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authorMax <msuraev@sysmocom.de>2019-03-25 16:38:53 +0100
committerHarald Welte <laforge@gnumonks.org>2019-04-08 07:35:19 +0000
commit902e3e58db69c33d375357b47f5511e4bbf891c4 (patch)
treea14863b2a84d79bf72317a81d97086bde5c0fa1c
parent12a0987b360f6825217aa25249719f1ef85f4a1c (diff)
Update MCS selection for retransmission
In 3GPP TS 44.060 the selection of MCS for retransmissions is defined as separate tables (8.1.1.1 and 8.1.1.2) depending on the value of resegmentation bit (which is opposite to the way EGPRS_ARQ are defined in the source code). Let's follow the same idea and explicitly check for resegmentation bit value and use separate tables. This also makes it easier to add proper support for special cases (MCS-6-9 and MCS-5-7) and padding in future independently for different ARQ types. The code is also moved to c to avoid unnecessary conversions to and from cpp class. Change-Id: Ia73baeefee7a58834f0fc50e3b8bf8d5e3eb7815
-rw-r--r--src/coding_scheme.c36
-rw-r--r--src/coding_scheme.h1
-rw-r--r--src/gprs_coding_scheme.cpp42
-rw-r--r--src/gprs_coding_scheme.h3
-rw-r--r--src/tbf_dl.cpp8
5 files changed, 40 insertions, 50 deletions
diff --git a/src/coding_scheme.c b/src/coding_scheme.c
index a4ae882..eaa4953 100644
--- a/src/coding_scheme.c
+++ b/src/coding_scheme.c
@@ -127,3 +127,39 @@ const struct value_string mode_names[] = {
const char *mode_name(enum mcs_kind val) {
return get_value_string(mode_names, val);
}
+
+/* FIXME: take into account padding and special cases of commanded MCS (MCS-6-9 and MCS-5-7) */
+enum CodingScheme get_retx_mcs(enum CodingScheme initial_mcs, enum CodingScheme commanded_mcs, bool resegment_bit)
+{
+ OSMO_ASSERT(mcs_is_edge(initial_mcs));
+ OSMO_ASSERT(mcs_is_edge(commanded_mcs));
+ OSMO_ASSERT(NUM_SCHEMES - MCS1 == 9);
+
+ if (resegment_bit) { /* 3GPP TS 44.060 Table 8.1.1.1, reflected over antidiagonal */
+ enum CodingScheme egprs_reseg[NUM_SCHEMES - MCS1][NUM_SCHEMES - MCS1] = {
+ { MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1 },
+ { MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2 },
+ { MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3 },
+ { MCS1, MCS1, MCS1, MCS4, MCS4, MCS4, MCS4, MCS4, MCS4 },
+ { MCS2, MCS2, MCS2, MCS2, MCS5, MCS5, MCS7, MCS7, MCS7 },
+ { MCS3, MCS3, MCS3, MCS3, MCS3, MCS6, MCS6, MCS6, MCS9 },
+ { MCS2, MCS2, MCS2, MCS2, MCS5, MCS5, MCS7, MCS7, MCS7 },
+ { MCS3, MCS3, MCS3, MCS3, MCS3, MCS6, MCS6, MCS8, MCS8 },
+ { MCS3, MCS3, MCS3, MCS3, MCS3, MCS6, MCS6, MCS6, MCS9 },
+ };
+ return egprs_reseg[mcs_chan_code(initial_mcs)][mcs_chan_code(commanded_mcs)];
+ } else { /* 3GPP TS 44.060 Table 8.1.1.2, reflected over antidiagonal */
+ enum CodingScheme egprs_no_reseg[NUM_SCHEMES - MCS1][NUM_SCHEMES - MCS1] = {
+ { MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1 },
+ { MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2 },
+ { MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3 },
+ { MCS4, MCS4, MCS4, MCS4, MCS4, MCS4, MCS4, MCS4, MCS4 },
+ { MCS5, MCS5, MCS5, MCS5, MCS5, MCS5, MCS7, MCS7, MCS7 },
+ { MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS9 },
+ { MCS5, MCS5, MCS5, MCS5, MCS5, MCS5, MCS7, MCS7, MCS7 },
+ { MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS8, MCS8 },
+ { MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS9 },
+ };
+ return egprs_no_reseg[mcs_chan_code(initial_mcs)][mcs_chan_code(commanded_mcs)];
+ }
+}
diff --git a/src/coding_scheme.h b/src/coding_scheme.h
index aac4bba..24db86d 100644
--- a/src/coding_scheme.h
+++ b/src/coding_scheme.h
@@ -32,6 +32,7 @@ enum CodingScheme {
