Method for routing a call

• US 6,009,160 A
• Filed: 10/28/1997
• Issued: 12/28/1999
• Est. Priority Date: 06/30/1995
• Status: Expired due to Fees

• Current Assignee: Nokia Siemens Networks GmbH & Company KG (Nokia Corporation)
• Original Assignee: Siemens Information And Communication Networks, Inc.
• Inventors: Sonnenberg, Edward
• Primary Examiner(s): Wolinsky, Scott
• Application Number:
  US08/963,256
• Time in Patent Office: 791 Days
• Field of Search: 379/221, 379/201, 379/207, 379/219, 379/220, 379/211, 379/210, 379/127, 379/265, 379/112, 379/114, 379/115, 379/229
• US Class Current: 379/220.01
• CPC Class Codes: H04M 3/42297 with number portability
• CPC Class Codes: H04Q 3/005 Personal communication services, e.g. provisions for portability of subscriber numbers

Abstract

A method for enabling a plurality of Local Service Providers within a common Numbering Plan Area (NPA) to serve Subscribers of the plurality of Local Service Providers. The method includes the step of assigning to each Subscriber of a Local Service Provider within the common NPA a unique three digit code, hereinafter referred to as a SPA code. The service provider area (SPA) code is used by the telephone system in the same manner presently used for routing calls made when a calling Subscriber dials the NPA code of the called party. Here, however, the SPA code is not dialed by the calling Subscriber. The dialed directory number, NXX-XXXX, of a called Subscriber subscribed to a different Local Service Provider, is sent to a database. The database maintains a record of the relationships between the directory numbers of Subscribers and the SPA codes of the Subscribers. The database retrieves the SPA code associated with the dialed directory number presently serving the called Subscriber. The call is routed as SPA-NXX-XXXX. Because the ten digit format, SPA-NXX-XXXX, is the same as the present NPA-NXX-XXXX, ten digit format, existing signaling and routing mechanisms may be used to route the call. Thus, each one of the Subscribers of each one of the plurality of Local Service Providers is assigned a common SPA code, each one of the Local Service Providers having a different SPA code.

Claims

1. A method for routing a call to a called Subscriber using a dialed number, such dialed number being either NXX-XXXX or NPA-NXX-XXXX, comprising the step of:

determining from the dialed number, whether;

(1) the dialed number is served by a local switch serving a line from which the call is placed;

or,

(2) the call is an intra-LATA call and the dialed number is not served by the local switch; and

,

(i) if the dialed number is served by the local switch, then using the local switch to route the call to the called Subscriber using the dialed number; and

,

(ii) if the call is an intra-LATA call and the dialed number is not served by the local switch, determining, based on an NPA of the dialed number and the exchange code NXX of the dialed number, whether local number portability is available for the dialed number; and

(A) if local number portability is available for the dialed number, then accessing an External Local Number Portability Database using the dialed number to retrieve routing information comprising a Service Provider Area (SPA) code and routing the call using the dialed number and the routing information, wherein;

SPA code is a three digit designation code assigned to each one of a plurality of Local Service Providers with a common Numbering Plan Area (NPA), each one of the Local Service Providers being assigned a different Service Provider Area (SPA) code in the common Numbering Plan Area (NPA); and

,

(B) if local number portability is not available for the dialed number, routing the call using the dialed number.

2. The method of claim 1, wherein prior to accessing the External Local Number Portability Database, if an NPA code is absent from a dialed number, prefixing an NPA code corresponding to the NPA of the dialed number to the dialed number and using the prefixed dialed number to access the External Local Number Portability Database.

3. The method of claim 1, further comprising using the routing information to provide a number SPA-NXX-XXXX and routing the call using the number SPA-NXX-XXXX.

4. A method for routing a call from a calling party to a called subscriber through a telephone network served by service providers, each one of said service providers having a set of call routing switches, the called subscriber being served by one of the switches in the set of switches of one of the service providers assigned to the called subscriber, the method comprising:

receiving a dialed number identifying the called subscriber;

determining in the network, a 3-digit Service Provider Area (SPA) code of said one of the service providers assigned to the called subscriber, such SPA code identifying the set of switches of said one of the service providers;

prefixing the dialed number, in whole or in part, with said SPA code to provide a call routing number SPA-NXX-XXXX for routing the call; and

routing, in response to the call routing number SPA-NXX-XXXX, the call to the called subscriber through said one of the switches.

5. The method of claim 4 wherein the service providers serve subscribers within a common Numbering Plan Area (NPA), the set of switches of said one of the service providers serving at least a portion of the subscribers within the common NPA.

