System and method having a distributed external database

• US 5,883,950 A
• Filed: 07/21/1997
• Issued: 03/16/1999
• Est. Priority Date: 06/30/1995
• Status: Expired due to Fees

• Current Assignee: Siemens Information And Communication Networks, Inc.
• Original Assignee: Siemens Information And Communication Networks, Inc.
• Inventors: Sonnenberg, Edward
• Primary Examiner(s): Matar, Ahmad F.
• Assistant Examiner(s): Wolinsky, Scott
• Application Number:
  US08/897,394
• Time in Patent Office: 603 Days
• Field of Search: 379/114, 379/112, 379/201, 379/207, 379/127, 379/211, 379/219, 379/220, 379/221, 379/229, 379/265, 379/115, 379/210, 379/242, 379/243, 379/269
• US Class Current: 379/221.13
• CPC Class Codes: H04M 3/42297 with number portability
• CPC Class Codes: H04Q 2213/13097 Numbering, addressing
• CPC Class Codes: H04Q 2213/13102 Common translator
• CPC Class Codes: H04Q 2213/13103 Memory
• CPC Class Codes: H04Q 2213/13107 Control equipment for a part of the connection, distributed control, co-processing
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13149 Change of provider, e.g. network or service
• CPC Class Codes: H04Q 2213/13176 Common channel signaling, CCS7
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/13296 Packet switching, X.25, frame relay
• CPC Class Codes: H04Q 2213/13345 Intelligent networks, SCP
• CPC Class Codes: H04Q 2213/13405 Dual frequency signaling, DTMF
• CPC Class Codes: H04Q 2213/13513 UPT - personal as opposed to terminal mobility, inc. number portability
• CPC Class Codes: H04Q 2213/13527 protocols - X.25, TCAP etc.
• CPC Class Codes: H04Q 2213/13533 multivendor and hybrid, e.g. public/private, networks, inc. international
• CPC Class Codes: H04Q 2213/13541 routing
• CPC Class Codes: H04Q 2213/13542 numbering plans, e.g. number re-allocation
• CPC Class Codes: H04Q 3/005 Personal communication services, e.g. provisions for portability of subscriber numbers
• CPC Class Codes: H04Q 3/66 Traffic distributors

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 system used in routing a call to a called subscriber having been assigned a directory number NXX-XXXX by one Local Service Provider in a Numbering Plan Area (NPA) and having changed to a different Local Service Provider within the Numbering Plan Area, such system comprising:

a plurality of databases, each one thereof storing relationships between NXX-XXXX directory numbers assigned to called subscribers within a corresponding one of a plurality of different Numbering Plan Areas (NPAs) and call routing identifiers, SPAs, used for routing calls to the called subscribers, where an SPA is associated with each directory number, where;

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

, NXX is a three digit exchange code representative of a local exchange area within a Numbering Plan Area.

2. The system recited in claim 1 wherein the plurality of databases is distributed among different local switches, all subscriber directory numbers having a common NPA-NXX being stored in one of the plurality of databases.

3. A method for routing a call to a called Subscriber having been assigned a directory number NXX-XXXX by one Local Service Provider and having changed to a different Local Service Provider, both Local Service Providers providing service within a Numbering Plan Area (NPA), comprising:

(a) providing a plurality of databases, each one thereof storing relationships between NXX-XXXX directory numbers assigned to called Subscribers within a corresponding one of a plurality of different Numbering Plan Areas (NPAs), and call routing identifiers, SPAs, associated with the NXX-XXXX directory numbers, where;

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

and, NXX is a three digit exchange code representative of a local exchange area within a Numbering Plan Area (NPA);

(b) retrieving from a corresponding one of the plurality of databases, an SPA call routing identifier associated with the directory number NXX-XXXX assigned to the called Subscriber, in response to a calling party dialing the directory number NXX-XXXX to place a call to the called subscriber; and

(c) routing the call placed by the calling party to the called Subscriber using the retrieved SPA call routing identifier prefixed to the last seven digits of the dialed number, SPA-NXX-XXXX.

4. The method recited in claim 3 wherein the plurality of databases is distributed among different local switches, all Subscriber directory numbers having a common NPA-NXX being stored in one of the plurality of databases.

5. A system for routing a call to a called subscriber having been assigned a directory number NXX-XXXX by one Local Service Provider in a Numbering Plan Area (NPA) and having changed to a different Local Service Provider within the Numbering Plan Area, such system comprising:

a plurality of local switch internal databases, each one thereof storing relationships between NXX-XXXX directory numbers assigned to called subscribers within a corresponding one of the plurality of different Numbering Plan Areas and call routing identifiers associated with the directory numbers, used for routing calls to the called subscribers, wherein the call routing identifiers are assigned to the Local Service Providers; and

,

means for enabling the Local Service Providers to access the databases and retrieve a call routing identifier associated with the directory number, to route the call to the called subscriber.

6. The system recited in claim 5 wherein all subscriber directory numbers having a common NPA-NXX are stored in one of the plurality of databases.

7. A method for routing a call to a called Subscriber having been assigned a directory number NXX-XXXX by one Local Service Provider and having changed to a different Local Service Provider, both Local Service Providers providing service within a Numbering Plan Area (NPA), comprising:

(a) providing a plurality of local switch internal databases, each one thereof being accessible to at least one of the Local Service Providers and storing relationships between NXX-XXXX directory numbers assigned to called Subscribers within a corresponding one of a plurality of different Numbering Plan Areas (NPAs), and call routing identifiers, wherein the call routing identifiers are assigned to the Local Service Providers;

(b) retrieving from a corresponding one of the plurality of databases, a call routing identifier associated with the directory number NXX-XXXX assigned to the called Subscriber, in response to a calling party dialing the directory number NXX-XXXX to place a call; and

(c) routing the call placed by the calling party to the called Subscriber using the retrieved call routing identifier.

8. The method recited in claim 7 wherein all Subscriber directory numbers having a common NPA-NXX are stored in one of the plurality of databases.