Proposal for a "channel request" interface...

Reuqests for a subscriber a stored within the gsm_subscriber
datastructure and it will keep track how many channels are
allocated for this user and of which type to decide on policy...

e.g. attempt to submit SMS during a phone call and not doing
paging but a simple (immediate) assignment of the channel...
diff --git a/openbsc/src/paging.c b/openbsc/src/paging.c
index df11da0..8f15e16 100644
--- a/openbsc/src/paging.c
+++ b/openbsc/src/paging.c
@@ -237,13 +237,13 @@
 		bsc_schedule_timer(&bts_entry->work_timer, 1, 0);
 }
 
-void paging_request(struct gsm_bts *_bts, struct gsm_subscriber *subscr,
+void paging_request(struct gsm_network *network, struct gsm_subscriber *subscr,
 		    int type, gsm_cbfn *cbfn, void *data)
 {
 	struct gsm_bts *bts = NULL;
 
 	do {
-		bts = gsm_bts_by_lac(_bts->network, subscr->lac, bts);
+		bts = gsm_bts_by_lac(network, subscr->lac, bts);
 		if (!bts)
 			break;