fixeria has submitted this change. ( https://gerrit.osmocom.org/c/osmocom-bb/+/34514?usp=email )
Change subject: modem: grr: implement RACH.req retransmission ......................................................................
modem: grr: implement RACH.req retransmission
Sometimes sending one Access Burst is not enough, so we need to repeat sending it a few more more times changing the 3 LSBs randomly. This is what we already do in the mobile app, but not in the modem app.
* Rename GRR_EV_RACH_{REQ,CNF} to GRR_EV_CHAN_ACCESS_{REQ,CNF}. * Rename VTY command 'grr tx-chan-req' to 'grr start-chan-access'. * Add an intermediate state GRR_ST_PACKET_ACCESS. ** The GRR_EV_CHAN_ACCESS_REQ transitions to this state. ** One RACH.req gets transmitted when entering this state. ** The GRR_EV_CHAN_ACCESS_CNF confirms transmission of a RACH.req. ** Upon the timeout (300 ms) expiry, a loop state transition happens. ** After 3 loop-transitions, transition to GRR_ST_PACKET_NOT_READY.
Change-Id: Iab6d9147f6e0aeb99239affacf318a3897fd6ffe Related: libosmo-gprs.git If0de3ed86b1e2897d70183f3b0f4fbfd7d2bda80 Related: OS#5500, OS#6131 --- M src/host/layer23/include/osmocom/bb/modem/grr.h M src/host/layer23/src/modem/grr.c M src/host/layer23/src/modem/rlcmac.c M src/host/layer23/src/modem/vty.c 4 files changed, 189 insertions(+), 78 deletions(-)
Approvals: osmith: Looks good to me, but someone else must approve fixeria: Looks good to me, approved Jenkins Builder: Verified pespin: Looks good to me, but someone else must approve
diff --git a/src/host/layer23/include/osmocom/bb/modem/grr.h b/src/host/layer23/include/osmocom/bb/modem/grr.h index 8235d59..99800ad 100644 --- a/src/host/layer23/include/osmocom/bb/modem/grr.h +++ b/src/host/layer23/include/osmocom/bb/modem/grr.h @@ -11,14 +11,15 @@ enum grr_fsm_state { GRR_ST_PACKET_NOT_READY, GRR_ST_PACKET_IDLE, + GRR_ST_PACKET_ACCESS, GRR_ST_PACKET_TRANSFER, };
enum grr_fsm_event { GRR_EV_BCCH_BLOCK_IND, GRR_EV_PCH_AGCH_BLOCK_IND, - GRR_EV_RACH_REQ, - GRR_EV_RACH_CNF, + GRR_EV_CHAN_ACCESS_REQ, + GRR_EV_CHAN_ACCESS_CNF, GRR_EV_PDCH_ESTABLISH_REQ, GRR_EV_PDCH_RELEASE_REQ, GRR_EV_PDCH_UL_TBF_CFG_REQ, @@ -31,4 +32,3 @@ extern struct osmo_fsm grr_fsm_def;
int modem_grr_rslms_cb(struct msgb *msg, struct lapdm_entity *le, void *ctx); -uint8_t modem_grr_gen_chan_req(bool single_block); diff --git a/src/host/layer23/src/modem/grr.c b/src/host/layer23/src/modem/grr.c index af773a3..a029dd8 100644 --- a/src/host/layer23/src/modem/grr.c +++ b/src/host/layer23/src/modem/grr.c @@ -63,7 +63,7 @@ }
