !' wildcard to osmo_interact_common.py.) I considered leaving parts of this more readable, but in the end decided for heavy use of macros to define and declare the API, because more values will be added in upcoming patches and I want to prevent myself from messing them up. Inspired-by: jolly/new_handover branch, which moves the config to 'bts' level Depends: I7c1ebb2e7f059047903a53de26a0ec1ce7fa9b98 (osmo-python-tests) Change-Id: I79d35f6d3c0fbee67904378ad7f216df34fde79a
2017-11-27 20:29:33 +00:00
struct gsm_bts *bts = mr->lchan->ts->trx->bts;
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
int av_rxlev;
HO prep: introduce per-BTS handover config, with defaults on net node It is desirable to allow configuring handover for each individual network cell. At the same time, it is desirable to set global defaults. Treat the 'network' node handover parameters as global defaults, add another set of parameters for each individual BTS. This raises questions on how the 'network' node should affect the individual BTS. The simplistic solution would have been: on creating a BTS in the config, just copy the current defaults; with serious drawbacks: - tweaking any parameter in the telnet VTY on network node will never affect any running BTS. - network node defaults *must* be issued before the bts sections in the config file. - when writing a config back to file, we would copy all net node defaults to each BTS node, making the network node configs pointless. Instead, add a handover_cfg API that tracks whether a given node has a value set or not. A bts node ho_cfg gets a pointer to the network node config and returns those values if locally unset. If no value is set on any node, use the "factory" defaults, which are hardcoded in the API. Only write back exactly those config items that were actually issued in a config file / on the telnet VTY. (ho_cfg API wise, we could trivially add another ho_cfg level per TRX if we so desire in the future.) Implement ho parameters as an opaque config struct with getters and setters to ensure the tracking is always heeded. Opaqueness dictates allocating instead of direct embedding in gsm_network and gsm_bts structs, ctx is gsm_net / bts. This is 100% backwards compatible to old configs. - No VTY command syntax changes (only the online help). - If a 'bts' sets nothing, it will use the 'network' defaults. - The 'show network' output only changes in presence of individual BTS configs. On 'show network', say "Handover: On|Off" as before, iff all BTS reflect identical behavior. Otherwise, output BTS counts of handover being enabled or not. Use the same set of VTY commands (same VTY cmd syntax as before) on network and BTS nodes, i.e. don't duplicate VTY code. From the current vty->node, figure out which ho_cfg to modify. For linking, add handover_cfg.c (the value API) in libcommon, while the handover_vty.c is in libbsc. This is mainly because some utility programs use gsm_network and hence suck in the ho stuff, but don't need the VTY commands. Review the VTY online help strings. Add VTY transcript test for handover options, testing config propagation from network to bts nodes, 'show network' output and VTY online help strings. (Needs recent addition of '... !' wildcard to osmo_interact_common.py.) I considered leaving parts of this more readable, but in the end decided for heavy use of macros to define and declare the API, because more values will be added in upcoming patches and I want to prevent myself from messing them up. Inspired-by: jolly/new_handover branch, which moves the config to 'bts' level Depends: I7c1ebb2e7f059047903a53de26a0ec1ce7fa9b98 (osmo-python-tests) Change-Id: I79d35f6d3c0fbee67904378ad7f216df34fde79a
2017-11-27 20:29:33 +00:00
unsigned int pwr_interval;
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
HO: add handover algo 2 parameters; skip HO 1 if HO 2 is configured Change-Id: I8811ee8a75be09048042b511ee4bd9bc1de63976
2017-12-07 00:55:58 +00:00
/* If this cell does not use handover algorithm 1, then we're not responsible. */
if (ho_get_algorithm(bts->ho) != 1)
