From 6f6560f12b2039aeb7fda90bf7641aabbfc3a8bd Mon Sep 17 00:00:00 2001 From: Xavier Arteaga Date: Fri, 24 May 2019 17:14:40 +0200 Subject: [PATCH] SRSUE RRC: More stable Reestablishment after RLF --- srsue/src/phy/sync.cc | 1 + srsue/src/stack/rrc/rrc.cc | 157 ++++++++++++++++++++++--------------- 2 files changed, 95 insertions(+), 63 deletions(-) diff --git a/srsue/src/phy/sync.cc b/srsue/src/phy/sync.cc index c13f8ece1..12cb4817e 100644 --- a/srsue/src/phy/sync.cc +++ b/srsue/src/phy/sync.cc @@ -420,6 +420,7 @@ void sync::run_thread() */ switch(sfn_p.run_subframe(&cell, &tti)) { case sfn_sync::SFN_FOUND: + stack->in_sync(); phy_state.state_exit(); break; case sfn_sync::IDLE: diff --git a/srsue/src/stack/rrc/rrc.cc b/srsue/src/stack/rrc/rrc.cc index 4d72934d4..87736adb8 100644 --- a/srsue/src/stack/rrc/rrc.cc +++ b/srsue/src/stack/rrc/rrc.cc @@ -634,12 +634,18 @@ void rrc::out_of_sync() // CAUTION: We do not lock in this function since they are called from real-time threads serving_cell->in_sync = false; - rrc_log->info("Received out-of-sync while in state %s. n310=%d, t311=%s, t310=%s\n", - rrc_state_text[state], n310_cnt, - mac_timers->timer_get(t311)->is_running()?"running":"stop", - mac_timers->timer_get(t310)->is_running()?"running":"stop"); + + // upon receiving N310 consecutive "out-of-sync" indications for the PCell from lower layers while neither T300, + // T301, T304 nor T311 is running: if (state == RRC_STATE_CONNECTED) { - if (!mac_timers->timer_get(t311)->is_running() && !mac_timers->timer_get(t310)->is_running()) { + if (!mac_timers->timer_get(t300)->is_running() && !mac_timers->timer_get(t301)->is_running() && + !mac_timers->timer_get(t304)->is_running() && !mac_timers->timer_get(t310)->is_running() && + !mac_timers->timer_get(t311)->is_running()) { + rrc_log->info("Received out-of-sync while in state %s. n310=%d, t311=%s, t310=%s\n", + rrc_state_text[state], + n310_cnt, + mac_timers->timer_get(t311)->is_running() ? "running" : "stop", + mac_timers->timer_get(t310)->is_running() ? "running" : "stop"); n310_cnt++; if (n310_cnt == N310) { rrc_log->info("Detected %d out-of-sync from PHY. Trying to resync. Starting T310 timer %d ms\n", @@ -1690,6 +1696,7 @@ void rrc::leave_connected() { rrc_log->console("RRC IDLE\n"); rrc_log->info("Leaving RRC_CONNECTED state\n"); + m_reest_cause = asn1::rrc::reest_cause_e::nulltype; state = RRC_STATE_IDLE; rlc_flush_counter = 0; drb_up = false; @@ -1720,82 +1727,106 @@ void rrc::stop_timers() mac_timers->timer_get(t304)->stop(); } +/* Implementation of procedure in 3GPP 36.331 Section 5.3.7.2: Initiation + * + * This procedure shall be only initiated when: + * - upon detecting radio link failure, in accordance with 5.3.11; or + * - upon handover failure, in accordance with 5.3.5.6; or + * - upon mobility from E-UTRA failure, in accordance with 5.4.3.5; or + * - upon integrity check failure indication from lower layers; or + * - upon an RRC connection reconfiguration failure, in accordance with 5.3.5.5; + * + * The parameter cause shall indicate the cause of the reestablishment according to the sections mentioned adobe. + */ void rrc::init_con_restablish_request(asn1::rrc::reest_cause_e cause) { - // Save reestablishment cause - m_reest_cause = cause; - // Save Current RNTI before MAC Reset mac_interface_rrc::ue_rnti_t uernti; mac->get_rntis(&uernti); - m_reest_rnti = uernti.crnti; - // initiation of reestablishment procedure as indicates in 3GPP 36.331 Section 5.3.7.2 - rrc_log->info("Initiating RRC Connection Reestablishment Procedure\n"); - rrc_log->console("Initiating RRC Connection Reestablishment Procedure (crnti=x%04x, t311=%d)\n", - m_reest_rnti, - mac_timers->timer_get(t311)->get_timeout()); + // If security is activated, RRC connected and C-RNTI available + if (security_is_activated && state == RRC_STATE_CONNECTED && uernti.crnti != 0) { + // Save reestablishment cause and current C-RNTI + m_reest_rnti = uernti.crnti; + m_reest_cause = cause; - // stop timer T310, if running; - mac_timers->timer_get(t310)->stop(); + // initiation of reestablishment procedure as indicates in 3GPP 36.331 Section 5.3.7.2 + rrc_log->info("Initiating RRC Connection Reestablishment Procedure\n"); + rrc_log->console("Initiating RRC Connection