/* Generate an 8-bit CHANNEL REQUEST message as per 3GPP TS 44.018, 9.1.8 */ -uint8_t modem_grr_gen_chan_req(bool single_block) +static uint8_t grr_gen_chan_req(bool single_block) { uint8_t rnd = (uint8_t)rand();
@@ -408,7 +408,7 @@
switch (ch->c.msg_type) { case RSL_MT_CHAN_CONF: /* RACH.conf */ - return osmo_fsm_inst_dispatch(ms->grr_fi, GRR_EV_RACH_CNF, + return osmo_fsm_inst_dispatch(ms->grr_fi, GRR_EV_CHAN_ACCESS_CNF, (void *)&ch->data[1]); default: LOGP(DRSL, LOGL_NOTICE, "Unhandled RSLms CCHAN message " @@ -449,6 +449,78 @@
#include <osmocom/gsm/gsm0502.h> // XXX
+/* RACH re-transmission delay value (in ms) */ +#define GRR_PACKET_ACCESS_DELAY_MS 300 +/* RACH max number of transmissions */ +#define GRR_PACKET_ACCESS_MAX_CHAN_REQ 3 + +static void handle_chan_access_req(struct osmo_fsm_inst *fi, + const struct osmo_gprs_rlcmac_l1ctl_prim *lp) +{ + struct osmocom_ms *ms = fi->priv; + struct gsm48_rrlayer *rr = &ms->rrlayer; + + if (lp->rach_req.is_11bit) { /* TODO: implement 11-bit RACH */ + LOGPFSML(fi, LOGL_ERROR, "11-bit RACH is not supported\n"); + return; + } + + memset(&rr->cr_hist[0], 0x00, sizeof(rr->cr_hist)); + rr->chan_req_val = lp->rach_req.ra & ~0x07; + rr->n_chan_req = GRR_PACKET_ACCESS_MAX_CHAN_REQ; + rr->state = GSM48_RR_ST_CONN_PEND; + + osmo_fsm_inst_state_chg_ms(fi, GRR_ST_PACKET_ACCESS, + GRR_PACKET_ACCESS_DELAY_MS, 0); +} + +static void handle_pdch_establish_req(struct osmo_fsm_inst *fi, + const struct osmo_gprs_rlcmac_l1ctl_prim *lp) +{ + struct osmocom_ms *ms = fi->priv; + + if (!lp->pdch_est_req.fh) { + LOGPFSML(fi, LOGL_INFO, + "PDCH Establish.Req: TSC=%u, H0, ARFCN=%u\n", + lp->pdch_est_req.tsc, lp->pdch_est_req.arfcn); + l1ctl_tx_dm_est_req_h0(ms, lp->pdch_est_req.arfcn, + RSL_CHAN_OSMO_PDCH | lp->pdch_est_req.ts_nr, + lp->pdch_est_req.tsc, GSM48_CMODE_SIGN, 0); + } else { + /* Hopping */ + uint8_t ma_len = 0; + uint16_t ma[64]; + + LOGPFSML(fi, LOGL_INFO, + "PDCH Establish.Req: TSC=%u, H1, HSN=%u, MAIO=%u\n", + lp->pdch_est_req.tsc, + lp->pdch_est_req.fhp.hsn, + lp->pdch_est_req.fhp.maio); + + for (unsigned int i = 1, j = 0; i <= 1024; i++) { + unsigned int arfcn = i & 1023; + unsigned int k; + + if (~ms->cellsel.sel_si.freq[arfcn].mask & 0x01) + continue; + + k = lp->pdch_est_req.fhp.ma_len - (j >> 3) - 1; + if (lp->pdch_est_req.fhp.ma[k] & (1 << (j & 7))) + ma[ma_len++] = arfcn; + j++; + } + + l1ctl_tx_dm_est_req_h1(ms, + lp->pdch_est_req.fhp.maio, + lp->pdch_est_req.fhp.hsn, + &ma[0], ma_len, + RSL_CHAN_OSMO_PDCH | lp->pdch_est_req.ts_nr, + lp->pdch_est_req.tsc, GSM48_CMODE_SIGN, 0); + } + + osmo_fsm_inst_state_chg(fi, GRR_ST_PACKET_TRANSFER, 0, 