extern const struct value_string mcs_names[];
const char *mcs_name(enum CodingScheme val);
+enum CodingScheme get_retx_mcs(enum CodingScheme initial_mcs, enum CodingScheme commanded_mcs, bool resegment_bit);
bool mcs_is_gprs(enum CodingScheme cs);
bool mcs_is_edge(enum CodingScheme cs);
diff --git a/src/gprs_coding_scheme.cpp b/src/gprs_coding_scheme.cpp
index a149f81..0c22670 100644
--- a/src/gprs_coding_scheme.cpp
+++ b/src/gprs_coding_scheme.cpp
@@ -21,41 +21,6 @@
#include "gprs_coding_scheme.h"
-#define MAX_NUM_ARQ 2 /* max. number of ARQ */
-#define MAX_NUM_MCS 9 /* max. number of MCS */
-
-/*
- * 44.060 Table 8.1.1.1 and Table 8.1.1.2
- * It has 3 level indexing. 0th level is ARQ type
- * 1st level is Original MCS( index 0 corresponds to MCS1 and so on)
- * 2nd level is MS MCS (index 0 corresponds to MCS1 and so on)
- */
-static enum CodingScheme egprs_mcs_retx_tbl[MAX_NUM_ARQ]
- [MAX_NUM_MCS][MAX_NUM_MCS] = {
- {
- {MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1},
- {MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2},
- {MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3},
- {MCS1, MCS1, MCS1, MCS4, MCS4, MCS4, MCS4, MCS4, MCS4},
- {MCS2, MCS2, MCS2, MCS2, MCS5, MCS5, MCS7, MCS7, MCS7},
- {MCS3, MCS3, MCS3, MCS3, MCS3, MCS6, MCS6, MCS6, MCS9},
- {MCS2, MCS2, MCS2, MCS2, MCS5, MCS5, MCS7, MCS7, MCS7},
- {MCS3, MCS3, MCS3, MCS3, MCS3, MCS6, MCS6, MCS8, MCS8},
- {MCS3, MCS3, MCS3, MCS3, MCS3, MCS6, MCS6, MCS6, MCS9}
- },
- {
- {MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1, MCS1},
- {MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2, MCS2},
- {MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3, MCS3},
- {MCS4, MCS4, MCS4, MCS4, MCS4, MCS4, MCS4, MCS4, MCS4},
- {MCS5, MCS5, MCS5, MCS5, MCS5, MCS5, MCS7, MCS7, MCS7},
- {MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS9},
- {MCS5, MCS5, MCS5, MCS5, MCS5, MCS5, MCS7, MCS7, MCS7},
- {MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS8, MCS8},
- {MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS6, MCS9}
- }
- };
-
enum Family {
FAMILY_INVALID,
FAMILY_A,
@@ -63,13 +28,6 @@ enum Family {
FAMILY_C,
};
-CodingScheme GprsCodingScheme::get_retx_mcs(const GprsCodingScheme mcs,
- const GprsCodingScheme demanded_mcs,
- const unsigned arq_type)
-{
- return egprs_mcs_retx_tbl[arq_type][mcs_chan_code(mcs)][mcs_chan_code(demanded_mcs)];
-}
-
static struct {
struct {
uint8_t bytes;
diff --git a/src/gprs_coding_scheme.h b/src/gprs_coding_scheme.h
index d5604fb..c31f58f 100644
--- a/src/gprs_coding_scheme.h
+++ b/src/gprs_coding_scheme.h
@@ -73,9 +73,6 @@ public:
static GprsCodingScheme getGprsByNum(unsigned num);
static GprsCodingScheme getEgprsByNum(unsigned num);
- static CodingScheme get_retx_mcs(const GprsCodingScheme mcs,
- const GprsCodingScheme retx_mcs,
- const unsigned arq_type);
private:
GprsCodingScheme(int s); /* fail on use */
GprsCodingScheme& operator =(int s); /* fail on use */
diff --git a/src/tbf_dl.cpp b/src/tbf_dl.cpp
index 08df05a..c97436a 100644
--- a/src/tbf_dl.cpp
+++ b/src/tbf_dl.cpp
@@ -378,11 +378,9 @@ int gprs_rlcmac_dl_tbf::take_next_bsn(uint32_t fn,
if (is_egprs_enabled()) {
/* Table 8.1.1.2 and Table 8.1.1.1 of 44.060 */
- m_rlc.block(bsn)->cs_current_trans =
- GprsCodingScheme::get_retx_mcs(
- m_rlc.block(bsn)->cs_init,
- ms()->current_cs_dl(),
- bts->bts_data()->dl_arq_type);
+ m_rlc.block(bsn)->cs_current_trans = get_retx_mcs(m_rlc.block(bsn)->cs_init,
+ ms()->current_cs_dl(),
+ !bts->bts_data()->dl_arq_type);
LOGPTBFDL(this, LOGL_DEBUG,
"initial_cs_dl(%s) last_mcs(%s) demanded_mcs(%s) cs_trans(%s) arq_type(%d) bsn(%d)\n",