Osmocom Packet control Unit (PCU): Network-side GPRS (RLC/MAC); BTS- or BSC-colocated https://osmocom.org/projects/osmopcu
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.

329 lines
10 KiB

/* gprs_rlcmac.h
* Copyright (C) 2012 Ivan Klyuchnikov
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (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
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
#ifdef __cplusplus
#include <bitvector.h>
#include <gsm_rlcmac.h>
#include <gsm_timer.h>
extern "C" {
#include <osmocom/core/linuxlist.h>
#include <osmocom/core/timer.h>
/* This special feature will delay assignment of downlink TBF by one second,
* in case there is already a TBF.
* This is usefull to debug downlink establishment during packet idle mode.
* PDCH instanc
struct gprs_rlcmac_tbf;
struct gprs_rlcmac_pdch {
uint8_t enable; /* TS is enabled */
uint8_t tsc; /* TSC of this slot */
uint8_t next_ul_tfi; /* next uplink TBF/TFI to schedule (0..31) */
uint8_t next_dl_tfi; /* next downlink TBF/TFI to schedule (0..31) */
struct gprs_rlcmac_tbf *ul_tbf[32]; /* array of UL TBF, by UL TFI */
struct gprs_rlcmac_tbf *dl_tbf[32]; /* array of DL TBF, by DL TFI */
struct llist_head paging_list; /* list of paging messages */
uint32_t last_rts_fn; /* store last frame number of RTS */
struct gprs_rlcmac_trx {
uint16_t arfcn;
struct gprs_rlcmac_pdch pdch[8];
struct gprs_rlcmac_bts {
uint8_t cs1;
uint8_t cs2;
uint8_t cs3;
uint8_t cs4;
uint8_t initial_cs;
uint8_t force_cs; /* 0=use from BTS 1=use from VTY */
uint16_t force_llc_lifetime; /* overrides lifetime from SGSN */
uint8_t t3142;
uint8_t t3169;
uint8_t t3191;
uint16_t t3193_msec;
uint8_t t3195;
uint8_t n3101;
uint8_t n3103;
uint8_t n3105;
struct gprs_rlcmac_trx trx[8];
int (*alloc_algorithm)(struct gprs_rlcmac_tbf *old_tbf,
struct gprs_rlcmac_tbf *tbf, uint32_t cust);
uint32_t alloc_algorithm_curst; /* options to customize algorithm */
extern struct gprs_rlcmac_bts *gprs_rlcmac_bts;
#ifdef __cplusplus
* TBF instance
#define LLC_MAX_LEN 1543
#define RLC_MAX_SNS 128 /* GPRS, must be power of 2 */
#define RLC_MAX_WS 64 /* max window size */
#define RLC_MAX_LEN 54 /* CS-4 including spare bits */
#define Tassign_agch 0,500000/* wait for assignment, before transmitting DL */
#define Tassign_pacch 0,100000/* wait for assignment, before transmitting DL */
enum gprs_rlcmac_tbf_state {
GPRS_RLCMAC_NULL = 0, /* new created TBF */
GPRS_RLCMAC_ASSIGN, /* wait for downlink assignment */
GPRS_RLCMAC_FLOW, /* RLC/MAC flow, ressource needed */
GPRS_RLCMAC_FINISHED, /* flow finished, wait for release */
GPRS_RLCMAC_WAIT_RELEASE,/* wait for release or restart of DL TBF */
GPRS_RLCMAC_RELEASING, /* releasing, wait to free TBI/USF */
enum gprs_rlcmac_tbf_poll_state {
GPRS_RLCMAC_POLL_SCHED, /* a polling was scheduled */
enum gprs_rlcmac_tbf_dl_ass_state {
GPRS_RLCMAC_DL_ASS_SEND_ASS, /* send downlink assignment on next RTS */
enum gprs_rlcmac_tbf_ul_ass_state {
GPRS_RLCMAC_UL_ASS_SEND_ASS, /* send uplink assignment on next RTS */
enum gprs_rlcmac_tbf_ul_ack_state {
GPRS_RLCMAC_UL_ACK_SEND_ACK, /* send acknowledge on next RTS */