0); +} + static void handle_pdch_block_ind(struct osmocom_ms *ms, struct msgb *msg) { const struct l1ctl_gprs_dl_block_ind *ind = (void *)msg->l1h; @@ -547,27 +619,60 @@ case GRR_EV_PCH_AGCH_BLOCK_IND: grr_rx_ccch(ms, (struct msgb *)data); break; - case GRR_EV_RACH_REQ: - { - const struct osmo_gprs_rlcmac_l1ctl_prim *lp = data; - struct gsm48_rrlayer *rr = &ms->rrlayer; - - if (lp->rach_req.is_11bit) { /* TODO: implement 11-bit RACH */ - LOGPFSML(fi, LOGL_ERROR, "11-bit RACH is not supported\n"); - return; - } - - rr->cr_ra = lp->rach_req.ra; - memset(&rr->cr_hist[0], 0x00, sizeof(rr->cr_hist)); - - LOGPFSML(fi, LOGL_INFO, "Sending CHANNEL REQUEST (0x%02x)\n", rr->cr_ra); - l1ctl_tx_rach_req(ms, RSL_CHAN_RACH, 0x00, rr->cr_ra, 0, - ms->cellsel.ccch_mode == CCCH_MODE_COMBINED); - - rr->state = GSM48_RR_ST_CONN_PEND; + case GRR_EV_CHAN_ACCESS_REQ: + handle_chan_access_req(fi, data); break; + case GRR_EV_PDCH_ESTABLISH_REQ: + handle_pdch_establish_req(fi, data); + break; + default: + OSMO_ASSERT(0); } - case GRR_EV_RACH_CNF: +} + +static void grr_st_packet_access_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state) +{ + struct osmocom_ms *ms = fi->priv; + struct gsm48_rrlayer *rr = &ms->rrlayer; + + if (rr->n_chan_req == 0) { + LOGPFSML(fi, LOGL_ERROR, "Packet access failed (no more attempts left)\n"); + osmo_fsm_inst_state_chg(fi, GRR_ST_PACKET_NOT_READY, 0, 0); + return; + } + + /* (re-)generate the RA value */ + if ((rr->chan_req_val >> 3) == 0x0e) /* 01110xxx */ + rr->cr_ra = grr_gen_chan_req(true); + else /* 011110xx or 01111x0x or 01111xx0 */ + rr->cr_ra = grr_gen_chan_req(false); + rr->n_chan_req--; + + LOGPFSML(fi, LOGL_INFO, + "Sending CHANNEL REQUEST (ra=0x%02x, num_attempts=%u)\n", + rr->cr_ra, rr->n_chan_req); + + l1ctl_tx_rach_req(ms, RSL_CHAN_RACH, 0x00, rr->cr_ra, 0, + ms->cellsel.ccch_mode == CCCH_MODE_COMBINED); +} + +static void grr_st_packet_access_action(struct osmo_fsm_inst *fi, + uint32_t event, void *data) +{ + struct osmocom_ms *ms = fi->priv; + + switch (event) { + case GRR_EV_BCCH_BLOCK_IND: + grr_rx_bcch(ms, (struct msgb *)data); + if (!grr_cell_is_usable(ms)) { + LOGPFSML(fi, LOGL_NOTICE, "Cell is not usable, GRR becomes not ready\n"); + osmo_fsm_inst_state_chg(fi, GRR_ST_PACKET_NOT_READY, 0, 0); + } + break; + case GRR_EV_PCH_AGCH_BLOCK_IND: + grr_rx_ccch(ms, (struct msgb *)data); + break; + case GRR_EV_CHAN_ACCESS_CNF: { struct gsm48_rrlayer *rr = &ms->rrlayer; const struct gsm48_req_ref *ref = data; @@ -591,50 +696,8 @@ break; } case GRR_EV_PDCH_ESTABLISH_REQ: - { - const struct osmo_gprs_rlcmac_l1ctl_prim *lp = data; - - if (!lp->pdch_est_req.fh) { - LOGPFSML(fi, LOGL_INFO, - "PDCH Establish.Req: TSC=%u, H0, ARFCN=%u\n", - lp->pdch_est_req.tsc, lp->pdch_est_req.arfcn); - l1ctl_tx_dm_est_req_h0(ms, lp->pdch_est_req.arfcn, - RSL_CHAN_OSMO_PDCH | lp->pdch_est_req.ts_nr, - lp->pdch_est_req.tsc, GSM48_CMODE_SIGN, 0); - } else { - /* Hopping */ - uint8_t ma_len = 0; - uint16_t ma[64]; - - LOGPFSML(fi, LOGL_INFO, - "PDCH Establish.Req: TSC=%u, H1, HSN=%u, MAIO=%u\n", - lp->pdch_est_req.tsc, - lp->pdch_est_req.fhp.hsn, - lp->pdch_est_req.fhp.maio); - - for (unsigned int i = 1, j = 0; i <= 1024; i++) { - unsigned int arfcn = i & 1023; - unsigned int k; - - if (~ms->cellsel.sel_si.freq[arfcn].mask & 0x01) - continue; - - k = lp->pdch_est_req.fhp.ma_len - (j >> 3) - 1; - if (lp->pdch_est_req.fhp.ma[k] & (1 << (j & 7))) - ma[ma_len++] = arfcn; - j++; - } - - l1ctl_tx_dm_est_req_h1(ms, - lp->pdch_est_req.fhp.maio, - lp->pdch_est_req.fhp.hsn, - &ma[0], ma_len, - RSL_CHAN_OSMO_PDCH | lp->pdch_est_req.ts_nr, - lp->pdch_est_req.tsc, GSM48_CMODE_SIGN, 0); - } - osmo_fsm_inst_state_chg(fi, GRR_ST_PACKET_TRANSFER, 0, 0); + handle_pdch_establish_req(fi, data); break; - } default: OSMO_ASSERT(0); } @@ -704,6 +767,19 @@ } }
+static int grr_fsm_timer_cb(struct osmo_fsm_inst *fi) +{ + switch (fi->state) { + case GRR_ST_PACKET_ACCESS: + /* perform a loop transaction, restarting the timer */ + osmo_fsm_inst_state_chg_ms(fi, GRR_ST_PACKET_ACCESS, + GRR_PACKET_ACCESS_DELAY_MS, 0); + return 0; + default: + OSMO_ASSERT(0); + } +} + static const struct osmo_fsm_state grr_fsm_states[] = { [GRR_ST_PACKET_NOT_READY] = { .name = "PACKET_NOT_READY", @@ -715,15 +791,26 @@ [GRR_ST_PACKET_IDLE] = { .name = "PACKET_IDLE", .out_state_mask = S(GRR_ST_PACKET_NOT_READY) + | S(GRR_ST_PACKET_ACCESS) | S(GRR_ST_PACKET_TRANSFER), .in_event_mask = S(GRR_EV_BCCH_BLOCK_IND) | S(GRR_EV_PCH_AGCH_BLOCK_IND) - | S(GRR_EV_RACH_REQ) - | S(GRR_EV_RACH_CNF) - | S(GRR_EV_PDCH_ESTABLISH_REQ), + | S(GRR_EV_CHAN_ACCESS_REQ) + | S(GRR_EV_PDCH_ESTABLISH_REQ), /* DL TBF ASS */ .action = &grr_st_packet_idle_action, .onenter = &grr_st_packet_idle_onenter, }, + [GRR_ST_PACKET_ACCESS] = { + .name = "PACKET_ACCESS", + .out_state_mask = S(GRR_ST_PACKET_NOT_READY) + | S(GRR_ST_PACKET_TRANSFER), + .in_event_mask = S(GRR_EV_BCCH_BLOCK_IND) + | S(GRR_EV_PCH_AGCH_BLOCK_IND) + | S(GRR_EV_CHAN_ACCESS_CNF) + | S(GRR_EV_PDCH_ESTABLISH_REQ), /* UL TBF ASS */ + .onenter = &grr_st_packet_access_onenter, + .action = &grr_st_packet_access_action, + }, [GRR_ST_PACKET_TRANSFER] = { .name = "PACKET_TRANSFER", .out_state_mask = S(GRR_ST_PACKET_NOT_READY), @@ -742,8 +829,8 @@ static const struct value_string grr_fsm_event_names[] = { OSMO_VALUE_STRING(GRR_EV_BCCH_BLOCK_IND), OSMO_VALUE_STRING(GRR_EV_PCH_AGCH_BLOCK_IND), - OSMO_VALUE_STRING(GRR_EV_RACH_REQ), - OSMO_VALUE_STRING(GRR_EV_RACH_CNF), + OSMO_VALUE_STRING(GRR_EV_CHAN_ACCESS_REQ), + OSMO_VALUE_STRING(GRR_EV_CHAN_ACCESS_CNF), OSMO_VALUE_STRING(GRR_EV_PDCH_ESTABLISH_REQ), OSMO_VALUE_STRING(GRR_EV_PDCH_RELEASE_REQ), OSMO_VALUE_STRING(GRR_EV_PDCH_UL_TBF_CFG_REQ), @@ -760,6 +847,7 @@ .states = grr_fsm_states, .num_states = ARRAY_SIZE(grr_fsm_states), .event_names = grr_fsm_event_names, + .timer_cb = &grr_fsm_timer_cb, };
static __attribute__((constructor)) void on_dso_load(void) diff --git a/src/host/layer23/src/modem/rlcmac.c b/src/host/layer23/src/modem/rlcmac.c index 5037d99..a9588f7 100644 --- a/src/host/layer23/src/modem/rlcmac.c +++ b/src/host/layer23/src/modem/rlcmac.c @@ -145,7 +145,7 @@
switch (OSMO_PRIM_HDR(&prim->oph)) { case OSMO_PRIM(OSMO_GPRS_RLCMAC_L1CTL_RACH, PRIM_OP_REQUEST): - return osmo_fsm_inst_dispatch(ms->grr_fi, GRR_EV_RACH_REQ, lp); + return osmo_fsm_inst_dispatch(ms->grr_fi, GRR_EV_CHAN_ACCESS_REQ, lp); case OSMO_PRIM(OSMO_GPRS_RLCMAC_L1CTL_PDCH_DATA, PRIM_OP_REQUEST): return osmo_fsm_inst_dispatch(ms->grr_fi, GRR_EV_PDCH_BLOCK_REQ, lp); case OSMO_PRIM(OSMO_GPRS_RLCMAC_L1CTL_CFG_UL_TBF, PRIM_OP_REQUEST): diff --git a/src/host/layer23/src/modem/vty.c b/src/host/layer23/src/modem/vty.c index da29165..f42aa66 100644 --- a/src/host/layer23/src/modem/vty.c +++ b/src/host/layer23/src/modem/vty.c @@ -73,27 +73,26 @@ /* testing commands */ DEFUN_HIDDEN(test_grr_tx_chan_req, test_grr_tx_chan_req_cmd, - "test MS_NAME grr tx-chan-req (1phase|2phase)", + "test MS_NAME grr start-chan-access (1phase|2phase)", TEST_CMD_DESC MS_NAME_DESC GRR_CMDG_DESC "Send a CHANNEL REQUEST (RACH) to the network\n" "One-phase packet access (011110xx or 01111x0x or 01111xx0)\n" "Two-phase (single block) packet access (01110xxx)\n") { struct osmocom_ms *ms; - uint8_t chan_req;
if ((ms = l23_vty_get_ms(argv[0], vty)) == NULL) return CMD_WARNING;
- chan_req = modem_grr_gen_chan_req(argv[1][0] == '2'); const struct osmo_gprs_rlcmac_l1ctl_prim lp = { .rach_req = { .is_11bit = false, - .ra = chan_req, + /* the 3 LSBs are randomized during (re)transmission */ + .ra = argv[1][0] == '1' ? 0x78 : 0x70, } };
- if (osmo_fsm_inst_dispatch(ms->grr_fi, GRR_EV_RACH_REQ, (void *)&lp)) { + if (osmo_fsm_inst_dispatch(ms->grr_fi, GRR_EV_CHAN_ACCESS_REQ, (void *)&lp)) { vty_out(vty, "Failed to send a CHANNEL REQUEST%s", VTY_NEWLINE); return CMD_WARNING; }
-
fixeria