diff options
Diffstat (limited to 'src/common')
| -rw-r--r-- | src/common/bts.c | 90 |
1 files changed, 89 insertions, 1 deletions
diff --git a/src/common/bts.c b/src/common/bts.c index 7bbf5870..e82656dd 100644 --- a/src/common/bts.c +++ b/src/common/bts.c @@ -42,6 +42,7 @@ #include <osmo-bts/bts_model.h> #include <osmo-bts/rsl.h> #include <osmo-bts/oml.h> +#include <osmo-bts/signal.h> struct gsm_network bts_gsmnet = { @@ -51,11 +52,32 @@ struct gsm_network bts_gsmnet = { void *tall_bts_ctx; +/* Table 3.1 TS 04.08: Values of parameter S */ +static const uint8_t tx_integer[] = { + 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 14, 16, 20, 25, 32, 50, +}; + +static const uint8_t s_values[][2] = { + { 55, 41 }, { 76, 52 }, { 109, 58 }, { 163, 86 }, { 217, 115 }, +}; + +static int bts_signal_cbfn(unsigned int subsys, unsigned int signal, + void *hdlr_data, void *signal_data) +{ + if (subsys == SS_GLOBAL && signal == S_NEW_SYSINFO) { + struct gsm_bts *bts = signal_data; + + bts_update_agch_max_queue_length(bts); + } + return 0; +} + int bts_init(struct gsm_bts *bts) { struct gsm_bts_role_bts *btsb; struct gsm_bts_trx *trx; int rc; + static int initialized = 0; /* add to list of BTSs */ llist_add_tail(&bts->list, &bts_gsmnet.bts_list); @@ -110,6 +132,11 @@ int bts_init(struct gsm_bts *bts) bts_gsmnet.num_bts++; + if (!initialized) { + osmo_signal_register_handler(SS_GLOBAL, bts_signal_cbfn, NULL); + initialized = 1; + } + return rc; } @@ -209,11 +236,72 @@ int lchan_init_lapdm(struct gsm_lchan *lchan) return 0; } +#define CCCH_RACH_RATIO_COMBINED256 (256*1/9) +#define CCCH_RACH_RATIO_SEPARATE256 (256*10/55) + +int bts_agch_max_queue_length(int T, int bcch_conf) +{ + int S, ccch_rach_ratio256, i; + int T_group = 0; + int is_ccch_comb = 0; + + if (bcch_conf == RSL_BCCH_CCCH_CONF_1_C) + is_ccch_comb = 1; + + /* + * The calculation is based on the ratio of the number RACH slots and + * CCCH blocks per time: + * Lmax = (T + 2*S) / R_RACH * R_CCCH + * where + * T3126_min = (T + 2*S) / R_RACH, as defined in GSM 04.08, 11.1.1 + * R_RACH is the RACH slot rate (e.g. RACHs per multiframe) + * R_CCCH is the CCCH block rate (same time base like R_RACH) + * S and T are defined in GSM 04.08, 3.3.1.1.2 + * The ratio is mainly influenced by the downlink only channels + * (BCCH, FCCH, SCH, CBCH) that can not be used for CCCH. + * An estimation with an error of < 10% is used: + * ~ 1/9 if CCCH is combined with SDCCH, and + * ~ 1/5.5 otherwise. + */ + ccch_rach_ratio256 = is_ccch_comb ? + CCCH_RACH_RATIO_COMBINED256 : + CCCH_RACH_RATIO_SEPARATE256; + + for (i = 0; i < ARRAY_SIZE(tx_integer); i++) { + if (tx_integer[i] == T) { + T_group = i % 5; + break; + } + } + S = s_values[T_group][is_ccch_comb]; + + return (T + 2 * S) * ccch_rach_ratio256 / 256; +} + +void bts_update_agch_max_queue_length(struct gsm_bts *bts) +{ + struct gsm_bts_role_bts *btsb = bts_role_bts(bts); + struct gsm48_system_information_type_3 *si3; + int old_max_length = btsb->agch_max_queue_length; + + if (!(bts->si_valid & (1<<SYSINFO_TYPE_3))) + return; + + si3 = GSM_BTS_SI(bts, SYSINFO_TYPE_3); + + btsb->agch_max_queue_length = + bts_agch_max_queue_length(si3->rach_control.tx_integer, + si3->control_channel_desc.ccch_conf); + + if (btsb->agch_max_queue_length != old_max_length) + LOGP(DRSL, LOGL_INFO, "Updated AGCH max queue length to %d\n", + btsb->agch_max_queue_length); +} + int bts_agch_enqueue(struct gsm_bts *bts, struct msgb *msg) { struct gsm_bts_role_bts *btsb = bts_role_bts(bts); - /* FIXME: implement max queue length */ msgb_enqueue(&btsb->agch_queue, msg); btsb->agch_queue_length++; |