System and method for reconnecting a mobile station to an emergency operator

• US 6,990,349 B1
• Filed: 11/01/2001
• Issued: 01/24/2006
• Est. Priority Date: 11/20/1998
• Status: Expired due to Term

• Current Assignee: Apple Inc.
• Original Assignee: Nortel Networks Limited (Nortel Networks Corporation)
• Inventors: Idrissi, Yahya
• Primary Examiner(s): Trinh, Sonny
• Application Number:
  US10/003,485
• Time in Patent Office: 1,545 Days
• Field of Search: 455/404.1, 455/414.1, 455/423, 455/403, 455/421, 455/433, 455/450, 455/521, 455/458, 455/510, 455/517, 455/445
• US Class Current: 455/450
• CPC Class Codes: H04M 3/42195 Arrangements for calling back a calling subscriber when the wanted subscriber ceases to be busy H04M3/48
• CPC Class Codes: H04Q 3/0079 involving restoration of networks, e.g. disaster recovery, self-healing networks
• CPC Class Codes: H04W 4/90 Services for handling of emergency or hazardous situations, e.g. earthquake and tsunami warning systems [ETWS]
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 76/50 for emergency connections

Abstract

A technique for automatically reconnecting a mobile unit to an emergency operator when the connection therebetween is interrupted is described. In a preferred embodiment, when such a call is dropped, a mobile switching center (“MSC”) though which the call is connected detects that the call has been dropped and, after determining that the call is an emergency call, based on the number originally dialed by the mobile unit, automatically reestablishes the connection with the mobile unit, thereby reestablishing the emergency call.

Claims

1. A method of automatically reestablishing a call placed by a mobile unit operating within a radio frequency (“

RF”

) communications network to a called party after said call has been dropped, the method comprising;

detecting that said call has been dropped;

determining whether said call was placed to an emergency number, wherein said call is to be automatically reestablished by said RF communications network if said call was placed to an emergency number; and

responsive to a determination that said call is to be automatically reestablished by said RF communications network, a mobile switching center (“

MSC”

) of said RF communications network reestablishing said call between said mobile unit and said called party, wherein said reestablishing comprises said MSC reconnecting to said mobile unit as if the dropped call was suspended by a call waiting mechanism.

2. The method of claim 1 wherein said determining comprises determining whether said called party is an emergency operator.

3. A mobile switching center (“

MSC”

) for automatically reestablishing a call placed by a mobile unit operating within a radio frequency (“

RF”

) communications network to a called party connected to a public switched telephone network (“

PSTN”

) after said call has been dropped, the MSC comprising software instructions executable by said MSC for;

detecting that said call has been dropped;

determining whether said call was placed to an emergency operator, wherein said call is to be automatically reestablished by said RF communications network if said call was placed to an emergency operator;

maintaining a connection between the emergency operator and the MSC after said call is dropped; and

responsive to a determination that said call is to be automatically reestablished by said RF communications network, reestablishing a connection with said mobile unit and connecting the reestablished connection with the maintained connection between the emergency operator and the MSC, thereby to reestablish said call between said mobile unit and said emergency operator, wherein said software instructions for reestablishing comprise software instructions for causing said MSC to dial back said mobile unit using a call waiting mechanism.

4. The MSC of claim 3 wherein said software instructions for determining comprise software instructions for determining whether said call was placed to an emergency number.

5. Apparatus for automatically reestablishing a call placed by a mobile unit operating within a radio frequency (“

RF”

) communications network to a called party after said call has been dropped, the apparatus comprising;

means for detecting that said call has been dropped;

means for determining whether said call was placed to an emergency number, wherein said call is to be automatically reestablished by said RF communications network if said call was placed to an emergency number; and

means responsive to a determination that said call is to be automatically reestablished by said RF communications network for reestablishing said call between said mobile unit and said called party, wherein said means for reestablishing comprises means for reconnecting to said mobile unit using a call waiting mechanism.

6. The apparatus of claim 5 wherein said means for determining comprises means for determining whether said called party is an emergency operator.

7. The apparatus of claim 5 wherein said called party is connected to said RF communications network via a public switched telephone network (“

PSTN”

).