rlc: Support encoding of EGPRS header type 1 + 2
Currently only header type 3 (MCS-1 to MCS-4) is supported.
Add header structs to rlc.h and extend
Encoding::rlc_write_dl_data_header accordingly.
Sponsored-by: On-Waves ehf
diff --git a/src/encoding.cpp b/src/encoding.cpp
index e3e1245..a7d7b16 100644
--- a/src/encoding.cpp
+++ b/src/encoding.cpp
@@ -711,10 +711,14 @@
int Encoding::rlc_write_dl_data_header(const struct gprs_rlc_data_info *rlc,
uint8_t *data)
{
+ struct gprs_rlc_dl_header_egprs_1 *egprs1;
+ struct gprs_rlc_dl_header_egprs_2 *egprs2;
struct gprs_rlc_dl_header_egprs_3 *egprs3;
struct rlc_dl_header *gprs;
unsigned int e_fbi_header;
GprsCodingScheme cs = rlc->cs;
+ unsigned int offs;
+ unsigned int bsn_delta;
switch(cs.headerTypeData()) {
case GprsCodingScheme::HEADER_GPRS_DATA:
@@ -733,6 +737,65 @@
gprs->bsn = rlc->block_info[0].bsn;
break;
+ case GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_1:
+ egprs1 = static_cast<struct gprs_rlc_dl_header_egprs_1 *>
+ ((void *)data);
+
+ egprs1->usf = rlc->usf;
+ egprs1->es_p = rlc->es_p;
+ egprs1->rrbp = rlc->rrbp;
+ egprs1->tfi_a = rlc->tfi >> 0; /* 1 bit LSB */
+ egprs1->tfi_b = rlc->tfi >> 1; /* 4 bits */
+ egprs1->pr = rlc->pr;
+ egprs1->cps = rlc->cps;
+
+ egprs1->bsn1_a = rlc->block_info[0].bsn >> 0; /* 2 bits LSB */
+ egprs1->bsn1_b = rlc->block_info[0].bsn >> 2; /* 8 bits */
+ egprs1->bsn1_c = rlc->block_info[0].bsn >> 10; /* 1 bit */
+
+ bsn_delta = (rlc->block_info[1].bsn - rlc->block_info[0].bsn) &
+ (RLC_EGPRS_SNS - 1);
+
+ egprs1->bsn2_a = bsn_delta >> 0; /* 7 bits LSB */
+ egprs1->bsn2_b = bsn_delta >> 7; /* 3 bits */
+
+ /* first FBI/E header */
+ e_fbi_header = rlc->block_info[0].e ? 0x01 : 0;
+ e_fbi_header |= rlc->block_info[0].cv == 0 ? 0x02 : 0; /* FBI */
+ e_fbi_header <<= 0;
+ data[5] = (data[5] & 0b11111100) | e_fbi_header;
+
+ /* second FBI/E header */
+ e_fbi_header = rlc->block_info[1].e ? 0x01 : 0;
+ e_fbi_header |= rlc->block_info[1].cv == 0 ? 0x02 : 0; /* FBI */
+ offs = rlc->data_offs_bits[1] / 8;
+ OSMO_ASSERT(rlc->data_offs_bits[1] % 8 == 4);
+ e_fbi_header <<= 2;
+ data[offs] = (data[offs] & 0b11110011) | e_fbi_header;
+ break;
+
+ case GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_2:
+ egprs2 = static_cast<struct gprs_rlc_dl_header_egprs_2 *>
+ ((void *)data);
+
+ egprs2->usf = rlc->usf;
+ egprs2->es_p = rlc->es_p;
+ egprs2->rrbp = rlc->rrbp;
+ egprs2->tfi_a = rlc->tfi >> 0; /* 1 bit LSB */
+ egprs2->tfi_b = rlc->tfi >> 1; /* 4 bits */
+ egprs2->pr = rlc->pr;
+ egprs2->cps = rlc->cps;
+
+ egprs2->bsn1_a = rlc->block_info[0].bsn >> 0; /* 2 bits LSB */
+ egprs2->bsn1_b = rlc->block_info[0].bsn >> 2; /* 8 bits */
+ egprs2->bsn1_c = rlc->block_info[0].bsn >> 10; /* 1 bit */
+
+ e_fbi_header = rlc->block_info[0].e ? 0x01 : 0;
+ e_fbi_header |= rlc->block_info[0].cv == 0 ? 0x02 : 0; /* FBI */
+ e_fbi_header <<= 4;
+ data[3] = (data[3] & 0b11001111) | e_fbi_header;
+ break;
+
case GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_3:
egprs3 = static_cast<struct gprs_rlc_dl_header_egprs_3 *>
((void *)data);
@@ -758,10 +821,6 @@
data[4] = (data[4] & 0b11111110) | (e_fbi_header >> 8);
break;
- case GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_1:
- case GprsCodingScheme::HEADER_EGPRS_DATA_TYPE_2:
- /* TODO: Support both header types */
- /* fall through */
default:
LOGP(DRLCMACDL, LOGL_ERROR,
"Encoding of uplink %s data blocks not yet supported.\n",