enum gprs_rlcmac_tbf_direction {
struct gprs_rlcmac_tbf {
struct llist_head list;
enum gprs_rlcmac_tbf_state state;
enum gprs_rlcmac_tbf_direction direction;
uint8_t tfi;
uint32_t tlli;
uint8_t tlli_valid;
uint8_t contention_resolution_done; /* set after done */
uint8_t trx;
uint16_t arfcn;
uint8_t tsc;
uint8_t first_ts; /* first TS used by TBF */
uint8_t first_common_ts; /* first TS that the phone can send and
reveive simultaniously */
uint8_t control_ts; /* timeslot control messages and polling */
uint8_t ms_class;
struct gprs_rlcmac_pdch *pdch[8]; /* list of PDCHs allocated to TBF */
uint16_t ta;
uint8_t llc_frame[LLC_MAX_LEN]; /* current DL or UL frame */
uint16_t llc_index; /* current write/read position of frame */
uint16_t llc_length; /* len of current DL LLC_frame, 0 == no frame */
struct llist_head llc_queue; /* queued LLC DL data */
enum gprs_rlcmac_tbf_dl_ass_state dl_ass_state;
enum gprs_rlcmac_tbf_ul_ass_state ul_ass_state;
enum gprs_rlcmac_tbf_ul_ack_state ul_ack_state;
enum gprs_rlcmac_tbf_poll_state poll_state;
uint32_t poll_fn; /* frame number to poll */
uint16_t ws; /* window size */
uint16_t sns; /* sequence number space */
/* Please note that all variables here will be reset when changing
* from WAIT RELEASE back to FLOW state (re-use of TBF).
* All states that need reset must be in this struct, so this is why
* variables are in both (dl and ul) structs and not outside union.
union {
struct {
uint16_t bsn; /* block sequence number */
uint16_t v_s; /* send state */
uint16_t v_a; /* ack state */
char v_b[RLC_MAX_SNS/2]; /* acknowledge state array */
int32_t tx_counter; /* count all transmitted blocks */
uint8_t n3105; /* N3105 counter */
} dl;
struct {
uint16_t bsn; /* block sequence number */
uint16_t v_r; /* receive state */
uint16_t v_q; /* receive window state */
char v_n[RLC_MAX_SNS/2]; /* receive state array */
int32_t rx_counter; /* count all received blocks */
uint8_t n3103; /* N3103 counter */
uint8_t usf[8]; /* list USFs per PDCH (timeslot) */
} ul;
} dir;
uint8_t rlc_block[RLC_MAX_SNS/2][RLC_MAX_LEN]; /* block history */
uint8_t rlc_block_len[RLC_MAX_SNS/2]; /* block len of history */
struct osmo_timer_list timer;
unsigned int T; /* Txxxx number */
unsigned int num_T_exp; /* number of consecutive T expirations */
struct osmo_gsm_timer_list gsm_timer;
unsigned int fT; /* fTxxxx number */
unsigned int num_fT_exp; /* number of consecutive fT expirations */
extern struct llist_head gprs_rlcmac_ul_tbfs; /* list of uplink TBFs */
extern struct llist_head gprs_rlcmac_dl_tbfs; /* list of downlink TBFs */
* paging entry
struct gprs_rlcmac_paging {
struct llist_head list;
uint8_t chan_needed;
uint8_t identity_lv[9];
int tfi_alloc(enum gprs_rlcmac_tbf_direction dir, uint8_t *_trx, uint8_t *_ts,
uint8_t use_trx, uint8_t first_ts);
struct gprs_rlcmac_tbf *tbf_alloc(struct gprs_rlcmac_tbf *old_tbf,
enum gprs_rlcmac_tbf_direction dir, uint8_t tfi, uint8_t trx,
uint8_t first_ts, uint8_t ms_class, uint8_t single_slot);
int alloc_algorithm_a(struct gprs_rlcmac_tbf *old_tbf,
struct gprs_rlcmac_tbf *tbf, uint32_t cust);
