support for Ericsson RBS E1 CCU
Ericsson RBS series BTSs do not have a built in PCU. Rather than having
the PCU on board the PCU is co-located to the BSC in those cases. Just
like the MGW the PCU would connect to the CCU (Channel Coding Unit) via
E1 line. The PCU is connected via an unix domain socket (pcu_sock) to
the BSC to receive RACH requests and to control Paging and TBF assignment.
This patch adds all the required functionality to run an Ercisson RBS in
GPRS/EGPRS mode. It supports 16k I.460 E1 subslots and full 64k E1
timeslots (recommended)
Change-Id: I5c0a76667339ca984a12cbd2052f5d9e5b0f9c4d
Related: OS#5198
diff --git a/src/pcu_l1_if.cpp b/src/pcu_l1_if.cpp
index 14cc778..6ec806b 100644
--- a/src/pcu_l1_if.cpp
+++ b/src/pcu_l1_if.cpp
@@ -61,6 +61,23 @@
#define PAGING_GROUP_LEN 3
+struct e1_ccu_conn_pars {
+ struct llist_head entry;
+
+ /* Related air interface */
+ uint8_t bts_nr;
+ uint8_t trx_nr;
+ uint8_t ts_nr;
+
+ /* E1 communication parameter */
+ struct e1_conn_pars e1_conn_pars;
+};
+
+/* List storage to collect E1 connection information that we receive through the pcu_sock. The collected data serves as
+ * a lookup table so that we can lookup the E1 connection information for each PDCH (trx number and timeslot number)
+ * when it is needed. */
+static LLIST_HEAD(e1_ccu_table);
+
/* returns [0,999] on success, > 999 on error */
uint16_t imsi2paging_group(const char* imsi)
{
@@ -962,6 +979,73 @@
return rc;
}
+/* Query E1 CCU connection parameters by TS and TRX number */
+int pcu_l1if_get_e1_ccu_conn_pars(struct e1_conn_pars **e1_conn_pars, uint8_t bts_nr, uint8_t trx_nr, uint8_t ts_nr)
+{
+ struct e1_ccu_conn_pars *e1_ccu_conn_pars;
+
+ llist_for_each_entry(e1_ccu_conn_pars, &e1_ccu_table, entry) {
+ if (e1_ccu_conn_pars->bts_nr == bts_nr && e1_ccu_conn_pars->trx_nr == trx_nr
+ && e1_ccu_conn_pars->ts_nr == ts_nr) {
+ *e1_conn_pars = &e1_ccu_conn_pars->e1_conn_pars;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+/* Allocate a new connection parameter struct and store connection parameters */
+static void new_e1_ccu_conn_pars(const struct gsm_pcu_if_e1_ccu_ind *e1_ccu_ind, uint8_t bts_nr)
+{
+ struct e1_ccu_conn_pars *e1_ccu_conn_pars;
+
+ e1_ccu_conn_pars = talloc_zero(tall_pcu_ctx, struct e1_ccu_conn_pars);
+ OSMO_ASSERT(e1_ccu_conn_pars);
+ e1_ccu_conn_pars->bts_nr = bts_nr;
+ e1_ccu_conn_pars->trx_nr = e1_ccu_ind->trx_nr;
+ e1_ccu_conn_pars->ts_nr = e1_ccu_ind->ts_nr;
+ e1_ccu_conn_pars->e1_conn_pars.e1_nr = e1_ccu_ind->e1_nr;
+ e1_ccu_conn_pars->e1_conn_pars.e1_ts = e1_ccu_ind->e1_ts;
+ e1_ccu_conn_pars->e1_conn_pars.e1_ts_ss = e1_ccu_ind->e1_ts_ss;
+ llist_add(&e1_ccu_conn_pars->entry, &e1_ccu_table);
+}
+
+static int pcu_rx_e1_ccu_ind(struct gprs_rlcmac_bts *bts, const struct gsm_pcu_if_e1_ccu_ind *e1_ccu_ind)
+{
+ struct e1_conn_pars *e1_conn_pars;
+ uint8_t rate;
+ uint8_t subslot_nr;
+ int rc;
+
+ /* only used with log statement below, no technical relevance otherwise. */
+ if (e1_ccu_ind->e1_ts_ss > 3) {
+ rate = 64;
+ subslot_nr = 0;
+ } else {
+ rate = 16;
+ subslot_nr = e1_ccu_ind->e1_ts_ss;
+ }
+
+ LOGP(DL1IF, LOGL_NOTICE,
+ "(ts=%u,trx=%u) new E1 CCU communication parameters for CCU (E1-line:%u, E1-TS:%u, E1-SS:%u, rate:%ukbps)\n",
+ e1_ccu_ind->ts_nr, e1_ccu_ind->trx_nr, e1_ccu_ind->e1_nr, e1_ccu_ind->e1_ts,
+ subslot_nr, rate);
+
+ /* Search for an existing entry, when found, update it. */
+ rc = pcu_l1if_get_e1_ccu_conn_pars(&e1_conn_pars, bts->nr, e1_ccu_ind->trx_nr, e1_ccu_ind->ts_nr);
+ if (rc == 0) {
+ e1_conn_pars->e1_nr = e1_ccu_ind->e1_nr;
+ e1_conn_pars->e1_ts = e1_ccu_ind->e1_ts;
+ e1_conn_pars->e1_ts_ss = e1_ccu_ind->e1_ts_ss;
+ return 0;
+ }
+
+ /* Create new connection parameter entry */
+ new_e1_ccu_conn_pars(e1_ccu_ind, bts->nr);
+ return 0;
+}
+
static int pcu_rx_time_ind(struct gprs_rlcmac_bts *bts, struct gsm_pcu_if_time_ind *time_ind)
{
uint8_t fn13 = time_ind->fn % 13;
@@ -1194,6 +1278,10 @@
CHECK_IF_MSG_SIZE(pcu_prim_length, pcu_prim->u.info_ind);
rc = pcu_rx_info_ind(bts, &pcu_prim->u.info_ind);
break;
+ case PCU_IF_MSG_E1_CCU_IND:
+ CHECK_IF_MSG_SIZE(pcu_prim_length, pcu_prim->u.e1_ccu_ind);
+ rc = pcu_rx_e1_ccu_ind(bts, &pcu_prim->u.e1_ccu_ind);
+ break;
case PCU_IF_MSG_TIME_IND:
CHECK_IF_MSG_SIZE(pcu_prim_length, pcu_prim->u.time_ind);
rc = pcu_rx_time_ind(bts, &pcu_prim->u.time_ind);