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doc: Update Abis manual RSL section with ETWS related infomration 

Change-Id: I969153a204c167783ba394c9a911ff4484ded759
This commit is contained in:
Harald Welte 2019-09-07 11:31:23 +02:00
parent 2588b2abf6
commit faf861b881
1 changed files with 48 additions and 0 deletions
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doc/manuals/abis/rsl.adoc
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@ -81,6 +81,8 @@ Specific additions and limitations apply, see the linked sections.
.3+.| <<pdch_deact>> | <<rsl_pdch_deact>> | RSL PDCH Deactivation | <- | Received
| <<rsl_pdch_deact_ack>> | RSL PDCH Deactivation ACK | -> | Sent
| <<rsl_pdch_deact_nack>> | RSL PDCH Deactivation NACK | -> | Sent
5+<| *COMMON CHANNEL MANAGEMENT MESSAGES*
.3+.| <<etws>> | <<OSMO_ETWS_CMD>> | Osmocom ETWS Command | <- | Received
|===
==== Messages Not Implemented by OsmoBTS
@ -455,6 +457,25 @@ include::dyn_ts_osmocom_style1.msc[]
include::dyn_ts_osmocom_style2.msc[]
----
[[etws]]
=== ETWS (Earthquake and Tsunami Warning System)
ETWS as specified in 3GPP TS 23.041 includes not only notification via
SMSCB, but also so-called Primary Notifications (PN). The ETWS PN are
transmitted
* by the BSC to all subscribers with active dedicated channels
* by the BTS on the PCH to all subscribers in idle mode
* by the PCU on the PACCH to all subscribers with active TBF
Unfortunately, 3GPP forgot to update their specifications with any
information as to how the ETWS PN is transmitted from BSC to BTS in
a portable way, and Osmocom had to invent their own non-standard
signaling for it.
See <<OSMO_ETWS_CMD>> for the Osmocom implementation.
=== Message Formats and Contents
[[rsl_crcx_msg]]
@ -754,6 +775,32 @@ on a IPA style dynamic TCH/F+PDCH channel.
NOTE:: This message is *not* used by Osmocom style dynamic channels
[[OSMO_ETWS_CMD]]
==== Osmocom ETWS Command
This message is sent by the BSC to transfer the ETWS Primary Notification (PN)
from BSC to BTS and enable/disable transmission of ETWS PN by the BTS. For more
information about ETWS, see 3GPP TS 23.041.
If the ETWS PN length is > 0, the BTS will immediately start transmission
of the received ETWS PN on the PCH using P1 Rest Octets. It will also forward
he ETWS PN to the PCU to enable the PCU to transmit it via PACCH on active TBF.
If the ETWS PN length is 0, the BTS will stop any ETWS PN broadcast via the PCH.
The Channel Number IE is set to the Downlink CCCH (PCH).
[options="header"]
[cols="30%,25%,15%,15%,15%"]
|===
| INFORMATION ELEMENT | REFERENCE | PRESENCE | FORMAT | LENGTH
| Message discriminator | 08.58 9.1 | M | V | 1
| Message type | <<own_msg_types>> | M | V | 1
| Channel number | 08.58 9.3.1 | M | TV | 2
| SMSCB Message | 08.58 9.3.42 | M | TLV | 2-58
|===
=== Information Element Codings
[[own_msg_types]]
@ -776,6 +823,7 @@ indicated in 3GPP TS 08.58 Section 9.1:
| 0x77 | Delete Connection (DLCX) | <<rsl_dlcx_msg>>
| 0x78 | Delete Connection (DLCX) ACK | <<rsl_dlcx_msg_ack>>
| 0x79 | Delete Connection (DLCX) NACK | <<rsl_dlcx_msg_nack>>
| 0x7f | Osmocom ETWS Command | <<OSMO_ETWS_CMD>>
| 0x48 | PDCH Activate | <<rsl_pdch_act>>
| 0x49 | PDCH Activate ACK | <<rsl_pdch_act_ack>>
| 0x4a | PDCH Activate NACK | <<rsl_pdch_act_nack>>