diff options
Diffstat (limited to 'include/osmocom/bsc/handover_fsm.h')
-rw-r--r-- | include/osmocom/bsc/handover_fsm.h | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/include/osmocom/bsc/handover_fsm.h b/include/osmocom/bsc/handover_fsm.h new file mode 100644 index 000000000..4db08901d --- /dev/null +++ b/include/osmocom/bsc/handover_fsm.h @@ -0,0 +1,80 @@ +/* Handover FSM API for intra-BSC and inter-BSC Handover. */ +#pragma once + +#include <osmocom/bsc/debug.h> +#include <osmocom/bsc/handover.h> + +const char *handover_status(struct gsm_subscriber_connection *conn); + +/* This macro automatically includes a final \n, if omitted. */ +#define LOG_HO(conn, level, fmt, args...) do { \ + if (conn->ho.fi) \ + LOGPFSML(conn->ho.fi, level, "%s: " fmt, \ + handover_status(conn), ## args); \ + else \ + LOGP(DHODEC, level, "%s: " fmt, \ + handover_status(conn), ## args); \ + } while(0) + +/* Terminology: + * Intra-Cell: stays within one BTS, this should actually be an Assignment. + * Intra-BSC: stays within one BSC, but moves between BTSes. + * Inter-BSC: moves between BSCs. + * Inter-BSC Out: move away from this BSC to another one. + * Inter-BSC In: move from another BSC to this one. + */ + +enum handover_fsm_state { + HO_ST_NOT_STARTED, + + HO_ST_WAIT_LCHAN_ACTIVE, + HO_ST_WAIT_RR_HO_DETECT, + HO_ST_WAIT_RR_HO_COMPLETE, + HO_ST_WAIT_LCHAN_ESTABLISHED, + HO_ST_WAIT_MGW_ENDPOINT_TO_MSC, + + /* The inter-BSC Outgoing Handover FSM has completely separate states, but since it makes sense for it + * to also live in conn->ho.fi, it should share the same event enum. From there it is merely + * cosmetic to just include the separate fairly trivial states in the same FSM definition. + * An inter-BSC Outgoing FSM is almost unnecessary. The sole reason is to wait whether the MSC + * indeed clears the conn, and if not to log and count a failed handover attempt. */ + HO_OUT_ST_WAIT_HO_COMMAND, + HO_OUT_ST_WAIT_CLEAR, +}; + +enum handover_fsm_event { + HO_EV_LCHAN_ACTIVE, + HO_EV_LCHAN_ESTABLISHED, + HO_EV_LCHAN_ERROR, + HO_EV_RR_HO_DETECT, + HO_EV_RR_HO_COMPLETE, + HO_EV_RR_HO_FAIL, + HO_EV_MSC_MGW_OK, + HO_EV_MSC_MGW_FAIL, + HO_EV_CONN_RELEASING, + + HO_OUT_EV_BSSMAP_HO_COMMAND, +}; + +struct ho_out_rx_bssmap_ho_command { + const uint8_t *l3_info; + const uint8_t l3_info_len; +}; + +/* To be sent along with the HO_EV_RR_HO_DETECT */ +struct handover_rr_detect_data { + struct msgb *msg; + const uint8_t *access_delay; +}; + +void handover_fsm_init(); + +void handover_request(struct handover_out_req *req); +void handover_start(struct handover_out_req *req); +void handover_start_inter_bsc_in(struct gsm_subscriber_connection *conn, + struct msgb *ho_request_msg); +void handover_end(struct gsm_subscriber_connection *conn, enum handover_result result); + +const char *handover_status(struct gsm_subscriber_connection *conn); +bool handover_is_sane(struct gsm_subscriber_connection *conn, struct gsm_lchan *old_lchan, + struct gsm_lchan *new_lchan); |