doc/handover-inter-bsc-out.msc

msc {
	hscale=2;
	ms [label="MS/BTS"], ho[label="BSC Handover FSM"], gscon[label="BSC conn FSM"], msc_[label="MSC"];

	ms note msc_ [label="inter-BSC Handover to another BSS"];

	gscon abox gscon [label="ST_ACTIVE"];

	ms => ho [label="Measurement Report"];
	ho box ho [label="Handover Decision"];
	ho box ho [label="handover_request\n(struct handover_out_req)"];
	ho note gscon [label="To make sure the conn FSM permits a handover, trigger an event:"];
	ho -> gscon [label="GSCON_EV_HANDOVER_START\ndata=handover_out_req"];
	gscon abox gscon [label="ST_HANDOVER"];
	ho <- gscon [label="handover_start\n(handover_out_req)"];
	ho box ho [label="handover_start_inter_bsc_out()"];
	ho => msc_ [label="BSSMAP Handover Required"];
	ho abox ho [label="HO_OUT_ST_WAIT_HO_COMMAND"];
	...;
	...;
	--- [label="On Timeout"];
	ho box ho [label="handover_end(fail)"];
	ho -> gscon [label="GSCON_EV_HANDOVER_END"];
	gscon abox gscon [label="ST_ACTIVE"];
	ms note gscon [label="MS happily continues on the old lchan."];
	--- [label="END: 'On Timeout'"];
	...;
	...;
	ho <= msc_ [label="BSSMAP Handover Command\n HO_OUT_EV_BSSMAP_HO_COMMAND"];
	ms <= ho [label="Forward L3 Info (RR Handover Command from new BSS)"];
	ho abox ho [label="HO_OUT_ST_WAIT_CLEAR"];
	...;
	gscon abox gscon [label="ST_HANDOVER_MO_\nWAIT_CLEAR_CMD\nT8"];
	ms <= gscon [label="RR Handover Command"];
	...;
	ho rbox gscon [label="On Timeout: same as above"];
	...;
	msc_ note msc_ [label="Remote BSS reported Handover Complete to the MSC,
	     this connection has been superseded."];
	gscon <= msc_ [label="BSSMAP Clear Command\n GSCON_EV_A_CLEAR_CMD"];
	gscon abox gscon [label="ST_CLEARING"];
	gscon => msc_ [label="BSSMAP Clear Complete"];
	...;
	gscon <= msc_ [label="DISC IND\n GSCON_EV_A_DISC_IND"];
	ho abox ho [label="terminate\n(child of conn FSM)"];
	gscon abox gscon [label="terminate"];
}