Method and apparatus for routing emergency services calls in an intelligent network
First Claim
1. A method of handling emergency services calls from calling parties in an intelligent network having a plurality of emergency services operator stations (PSAPs), at least one Service Control Point (SCP) equipped with software for providing service features and having access to databases including routing data for said plurality of emergency services operator stations and a plurality of Service Switching Points (SSP) equipped with call processing software having point-in-call triggers for interrupting processing of a call and exchanging signalling messages with the Service Control Point (SCP) to obtain instructions for further processing of the call, the Service Switching Points and Service Control Point (SCP) being interconnected by a data communication signalling system, the Service Switching Points being interconnected by trunks for calls therebetween, and the plurality of emergency services operator stations being each connected by trunks or lines to at least one of said Service Switching Points, the said routing data comprising routing numbers each identifying a network location for a respective one of said plurality of emergency services operator stations, the routing data associating with each calling party a primary emergency services operator station and at least one alternative emergency services operator station, the method comprising the steps of:
- (i) at a particular Service Switching Point, presetting a point-in-call trigger to operate at a predetermined point in a call for emergency services, (ii) subsequently, when said particular Service Switching Point is processing an emergency services call, interrupting processing of the call and transmitting to the Service Control Point (SCP) a query signalling message requesting routing information, (iii) at the Service Control Point (SCP), upon receipt of the query signalling message, accessing said routing data in dependence upon parameters in the query signalling messages, and selecting a routing number corresponding to said alternative emergency services operator station for that calling party, forming a response signalling message including the selected routing number and returning such response signalling message to said particular Service Switching Point, (iv) at said particular Service Switching Point, upon receipt of said response signalling message, detecting the selected routing number, and routing the call to the network location corresponding to the selected routing number for completion to said alternative emergency services operator station.
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Accused Products
Abstract
Emergency services calls may be alternate-routed in an intelligent network having at least one Service Control Point (SCP) with access to a routing table, a plurality of Service Switching Points (SSP) equipped with point-in-call triggers and one or more emergency services stations (PSAP). The routing table lists a routing number for each of the emergency services stations. The alternate routing involves presetting a point-in-call trigger at a Service Switching Point to operate at a predetermined point in a call for emergency services. During subsequent processing of an emergency services call, the trigger interrupts processing of the call and and prompts transmission to the SCP of a query signalling message requesting routing information. Upon receipt, the SCP accesses the routing table in dependence upon parameters in the query signalling message and obtains a routing number for a selected emergency services operator station, forms a response signalling message including the routing number and returns such response signalling message to the SSP. Upon receipt of the response signalling message, the SSP detects the routing number, and routes the call to the emergency services operator station.
There is also provided a method of translating signalling message parameters from a mobile protocol to an intelligent network protocol, and vice versa, to enable emergency services calls from mobile users to be routed to one or more PSAPs in the intelligent network.
