Emergency call back for roaming mobile subscribers
First Claim
1. A method for establishing a call connection between a mobile station (MS) having an identification number and a telecommunications terminal (TT), said method comprising the steps of:
- receiving a first signal at a first mobile switching center (MSC), said first signal being transmitted by said MS and requesting a call connection with said TT;
assigning a first wireline directory number associated with said first MSC to said mobile station;
setting a particular timer to a preselected value and associating said particular timer with said assigned first wireline directory number;
storing first data correlating said particular timer and its associated first wireline directory number with said identification number;
establishing a call connection between said MS and said TT using said first wireline directory number as a Calling Party Number (Cgpn);
determining that said first MSC needs to deregister said MS as a result of said MS roaming into another geographic area served by a second MSC;
determining whether said preselected value set for said particular timer has expired; and
maintaining said first data correlating said first wireline directory number with said identification number representing said mobile station in response to a determination that said timer has not expired.
1 Assignment
0 Petitions
Accused Products
Abstract
Whenever a mobile station originates an emergency call connection towards a Public Safety Answering Point (PSAP), a first mobile switching center (MSC) serving the mobile station assigns a first temporary local directory number (TLDN) to the call connection. The assigned TLDN is also utilized as the calling party number (CgPn). Subsequently, whenever the mobile station roams out of the first MSC coverage area, the data correlating the first TLDN with the Mobile Station Integrated Service Digital Network (MSISDN) number associated with the roaming mobile station are maintained by the first MSC if a timer assigned to the first TLDN has not expired. Alternatively, the first MSC may also communicate with the second MSC newly serving the mobile station to request and receive a second TLDN associated with the second MSC. Whenever the PSAP requests a call back connection in response to a disconnection of the original emergency call connection, the first MSC forwards the received call setup signal using the stored MSISDN or second TLDN as the new Called Party Number (CdPn).
168 Citations
28 Claims
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1. A method for establishing a call connection between a mobile station (MS) having an identification number and a telecommunications terminal (TT), said method comprising the steps of:
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receiving a first signal at a first mobile switching center (MSC), said first signal being transmitted by said MS and requesting a call connection with said TT; assigning a first wireline directory number associated with said first MSC to said mobile station; setting a particular timer to a preselected value and associating said particular timer with said assigned first wireline directory number; storing first data correlating said particular timer and its associated first wireline directory number with said identification number; establishing a call connection between said MS and said TT using said first wireline directory number as a Calling Party Number (Cgpn); determining that said first MSC needs to deregister said MS as a result of said MS roaming into another geographic area served by a second MSC; determining whether said preselected value set for said particular timer has expired; and maintaining said first data correlating said first wireline directory number with said identification number representing said mobile station in response to a determination that said timer has not expired. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A system for establishing a call connection between a mobile station (MS) having an identification number and a telecommunications terminal (TT), said system comprising:
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means for receiving a first signal at a first mobile switching center (MSC), said first signal being transmitted by said MS and requesting a call connection with said TT; means for assigning a first wireline directory number associated with said first MSC to said mobile station; means for setting a particular timer to a preselected value and associating said particular timer with said assigned first wireline directory number; means for storing first data correlating said particular timer and its associated first wireline directory number with said identification number; means for establishing a call connection between said MS and said TT using said first wireline directory number as a Calling Party Number (CgPn); means for determining that said first MSC needs to deregister said MS as a result of said MS roaming into another geographic area served by a second MSC; means for determining whether said preselected value set for said particular timer has expired; and means for maintaining said first data correlating said first wireline directory number with said identification number representing said mobile station in response to a determination that said timer has not expired. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method for establishing a call back connection between a mobile station (MS) and a telecommunications terminal (TT), wherein said MS initially originated a call connection with said TT using a first wireline directory number associated with a first mobile switching center (MSC) serving said MS as a Calling Party Number (CgPn), said first wireline directory number has been assigned to a timer for a certain period of expiration time by said first MSC, and wherein said first MSC further stores first data correlating said first wireline directory number and said timer with an identification number representing said MS, said method comprising the steps of:
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in response to a determination that said first MSC needs to deregister said MS as a result of said MS traveling into another geographic area served by a second MSC; determining whether said timer correlated with said first wireline directory number associated with said MS has expired; and maintaining said first data correlating said first wireline directory number with said identification number representing said MS in response to a determination that said timer has not expired; and receiving a request by said first MSC, in response to a disconnection of said call connection, to establish a call back connection from said TT to said MS, said request using said first wireline directory number as a Called Party Number (CdPn); and forwarding said request by said first MSC using said identification number associated with said received first wireline directory number as said CdPn. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28)
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Specification