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Abis manual: add RSL_IE_OSMO_TRAINING_SEQUENCE 

Change-Id: Ie583bd5969fdb45f772af198033e58d7c4077306
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Neels Hofmeyr 2021-04-20 23:03:35 +02:00
parent 7177e666bb
commit 823cd52964
1 changed files with 74 additions and 0 deletions
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doc/manuals/abis/rsl.adoc
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@ -843,6 +843,7 @@ addition to those indicated in 3GPP TS 08.58 Section 9.3:
| IEI | Name | This document §
| 0x01 | RSL_IE_CHAN_NR | <<RSL_IE_CHAN_NR>>
| 0x60 | RSL_IE_OSMO_REP_ACCH_CAP | <<RSL_IE_OSMO_REP_ACCH_CAP>>
| 0x61 | RSL_IE_OSMO_TRAINING_SEQUENCE | <<RSL_IE_OSMO_TRAINING_SEQUENCE>>
| 0xf0 | RSL_IE_IPAC_REMOTE_IP | <<RSL_IE_IPAC_REMOTE_IP>>
| 0xf1 | RSL_IE_IPAC_REMOTE_PORT | <<RSL_IE_IPAC_REMOTE_PORT>>
| 0xf3 | RSL_IE_IPAC_LOCAL_PORT | <<RSL_IE_IPAC_LOCAL_PORT>>
@ -979,6 +980,79 @@ If the IE is not present, then ACCH repetition completely is disabled.
(Bits 7 is reserved for future use and must be set to zero.)
[[RSL_IE_OSMO_TRAINING_SEQUENCE]]
==== RSL_IE_OSMO_TRAINING_SEQUENCE
This TLV IE instructs the BTS to use a specific training sequence set and
training sequence code for a given lchan. It is sent by OsmoBSC in RSL CHANNEL
ACTIVATION and MODE MODIFY messages to the BTS, iff the BTS is VAMOS-capable,
i.e. if an Abis-over-IP connected BTS indicated BTS_FEAT_VAMOS in the OML BTS
features (Manufacturer Id information element, see <<NM_ATT_MANUF_ID>>).
If this information element is present, the receiver shall ignore any other
training sequence set and training sequence code bits from other information
elements of the same RSL message.
This is an Osmocom-specific extension of the RSL layer, which was added to
express more than two TSC sets. For VAMOS operation, OsmoBSC selects from one
of four separate training sequence codings per modulation scheme, while usual
RSL IEs are only able to express a single-bit TSC set number. For clarity, this
IE contains both the TSC set and the TSC in one IE, and is defined as
overruling any other IEs containing TSC or TSC set numbers.
The first value octet indicates the training sequence set, and the second octet
indicates the training sequence code to be used. Receiving values from a
reserved value range should be considered an error condition.
.RSL_IE_OSMO_TRAINING_SEQUENCE
[options="header",width="80%",cols="20%,80%"]
|===
| IE octet | value
| octet 1 | RSL_IE_OSMO_TRAINING_SEQUENCE IEI (0x61)
| octet 2 | length of the value part (2)
| octet 3 | TSC set
| octet 4 | TSC
|===
The training sequence set (TSC set) is coded like the 'CS Domain TSC Set' bits,
as defined in the 'Extended TSC Set' IE in 3GPP TS 44.018 10.5.2.82
<<3gpp-ts-44-018>>, and corresponds to the 'TSC Set' as defined in 3GPP TS
45.002 <<3gpp-ts-45-002>>. The encoded training sequence set number ranges from
0 to 3, any other values are reserved for future use. The encoded 0 corresponds
to TSC Set 1, see <<RSL_IE_OSMO_TRAINING_SEQUENCE__TSC_set_coding>>.
[[RSL_IE_OSMO_TRAINING_SEQUENCE__TSC_set_coding]]
.TSC set (octet 3) coding
[options="header",width="80%",cols="20%,80%"]
|===
| octet 3 value | interpretation
| 0 | 'TSC Set 1' as in 3GPP TS 45.002
| 1 | 'TSC Set 2'
| 2 | 'TSC Set 3'
| 3 | 'TSC Set 4'
| 4..255 | reserved values
|===
The training sequence code (TSC) corresponds to the 'TSC' bits as defined in
the 'Channel Description 2' IE in 3GPP TS 44.018 10.5.2.5a <<3gpp-ts-44-018>>.
The training sequence code ranges from 0 to 7, any other values are reserved
for future use.
.TSC (octet 4) coding
[options="header",width="80%",cols="20%,80%"]
|===
| octet 4 value | interpretation
| 0 | 'Training Sequence Code (TSC) 0' as in 3GPP TS 45.002
| 1 | 'Training Sequence Code (TSC) 1'
| 2 | 'Training Sequence Code (TSC) 2'
| 3 | 'Training Sequence Code (TSC) 3'
| 4 | 'Training Sequence Code (TSC) 4'
| 5 | 'Training Sequence Code (TSC) 5'
| 6 | 'Training Sequence Code (TSC) 6'
| 7 | 'Training Sequence Code (TSC) 7'
| 8..255 | reserved values
|===
=== A-bis RSL Initialization / BTS bring-up
Upon receiving the 'IPA RSL CONNECT' OML message by the respective