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authorPhilipp Maier <pmaier@sysmocom.de>2016-12-20 14:23:45 +0100
committerPhilipp Maier <pmaier@sysmocom.de>2017-02-24 15:18:21 +0100
commitee1649292d0516fd64562ef4dd2a5c9d62520566 (patch)
tree27f1bce191d4e83988829957345ac0f77c193fa4
parent59400659bc6673f07b9db9d38bbbae190f10e944 (diff)
gprs: fix T3186 encoding in Sysinfo 13
The timer T3186, which is described in 3GPP TS 44.060, is using 3 bits of the si13 mac block. This requires special encoding. In the case of T3186, the value is encoded by the formula: bits = t/500-1. Our implementation uses the formula bits=t/500, which is incorrect.
-rw-r--r--openbsc/src/libbsc/rest_octets.c8
1 files changed, 7 insertions, 1 deletions
diff --git a/openbsc/src/libbsc/rest_octets.c b/openbsc/src/libbsc/rest_octets.c
index 6fae9cd87..ed6c573d5 100644
--- a/openbsc/src/libbsc/rest_octets.c
+++ b/openbsc/src/libbsc/rest_octets.c
@@ -566,6 +566,8 @@ static int append_gprs_mobile_alloc(struct bitvec *bv)
static int encode_t3192(unsigned int t3192)
{
+ /* See also 3GPP TS 44.060
+ Table 12.24.2: GPRS Cell Options information element details */
if (t3192 == 0)
return 3;
else if (t3192 <= 80)
@@ -645,7 +647,11 @@ static int append_gprs_cell_opt(struct bitvec *bv,
return drx_timer_max;
bitvec_set_uint(bv, gco->nmo, 2);
- bitvec_set_uint(bv, gco->t3168 / 500, 3);
+
+ /* See also 3GPP TS 44.060
+ Table 12.24.2: GPRS Cell Options information element details */
+ bitvec_set_uint(bv, gco->t3168 / 500 - 1, 3);
+
bitvec_set_uint(bv, t3192, 3);
bitvec_set_uint(bv, drx_timer_max, 3);
/* ACCESS_BURST_TYPE: Hard-code 8bit */