Add data structure for ARQ-II in EGPRS DL

Modify the existing data structure to support ARQ-II for Retx in EGPRS DL.
This will also hadle compilation issue related to renaming the variable.

Change-Id: I734b1024bb32f2daa43af4adf59f4a17f2294afe

5 files changed, 60 insertions, 10 deletions

diff --git a/src/gprs_coding_scheme.cpp b/src/gprs_coding_scheme.cpp
index 8601d4f5..719cbb28 100644
--- a/src/gprs_coding_scheme.cpp
+++ b/src/gprs_coding_scheme.cpp
@@ -21,6 +21,38 @@
 
 #include "gprs_coding_scheme.h"
 
+/*
+ * 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)
+ */
+enum GprsCodingScheme::Scheme GprsCodingScheme::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}
+		}
+	};
+
 static struct {
 	struct {
 		unsigned int bytes;
diff --git a/src/gprs_coding_scheme.h b/src/gprs_coding_scheme.h
index aec37623..bb0bad44 100644
--- a/src/gprs_coding_scheme.h
+++ b/src/gprs_coding_scheme.h
@@ -26,6 +26,12 @@
 
 class GprsCodingScheme {
 public:
+
+#define MAX_NUM_ARQ           2      /* max. number of ARQ */
+#define MAX_NUM_MCS           9     /* max. number of MCS */
+#define EGPRS_ARQ1            0x0
+#define EGPRS_ARQ2            0x1
+
 	enum Scheme {
 		UNKNOWN,
 		CS1, CS2, CS3, CS4,
@@ -105,6 +111,8 @@ public:
 	static GprsCodingScheme getEgprsByNum(unsigned num);
 
 	static const char *modeName(Mode mode);
+	static enum Scheme egprs_mcs_retx_tbl[MAX_NUM_ARQ]
+			[MAX_NUM_MCS][MAX_NUM_MCS];
 private:
 	GprsCodingScheme(int s); /* fail on use */
 	GprsCodingScheme& operator =(int s); /* fail on use */
diff --git a/src/rlc.h b/src/rlc.h
index ad10b3ab..082db898 100644
--- a/src/rlc.h
+++ b/src/rlc.h
@@ -119,7 +119,17 @@ struct gprs_rlc_data {
 	uint8_t len;
 
 	struct gprs_rlc_data_block_info block_info;
-	GprsCodingScheme cs;
+	/*
+	 * cs_current_trans is variable to hold the cs_last value for
+	 * current transmission. cs_current_trans is same as cs_last during
+	 * transmission case. during retransmission cs_current_trans is
+	 * fetched from egprs_mcs_retx_tbl table based on
+	 * cs and demanded cs.reference is 44.060 Table
+	 * 8.1.1.1 and Table 8.1.1.2
+	 * For UL. cs_last shall be used everywhere.
+	 */
+	GprsCodingScheme cs_current_trans;
+	GprsCodingScheme cs_last;
 
 	/* puncturing scheme value to be used for next transmission*/
 	enum egprs_puncturing_values next_ps;
diff --git a/src/tbf_dl.cpp b/src/tbf_dl.cpp
index 9dd4bfc0..1ca9c4ae 100644
--- a/src/tbf_dl.cpp
+++ b/src/tbf_dl.cpp
@@ -361,7 +361,7 @@ int gprs_rlcmac_dl_tbf::take_next_bsn(uint32_t fn,
 	bsn = m_window.resend_needed();
 
 	if (previous_bsn >= 0) {
-		force_cs = m_rlc.block(previous_bsn)->cs;
+		force_cs = m_rlc.block(previous_bsn)->cs_last;
 		if (!force_cs.isEgprs())
 			return -1;
 		force_data_len = m_rlc.block(previous_bsn)->len;
@@ -375,7 +375,7 @@ int gprs_rlcmac_dl_tbf::take_next_bsn(uint32_t fn,
 			m_window.mod_sns(bsn - previous_bsn) > RLC_EGPRS_MAX_BSN_DELTA)
 			return -1;
 