HO: cosmetic: handover_decision.c: make process_meas_rep() return void The function's return value is ignored. An upcoming patch will use this as callback function and requires a void return. Change-Id: Id455a8becbb43884e8205d87b0371b216d0119fc
2018-02-15 13:12:40 +00:00
return;
HO: add handover algo 2 parameters; skip HO 1 if HO 2 is configured Change-Id: I8811ee8a75be09048042b511ee4bd9bc1de63976
2017-12-07 00:55:58 +00:00
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
/* we currently only do handover for TCH channels */
switch (mr->lchan->type) {
case GSM_LCHAN_TCH_F:
case GSM_LCHAN_TCH_H:
break;
default:
HO: cosmetic: handover_decision.c: make process_meas_rep() return void The function's return value is ignored. An upcoming patch will use this as callback function and requires a void return. Change-Id: Id455a8becbb43884e8205d87b0371b216d0119fc
2018-02-15 13:12:40 +00:00
return;
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
}
/* parse actual neighbor cell info */
if (mr->num_cell > 0 && mr->num_cell < 7)
process_meas_neigh(mr);
hodec1: use same automatic FULL/SUBSET choice as in hodec2 So far handover decision 1 uses the FULL or SUBSET TDMA measurements across all measurement reports, depending on whether the last measurement report indicates that DTX is in use or not. Handover decision 2 since recently uses TDMA_MEAS_SET_AUTO to choose for each individual measurement report whether to use the FULL or the SUBSET value, depending on each single report's DTX use flag. Also switch handover decision 1 to heed every single report's DTX flag, by simply using TDMA_MEAS_SET_AUTO, replacing the current decision. Change-Id: Iebe980254b8c4a53ef9e7d720e417dc67077eff7
2021-07-05 10:59:50 +00:00
av_rxlev = get_meas_rep_avg(mr->lchan, TDMA_MEAS_FIELD_RXLEV, TDMA_MEAS_DIR_DL, TDMA_MEAS_SET_AUTO,
HO: cfg: separate hodec1 from hodec2 parameters Do not share config items between the current handover decision and the upcoming handover_decision_2. Rename current handover config items to hodec2_* and duplicate the ones relevant to handover decision algorithm 1 with name prefix of hodec1_*. I considered moving hodec2 parameters to an entirely separate .c file and struct, but that causes considerable code bloat. Rather use the nice handover_cfg net/bts level mechanism as-is, and simply prefix the names. In the VTY, the hodec1 parameters are configurable by 'handover foo 23' commands, while the hodec2 parameters are by 'handover2 foo 23'. The generic VTY commands to enable/disable handover and to choose the algorithm are still 'handover (0|1)' and 'handover algorithm (1|2)'. (Note, a subsequent commit will rename the 'handover foo' for hodec1 to 'handover1 foo' and add backwards-compat aliases.) For example, the 'window rxlev averaging 5' command now exists both for handover decision 1 and handover decision 2, and its values are independent. This is valid config: network # set up handover decision algorithm 1 # (pending rename of these items to 'handover1 ...') handover window rxlev averaging 5 handover window rxlev neighbor averaging 5 # set up handover decision algorithm 2 handover2 window rxlev averaging 7 handover2 window rxlev neighbor averaging 7 handover2 penalty-time max-distance 10 # enable handover handover 1 bts 0 handover algorithm 1 bts 1 handover algorithm 2 In this example, bts 0 uses algo 1 with rxlev averaging of 5, while bts 1 uses algorithm 2 where rxlev averaging of 7 is in effect. Change-Id: I6475b2543b18d21710a6d774b214cb484f36ec8e
2018-02-14 18:56:23 +00:00
ho_get_hodec1_rxlev_avg_win(bts->ho));
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
/* Interference HO */
if (rxlev2dbm(av_rxlev) > -85 &&
hodec1: use same automatic FULL/SUBSET choice as in hodec2 So far handover decision 1 uses the FULL or SUBSET TDMA measurements across all measurement reports, depending on whether the last measurement report indicates that DTX is in use or not. Handover decision 2 since recently uses TDMA_MEAS_SET_AUTO to choose for each individual measurement report whether to use the FULL or the SUBSET value, depending on each single report's DTX use flag. Also switch handover decision 1 to heed every single report's DTX flag, by simply using TDMA_MEAS_SET_AUTO, replacing the current decision. Change-Id: Iebe980254b8c4a53ef9e7d720e417dc67077eff7
