From: Sylvain Munaut &lt;tnt(a)246tNt.com&gt; 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 &lt;tnt(a)246tNt.com&gt; --- openbsc/include/openbsc/gsm_utils.h | 7 +++++++ openbsc/src/bsc_init.c | 5 ----- openbsc/src/gsm_data.c | 4 ++++ openbsc/src/vty_interface.c | 32 ++++++++++++++++++++++++++++++++ 4 files changed, 43 insertions(+), 5 deletions(-) diff --git a/openbsc/include/openbsc/gsm_utils.h b/openbsc/include/openbsc/gsm_utils.h index 5809221..56a4120 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 diff --git a/openbsc/src/bsc_init.c b/openbsc/src/bsc_init.c index 547aaa9..c6d891c 100644 --- a/openbsc/src/bsc_init.c +++ b/openbsc/src/bsc_init.c @@ -825,11 +825,6 @@ static int bootstrap_bts(struct gsm_bts *bts) /* T3212 is set from vty/config */ /* some defaults for our system information */ - bts->si_common.rach_control.re = 1; /* no re-establishment */ - bts->si_common.rach_control.tx_integer = 5; /* 8 slots spread */ - bts->si_common.rach_control.max_trans = 3; /* 7 retransmissions */ - bts->si_common.rach_control.t2 = 4; /* no emergency calls */ - bts->si_common.cell_options.radio_link_timeout = 2; /* 12 */ bts->si_common.cell_options.dtx = 2; /* MS shall not use upplink DTX */ bts->si_common.cell_options.pwrc = 0; /* PWRC not set */ diff --git a/openbsc/src/gsm_data.c b/openbsc/src/gsm_data.c index 12f439b..d6ebd92 100644 --- a/openbsc/src/gsm_data.c +++ b/openbsc/src/gsm_data.c @@ -175,6 +175,10 @@ struct gsm_bts *gsm_bts_alloc(struct gsm_network *net, enum gsm_bts_type type, bts->si_common.cell_alloc.data = bts->si_common.data.cell_alloc; bts->si_common.cell_alloc.data_len = sizeof(bts->si_common.data.cell_alloc); + bts->si_common.rach_control.re = 1; /* no re-establishment */ + bts->si_common.rach_control.tx_integer = 9; /* 12 slots spread - 217/115 slots delay */ + bts->si_common.rach_control.max_trans = 3; /* 7 retransmissions */ + bts->si_common.rach_control.t2 = 4; /* no emergency calls */ for (i = 0; i < ARRAY_SIZE(bts->gprs.nsvc); i++) { bts->gprs.nsvc[i].bts = bts; diff --git a/openbsc/src/vty_interface.c b/openbsc/src/vty_interface.c index b13dc5f..5e42e6b 100644 --- a/openbsc/src/vty_interface.c +++ b/openbsc/src/vty_interface.c @@ -140,6 +140,11 @@ static void bts_dump_vty(struct vty *vty, struct gsm_bts *bts) VTY_NEWLINE); vty_out(vty, "Cell Reselection Hysteresis: %u dBm%s", bts->si_common.cell_sel_par.cell_resel_hyst*2, VTY_NEWLINE); + vty_out(vty, "RACH TX-Integer: %u%s", bts->si_common.rach_control.tx_integer, + VTY_NEWLINE); + vty_out(vty, "RACH Max transmissions: %u%s", + rach_max_trans_raw2val(bts->si_common.rach_control.max_trans), + VTY_NEWLINE); if (bts->si_common.rach_control.cell_bar) vty_out(vty, " CELL IS BARRED%s", VTY_NEWLINE); if (is_ipaccess_bts(bts)) @@ -258,6 +263,11 @@ static void config_write_bts_single(struct vty *vty, struct gsm_bts *bts) vty_out(vty, " channel allocator %s%s", bts->chan_alloc_reverse ? "descending" : "ascending", VTY_NEWLINE); + vty_out(vty, " rach tx integer %u%s", + bts->si_common.rach_control.tx_integer, VTY_NEWLINE); + vty_out(vty, " rach max transmission %u%s", + rach_max_trans_raw2val(bts->si_common.rach_control.max_trans), + VTY_NEWLINE); if (bts->si_common.rach_control.cell_bar) vty_out(vty, " cell barred 1%s", VTY_NEWLINE); if (is_ipaccess_bts(bts)) { @@ -1196,6 +1206,26 @@ DEFUN(cfg_bts_challoc, cfg_bts_challoc_cmd, return CMD_SUCCESS; } +DEFUN(cfg_bts_rach_tx_integer, + cfg_bts_rach_tx_integer_cmd, + "rach tx integer <0-15>", + "Set the raw tx integer value in RACH Control parameters IE") +{ + struct gsm_bts *bts = vty->index; + bts->si_common.rach_control.tx_integer = atoi(argv[0]) & 0xf; + return CMD_SUCCESS; +} + +DEFUN(cfg_bts_rach_max_trans, + cfg_bts_rach_max_trans_cmd, + "rach max transmission (1|2|4|7)", + "Set the maximum number of RACH burst transmissions") +{ + struct gsm_bts *bts = vty->index; + bts->si_common.rach_control.max_trans = rach_max_trans_val2raw(atoi(argv[0])); + return CMD_SUCCESS; +} + DEFUN(cfg_bts_cell_barred, cfg_bts_cell_barred_cmd, "cell barred (0|1)", "Should this cell be barred from access?") @@ -1482,6 +1512,8 @@ int bsc_vty_init(struct gsm_network *net) install_element(BTS_NODE, &cfg_bts_oml_e1_cmd); install_element(BTS_NODE, &cfg_bts_oml_e1_tei_cmd); install_element(BTS_NODE, &cfg_bts_challoc_cmd); + install_element(BTS_NODE, &cfg_bts_rach_tx_integer_cmd); + install_element(BTS_NODE, &cfg_bts_rach_max_trans_cmd); install_element(BTS_NODE, &cfg_bts_cell_barred_cmd); install_element(BTS_NODE, &cfg_bts_ms_max_power_cmd); install_element(BTS_NODE, &cfg_bts_per_loc_upd_cmd); -- 1.6.5.1