Reestablishment Procedure\n"); - // start timer T311; - mac_timers->timer_get(t311)->reset(); - mac_timers->timer_get(t311)->run(); + // stop timer T310, if running; + mac_timers->timer_get(t310)->stop(); - // suspend all RBs except SRB0; - // rlc->reset(); + // start timer T311; + mac_timers->timer_get(t311)->reset(); + mac_timers->timer_get(t311)->run(); - // reset MAC; - mac->reset(); + // suspend all RBs except SRB0; + // rlc->reestablish(); + // pdcp->reset(); - // apply the default physical channel configuration as specified in 9.2.4; - set_phy_default_pucch_srs(); + // reset MAC; + mac->reset(); - // apply the default semi-persistent scheduling configuration as specified in 9.2.3; - // N.A. + // apply the default physical channel configuration as specified in 9.2.4; + set_phy_default_pucch_srs(); - // apply the default MAC main configuration as specified in 9.2.2; - apply_mac_config_dedicated_default(); + // apply the default semi-persistent scheduling configuration as specified in 9.2.3; + // N.A. - // perform cell selection in accordance with the cell selection process as specified in TS 36.304 [4]; - // ... this happens in rrc::run_tti() -} + // apply the default MAC main configuration as specified in 9.2.2; + apply_mac_config_dedicated_default(); -void rrc::proc_con_restablish_request() -{ - if (mac_timers->timer_get(t311)->is_running()) { - if (serving_cell->in_sync) { - if (cell_selection_criteria(serving_cell->get_rsrp())) { - // Perform cell selection in accordance to 36.304 - if (phy->cell_select(&serving_cell->phy_cell)) { - - if (mac_timers->timer_get(t311)->is_running()) { - // Actions following cell reselection while T311 is running 5.3.7.3 - rrc_log->info( - "Cell Selection finished. Initiating transmission of RRC Connection Reestablishment Request\n"); - mac_timers->timer_get(t301)->reset(); - mac_timers->timer_get(t301)->run(); - mac_timers->timer_get(t311)->stop(); - send_con_restablish_request(); - } else { - rrc_log->info("T311 expired while selecting cell. Going to IDLE\n"); - go_idle = true; - } - } else { - rrc_log->warning("Could not re-synchronize with cell.\n"); - go_idle = true; - } - } else { - go_idle = false; - } - } - } else if (mac_timers->timer_get(t311)->is_expired()) { + // perform cell selection in accordance with the cell selection process as specified in TS 36.304 [4]; + // ... this happens in rrc::run_tti() + } else { + // 3GPP 36.331 Section 5.3.7.1 + // If AS security has not been activated, the UE does not initiate the procedure but instead + // moves to RRC_IDLE directly go_idle = true; } +} - if (go_idle) { - m_reest_cause = asn1::rrc::reest_cause_e::nulltype; +/* Implementation of procedure in 3GPP 36.331 Section 5.3.7.3: Actions following cell selection while T311 is running + */ +void rrc::proc_con_restablish_request() +{ + // Check timer... + if (mac_timers->timer_get(t311)->is_running()) { + // Check for synchronism + if (serving_cell->in_sync) { + // Perform cell selection in accordance to 36.304 + if (cell_selection_criteria(serving_cell->get_rsrp())) { + // Actions following cell reselection while T311 is running 5.3.7.3 + // Upon selecting a suitable E-UTRA cell, the UE shall: + rrc_log->info("Cell Selection criteria passed after %dms. Sending RRC Connection Reestablishment Request\n", + mac_timers->timer_get(t311)->value()); + + // stop timer T311; + mac_timers->timer_get(t301)->reset(); + + // start timer T301; + mac_timers->timer_get(t301)->run(); + + // apply the timeAlignmentTimerCommon included in SystemInformationBlockType2; + mac_timers->timer_get(t311)->stop(); + + // initiate transmission of the RRCConnectionReestablishmentRequest message in accordance with 5.3.7.4; + send_con_restablish_request(); + } else { + // Upon selecting an inter-RAT cell + rrc_log->warning("Reestablishment Cell Selection criteria failed.\n"); + rrc_log->console("Reestablishment Cell Selection criteria failed. in_sync=%d\n", serving_cell->in_sync); + leave_connected(); + } + } else { + // No synchronized, do nothing + } + } else { + // t311 expired or stopped + rrc_log->info("T311 expired while selecting cell. Going to IDLE\n"); + rrc_log->console("T311 expired while selecting cell. Going to IDLE\n"); + leave_connected(); } }