2021-07-05 10:59:50 +00:00
meas_rep_n_out_of_m_be(mr->lchan, TDMA_MEAS_FIELD_RXQUAL, TDMA_MEAS_DIR_DL, TDMA_MEAS_SET_AUTO, 3, 4, 5)) {
handover_decision: log HO causes more accurately Tweaked-by: nhofmeyr@sysmocom.de Change-Id: Ib0a0787ac8b877ac63455d72886389b546e7a337
2017-08-23 14:51:22 +00:00
LOGPC(DHO, LOGL_INFO, "HO cause: Interference HO av_rxlev=%d dBm\n",
rxlev2dbm(av_rxlev));
HO: cosmetic: handover_decision.c: make process_meas_rep() return void The function's return value is ignored. An upcoming patch will use this as callback function and requires a void return. Change-Id: Id455a8becbb43884e8205d87b0371b216d0119fc
2018-02-15 13:12:40 +00:00
attempt_handover(mr);
return;
handover_decision: log HO causes more accurately Tweaked-by: nhofmeyr@sysmocom.de Change-Id: Ib0a0787ac8b877ac63455d72886389b546e7a337
2017-08-23 14:51:22 +00:00
}
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
/* Bad Quality */
hodec1: use same automatic FULL/SUBSET choice as in hodec2 So far handover decision 1 uses the FULL or SUBSET TDMA measurements across all measurement reports, depending on whether the last measurement report indicates that DTX is in use or not. Handover decision 2 since recently uses TDMA_MEAS_SET_AUTO to choose for each individual measurement report whether to use the FULL or the SUBSET value, depending on each single report's DTX use flag. Also switch handover decision 1 to heed every single report's DTX flag, by simply using TDMA_MEAS_SET_AUTO, replacing the current decision. Change-Id: Iebe980254b8c4a53ef9e7d720e417dc67077eff7
2021-07-05 10:59:50 +00:00
if (meas_rep_n_out_of_m_be(mr->lchan, TDMA_MEAS_FIELD_RXQUAL, TDMA_MEAS_DIR_DL, TDMA_MEAS_SET_AUTO, 3, 4, 5)) {
handover_decision: log HO causes more accurately Tweaked-by: nhofmeyr@sysmocom.de Change-Id: Ib0a0787ac8b877ac63455d72886389b546e7a337
2017-08-23 14:51:22 +00:00
LOGPC(DHO, LOGL_INFO, "HO cause: Bad Quality av_rxlev=%d dBm\n", rxlev2dbm(av_rxlev));
HO: cosmetic: handover_decision.c: make process_meas_rep() return void The function's return value is ignored. An upcoming patch will use this as callback function and requires a void return. Change-Id: Id455a8becbb43884e8205d87b0371b216d0119fc
2018-02-15 13:12:40 +00:00
attempt_handover(mr);
return;
handover_decision: log HO causes more accurately Tweaked-by: nhofmeyr@sysmocom.de Change-Id: Ib0a0787ac8b877ac63455d72886389b546e7a337
2017-08-23 14:51:22 +00:00
}
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
/* Low Level */
handover_decision: log HO causes more accurately Tweaked-by: nhofmeyr@sysmocom.de Change-Id: Ib0a0787ac8b877ac63455d72886389b546e7a337
2017-08-23 14:51:22 +00:00
if (rxlev2dbm(av_rxlev) <= -110) {
LOGPC(DHO, LOGL_INFO, "HO cause: Low Level av_rxlev=%d dBm\n", rxlev2dbm(av_rxlev));
HO: cosmetic: handover_decision.c: make process_meas_rep() return void The function's return value is ignored. An upcoming patch will use this as callback function and requires a void return. Change-Id: Id455a8becbb43884e8205d87b0371b216d0119fc
2018-02-15 13:12:40 +00:00
attempt_handover(mr);
return;
handover_decision: log HO causes more accurately Tweaked-by: nhofmeyr@sysmocom.de Change-Id: Ib0a0787ac8b877ac63455d72886389b546e7a337
2017-08-23 14:51:22 +00:00
}
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
/* Distance */
HO: cfg: separate hodec1 from hodec2 parameters Do not share config items between the current handover decision and the upcoming handover_decision_2. Rename current handover config items to hodec2_* and duplicate the ones relevant to handover decision algorithm 1 with name prefix of hodec1_*. I considered moving hodec2 parameters to an entirely separate .c file and struct, but that causes considerable code bloat. Rather use the nice handover_cfg net/bts level mechanism as-is, and simply prefix the names. In the VTY, the hodec1 parameters are configurable by 'handover foo 23' commands, while the hodec2 parameters are by 