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Review at https://gerrit.osmocom.org/1187
rtp-amr.adoc: TCH/AFS Downlink: Inhibiting
Add two new chapters contributed by Nutaq:
* TCH/AFS Downlink: Inhibiting a SID_FIRST frame
* TCH/AFS Downlink: FACCH/F During DTX Operation
Change-Id: Ic39d035f9d17bd0634c2df78ae3359a5eb7dfd46
---
M OsmoBTS/abis/rtp-amr.adoc
1 file changed, 85 insertions(+), 4 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/osmo-gsm-manuals refs/changes/87/1187/1
diff --git a/OsmoBTS/abis/rtp-amr.adoc b/OsmoBTS/abis/rtp-amr.adoc
index f82b420..c67a1ad 100644
--- a/OsmoBTS/abis/rtp-amr.adoc
+++ b/OsmoBTS/abis/rtp-amr.adoc
@@ -495,10 +495,91 @@
}
----
-DLOS1:: The SID_ONSET and the first voice frame are sent in the same
-block of four radio busts. Hence, the BTS must be able ot to send
-actual codec payload along with the GsmL1_TchPlType_Amr_Onset
-primitive.
+==== TCH/AFS Downlink: Inhibiting a SID_FIRST frame
+
+Here is the procedure to inhibit a SID_FIRST frame in order to quickly resume speech.
+
+["mscgen"]
+----
+msc {
+ hscale = 2;
+ ms [label="MS"], phy [label="BTS-PHY"], bts [label="BTS"], mgw [label="MGW"];
+
+ ...;
+ --- [label="Inhibiting a SID_FIRST frame"];
+
+ bts <= mgw [label="RTP (AMR FT=SID,Q=1)"];
+ phy => bts [label="PH-RTS.ind (TCH)"];
+ phy <= bts [label="PH-DATA.req GsmL1_TchPlType_Amr (SID_FIRST)"];
+ bts => bts [label="Store SID frame in case it contains comfort noise parameters"];
+ ms <= phy [label="L1 burst (sub-block 5 of speech frame N-1 + sub-block 1 of SID_FIRST)"];
+ ms <= phy [label="L1 burst (sub-block 6 of speech frame N-1 + sub-block 2 of SID_FIRST)"];
+ ms <= phy [label="L1 burst (sub-block 7 of speech frame N-1 + sub-block 3 of SID_FIRST)"];
+ ms <= phy [label="L1 burst (sub-block 8 of speech frame N-1 + sub-block 4 of SID_FIRST)"];
+
+ bts <= mgw [label="RTP (AMR FT=0..7,Q=1) MARKER=1"];
+ phy => bts [label="PH-RTS.ind (TCH)"];
+ phy <= bts [label="PH-DATA.req GsmL1_TchPlType_Amr_Onset"];
+ phy <= bts [label="PH-DATA.req GsmL1_TchPlType_Amr (N)"];
+ ms <= phy [label="L1 burst (block 1 of SID_ONSET + sub-block 1 of speech frame N)"];
+ ms <= phy [label="L1 burst (block 2 of SID_ONSET + sub-block 2 of speech frame N)"];
+ ms <= phy [label="L1 burst (block 3 of SID_ONSET + sub-block 3 of speech frame N)"];
+ ms <= phy [label="L1 burst (block 4 of SID_ONSET + sub-block 4 of speech frame N)"];
+
+ bts <= mgw [label="RTP (AMR FT=0..7,Q=1)"];
+ phy => bts [label="PH-RTS.ind (TCH)"];
+ phy <= bts [label="PH-DATA.req GsmL1_TchPlType_Amr (N+1)"];
+ ms <= phy [label="L1 burst (sub-block 5 of speech frame N + sub-block 1 of speech frame N+1)"];
+ ms <= phy [label="L1 burst (sub-block 6 of speech frame N + sub-block 2 of speech frame N+1)"];
+ ms <= phy [label="L1 burst (sub-block 7 of speech frame N + sub-block 2 of speech frame N+1)"];
+ ms <= phy [label="L1 burst (sub-block 8 of speech frame N + sub-block 2 of speech frame N+1)"];
+ }
+----
+
+==== TCH/AFS Downlink: FACCH/F During DTX Operation
+
+The following procedure must be observed if a FACCH/F frame must be transmitted during DTX operation.
+
+["mscgen"]
+----
+msc {
+ hscale = 2;
+ ms [label="MS"], phy [label="BTS-PHY"], bts [label="BTS"], mgw [label="MGW"];
+
+ ...;
+ --- [label="FACCH/F Frame During DTX"];
+
+ bts <= mgw [label="FACCH/F"];
+ phy => bts [label="PH-RTS.ind (FACCH/F)"];
+ phy => bts [label="PH-RTS.ind (TCH/F)"];
+ phy <= bts [label="PH-DATA.req (FACCH/F)"];
+ phy <= bts [label="PH-DATA.req GsmL1_TchPlType_Amr_Onset(TCH/F)", id="NOTE"];
+ ms <= phy [label="L1 burst (block 1 of SID_ONSET + sub-block 1 of FACCH/F)"];
+ ms <= phy [label="L1 burst (block 2 of SID_ONSET + sub-block 2 of FACCH/F)"];
+ ms <= phy [label="L1 burst (block 3 of SID_ONSET + sub-block 3 of FACCH/F)"];
+ ms <= phy [label="L1 burst (block 4 of SID_ONSET + sub-block 4 of FACCH/F)"];
+
+ phy => bts [label="PH-RTS.ind (FACCH)"];
+ phy => bts [label="PH-RTS.ind (TCH)"];
+ phy <= bts [label="PH-EMPTY-FRAME.req (FACCH/F)"];
+ phy <= bts [label="PH-DATA.req GsmL1_TchPlType_Amr (SID_FIRST)"];
+ ms x- phy [label="L1 burst (sub-block 5 of FACCH/F + sub-block 1 of SID_FIRST)"];
+ ms x- phy [label="L1 burst (sub-block 6 of FACCH/F + sub-block 2 of SID_FIRST)"];
+ ms x- phy [label="L1 burst (sub-block 7 of FACCH/F + sub-block 3 of SID_FIRST)"];
+ ms x- phy [label="L1 burst (sub-block 8 of FACCH/F + sub-block 4 of SID_FIRST)"];
+
+ phy => bts [label="PH-RTS.ind (FACCH)"];
+ phy => bts [label="PH-RTS.ind (TCH)"];
+ phy <= bts [label="PH-EMPTY-FRAME.req (FACCH/F)"];
+ phy <= bts [label="PH-EMPTY-FRAME.req (TCH/F)"];
+ ms x- phy [label="Supressed burst"];
+ ms x- phy [label="Supressed burst"];
+ ms x- phy [label="Supressed burst"];
+ ms x- phy [label="Supressed burst"];
+}
+----
+
+NOTE:: The ONSET and the FACCH/F PH-DATA requests must both be sent to the PHY.
== Half-Rate (TCH/AHS)
--
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Gerrit-MessageType: newchange
Gerrit-Change-Id: Ic39d035f9d17bd0634c2df78ae3359a5eb7dfd46
Gerrit-PatchSet: 1
Gerrit-Project: osmo-gsm-manuals
Gerrit-Branch: master
Gerrit-Owner: Max <msuraev at sysmocom.de>