Reconnection of wireless calls to mobile units in border cells
View Patent ↗Reconnection of a mobile unit to a call session controlled by a first MSC is supported responsive to a network-initiated or mobile-originated reconnect attempt even in instances where the mobile unit has roamed to a border cell controlled by a second MSC. In a network-initiated reconnect attempt, the first MSC sends a suspended call page request to a second MSC. The second MSC pages the mobile unit, sets up a bearer channel to the mobile unit, and sends to the first MSC a suspended call page response including indicia of the bearer channel set up by the second MSC. The first MSC establishes a bearer channel to the second MSC thereby reconnecting the mobile unit to the call session. In a mobile-originated reconnect attempt, the mobile unit sends a mobile-originated reconnect message to the second MSC. If the second MSC does not find session information associated with the call, it sends a suspended call handoff request to the first MSC causing the first MSC to query a database to find indicia of the call session, establish a bearer channel to the second MSC and send to the second MSC a suspended call handoff acknowledgement including information associated with the call session. The second MSC establishes a bearer channel to the mobile unit thereby reconnecting the mobile unit to the call session.
1. A method of performing a mobile-originated reconnect of a mobile unit having experienced a service interruption during a call session controlled by a first mobile switching center (MSC), yielding a suspended call session, the method comprising the first MSC:
receiving, from a second MSC, a suspended call handoff request;
querying a database to find indicia of the suspended call session;
sending to the second MSC a suspended call handoff acknowledgement including information associated with the suspended call session; and
establishing a bearer channel to the second MSC, so as to facilitate reconnecting the mobile unit to the suspended call session.
2. The method of claim 1 , further comprising the second MSC:
receiving the suspended call handoff acknowledgement; and
establishing a bearer channel to the mobile unit thereby reconnecting the mobile unit to the call session.
3. The method of claim 1 , wherein the step of the first MSC receiving a suspended call handoff request is preceded by the second MSC:
receiving a mobile-originated reconnect (MORC) message issued by the mobile unit; and
querying a database for indicia of the call session; and
sending to the first MSC the suspended call handoff request responsive to not finding indicia of the call session.
4. In a wireless communication system wherein a call is established between a mobile unit and one or more participating units, the mobile unit being served by a first mobile switching center (MSC) when a service interruption is detected to the mobile unit, yielding a suspended call session, a method comprising a second MSC:
maintaining a database of session information associated with a plurality of suspended calls;
receiving a mobile-originated reconnect (MORC) message issued by the mobile unit, the MORC message including a mobile unit identifier associated with the mobile unit and indicating presence of the mobile unit within a location served by the second MSC;
querying the database for session information corresponding to the mobile unit identifier; and
if session information corresponding to the mobile unit identifier is not found, sending from the second MSC to the first MSC, a suspended call handoff request indicating presence of the mobile unit within the location served by the second MSC.
5. The method of claim 4 , further comprising the first MSC, responsive to receiving the suspended call handoff request from the second MSC:
retrieving session information associated with the interrupted call of the mobile unit; and
sending to the second MSC, a suspended call handoff acknowledgement including at least a portion of the session information.
6. The method of claim 5 , further comprising:
starting a wait timer defining a waiting period to allow for reconnect of the mobile unit to the call; and
ending the call if the mobile unit is not reconnected to the call before expiration of the waiting period.
7. In a wireless communication system wherein a call is established between a mobile unit and one or more participating units, the mobile unit being served by a first mobile switching center (MSC) when a service interruption is detected to the mobile unit, yielding a suspended call session, a method comprising a second MSC:
maintaining a database of session information associated with a plurality of suspended calls;
receiving a mobile-originated reconnect (MORC) message issued by the mobile unit, the MORC message indicating presence of the mobile unit within a location served by the second MSC and including a session identifier associated with the suspended call session;
querying the database for session information corresponding to the session identifier; and
if session information corresponding to the session identifier is not found, sending from the second MSC to the first MSC, a suspended call handoff request indicating presence of the mobile unit within the location served by the second MSC.
8. The method of claim 7 , further comprising the first MSC, responsive to receiving the suspended call handoff request from the second MSC:
retrieving session information associated with the interrupted call of the mobile unit; and
sending to the second MSC, a suspended call handoff acknowledgement including at least a portion of the session information.
9. The method of claim 8 , further comprising:
starting a wait timer defining a waiting period to allow for reconnect of the mobile unit to the call; and
ending the call if the mobile unit is not reconnected to the call before expiration of the waiting period.