<p>fixeria has uploaded this change for <strong>review</strong>.</p><p><a href="https://gerrit.osmocom.org/c/osmo-bts/+/15812">View Change</a></p><pre style="font-family: monospace,monospace; white-space: pre-wrap;">osmo-bts-trx/scheduler: refactor the first frame number calculation<br><br>In I6bc511223069f66b49109d3267bee7bd89585713 we have introduced<br>the storage for Uplink measurements (so called "history"), where<br>we can also store TDMA frame numbers of the related bursts.<br><br>This approach allows to look up frame number of the first Uplink<br>burst of a decoded block from the history. Thus neither we need<br>to store frame number of bid=0 in the logical channel state,<br>nor use complicated and buggy formulas.<br><br>This is not a silver bullet, because in some cases the measurement<br>history may be incomplete (until we start handling NOPE.ind from<br>the transceiver, see OS#3428). In such cases we would still need<br>to look up the first frame number using the block mapping tables<br>defined in 3GPP TS 45.002.<br><br>Change-Id: Iae9a0135595b0c56752723669a4ed2fc91f25785<br>Related: OS#3803<br>---<br>M include/osmo-bts/scheduler.h<br>M src/osmo-bts-trx/scheduler_trx.c<br>2 files changed, 54 insertions(+), 35 deletions(-)<br><br></pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;">git pull ssh://gerrit.osmocom.org:29418/osmo-bts refs/changes/12/15812/1</pre><pre style="font-family: monospace,monospace; white-space: pre-wrap;"><span>diff --git a/include/osmo-bts/scheduler.h b/include/osmo-bts/scheduler.h</span><br><span>index e6ec37d..f096374 100644</span><br><span>--- a/include/osmo-bts/scheduler.h</span><br><span>+++ b/include/osmo-bts/scheduler.h</span><br><span>@@ -72,6 +72,7 @@</span><br><span> /* A set of measurements attached to a burst */</span><br><span> struct l1sched_meas_set {</span><br><span> struct llist_head list; /* Link to the measurement history */</span><br><span style="color: hsl(120, 100%, 40%);">+ uint32_t fn; /* TDMA frame-number */</span><br><span> </span><br><span> int16_t toa256; /* Timing of Arrival (1/256 of a symbol) */</span><br><span> int16_t ci_cb; /* Carrier-to-Interference (cB) */</span><br><span>@@ -85,7 +86,6 @@</span><br><span> ubit_t *dl_bursts; /* burst buffer for TX */</span><br><span> enum trx_burst_type dl_burst_type; /* GMSK or 8PSK burst type */</span><br><span> sbit_t *ul_bursts; /* burst buffer for RX */</span><br><span style="color: hsl(0, 100%, 40%);">- uint32_t ul_first_fn; /* fn of first burst */</span><br><span> uint8_t ul_mask; /* mask of received bursts */</span><br><span> </span><br><span> /* loss detection */</span><br><span>diff --git a/src/osmo-bts-trx/scheduler_trx.c b/src/osmo-bts-trx/scheduler_trx.c</span><br><span>index ae23ddd..39f118d 100644</span><br><span>--- a/src/osmo-bts-trx/scheduler_trx.c</span><br><span>+++ b/src/osmo-bts-trx/scheduler_trx.c</span><br><span>@@ -898,6 +898,9 @@</span><br><span> set = talloc(tall_bts_ctx, struct l1sched_meas_set);</span><br><span> OSMO_ASSERT(set != NULL);</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ /* Attach TDMA frame number */</span><br><span style="color: hsl(120, 100%, 40%);">+ set->fn = bi->fn;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> set->toa256 = bi->toa256;</span><br><span> set->rssi = bi->rssi;</span><br><span> </span><br><span>@@ -962,6 +965,30 @@</span><br><span> }</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+/* Get TDMA frame number of N-th measurement from the history. */</span><br><span style="color: hsl(120, 100%, 40%);">+static uint32_t l1sched_meas_get_fn(const struct l1sched_chan_state *chan_state,</span><br><span style="color: hsl(120, 100%, 40%);">+ unsigned int num)</span><br><span style="color: hsl(120, 100%, 40%);">+{</span><br><span style="color: hsl(120, 100%, 40%);">+ const struct llist_head *hist = &chan_state->meas.hist;</span><br><span style="color: hsl(120, 100%, 40%);">+ struct l1sched_meas_set *set;</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* There shall be at least one set */</span><br><span style="color: hsl(120, 100%, 40%);">+ OSMO_ASSERT(chan_state->meas.num > 0);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Try to find N-th measurement in the history */</span><br><span style="color: hsl(120, 100%, 40%);">+ llist_for_each_entry(set, hist, list) {</span><br><span style="color: hsl(120, 100%, 40%);">+ if (num == 0)</span><br><span style="color: hsl(120, 100%, 40%);">+ return set->fn;</span><br><span style="color: hsl(120, 100%, 40%);">+ num -= 1;</span><br><span style="color: hsl(120, 100%, 40%);">+ }</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span style="color: hsl(120, 100%, 40%);">+ /* Not enough measurements in the history? */</span><br><span style="color: hsl(120, 100%, 40%);">+ LOGP(DL1P, LOGL_NOTICE, "Failed to find TDMA frame number in the history, "</span><br><span style="color: hsl(120, 100%, 40%);">+ "using frame number of the last burst\n");</span><br><span style="color: hsl(120, 100%, 40%);">+ set = llist_first_entry(hist, struct l1sched_meas_set, list);</span><br><span style="color: hsl(120, 100%, 40%);">+ return set->fn; /* return frame number of the last burst */</span><br><span style="color: hsl(120, 100%, 40%);">+}</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /*! \brief a single (SDCCH/SACCH) burst was received by the PHY, process it */</span><br><span> int rx_data_fn(struct l1sched_trx *l1t, enum trx_chan_type chan,</span><br><span> uint8_t bid, const struct trx_ul_burst_ind *bi)</span><br><span>@@ -969,11 +996,11 @@</span><br><span> struct l1sched_ts *l1ts = l1sched_trx_get_ts(l1t, bi->tn);</span><br><span> struct l1sched_chan_state *chan_state = &l1ts->chan_state[chan];</span><br><span> sbit_t *burst, **bursts_p = &chan_state->ul_bursts;</span><br><span style="color: hsl(0, 100%, 40%);">- uint32_t *first_fn = &chan_state->ul_first_fn;</span><br><span> uint8_t *mask = &chan_state->ul_mask;</span><br><span> uint8_t l2[GSM_MACBLOCK_LEN], l2_len;</span><br><span> struct l1sched_meas_set meas_set;</span><br><span> int n_errors, n_bits_total;</span><br><span style="color: hsl(120, 100%, 40%);">+ uint32_t first_fn;</span><br><span> uint16_t ber10k;</span><br><span> int rc;</span><br><span> </span><br><span>@@ -997,7 +1024,6 @@</span><br><span> if (bid == 0) {</span><br><span> memset(*bursts_p, 0, 464);</span><br><span> *mask = 0x0;</span><br><span style="color: hsl(0, 100%, 40%);">- *first_fn = bi->fn;</span><br><span> }</span><br><span> </span><br><span> /* store the measurements */</span><br><span>@@ -1045,18 +1071,21 @@</span><br><span> } else</span><br><span> l2_len = GSM_MACBLOCK_LEN;</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ /* Get frame number of the first burst (1/4) */</span><br><span style="color: hsl(120, 100%, 40%);">+ first_fn = l1sched_meas_get_fn(chan_state, 4);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* Average measurements of the last 4 bursts */</span><br><span> l1sched_meas_average(chan_state, &meas_set, 4);</span><br><span> /* Nothing to store for the next block */</span><br><span> l1sched_meas_squeeze(chan_state, 0);</span><br><span> </span><br><span> /* Send uplink measurement information to L2 */</span><br><span style="color: hsl(0, 100%, 40%);">- l1if_process_meas_res(l1t->trx, bi->tn, *first_fn,</span><br><span style="color: hsl(120, 100%, 40%);">+ l1if_process_meas_res(l1t->trx, bi->tn, first_fn,</span><br><span> trx_chan_desc[chan].chan_nr | bi->tn,</span><br><span> n_errors, n_bits_total,</span><br><span> meas_set.rssi, meas_set.toa256);</span><br><span> ber10k = compute_ber10k(n_bits_total, n_errors);</span><br><span style="color: hsl(0, 100%, 40%);">- return _sched_compose_ph_data_ind(l1t, bi->tn, *first_fn,</span><br><span style="color: hsl(120, 100%, 40%);">+ return _sched_compose_ph_data_ind(l1t, bi->tn, first_fn,</span><br><span> chan, l2, l2_len,</span><br><span> meas_set.rssi, meas_set.toa256,</span><br><span> meas_set.ci_cb, ber10k,</span><br><span>@@ -1070,11 +1099,11 @@</span><br><span> struct l1sched_ts *l1ts = l1sched_trx_get_ts(l1t, bi->tn);</span><br><span> struct l1sched_chan_state *chan_state = &l1ts->chan_state[chan];</span><br><span> sbit_t *burst, **bursts_p = &chan_state->ul_bursts;</span><br><span style="color: hsl(0, 100%, 40%);">- uint32_t *first_fn = &chan_state->ul_first_fn;</span><br><span> uint8_t *mask = &chan_state->ul_mask;</span><br><span> uint8_t l2[EGPRS_0503_MAX_BYTES];</span><br><span> struct l1sched_meas_set meas_set;</span><br><span> int n_errors, n_bursts_bits, n_bits_total;</span><br><span style="color: hsl(120, 100%, 40%);">+ uint32_t first_fn;</span><br><span> uint16_t ber10k;</span><br><span> int rc;</span><br><span> </span><br><span>@@ -1095,7 +1124,6 @@</span><br><span> if (bid == 0) {</span><br><span> memset(*bursts_p, 0, GSM0503_EGPRS_BURSTS_NBITS);</span><br><span> *mask = 0x0;</span><br><span style="color: hsl(0, 100%, 40%);">- *first_fn = bi->fn;</span><br><span> }</span><br><span> </span><br><span> /* store the measurements */</span><br><span>@@ -1143,13 +1171,16 @@</span><br><span> &n_errors, &n_bits_total);</span><br><span> }</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ /* Get frame number of the first burst (1/4) */</span><br><span style="color: hsl(120, 100%, 40%);">+ first_fn = l1sched_meas_get_fn(chan_state, 4);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* Average measurements of the last 4 bursts */</span><br><span> l1sched_meas_average(chan_state, &meas_set, 4);</span><br><span> /* Nothing to store for the next block */</span><br><span> l1sched_meas_squeeze(chan_state, 0);</span><br><span> </span><br><span> /* Send uplink measurement information to L2 */</span><br><span style="color: hsl(0, 100%, 40%);">- l1if_process_meas_res(l1t->trx, bi->tn, *first_fn,</span><br><span style="color: hsl(120, 100%, 40%);">+ l1if_process_meas_res(l1t->trx, bi->tn, first_fn,</span><br><span> trx_chan_desc[chan].chan_nr | bi->tn,</span><br><span> n_errors, n_bits_total,</span><br><span> meas_set.rssi, meas_set.toa256);</span><br><span>@@ -1163,7 +1194,7 @@</span><br><span> </span><br><span> ber10k = compute_ber10k(n_bits_total, n_errors);</span><br><span> return _sched_compose_ph_data_ind(l1t, bi->tn,</span><br><span style="color: hsl(0, 100%, 40%);">- *first_fn, chan, l2, rc,</span><br><span style="color: hsl(120, 100%, 40%);">+ first_fn, chan, l2, rc,</span><br><span> meas_set.rssi, meas_set.toa256,</span><br><span> meas_set.ci_cb, ber10k,</span><br><span> PRES_INFO_BOTH);</span><br><span>@@ -1176,12 +1207,12 @@</span><br><span> struct l1sched_ts *l1ts = l1sched_trx_get_ts(l1t, bi->tn);</span><br><span> struct l1sched_chan_state *chan_state = &l1ts->chan_state[chan];</span><br><span> sbit_t *burst, **bursts_p = &chan_state->ul_bursts;</span><br><span style="color: hsl(0, 100%, 40%);">- uint32_t *first_fn = &chan_state->ul_first_fn;</span><br><span> uint8_t *mask = &chan_state->ul_mask;</span><br><span> uint8_t rsl_cmode = chan_state->rsl_cmode;</span><br><span> uint8_t tch_mode = chan_state->tch_mode;</span><br><span> uint8_t tch_data[128]; /* just to be safe */</span><br><span> struct l1sched_meas_set meas_set;</span><br><span style="color: hsl(120, 100%, 40%);">+ uint32_t first_fn;</span><br><span> int rc, amr = 0;</span><br><span> int n_errors, n_bits_total;</span><br><span> bool bfi_flag = false;</span><br><span>@@ -1208,7 +1239,6 @@</span><br><span> if (bid == 0) {</span><br><span> memset(*bursts_p + 464, 0, 464);</span><br><span> *mask = 0x0;</span><br><span style="color: hsl(0, 100%, 40%);">- *first_fn = bi->fn;</span><br><span> }</span><br><span> </span><br><span> /* store the measurements */</span><br><span>@@ -1275,13 +1305,16 @@</span><br><span> }</span><br><span> memcpy(*bursts_p, *bursts_p + 464, 464);</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ /* Get frame number of the first burst (1/8) */</span><br><span style="color: hsl(120, 100%, 40%);">+ first_fn = l1sched_meas_get_fn(chan_state, 8);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* Average measurements of the last 8 bursts */</span><br><span> l1sched_meas_average(chan_state, &meas_set, 8);</span><br><span> /* Keep measurements of the last 4 bursts */</span><br><span> l1sched_meas_squeeze(chan_state, 4);</span><br><span> </span><br><span> /* Send uplink measurement information to L2 */</span><br><span style="color: hsl(0, 100%, 40%);">- l1if_process_meas_res(l1t->trx, bi->tn, *first_fn,</span><br><span style="color: hsl(120, 100%, 40%);">+ l1if_process_meas_res(l1t->trx, bi->tn, first_fn,</span><br><span> trx_chan_desc[chan].chan_nr | bi->tn,</span><br><span> n_errors, n_bits_total,</span><br><span> meas_set.rssi, meas_set.toa256);</span><br><span>@@ -1308,9 +1341,7 @@</span><br><span> /* FACCH */</span><br><span> if (rc == GSM_MACBLOCK_LEN) {</span><br><span> uint16_t ber10k = compute_ber10k(n_bits_total, n_errors);</span><br><span style="color: hsl(0, 100%, 40%);">- _sched_compose_ph_data_ind(l1t, bi->tn,</span><br><span style="color: hsl(0, 100%, 40%);">- /* FIXME: this calculation is wrong */</span><br><span style="color: hsl(0, 100%, 40%);">- (bi->fn + GSM_HYPERFRAME - 7) % GSM_HYPERFRAME, chan,</span><br><span style="color: hsl(120, 100%, 40%);">+ _sched_compose_ph_data_ind(l1t, bi->tn, first_fn, chan,</span><br><span> tch_data + amr, GSM_MACBLOCK_LEN,</span><br><span> meas_set.rssi, meas_set.toa256,</span><br><span> meas_set.ci_cb, ber10k,</span><br><span>@@ -1368,10 +1399,7 @@</span><br><span> </span><br><span> /* TCH or BFI */</span><br><span> compose_l1sap:</span><br><span style="color: hsl(0, 100%, 40%);">- return _sched_compose_tch_ind(l1t, bi->tn,</span><br><span style="color: hsl(0, 100%, 40%);">- /* FIXME: this calculation is wrong */</span><br><span style="color: hsl(0, 100%, 40%);">- (bi->fn + GSM_HYPERFRAME - 7) % GSM_HYPERFRAME, chan,</span><br><span style="color: hsl(0, 100%, 40%);">- tch_data, rc);</span><br><span style="color: hsl(120, 100%, 40%);">+ return _sched_compose_tch_ind(l1t, bi->tn, first_fn, chan, tch_data, rc);</span><br><span> }</span><br><span> </span><br><span> /*! \brief a single TCH/H burst was received by the PHY, process it */</span><br><span>@@ -1381,12 +1409,12 @@</span><br><span> struct l1sched_ts *l1ts = l1sched_trx_get_ts(l1t, bi->tn);</span><br><span> struct l1sched_chan_state *chan_state = &l1ts->chan_state[chan];</span><br><span> sbit_t *burst, **bursts_p = &chan_state->ul_bursts;</span><br><span style="color: hsl(0, 100%, 40%);">- uint32_t *first_fn = &chan_state->ul_first_fn;</span><br><span> uint8_t *mask = &chan_state->ul_mask;</span><br><span> uint8_t rsl_cmode = chan_state->rsl_cmode;</span><br><span> uint8_t tch_mode = chan_state->tch_mode;</span><br><span> uint8_t tch_data[128]; /* just to be safe */</span><br><span> struct l1sched_meas_set meas_set;</span><br><span style="color: hsl(120, 100%, 40%);">+ uint32_t first_fn;</span><br><span> int rc, amr = 0;</span><br><span> int n_errors, n_bits_total;</span><br><span> bool bfi_flag = false;</span><br><span>@@ -1418,7 +1446,6 @@</span><br><span> if (bid == 0) {</span><br><span> memset(*bursts_p + 464, 0, 232);</span><br><span> *mask = 0x0;</span><br><span style="color: hsl(0, 100%, 40%);">- *first_fn = bi->fn;</span><br><span> }</span><br><span> </span><br><span> /* store the measurements */</span><br><span>@@ -1496,6 +1523,9 @@</span><br><span> memcpy(*bursts_p, *bursts_p + 232, 232);</span><br><span> memcpy(*bursts_p + 232, *bursts_p + 464, 232);</span><br><span> </span><br><span style="color: hsl(120, 100%, 40%);">+ /* Get frame number of the first burst (either 1/4 or 1/6) */</span><br><span style="color: hsl(120, 100%, 40%);">+ first_fn = l1sched_meas_get_fn(chan_state, rc == GSM_MACBLOCK_LEN ? 