'handover2 foo 23'. The generic VTY commands to enable/disable handover and to choose the algorithm are still 'handover (0|1)' and 'handover algorithm (1|2)'. (Note, a subsequent commit will rename the 'handover foo' for hodec1 to 'handover1 foo' and add backwards-compat aliases.) For example, the 'window rxlev averaging 5' command now exists both for handover decision 1 and handover decision 2, and its values are independent. This is valid config: network # set up handover decision algorithm 1 # (pending rename of these items to 'handover1 ...') handover window rxlev averaging 5 handover window rxlev neighbor averaging 5 # set up handover decision algorithm 2 handover2 window rxlev averaging 7 handover2 window rxlev neighbor averaging 7 handover2 penalty-time max-distance 10 # enable handover handover 1 bts 0 handover algorithm 1 bts 1 handover algorithm 2 In this example, bts 0 uses algo 1 with rxlev averaging of 5, while bts 1 uses algorithm 2 where rxlev averaging of 7 is in effect. Change-Id: I6475b2543b18d21710a6d774b214cb484f36ec8e
2018-02-14 18:56:23 +00:00
if (mr->ms_l1.ta > ho_get_hodec1_max_distance(bts->ho)) {
HO prep: introduce per-BTS handover config, with defaults on net node It is desirable to allow configuring handover for each individual network cell. At the same time, it is desirable to set global defaults. Treat the 'network' node handover parameters as global defaults, add another set of parameters for each individual BTS. This raises questions on how the 'network' node should affect the individual BTS. The simplistic solution would have been: on creating a BTS in the config, just copy the current defaults; with serious drawbacks: - tweaking any parameter in the telnet VTY on network node will never affect any running BTS. - network node defaults *must* be issued before the bts sections in the config file. - when writing a config back to file, we would copy all net node defaults to each BTS node, making the network node configs pointless. Instead, add a handover_cfg API that tracks whether a given node has a value set or not. A bts node ho_cfg gets a pointer to the network node config and returns those values if locally unset. If no value is set on any node, use the "factory" defaults, which are hardcoded in the API. Only write back exactly those config items that were actually issued in a config file / on the telnet VTY. (ho_cfg API wise, we could trivially add another ho_cfg level per TRX if we so desire in the future.) Implement ho parameters as an opaque config struct with getters and setters to ensure the tracking is always heeded. Opaqueness dictates allocating instead of direct embedding in gsm_network and gsm_bts structs, ctx is gsm_net / bts. This is 100% backwards compatible to old configs. - No VTY command syntax changes (only the online help). - If a 'bts' sets nothing, it will use the 'network' defaults. - The 'show network' output only changes in presence of individual BTS configs. On 'show network', say "Handover: On|Off" as before, iff all BTS reflect identical behavior. Otherwise, output BTS counts of handover being enabled or not. Use the same set of VTY commands (same VTY cmd syntax as before) on network and BTS nodes, i.e. don't duplicate VTY code. From the current vty->node, figure out which ho_cfg to modify. For linking, add handover_cfg.c (the value API) in libcommon, while the handover_vty.c is in libbsc. This is mainly because some utility programs use gsm_network and hence suck in the ho stuff, but don't need the VTY commands. Review the VTY online help strings. Add VTY transcript test for handover options, testing config propagation from network to bts nodes, 'show network' output and VTY online help strings. (Needs recent addition of '... !' wildcard to osmo_interact_common.py.) I considered leaving parts of this more readable, but in the end decided for heavy use of macros to define and declare the API, because more values will be added in upcoming patches and I want to prevent myself from messing them up. Inspired-by: jolly/new_handover branch, which moves the config to 'bts' level Depends: I7c1ebb2e7f059047903a53de26a0ec1ce7fa9b98 (osmo-python-tests) Change-Id: I79d35f6d3c0fbee67904378ad7f216df34fde79a
