diff options
Diffstat (limited to 'src/tbf_ul.cpp')
| -rw-r--r-- | src/tbf_ul.cpp | 44 |
1 files changed, 41 insertions, 3 deletions
diff --git a/src/tbf_ul.cpp b/src/tbf_ul.cpp index 686eea5e..7486b477 100644 --- a/src/tbf_ul.cpp +++ b/src/tbf_ul.cpp @@ -173,6 +173,7 @@ struct gprs_rlcmac_ul_tbf *tbf_alloc_ul_ccch(struct gprs_rlcmac_bts *bts, struct } TBF_SET_STATE(tbf, GPRS_RLCMAC_FLOW); TBF_ASS_TYPE_SET(tbf, GPRS_RLCMAC_FLAG_CCCH); + tbf->contention_resolution_start(); OSMO_ASSERT(tbf->ms()); return tbf; @@ -300,6 +301,37 @@ bool gprs_rlcmac_ul_tbf::handle_ctrl_ack(enum pdch_ulc_tbf_poll_reason reason) return false; } +void gprs_rlcmac_ul_tbf::contention_resolution_start() +{ + /* 3GPP TS 44.018 sec 11.1.2 Timers on the network side: "This timer is + * started when a temporary block flow is allocated with an IMMEDIATE + * ASSIGNMENT or an IMMEDIATE PACKET ASSIGNMENT or an EC IMMEDIATE + * ASSIGNMENT TYPE 1 message during a packet access procedure. It is + * stopped when the mobile station has correctly seized the temporary + * block flow." + * In our code base, it means we want to do contention resolution + * timeout only for one-phase packet access, since two-phase is handled + * through SBA structs, which are freed by the PDCH UL Controller if the + * single allocated block is lost. */ + T_START(this, T3141, 3141, "Contention resolution (UL-TBF, CCCH)", true); +} +void gprs_rlcmac_ul_tbf::contention_resolution_success() +{ + if (m_contention_resolution_done) + return; + + /* 3GPP TS 44.060 sec 7a.2.1 Contention Resolution */ + /* 3GPP TS 44.018 3.5.2.1.4 Packet access completion: The one phase + packet access procedure is completed at a successful contention + resolution. The mobile station has entered the packet transfer mode. + Timer T3141 is stopped on the network side */ + t_stop(T3141, "Contention resolution success (UL-TBF, CCCH)"); + + /* now we must set this flag, so we are allowed to assign downlink + * TBF on PACCH. it is only allowed when TLLI is acknowledged. */ + m_contention_resolution_done = 1; +} + struct msgb *gprs_rlcmac_ul_tbf::create_ul_ack(uint32_t fn, uint8_t ts) { int final = (state_is(GPRS_RLCMAC_FINISHED)); @@ -333,9 +365,15 @@ struct msgb *gprs_rlcmac_ul_tbf::create_ul_ack(uint32_t fn, uint8_t ts) bitvec_pack(ack_vec, msgb_put(msg, 23)); bitvec_free(ack_vec); - /* now we must set this flag, so we are allowed to assign downlink - * TBF on PACCH. it is only allowed when TLLI is acknowledged. */ - m_contention_resolution_done = 1; + /* TS 44.060 7a.2.1.1: "The contention resolution is completed on + * the network side when the network receives an RLC data block that + * comprises the TLLI value that identifies the mobile station and the + * TFI value associated with the TBF." + * However, it's handier for us to mark contention resolution success + * here since according to spec upon rx UL ACK is the time at which MS + * realizes contention resolution succeeds. */ + if (ms_tlli(ms()) != GSM_RESERVED_TMSI) + contention_resolution_success(); if (final) { set_polling(new_poll_fn, ts, PDCH_ULC_POLL_UL_ACK); |