tbf: Set MS timeout

This commit sets the MS timeout when the MS object is created. The
value is taken from the ms_idle_sec field in gprs_rlcmac_bts which
can be changed by the VTY commands shown below.

The following VTY commands are added to the config-pcu node:

- ms-idle-time <1-7200>      Set the timeout in seconds
- no ms-idle-time            Disable the timeout

Another timer that is related is T3314 (Ready Timer, default 44s, GSM
24.008, 11.2.2) which requires the SGSN to use paging after its
expiry. Longer timeouts can help if adaptive coding scheme selection
is used (not yet implemented). On the other hand, measurement values
(TA, signal quality) can get invalid after some time, especially with
a moving MS. So a value slightly above T3314 is probably a good value
to start with.

Sponsored-by: On-Waves ehf

3 files changed, 31 insertions, 1 deletions

diff --git a/src/bts.h b/src/bts.h
index 28ecfc1c..af66dfc8 100644
--- a/src/bts.h
+++ b/src/bts.h
@@ -141,6 +141,7 @@ struct gprs_rlcmac_bts {
 	uint8_t force_two_phase;
 	uint8_t alpha, gamma;
 	uint32_t dl_tbf_idle_msec; /* hold time for idle DL TBFs */
+	uint32_t ms_idle_sec;
 
 	/* TBF handling, make private or move into TBFController */
 	/* list of uplink TBFs */
diff --git a/src/pcu_vty.c b/src/pcu_vty.c
index a08ec368..9490664f 100644
--- a/src/pcu_vty.c
+++ b/src/pcu_vty.c
@@ -483,6 +483,31 @@ DEFUN(cfg_pcu_no_dl_tbf_idle_time,
 	return CMD_SUCCESS;
 }
 
+#define MS_IDLE_TIME_STR "keep an idle MS object alive for the time given\n"
+DEFUN(cfg_pcu_ms_idle_time,
+      cfg_pcu_ms_idle_time_cmd,
+      "ms-idle-time <1-7200>",
+      MS_IDLE_TIME_STR "idle time in sec")
+{
+	struct gprs_rlcmac_bts *bts = bts_main_data();
+
+	bts->ms_idle_sec = atoi(argv[0]);
+
+	return CMD_SUCCESS;
+}
+
+DEFUN(cfg_pcu_no_ms_idle_time,
+      cfg_pcu_no_ms_idle_time_cmd,
+      "no ms-idle-time",
+      NO_STR MS_IDLE_TIME_STR)
+{
+	struct gprs_rlcmac_bts *bts = bts_main_data();
+
+	bts->ms_idle_sec = 0;
+
+	return CMD_SUCCESS;
+}
+
 DEFUN(show_tbf,
       show_tbf_cmd,
       "show tbf all",
@@ -555,6 +580,8 @@ int pcu_vty_init(const struct log_info *cat)
 	install_element(PCU_NODE, &cfg_pcu_gamma_cmd);
 	install_element(PCU_NODE, &cfg_pcu_dl_tbf_idle_time_cmd);
 	install_element(PCU_NODE, &cfg_pcu_no_dl_tbf_idle_time_cmd);
+	install_element(PCU_NODE, &cfg_pcu_ms_idle_time_cmd);
+	install_element(PCU_NODE, &cfg_pcu_no_ms_idle_time_cmd);
 
 	install_element_ve(&show_bts_stats_cmd);
 	install_element_ve(&show_tbf_cmd);
diff --git a/src/tbf.cpp b/src/tbf.cpp
index 53f1ae13..8501b161 100644
--- a/src/tbf.cpp
+++ b/src/tbf.cpp
@@ -126,8 +126,10 @@ void gprs_rlcmac_tbf::update_ms(uint32_t tlli, enum gprs_rlcmac_tbf_direction di
 {
 	if (!ms()) {
 		GprsMs *new_ms = bts->ms_store().get_ms(tlli);
-		if (!new_ms)
+		if (!new_ms) {
 			new_ms = bts->ms_store().create_ms(tlli, dir);
+			new_ms->set_timeout(bts->bts_data()->ms_idle_sec);
+		}
 
 		if (dir == GPRS_RLCMAC_UL_TBF)
 			new_ms->set_ta(m_ta);