6 : 4);</span><br><span style="color: hsl(120, 100%, 40%);">+</span><br><span> /* Average measurements of either the last 4 bursts (speech),</span><br><span> * or the last 6 bursts (in case if FACCH/H was received). */</span><br><span> l1sched_meas_average(chan_state, &meas_set, rc == GSM_MACBLOCK_LEN ? 6 : 4);</span><br><span>@@ -1503,8 +1533,7 @@</span><br><span> l1sched_meas_squeeze(chan_state, 2);</span><br><span> </span><br><span> /* Send uplink measurement information to L2 */</span><br><span style="color: hsl(0, 100%, 40%);">- l1if_process_meas_res(l1t->trx, bi->tn,</span><br><span style="color: hsl(0, 100%, 40%);">- *first_fn /* FIXME: this is wrong */,</span><br><span style="color: hsl(120, 100%, 40%);">+ l1if_process_meas_res(l1t->trx, bi->tn, first_fn,</span><br><span> trx_chan_desc[chan].chan_nr | bi->tn,</span><br><span> n_errors, n_bits_total,</span><br><span> meas_set.rssi, meas_set.toa256);</span><br><span>@@ -1532,9 +1561,7 @@</span><br><span> if (rc == GSM_MACBLOCK_LEN) {</span><br><span> chan_state->ul_ongoing_facch = 1;</span><br><span> uint16_t ber10k = compute_ber10k(n_bits_total, n_errors);</span><br><span style="color: hsl(0, 100%, 40%);">- _sched_compose_ph_data_ind(l1t, bi->tn,</span><br><span style="color: hsl(0, 100%, 40%);">- /* FIXME: what the hell is this?!? */</span><br><span style="color: hsl(0, 100%, 40%);">- (bi->fn + GSM_HYPERFRAME - 10 - ((bi->fn % 26) >= 19)) % GSM_HYPERFRAME, chan,</span><br><span style="color: hsl(120, 100%, 40%);">+ _sched_compose_ph_data_ind(l1t, bi->tn, first_fn, chan,</span><br><span> tch_data + amr, GSM_MACBLOCK_LEN,</span><br><span> meas_set.rssi, meas_set.toa256,</span><br><span> meas_set.ci_cb, ber10k,</span><br><span>@@ -1589,15 +1616,7 @@</span><br><span> </span><br><span> compose_l1sap:</span><br><span> /* TCH or BFI */</span><br><span style="color: hsl(0, 100%, 40%);">- /* Note on FN 19 or 20: If we received the last burst of a frame,</span><br><span style="color: hsl(0, 100%, 40%);">- * it actually starts at FN 8 or 9. A burst starting there, overlaps</span><br><span style="color: hsl(0, 100%, 40%);">- * with the slot 12, so an extra FN must be subtracted to get correct</span><br><span style="color: hsl(0, 100%, 40%);">- * start of frame.</span><br><span style="color: hsl(0, 100%, 40%);">- */</span><br><span style="color: hsl(0, 100%, 40%);">- return _sched_compose_tch_ind(l1t, bi->tn,</span><br><span style="color: hsl(0, 100%, 40%);">- /* FIXME: what the hell is this?!? */</span><br><span style="color: hsl(0, 100%, 40%);">- (bi->fn + GSM_HYPERFRAME - 10 - ((bi->fn%26)==19) - ((bi->fn%26)==20)) % GSM_HYPERFRAME,</span><br><span style="color: hsl(0, 100%, 40%);">- chan, tch_data, rc);</span><br><span style="color: hsl(120, 100%, 40%);">+ return _sched_compose_tch_ind(l1t, bi->tn, first_fn, chan, tch_data, rc);</span><br><span> }</span><br><span> </span><br><span> /* schedule all frames of all TRX for given FN */</span><br><span></span><br></pre><p>To view, visit <a href="https://gerrit.osmocom.org/c/osmo-bts/+/15812">change 15812</a>. 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<div style="display:none"> Gerrit-Project: osmo-bts </div>
<div style="display:none"> Gerrit-Branch: master </div>
<div style="display:none"> Gerrit-Change-Id: Iae9a0135595b0c56752723669a4ed2fc91f25785 </div>
<div style="display:none"> Gerrit-Change-Number: 15812 </div>
<div style="display:none"> Gerrit-PatchSet: 1 </div>
<div style="display:none"> Gerrit-Owner: fixeria <axilirator@gmail.com> </div>
<div style="display:none"> Gerrit-MessageType: newchange </div>