[PATCH] osmo-pcu[master]: Handle Timing Advance IE properly

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Max gerrit-no-reply at lists.osmocom.org
Wed Jul 20 09:43:40 UTC 2016


Hello Jenkins Builder,

I'd like you to reexamine a change.  Please visit

    https://gerrit.osmocom.org/552

to look at the new patch set (#2).

Handle Timing Advance IE properly

Move writing Timing Advance IE and Timing Advance Index into separate
functions to simplify adding PTCCH support. This also fixes previous
incorrect (and unused) code for writing Global Packet TA IE.

Change-Id: I786bf7fc999d401cc3d9e7f1e7a1fba953b5d458
Related: OS#1545
---
M src/encoding.cpp
M src/encoding.h
M src/tbf.cpp
3 files changed, 41 insertions(+), 35 deletions(-)


  git pull ssh://gerrit.osmocom.org:29418/osmo-pcu refs/changes/52/552/2

diff --git a/src/encoding.cpp b/src/encoding.cpp
index 9f3b31d..22fd538 100644
--- a/src/encoding.cpp
+++ b/src/encoding.cpp
@@ -32,6 +32,39 @@
 #include <errno.h>
 #include <string.h>
 
+/* { 0 | 1 < TIMING_ADVANCE_INDEX : bit (4) > } */
+static inline bool write_tai(bitvec *dest, unsigned& wp, int8_t tai)
+{
+	if (tai < 0) { /* No TIMING_ADVANCE_INDEX: */
+		bitvec_write_field(dest, wp, 0, 1);
+		return false;
+	}
+	/* TIMING_ADVANCE_INDEX: */
+	bitvec_write_field(dest, wp, 1, 1);
+	bitvec_write_field(dest, wp, tai, 4);
+	return true;
+}
+
+/* { 0 | 1 < TIMING_ADVANCE_VALUE : bit (6) > } */
+static inline void write_ta(bitvec *dest, unsigned& wp, int8_t ta)
+{
+	if (ta < 0) /* No TIMING_ADVANCE_VALUE: */
+		bitvec_write_field(dest, wp, 0, 1);
+	else { /* TIMING_ADVANCE_VALUE: */
+		bitvec_write_field(dest, wp, 1, 1);
+		bitvec_write_field(dest, wp, ta, 6);
+	}
+}
+
+/* 3GPP TS 44.060 § 12.12 */
+static inline void write_ta_ie(bitvec *dest, unsigned& wp,
+			       int8_t ta, int8_t tai, uint8_t ts)
+{
+	write_ta(dest, wp, ta);
+	if (write_tai(dest, wp, tai)) /* TIMING_ADVANCE_TIMESLOT_NUMBER: */
+		bitvec_write_field(dest, wp, ts, 3);
+}
+
 static int write_ia_rest_downlink(
 	gprs_rlcmac_dl_tbf *tbf,
 	bitvec * dest, unsigned& wp,
@@ -59,12 +92,7 @@
 	bitvec_write_field(dest, wp,gamma,5);   // GAMMA power control parameter
 	bitvec_write_field(dest, wp,polling,1);   // Polling Bit
 	bitvec_write_field(dest, wp,!polling,1);   // TA_VALID ???
-	if (ta_idx < 0) {
-		bitvec_write_field(dest, wp,0x0,1);   // switch TIMING_ADVANCE_INDEX = off
-	} else {
-		bitvec_write_field(dest, wp,0x1,1);   // switch TIMING_ADVANCE_INDEX = on
-		bitvec_write_field(dest, wp,ta_idx,4);   // TIMING_ADVANCE_INDEX
-	}
+	write_tai(dest, wp, ta_idx);
 	if (polling) {
 		bitvec_write_field(dest, wp,0x1,1);   // TBF Starting TIME present
 		bitvec_write_field(dest, wp,(fn / (26 * 51)) % 32,5); // T1'
@@ -107,12 +135,7 @@
 		} else
 			bitvec_write_field(dest, wp,0x0,1);   // ALPHA = not present
 		bitvec_write_field(dest, wp,gamma,5);   // GAMMA power control parameter
-		if (ta_idx < 0) {
-			bitvec_write_field(dest, wp,0x0,1);   // switch TIMING_ADVANCE_INDEX = off
-		} else {
-			bitvec_write_field(dest, wp,0x1,1);   // switch TIMING_ADVANCE_INDEX = on
-			bitvec_write_field(dest, wp,ta_idx,4);   // TIMING_ADVANCE_INDEX
-		}
+		write_tai(dest, wp, ta_idx);
 		bitvec_write_field(dest, wp, 1, 1);    // TBF_STARTING_TIME_FLAG
 		bitvec_write_field(dest, wp,(fn / (26 * 51)) % 32,5); // T1'
 		bitvec_write_field(dest, wp,fn % 51,6);               // T3
@@ -236,7 +259,7 @@
 	bitvec * dest, uint8_t old_tfi,
 	uint8_t old_downlink, uint32_t tlli, uint8_t use_tlli,
 	struct gprs_rlcmac_ul_tbf *tbf, uint8_t poll, uint8_t rrbp, uint8_t alpha,
-	uint8_t gamma, int8_t ta_idx, int8_t use_egprs)
+	uint8_t gamma, int8_t ta_idx, uint8_t ta_ts, int8_t use_egprs)
 {
 	// TODO We should use our implementation of encode RLC/MAC Control messages.
 	unsigned wp = 0;
@@ -263,16 +286,8 @@
 	if (!use_egprs) {
 		bitvec_write_field(dest, wp,0x0,1); // Message escape
 		bitvec_write_field(dest, wp,tbf->current_cs().to_num()-1, 2); // CHANNEL_CODING_COMMAND 
-		bitvec_write_field(dest, wp,0x1,1); // TLLI_BLOCK_CHANNEL_CODING 
-		bitvec_write_field(dest, wp,0x1,1); // switch TIMING_ADVANCE_VALUE = on
-		bitvec_write_field(dest, wp,tbf->ta(),6); // TIMING_ADVANCE_VALUE
-		if (ta_idx < 0) {
-			bitvec_write_field(dest, wp,0x0,1);   // switch TIMING_ADVANCE_INDEX = off
-		} else {
-			bitvec_write_field(dest, wp,0x1,1);   // switch TIMING_ADVANCE_INDEX = on
-			bitvec_write_field(dest, wp,ta_idx,4);   // TIMING_ADVANCE_INDEX
-		}
-
+		bitvec_write_field(dest, wp,0x1,1); // TLLI_BLOCK_CHANNEL_CODING
+		write_ta_ie(dest, wp,tbf->ta(), ta_idx, ta_ts);
 	} else { /* EPGRS */
 		unsigned int ws_enc = (tbf->m_window.ws() - 64) / 32;
 		bitvec_write_field(dest, wp,0x1,1); // Message escape
@@ -286,16 +301,7 @@
 		bitvec_write_field(dest, wp,0x0,1); // No ARAC RETRANSMISSION REQUEST
 		bitvec_write_field(dest, wp,0x1,1); // TLLI_BLOCK_CHANNEL_CODING 
 		bitvec_write_field(dest, wp,0x0,1); // No BEP_PERIOD2
-
-		bitvec_write_field(dest, wp,0x1,1); // switch TIMING_ADVANCE_VALUE = on
-		bitvec_write_field(dest, wp,tbf->ta(),6); // TIMING_ADVANCE_VALUE
-		if (ta_idx < 0) {
-			bitvec_write_field(dest, wp,0x0,1);   // switch TIMING_ADVANCE_INDEX = off
-		} else {
-			bitvec_write_field(dest, wp,0x1,1);   // switch TIMING_ADVANCE_INDEX = on
-			bitvec_write_field(dest, wp,ta_idx,4);   // TIMING_ADVANCE_INDEX
-		}
-
+		write_ta_ie(dest, wp,tbf->ta(), ta_idx, ta_ts);
 		bitvec_write_field(dest, wp,0x0,1); // No Packet Extended Timing Advance
 	}
 