int alloc_algorithm_b(struct gprs_rlcmac_tbf *old_tbf,
struct gprs_rlcmac_tbf *tbf, uint32_t cust);
struct gprs_rlcmac_tbf *tbf_by_tfi(uint8_t tfi, uint8_t trx, uint8_t ts,
enum gprs_rlcmac_tbf_direction dir);
struct gprs_rlcmac_tbf *tbf_by_tlli(uint32_t tlli,
enum gprs_rlcmac_tbf_direction dir);
struct gprs_rlcmac_tbf *tbf_by_poll_fn(uint32_t fn, uint8_t trx, uint8_t ts);
void tbf_free(struct gprs_rlcmac_tbf *tbf);
int tbf_update(struct gprs_rlcmac_tbf *tbf);
int tbf_assign_control_ts(struct gprs_rlcmac_tbf *tbf);
void tbf_new_state(struct gprs_rlcmac_tbf *tbf,
enum gprs_rlcmac_tbf_state state);
void tbf_timer_start(struct gprs_rlcmac_tbf *tbf, unsigned int T,
unsigned int seconds, unsigned int microseconds);
void tbf_timer_stop(struct gprs_rlcmac_tbf *tbf);
/* TS 44.060 Section 10.4.7 Table Payload Type field */
enum gprs_rlcmac_block_type {
int gprs_rlcmac_rcv_block(uint8_t trx, uint8_t ts, uint8_t *data, uint8_t len,
uint32_t fn);
int write_immediate_assignment(bitvec * dest, uint8_t downlink, uint8_t ra,
uint32_t fn, uint8_t ta, uint16_t arfcn, uint8_t ts, uint8_t tsc,
uint8_t tfi, uint8_t usf, uint32_t tlli, uint8_t polling,
uint32_t poll_fn);
void write_packet_uplink_assignment(bitvec * dest, uint8_t old_tfi,
uint8_t old_downlink, uint32_t tlli, uint8_t use_tlli,
struct gprs_rlcmac_tbf *tbf, uint8_t poll);
void write_packet_downlink_assignment(RlcMacDownlink_t * block, uint8_t old_tfi,
uint8_t old_downlink, struct gprs_rlcmac_tbf *tbf, uint8_t poll);
void write_packet_uplink_ack(RlcMacDownlink_t * block, struct gprs_rlcmac_tbf *tbf,
uint8_t final);
int gprs_rlcmac_tx_ul_ud(gprs_rlcmac_tbf *tbf);
void tbf_timer_cb(void *_tbf);
int gprs_rlcmac_poll_timeout(struct gprs_rlcmac_tbf *tbf);
int gprs_rlcmac_rcv_rach(uint8_t ra, uint32_t Fn, int16_t qta);
int gprs_rlcmac_rcv_control_block(bitvec *rlc_block, uint8_t trx, uint8_t ts,
uint32_t fn);
struct msgb *gprs_rlcmac_send_packet_uplink_assignment(
struct gprs_rlcmac_tbf *tbf, uint32_t fn);
struct msgb *gprs_rlcmac_send_packet_downlink_assignment(
struct gprs_rlcmac_tbf *tbf, uint32_t fn);
void gprs_rlcmac_trigger_downlink_assignment(gprs_rlcmac_tbf *tbf,
uint8_t old_downlink, char *imsi);
int gprs_rlcmac_downlink_ack(struct gprs_rlcmac_tbf *tbf, uint8_t final,
uint8_t ssn, uint8_t *rbb);
unsigned write_packet_paging_request(bitvec * dest);
unsigned write_repeated_page_info(bitvec * dest, unsigned& wp, uint8_t len,
uint8_t *identity, uint8_t chan_needed);
int gprs_rlcmac_rcv_data_block_acknowledged(uint8_t trx, uint8_t ts,
uint8_t *data, uint8_t len);
struct msgb *gprs_rlcmac_send_data_block_acknowledged(
struct gprs_rlcmac_tbf *tbf, uint32_t fn, uint8_t ts);
struct msgb *gprs_rlcmac_send_uplink_ack(struct gprs_rlcmac_tbf *tbf,
uint32_t fn);
int gprs_rlcmac_rcv_rts_block(uint8_t trx, uint8_t ts, uint16_t arfcn,
uint32_t fn, uint8_t block_nr);
int gprs_rlcmac_add_paging(uint8_t chan_needed, uint8_t *identity_lv);
struct gprs_rlcmac_paging *gprs_rlcmac_dequeue_paging(
struct gprs_rlcmac_pdch *pdch);
struct msgb *gprs_rlcmac_send_packet_paging_request(
struct gprs_rlcmac_pdch *pdch);
#endif // GPRS_RLCMAC_H