diff options
| author | Sylvain Munaut <246tnt@gmail.com> | 2009-12-22 13:43:26 +0100 |
|---|---|---|
| committer | Harald Welte <laforge@gnumonks.org> | 2009-12-22 13:43:26 +0100 |
| commit | 4010f1e6f4d3f1c702be836a2342aefd8de73f2a (patch) | |
| tree | 8ff802db314cb78a3b16452744a32fd28c0cd120 /openbsc/include | |
| parent | ff1f19e199bbb0cb9da55e0994d9b1443bba85f7 (diff) | |
bts: Allow config of RACH control parameters tx-integer & max retrans
Tweaking theses can be useful especially tx-integer that influence
both the spread of rach attemps and the delay between two attemps.
Looking up GSM 04.08 3.3.1.1.2 & 10.5.2.29 can help determine good
values. The default are choosed with a wide spacing between attemps
(tx integer = 9 -> T=12 & S=217 (non-combined CCCH/SDCCH) or 115 (for
combined CCCH/SDCCH)). This alleviates the problem of responding to
several RACH attempts by a same MS, allocating several RF channels when
only 1 is needed.
Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
Diffstat (limited to 'openbsc/include')
| -rw-r--r-- | openbsc/include/openbsc/gsm_utils.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/openbsc/include/openbsc/gsm_utils.h b/openbsc/include/openbsc/gsm_utils.h index 5809221a3..56a4120a5 100644 --- a/openbsc/include/openbsc/gsm_utils.h +++ b/openbsc/include/openbsc/gsm_utils.h @@ -37,5 +37,12 @@ int ms_pwr_dbm(enum gsm_band band, u_int8_t lvl); int rxlev2dbm(u_int8_t rxlev); u_int8_t dbm2rxlev(int dbm); +/* According to GSM 04.08 Chapter 10.5.2.29 */ +static inline int rach_max_trans_val2raw(int val) { return (val >> 1) & 3; } +static inline int rach_max_trans_raw2val(int raw) { + const int tbl[4] = { 1, 2, 4, 7 }; + return tbl[raw & 3]; +} + void generate_backtrace(); #endif |