2017-11-27 20:29:33 +00:00
LOGPC(DHO, LOGL_INFO, "HO cause: Distance av_rxlev=%d dBm ta=%d \n",
rxlev2dbm(av_rxlev), mr->ms_l1.ta);
HO: cosmetic: handover_decision.c: make process_meas_rep() return void The function's return value is ignored. An upcoming patch will use this as callback function and requires a void return. Change-Id: Id455a8becbb43884e8205d87b0371b216d0119fc
2018-02-15 13:12:40 +00:00
attempt_handover(mr);
return;
handover_decision: log HO causes more accurately Tweaked-by: nhofmeyr@sysmocom.de Change-Id: Ib0a0787ac8b877ac63455d72886389b546e7a337
2017-08-23 14:51:22 +00:00
}
[handover] Real handover algorithm This implements the handover algorithm (and associated parameters) as described in Chapter 8 of the book "Performance Enhancements in a Frequency |Hopping GSM Network" by Thomas Toftegard Nielsen and Jeroen Wigard. The parameters such as averaging windows are configured in struct gsm_network. We keep some state to trakc up to 10 neighbors as they are being reported from the MS. This has so far only been tested in a network with two BTS that have each other as neighbor. Networks with morge neighbors might encounter bugs.
2009-12-21 12:30:17 +00:00
/* Power Budget AKA Better Cell */
HO: cfg: separate hodec1 from hodec2 parameters Do not share config items between the current handover decision and the upcoming handover_decision_2. Rename current handover config items to hodec2_* and duplicate the ones relevant to handover decision algorithm 1 with name prefix of hodec1_*. I considered moving hodec2 parameters to an entirely separate .c file and struct, but that causes considerable code bloat. Rather use the nice handover_cfg net/bts level mechanism as-is, and simply prefix the names. In the VTY, the hodec1 parameters are configurable by 'handover foo 23' commands, while the hodec2 parameters are by 'handover2 foo 23'. The generic VTY commands to enable/disable handover and to choose the algorithm are still 'handover (0|1)' and 'handover algorithm (1|2)'. (Note, a subsequent commit will rename the 'handover foo' for hodec1 to 'handover1 foo' and add backwards-compat aliases.) For example, the 'window rxlev averaging 5' command now exists both for handover decision 1 and handover decision 2, and its values are independent. This is valid config: network # set up handover decision algorithm 1 # (pending rename of these items to 'handover1 ...') handover window rxlev averaging 5 handover window rxlev neighbor averaging 5 # set up handover decision algorithm 2 handover2 window rxlev averaging 7 handover2 window rxlev neighbor averaging 7 handover2 penalty-time max-distance 10 # enable handover handover 1 bts 0 handover algorithm 1 bts 1 handover algorithm 2 In this example, bts 0 uses algo 1 with rxlev averaging of 5, while bts 1 uses algorithm 2 where rxlev averaging of 7 is in effect. Change-Id: I6475b2543b18d21710a6d774b214cb484f36ec8e
2018-02-14 18:56:23 +00:00
pwr_interval = ho_get_hodec1_pwr_interval(bts->ho);
HO: process_meas_rep: guard against modulo zero Fixes: CID#182318 Change-Id: I3ad9d01cbffa287adce55b3569667b58a2d3556b
2018-02-12 20:16:44 +00:00
/* handover_cfg.h defines pwr_interval as [1..99], but since we're using it in a modulo below,
* assert non-zero to clarify. */
OSMO_ASSERT(pwr_interval);
HO prep: introduce per-BTS handover config, with defaults on net node It is desirable to allow configuring handover for each individual network cell. At the same time, it is desirable to set global defaults. Treat the 'network' node handover parameters as global defaults, add another set of parameters for each individual BTS. This raises questions on how the 'network' node should affect the individual BTS. The simplistic solution would have been: on creating a BTS in the config, just copy the current defaults; with serious drawbacks: - tweaking any parameter in the telnet VTY on network node will never affect any running BTS. - network node defaults *must* be issued before the bts sections in the config