111 Citations
10 Claims
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1. A method of handling emergency services calls from calling parties in an intelligent network having a plurality of emergency services operator stations (PSAPs), at least one Service Control Point (SCP) equipped with software for providing service features and having access to databases including routing data for said plurality of emergency services operator stations and a plurality of Service Switching Points (SSP) equipped with call processing software having point-in-call triggers for interrupting processing of a call and exchanging signalling messages with the Service Control Point (SCP) to obtain instructions for further processing of the call, the Service Switching Points and Service Control Point (SCP) being interconnected by a data communication signalling system, the Service Switching Points being interconnected by trunks for calls therebetween, and the plurality of emergency services operator stations being each connected by trunks or lines to at least one of said Service Switching Points, the said routing data comprising routing numbers each identifying a network location for a respective one of said plurality of emergency services operator stations, the routing data associating with each calling party a primary emergency services operator station and at least one alternative emergency services operator station, the method comprising the steps of:
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(i) at a particular Service Switching Point, presetting a point-in-call trigger to operate at a predetermined point in a call for emergency services, (ii) subsequently, when said particular Service Switching Point is processing an emergency services call, interrupting processing of the call and transmitting to the Service Control Point (SCP) a query signalling message requesting routing information, (iii) at the Service Control Point (SCP), upon receipt of the query signalling message, accessing said routing data in dependence upon parameters in the query signalling messages, and selecting a routing number corresponding to said alternative emergency services operator station for that calling party, forming a response signalling message including the selected routing number and returning such response signalling message to said particular Service Switching Point, (iv) at said particular Service Switching Point, upon receipt of said response signalling message, detecting the selected routing number, and routing the call to the network location corresponding to the selected routing number for completion to said alternative emergency services operator station. - View Dependent Claims (2, 3, 7)
at the MSC;
upon receipt of an emergency services call from a mobile station, forming a TCAP query message addressed to the destination point code of the HLR and routing the message to the SMP, the message including a mobile identification number (MIN) for the mobile station, a cell site number, and a mobile network address for the MSC, and the dialled digits, at the SMP;
detecting the dialled digits identifying the call as an emergency services call;
translating the parameters in the message as received into corresponding AIN/IN parameters according to the intelligent network protocol being used by the SCP, forming an AIN/IN TCAP message including the translated parameters, the network address of the MSC and the cell site number being combined in an Original Calling Party number, overriding the destination point code of the HLR and routing the message to the SCP, at the SCP, accessing the mobile routing table using the Original Calling Party number from the received query and obtaining a routing number for a PSAP, including the PSAP routing number in a TCAP response message and sending this response message to the SMP, at the SMP, translating the intelligent network parameters of the TCAP response message into corresponding mobile network parameters, and routing the response message to the MSC, at the MSC, extracting the PSAP routing number from the TCAP message and routing the emergency services call thereto via one or more of the SSPs.
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4. Apparatus for handling emergency services calls from calling parties in a telecommunications network employing a data communication signalling system, comprising a plurality of emergency services operator stations, at least one Service Control Point (SCP) equipped with software for providing service features and having access to databases including routing data for said plurality of emergency services operator stations, and a plurality of Service Switching Points equipped with call processing software having point-in-call triggers for interrupting processing of a call and exchanging signalling messages with the Service Control Point (SCP) to obtain instructions for further processing of the call, the Service Switching Points and Service Control Point (SCP) being interconnected by said data communication signalling system, the Service Switching Points being interconnected by trunks for calls therebetween, and each of the plurality of emergency services operator stations being connected by trunks to at least one of said plurality of Service Switching Points, the routing data comprising routing numbers each identifying a network location for a respective one of said plurality of emergency services operator stations, the routing data associating with each calling party a primary emergency services operator station and at least one alternative emergency services operator station;
- each Service Switching Point comprising
(i) means for presetting a point-in-call trigger to operate at a predetermined trigger detection point in the processing of an emergency services call from a calling party and (ii) means operative during processing of a subsequent emergency services call to interrupt processing of the call in response to said trigger and transmit to the Service Control Point (SCP) a signalling message requesting routing information, each Service Control Point (SCP) comprising (iii) means operative, upon receipt of said signalling message, for accessing said routing data in dependence upon parameters in said signalling message and selecting a routing number corresponding to said alternative emergency services operator station for that calling party, forming a response signalling message including the selected routing number and returning such response signalling message to the requesting Service Switching Point, each Service Switching Point further comprising (iv) means operative, upon receipt of said response signalling message, for routing the call to the network location corresponding to the selected routing number for completion to said alternative emergency services station. - View Dependent Claims (5, 6)