diff --git a/src/encoding.h b/src/encoding.h
index 710de78..91e011d 100644
--- a/src/encoding.h
+++ b/src/encoding.h
@@ -51,7 +51,7 @@
 			bitvec * dest, uint8_t old_tfi,
 			uint8_t old_downlink, uint32_t tlli, uint8_t use_tlli,
 			struct gprs_rlcmac_ul_tbf *tbf, uint8_t poll, uint8_t rrbp,
-			uint8_t alpha, uint8_t gamma, int8_t ta_idx,
+			uint8_t alpha, uint8_t gamma, int8_t ta_idx, uint8_t ts,
 			int8_t use_egprs);
 
 	static void write_packet_downlink_assignment(RlcMacDownlink_t * block,
diff --git a/src/tbf.cpp b/src/tbf.cpp
index 1fc1aef..3a9b193 100644
--- a/src/tbf.cpp
+++ b/src/tbf.cpp
@@ -1064,7 +1064,7 @@
 	Encoding::write_packet_uplink_assignment(bts_data(), ass_vec, m_tfi,
 		(direction == GPRS_RLCMAC_DL_TBF), tlli(),
 		is_tlli_valid(), new_tbf, 1, rrbp, bts_data()->alpha,
-		bts_data()->gamma, -1, is_egprs_enabled());
+		bts_data()->gamma, -1, 0, is_egprs_enabled());
 	bitvec_pack(ass_vec, msgb_put(msg, 23));
 	RlcMacDownlink_t * mac_control_block = (RlcMacDownlink_t *)talloc_zero(tall_pcu_ctx, RlcMacDownlink_t);
 	LOGP(DRLCMAC, LOGL_DEBUG, "+++++++++++++++++++++++++ TX : Packet Uplink Assignment +++++++++++++++++++++++++\n");

-- 
To view, visit https://gerrit.osmocom.org/552
To unsubscribe, visit https://gerrit.osmocom.org/settings

Gerrit-MessageType: newpatchset
Gerrit-Change-Id: I786bf7fc999d401cc3d9e7f1e7a1fba953b5d458
Gerrit-PatchSet: 2
Gerrit-Project: osmo-pcu
Gerrit-Branch: master
Gerrit-Owner: Max <msuraev at sysmocom.de>
Gerrit-Reviewer: Jenkins Builder



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