file. - when writing a config back to file, we would copy all net node defaults to each BTS node, making the network node configs pointless. Instead, add a handover_cfg API that tracks whether a given node has a value set or not. A bts node ho_cfg gets a pointer to the network node config and returns those values if locally unset. If no value is set on any node, use the "factory" defaults, which are hardcoded in the API. Only write back exactly those config items that were actually issued in a config file / on the telnet VTY. (ho_cfg API wise, we could trivially add another ho_cfg level per TRX if we so desire in the future.) Implement ho parameters as an opaque config struct with getters and setters to ensure the tracking is always heeded. Opaqueness dictates allocating instead of direct embedding in gsm_network and gsm_bts structs, ctx is gsm_net / bts. This is 100% backwards compatible to old configs. - No VTY command syntax changes (only the online help). - If a 'bts' sets nothing, it will use the 'network' defaults. - The 'show network' output only changes in presence of individual BTS configs. On 'show network', say "Handover: On|Off" as before, iff all BTS reflect identical behavior. Otherwise, output BTS counts of handover being enabled or not. Use the same set of VTY commands (same VTY cmd syntax as before) on network and BTS nodes, i.e. don't duplicate VTY code. From the current vty->node, figure out which ho_cfg to modify. For linking, add handover_cfg.c (the value API) in libcommon, while the handover_vty.c is in libbsc. This is mainly because some utility programs use gsm_network and hence suck in the ho stuff, but don't need the VTY commands. Review the VTY online help strings. Add VTY transcript test for handover options, testing config propagation from network to bts nodes, 'show network' output and VTY online help strings. (Needs recent addition of '... !' wildcard to osmo_interact_common.py.) I considered leaving parts of this more readable, but in the end decided for heavy use of macros to define and declare the API, because more values will be added in upcoming patches and I want to prevent myself from messing them up. Inspired-by: jolly/new_handover branch, which moves the config to 'bts' level Depends: I7c1ebb2e7f059047903a53de26a0ec1ce7fa9b98 (osmo-python-tests) Change-Id: I79d35f6d3c0fbee67904378ad7f216df34fde79a
2017-11-27 20:29:33 +00:00
if ((mr->nr % pwr_interval) == pwr_interval - 1)
HO: cosmetic: handover_decision.c: make process_meas_rep() return void The function's return value is ignored. An upcoming patch will use this as callback function and requires a void return. Change-Id: Id455a8becbb43884e8205d87b0371b216d0119fc
2018-02-15 13:12:40 +00:00
attempt_handover(mr);
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
}
HO: introduce ho decision callbacks Instead of reacting on S_LCHAN* signals in the handover decision code, introduce callbacks for the handover decision to be invoked by handover_logic.c at the appropriate time. The rationale is explained in a comment to struct handover_decision_callbacks, quoting: " All events that are interesting for handover decision are actually communicated by S_LCHAN_* signals, so theoretically, each handover algorithm could evaluate those. However, handover_logic.c cleans up handover operation state upon receiving some of these signals. To allow a handover decision algorithm to take advantage of e.g. the struct bsc_handover before it is discarded, the handover decision event handler needs to be invoked before handover_logic.c discards the state. For example, if the handover decision wants to place a penalty timer upon a handover failure, it still needs to know which target cell the handover failed for; handover_logic.c erases that knowledge on handover failure, since it needs to clean up the lchan's handover state. The most explicit and safest way to ensure the correct order of event handling is to invoke the handover decision algorithm's actions from handover_logic.c itself, before cleaning up. This struct provides the callback functions for this purpose. For