-		cs2 = m_rlc.block(bsn)->cs;
+		cs2 = m_rlc.block(bsn)->cs_last;
 		data_len2 = m_rlc.block(bsn)->len;
 		if (force_data_len > 0 && force_data_len != data_len2)
 			return -1;
@@ -500,7 +500,7 @@ int gprs_rlcmac_dl_tbf::create_new_bsn(const uint32_t fn, GprsCodingScheme cs)
 	/* now we still have untransmitted LLC data, so we fill mac block */
 	rlc_data = m_rlc.block(bsn);
 	data = rlc_data->prepare(block_data_len);
-	rlc_data->cs = cs;
+	rlc_data->cs_last = cs;
 	rlc_data->len = block_data_len;
 
 	rdbi = &(rlc_data->block_info);
@@ -565,7 +565,7 @@ int gprs_rlcmac_dl_tbf::create_new_bsn(const uint32_t fn, GprsCodingScheme cs)
 	} while (ar == Encoding::AR_COMPLETED_SPACE_LEFT);
 
 	LOGP(DRLCMACDL, LOGL_DEBUG, "data block (BSN %d, %s): %s\n",
-		bsn, rlc_data->cs.name(),
+		bsn, rlc_data->cs_last.name(),
 		osmo_hexdump(rlc_data->block, block_data_len));
 	/* raise send state and set ack state array */
 	m_window.m_v_b.mark_unacked(bsn);
@@ -604,7 +604,7 @@ struct msgb *gprs_rlcmac_dl_tbf::create_dl_acked_block(
 	 * be put into the data area, even if the resulting CS is higher than
 	 * the current limit.
 	 */
-	cs = m_rlc.block(index)->cs;
+	cs = m_rlc.block(index)->cs_last;
 	bsns[0] = index;
 	num_bsns = 1;
 
@@ -650,7 +650,7 @@ struct msgb *gprs_rlcmac_dl_tbf::create_dl_acked_block(
 		else
 			bsn = bsns[0];
 
-		cs_enc = m_rlc.block(bsn)->cs;
+		cs_enc = m_rlc.block(bsn)->cs_last;
 
 		/* get data and header from current block */
 		block_data = m_rlc.block(bsn)->block;
@@ -817,7 +817,7 @@ int gprs_rlcmac_dl_tbf::analyse_errors(char *show_rbb, uint8_t ssn,
 
 		/* Get statistics for current CS */
 
-		if (rlc_data->cs != current_cs()) {
+		if (rlc_data->cs_last != current_cs()) {
 			/* This block has already been encoded with a different
 			 * CS, so it doesn't help us to decide, whether the
 			 * current CS is ok. Ignore it. */
diff --git a/src/tbf_ul.cpp b/src/tbf_ul.cpp
index 4d283a9a..9c9154bc 100644
--- a/src/tbf_ul.cpp
+++ b/src/tbf_ul.cpp
@@ -51,7 +51,7 @@ int gprs_rlcmac_ul_tbf::assemble_forward_llc(const gprs_rlc_data *_data)
 	const uint8_t *data = _data->block;
 	uint8_t len = _data->len;
 	const struct gprs_rlc_data_block_info *rdbi = &_data->block_info;
-	GprsCodingScheme cs = _data->cs;
+	GprsCodingScheme cs = _data->cs_last;
 
 	Decoding::RlcData frames[16], *frame;
 	int i, num_frames = 0;
@@ -224,7 +224,7 @@ int gprs_rlcmac_ul_tbf::rcv_data_block_acknowledged(
 			m_window.mod_sns(m_window.v_q() + ws - 1));
 		block = m_rlc.block(rdbi->bsn);
 		block->block_info = *rdbi;
-		block->cs = rlc->cs;
+		block->cs_last = rlc->cs;
 		OSMO_ASSERT(rdbi->data_len <= sizeof(block->block));
 		rlc_data = &(block->block[0]);
 		/* TODO: Handle SPB != 0 -> Set length to 2*len, add offset if