- each Service Switching Point comprising
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8. Apparatus for handling emergency services calls from calling parties in a telecommunications network employing an SS7 signaling system, comprising
a plurality of emergency services operator stations, at least one Service Control Point (SCP) equipped with software for providing service features and having access to databases including routing data for said plurality of emergency services operator stations, and a plurality of Service Switching Points equipped with call processing software having point-in-call triggers for interrupting processing of a call and exchanging signaling messages with the Service Control Point (SCP) to obtain instructions for further processing of the call, the Service Switching Points and Service Control Point (SCP) being interconnected by said SS7 signaling system, the Service Switching Points being interconnected by trunks for calls therebetween, and each of the plurality of emergency services operator stations being connected by trunks to at least one of said plurality of Service Switching Points, the routing data comprising routing numbers each identifying a network location for a respective one of said plurality of emergency services operator stations, the routing data associating with each calling party a primary emergency services operator station and at least one alternative emergency services operator station; -
each Service Switching Point comprising (i) means for presetting a point-in-call trigger to operate at a predetermined trigger detection point in the processing of an emergency services call from a calling party, and (ii) means operative during processing of a subsequent emergency services call to interrupt processing of the call in response to said trigger and transmit to the Service Control Point (SCP) a signaling message requesting routing information, each Service Control Point (SCP) comprising (iii) means operative, upon receipt of said signaling message, for accessing said routing data in dependence upon parameters in said signaling message and selecting a routing number corresponding to said alternative emergency services operator station for that calling party, forming a response signaling message including the selected routing number and returning such response signaling message to the requesting Service Switching Point, each Service Switching Point further comprising (iv) means operative, upon receipt of said response signaling message, for routing the call to the network location corresponding to the selected routing number for completion to said alternative emergency services station, the apparatus further comprising Signal Mediation Point apparatus comprising SS7 software for processing TCAP messages and conversion software for translating parameters of such TCAP messages formulated according to one mobile protocol into parameters according to a different intelligent network protocol, and vice versa, the SMP having signaling links for connection to a Mobile Switching Centre, a Service Control Point SCP and a Home Location Register HLR, the conversion software being operative, upon receipt of a query from the MSC containing a destination point code for the HLR and dialed digits of an emergency services call to detect said digits, translate the parameters into corresponding intelligent network parameters, override the destination point code of the HLR and route the message to the SCP, and on receipt of a response from the SCP, translate the parameters into corresponding mobile network parameters, and route the response message to the MSC. - View Dependent Claims (9)
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10. In a telecommunications network comprising a Service Point (SP), a plurality of Service Switching Points (SSP), one or more Public Service Access Points (PSAP) and a Signal Mediation point (SMP), and a mobile network portion comprising a Mobile Services Switching Centre (MSC) for routing calls from mobile users in cell sites associated with such MSC and a Home Location Register (HLR), the MSC and SSPs being interconnected by trunks for routing calls therebetween, the MSC and SSPs being connected to the SMP by data communication signalling links, the SMP being connected to the SCP and the HLR by respective data communication links, the SCP having access to additional routing data including entries correlating routing numbers of PSAPs with cell site identifiers, the SMP having basic SCP software for handling mobile or wireline TCAP messages and additional conversion software and tables for translating TCAP message parameters according to mobile protocols to TCAP message parameters using intelligent network protocols, and vice versa, the method further comprising the steps of:
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at the MSC;
upon receipt of an emergency services call from a mobile station, forming a TCAP query message addressed to the destination point code of the HLR and routing the message to the SMP, the message including a mobile identification number (MIN) for the mobile station, a cell site number, and a mobile network address for the MSC, and the dialled digits, at the SMP;
detecting the dialled digits identifying the call as an emergency services call;
translating the parameters in the message as received into corresponding AIN/IN parameters according to the intelligent network protocol being used by the SCP, forming an AIN/IN TCAP message including the translated parameters, the network address of the MSC and the cell site number being combined in an Original Calling Party number, overriding the destination point code of the HLR and routing the message to the SCP, at the SCP, accessing the mobile routing table using the Original Calling Party number from the received query and obtaining a routing number for a PSAP, including the PSAP routing number in a TCAP response message and sending this response message to the SMP, at the SMP, translating the intelligent network parameters of the TCAP response message into corresponding mobile network parameters, and routing the response message to the MSC, at the MSC, extracting the PSAP routing number from the TCAP message and routing the emergency services call thereto via one or more of the SSPs.
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Specification