6. The method of claim 5 wherein said one of the service providers is assigned a different SPA code in a different Numbering Plan Area (NPA), said different SPA code identifying a second set of switches of said one of the service providers serving subscribers within said different NPA.

7. The method of claim 4 wherein the service providers include a plurality of Local Service Providers.

8. The method of claim 7 wherein the plurality of Local Service Providers serve subscribers within a common Numbering Plan Area (NPA).

9. A method for routing a call using a dialed number NXX-XXXX, or NPA-NXX-XXXX, comprising the steps of:

prefixing the dialed number, when the dialed number is NXX-XXXX, with an NPA code to provide a converted number NPA-NXX-XXXX;

replacing the NPA code in the converted number or the dialed number NPA-NXX-XXXX with a Service Provider Area (SPA) code to provide a number SPA-NXX-XXXX, where SPA is a three digit code, each one of a plurality of service providers having a different SPA code; and

routing the call using the number SPA-NXX-XXXX.

10. The method of claim 9 wherein at least one of the plurality of service providers has different SPA codes in at least two Numbering Plan Areas (NPAs).

11. The method of claim 9 wherein the plurality of service providers serve subscribers within a common Numbering Plan Area (NPA).

12. The method of claim 9 wherein the plurality of service providers includes a plurality of Local Service Providers.

13. The method of claim 12 wherein the plurality of Local Service Providers serve subscribers within a common Numbering Plan Area (NPA).

14. A method for routing a call from a calling party to a called subscriber through a telephone network served by service providers serving subscribers within a first predetermined area, the called subscriber being served by one of the service providers assigned to the called subscriber, said one of the service providers also serving subscribers within a second predetermined area, the method comprising:

receiving a dialed number identifying the called subscriber;

determining, in the network, a first service provider code of said one of the service providers assigned to the called subscriber, said first service provider code identifying said one of the service providers within the first predetermined area, and said first service provider code being different from a second service provider code identifying said one of the service providers within the second predetermined area; and

routing, in response to the determined service provider code and the dialed number, the call to the called subscriber through the network.

15. The method of claim 14 wherein the first and second predetermined areas are first and second Numbering Plan Areas (NPAs).

16. The method of claim 15 wherein the first and second NPAs are contiguous.

17. The method of claim 14 wherein the service providers include a plurality of Local Service Providers.

18. The method of claim 17 wherein said one of the service providers is one of the plurality of Local Service Providers.

19. A method for routing a call from a calling party to a a plurality of Service Provider Area (SPA) codes, the subscriber having been assigned said one of the plurality of SPA codes, directory numbers of subscribers to one of a plurality of Local Service Providers having a common one of the plurality of Service Provider Area (SPA) codes, and each one of the Local Service called subscriber through a telephone network served by Local Service Providers, each one of said Local Service Providers having a set of call routing switches, the called subscriber being served by one of the switches in the set of switches of one of the Local Service Providers assigned to the called subscriber, the method comprising:

receiving a dialed number identifying the called subscriber;

determining, in the network, a Service Provider Area (SPA) code of said one of the Local Service Providers assigned to the called subscriber, such code identifying the set of switches of said one of the Local Service Providers;

prefixing the dialed number, in whole or in part, with said SPA code to provide a call routing number for routing the call; and

routing, in response to the call routing number, the call to the called subscriber through said one of the switches.

20. The method of claim 19 wherein the Local Service Providers serve subscribers within a common Numbering Plan Area (NPA), the set of switches of said one of the Local Service Providers serving at least a portion of the subscribers within the common NPA.

21. The method of claim 20 wherein said one of the Local Service Providers has a different SPA code in a different Numbering Plan Area (NPA), said different SPA code identifying a second set of switches of said one of the Local Service Providers serving subscribers within said different NPA.

22. A method for routing a call to a called subscriber comprising the step of:

routing a call to a called subscriber in response to routing information for a switch of one of a plurality of Local Service Providers serving subscribers within a common Numbering Plan Area (NPA), wherein said routing information for said switch includes a code identifying said one of the plurality of Local Service Providers, said one of the plurality of Local Service Providers serving the called subscriber.

23. The method of 22 wherein said code identifying said one of the plurality of Local Service Providers comprises a Service Provider Area (SPA) code for said one of the plurality of Local Service Providers wherein SPA code is a three digit code and each one of the plurality of Local Service Providers has a different SPA code.

24. The method of 23 wherein said routing information for said switch comprises SPA-NXX.