consistency, also handle signals in this way that aren't actually in danger of interference from handover_logic.c (which also saves repeated lookup of handover state for lchans). Thus, handover decision algorithms should not register any signal handler at all. " Also: - Publish struct bsc_handover to use it as argument to above callbacks. - Add enum hodec_id to struct bsc_handover, to be able to signal the appropriate hodec algorithm per event. - Add hodec_id argument to bsc_handover_start*() to be placed in the bsc_handover struct. - Publish the LOGPHO logging macros in handover.h along with struct bsc_handover, convenient for logging in callback implementations. Replace handover_decision.c's signal handler with a registered handover_decision_callbacks instance. (Upcoming handover_decision_2 will use all of the callbacks introduced here.) Change-Id: Id5b64504007fe03e0406a4b395cd0359232b77d2
2018-02-15 13:10:12 +00:00
struct handover_decision_callbacks hodec1_callbacks = {
.hodec_id = HODEC1,
.on_measurement_report = on_measurement_report,
};
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
HO: enable handover by initializing at startup; rename init function Change-Id: I224884c84895ebf6c8cf498c16616214cb2b5779
2017-12-07 00:57:01 +00:00
void handover_decision_1_init(void)
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
{
HO: introduce ho decision callbacks Instead of reacting on S_LCHAN* signals in the handover decision code, introduce callbacks for the handover decision to be invoked by handover_logic.c at the appropriate time. The rationale is explained in a comment to struct handover_decision_callbacks, quoting: " All events that are interesting for handover decision are actually communicated by S_LCHAN_* signals, so theoretically, each handover algorithm could evaluate those. However, handover_logic.c cleans up handover operation state upon receiving some of these signals. To allow a handover decision algorithm to take advantage of e.g. the struct bsc_handover before it is discarded, the handover decision event handler needs to be invoked before handover_logic.c discards the state. For example, if the handover decision wants to place a penalty timer upon a handover failure, it still needs to know which target cell the handover failed for; handover_logic.c erases that knowledge on handover failure, since it needs to clean up the lchan's handover state. The most explicit and safest way to ensure the correct order of event handling is to invoke the handover decision algorithm's actions from handover_logic.c itself, before cleaning up. This struct provides the callback functions for this purpose. For consistency, also handle signals in this way that aren't actually in danger of interference from handover_logic.c (which also saves repeated lookup of handover state for lchans). Thus, handover decision algorithms should not register any signal handler at all. " Also: - Publish struct bsc_handover to use it as argument to above callbacks. - Add enum hodec_id to struct bsc_handover, to be able to signal the appropriate hodec algorithm per event. - Add hodec_id argument to bsc_handover_start*() to be placed in the bsc_handover struct. - Publish the LOGPHO logging macros in handover.h along with struct bsc_handover, convenient for logging in callback implementations. Replace handover_decision.c's signal handler with a registered handover_decision_callbacks instance. (Upcoming handover_decision_2 will use all of the callbacks introduced here.) Change-Id: Id5b64504007fe03e0406a4b395cd0359232b77d2
2018-02-15 13:10:12 +00:00
handover_decision_callbacks_register(&hodec1_callbacks);
[handover] first functional handover implementation With this commit, we can successfully hand over a channel from one cell to another cell. We implement asynchronous intra-BSC (but inter-BTS) handover. Changes: * introduce new DHO log category * extend rsl_chan_activate_lchan() with argument for HO reference * introduce actual minimal handover decision making in handover_decision.c * various fixes to bsc_handover_start() in handover_logic.c
2009-12-16 23:31:10 +00:00
}