From 218de9342d078f5a799f76b624bba0a386692f9e Mon Sep 17 00:00:00 2001 From: Guido Casati Date: Fri, 1 Oct 2021 15:58:40 +0200 Subject: [PATCH] Bugifx simultaneous RACH with multiple UEs - replaced taus with a random seed + random number generation - this fixes the bug with multiple UEs starting RA in the same time frame and slot and selecting the same preamble index --- openair2/LAYER2/NR_MAC_UE/nr_ra_procedures.c | 24 ++++++++++++-------- 1 file changed, 14 insertions(+), 10 deletions(-) diff --git a/openair2/LAYER2/NR_MAC_UE/nr_ra_procedures.c b/openair2/LAYER2/NR_MAC_UE/nr_ra_procedures.c index 83784634fc..5733f49542 100644 --- a/openair2/LAYER2/NR_MAC_UE/nr_ra_procedures.c +++ b/openair2/LAYER2/NR_MAC_UE/nr_ra_procedures.c @@ -30,9 +30,6 @@ * \warning */ -/* Tools */ -#include "SIMULATION/TOOLS/sim.h" // for taus - /* RRC */ #include "NR_RACH-ConfigCommon.h" #include "RRC/NR_UE/rrc_proto.h" @@ -280,6 +277,10 @@ void ra_preambles_config(NR_PRACH_RESOURCES_t *prach_resources, NR_UE_MAC_INST_t int PLThreshold = 0; long deltaPreamble_Msg3 = 0; uint8_t noGroupB = 0; + // Random seed generation + long long tmp = rdtsc_oai(); + unsigned short int *seed = (unsigned short int*)&tmp; + RA_config_t *ra = &mac->ra; NR_RACH_ConfigCommon_t *setup; if (mac->scc) setup = mac->scc->uplinkConfigCommon->initialUplinkBWP->rach_ConfigCommon->choice.setup; @@ -378,28 +379,28 @@ void ra_preambles_config(NR_PRACH_RESOURCES_t *prach_resources, NR_UE_MAC_INST_t if(ra->ra_PreambleIndex < 0 || ra->ra_PreambleIndex > 63) { if (noGroupB) { // use Group A preamble - ra->ra_PreambleIndex = ra->starting_preamble_nb + ((taus()) % ra->cb_preambles_per_ssb); + ra->ra_PreambleIndex = ra->starting_preamble_nb + (nrand48(seed) % ra->cb_preambles_per_ssb); ra->RA_usedGroupA = 1; } else if ((ra->Msg3_size < messageSizeGroupA) && (dl_pathloss > PLThreshold)) { // Group B is configured and RA preamble Group A is used // - todo add condition on CCCH_sdu_size for initiation by CCCH - ra->ra_PreambleIndex = ra->starting_preamble_nb + ((taus()) % sizeOfRA_PreamblesGroupA); + ra->ra_PreambleIndex = ra->starting_preamble_nb + (nrand48(seed) % sizeOfRA_PreamblesGroupA); ra->RA_usedGroupA = 1; } else { // Group B preamble is configured and used // the first sizeOfRA_PreamblesGroupA RA preambles belong to RA Preambles Group A // the remaining belong to RA Preambles Group B - ra->ra_PreambleIndex = ra->starting_preamble_nb + sizeOfRA_PreamblesGroupA + ((taus()) % (ra->cb_preambles_per_ssb - sizeOfRA_PreamblesGroupA)); + ra->ra_PreambleIndex = ra->starting_preamble_nb + sizeOfRA_PreamblesGroupA + (nrand48(seed) % (ra->cb_preambles_per_ssb - sizeOfRA_PreamblesGroupA)); ra->RA_usedGroupA = 0; } } } else { // Msg3 is being retransmitted if (ra->RA_usedGroupA && noGroupB) { - ra->ra_PreambleIndex = ra->starting_preamble_nb + ((taus()) % ra->cb_preambles_per_ssb); + ra->ra_PreambleIndex = ra->starting_preamble_nb + (nrand48(seed) % ra->cb_preambles_per_ssb); } else if (ra->RA_usedGroupA && !noGroupB){ - ra->ra_PreambleIndex = ra->starting_preamble_nb + ((taus()) % sizeOfRA_PreamblesGroupA); + ra->ra_PreambleIndex = ra->starting_preamble_nb + (nrand48(seed) % sizeOfRA_PreamblesGroupA); } else { - ra->ra_PreambleIndex = ra->starting_preamble_nb + sizeOfRA_PreamblesGroupA + ((taus()) % (ra->cb_preambles_per_ssb - sizeOfRA_PreamblesGroupA)); + ra->ra_PreambleIndex = ra->starting_preamble_nb + sizeOfRA_PreamblesGroupA + (nrand48(seed) % (ra->cb_preambles_per_ssb - sizeOfRA_PreamblesGroupA)); } } prach_resources->ra_PreambleIndex = ra->ra_PreambleIndex; @@ -837,6 +838,9 @@ void nr_ra_failed(uint8_t mod_id, uint8_t CC_id, NR_PRACH_RESOURCES_t *prach_res NR_UE_MAC_INST_t *mac = get_mac_inst(mod_id); RA_config_t *ra = &mac->ra; + // Random seed generation + long long tmp = rdtsc_oai(); + unsigned short int *seed = (unsigned short int*)&tmp; ra->first_Msg3 = 1; ra->ra_PreambleIndex = -1; @@ -850,7 +854,7 @@ void nr_ra_failed(uint8_t mod_id, uint8_t CC_id, NR_PRACH_RESOURCES_t *prach_res LOG_D(MAC, "In %s: [UE %d][%d.%d] Maximum number of RACH attempts (%d) reached, selecting backoff time...\n", __FUNCTION__, mod_id, frame, slot, ra->preambleTransMax); - ra->RA_backoff_cnt = rand() % (prach_resources->RA_PREAMBLE_BACKOFF + 1); + ra->RA_backoff_cnt = nrand48(seed) % (prach_resources->RA_PREAMBLE_BACKOFF + 1); prach_resources->RA_PREAMBLE_TRANSMISSION_COUNTER = 1; prach_resources->RA_PREAMBLE_POWER_RAMPING_STEP += 2; // 2 dB increment prach_resources->ra_PREAMBLE_RECEIVED_TARGET_POWER = nr_get_Po_NOMINAL_PUSCH(prach_resources, mod_id, CC_id);