Number portability using enhanced routing table

• US 6,002,757 A
• Filed: 03/08/1996
• Issued: 12/14/1999
• Est. Priority Date: 03/08/1996
• Status: Expired due to Term

• Current Assignee: Stentor Resource Centre, Inc.
• Original Assignee: Stentor Resource Centre, Inc.
• Inventors: Williams, L. Lloyd, Carkner, R. William
• Primary Examiner(s): Hong, Harry S.
• Application Number:
  US08/612,660
• Time in Patent Office: 1,376 Days
• Field of Search: 379/201, 379/207, 379/210, 379/211, 379/212, 379/219, 379/220, 379/221, 379/222, 379/224, 379/225, 379/229, 379/230, 370/385
• US Class Current: 379/201.01
• CPC Class Codes: H04M 3/42297 with number portability
• CPC Class Codes: H04Q 2213/13097 Numbering, addressing
• CPC Class Codes: H04Q 2213/13098 Mobile subscriber
• CPC Class Codes: H04Q 2213/13102 Common translator
• CPC Class Codes: H04Q 2213/13103 Memory
• 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 2213/13349 Network management
• CPC Class Codes: H04Q 2213/13353 Routing table, map memory
• CPC Class Codes: H04Q 2213/13513 UPT - personal as opposed to terminal mobility, inc. number portability
• CPC Class Codes: H04Q 2213/13541 routing
• CPC Class Codes: H04Q 3/0016 Arrangements providing connection between exchanges
• CPC Class Codes: H04Q 3/005 Personal communication services, e.g. provisions for portability of subscriber numbers
• CPC Class Codes: H04Q 3/665 Circuit arrangements therefor

Abstract

A method of providing number portability for the treatment of calls from a calling party to a specific number of a called party is disclosed. Once the dialed digits are received at a switching office serving the calling party, a determination is made of whether the call is directed to a portable number. In a first embodiment, if the call is directed to a portable number, a TCAP query is launched from the originating office to an SCP. At the SCP, the dialed digits are translated to obtain new routing information. The new routing information, which is returned to the originating office is used to create an Initial Address Message (IAM) containing the calling and called party'"'"'s numbers to enable said call to reach said terminating office associated with the new routing information. In a second embodiment, the new routing information is obtained from a directory number table resident at the originating office. If the dialed digits contain an area code indicative of a toll call, the originating office forwards the call directly to a tandem exchange, where the determination is made of whether the dialed digits are associated with a portable number.

Claims

1. A method of providing network-wide number portablility for the treatment of calls in a telephone network of telephone exchanges equipped with SSPs (Service Switching Points) operating with IN (Intelligent Network) application software, comprising:

a) providing a table at each telephone exchange in the network in which any number in a numbering plan supported by the network can be a ported number to permit a search to be performed to determine, each time a called number associated with a call is received at the telephone exchange, whether the called number is a ported number for which the telephone exchange must obtain routing information by searching the table for the called number;

b) providing at least one database, the at least one database collectively containing a routing option for each ported number in the network; and

c) when the table at a telephone exchange in the network indicates that a called number is a ported number, obtaining a routing option from the at least one database to enable the call to reach its final destination.

2. A method of providing network-wide number portability as claimed it claim 1 wherein step c) includes steps of:

d) querying a first database local to the telephone exchange when the table at the telephone exchange indicates that a called number is a ported number; and

e) launching a query to a second database at a Service Control Point (SCP) in response to an instruction in the first database, in order to obtain a routing option for the call.

3. A method of providing network-wide number portablility as claimed claim 1 wherein the table at each telephone exchange in the network permits a binary search to be performed to determine whether the called number is a ported number.

4. A method of providing network-wide number portablility as claimed in claim 1 wherein the tables are not identical on each telephone exchange.

5. A method of providing network-wide number portablility as claimed in claim 1 wherein the at least one database includes a local database at each telephone exchange, the local database containing a routing option for each ported number in the table of the telephone exchange.

6. A method of providing network-wide number portablility as claimed in claim 1 wherein the at least one database includes a database located at a Service Control Point (SCP) in the network, the SCP containing routing options for the ported numbers in a plurality of tables in telephone exchanges in the network.

7. A method of providing network-wide number portablility as claimed in claim 1 wherein the routing option is a telephone number, and the called number is replaced with the routing option.

8. A system for providing network-wide number portability for the treatment of calls in a telephone network of telephone exchange equipped with SSPs (Service Switching Points) operating with IN (Intelligent Network) application software, comprising:

a table at each of the telephone exchanges in the network in which any telephone number in a numbering plan supported by the network can be a ported number, each table adapted to enable a search to determine whether a called number associated with a call received at a telephone exchange is a ported number for which the exchange must obtain routing information, each telephone exchange adapted to execute the search to locate the called number each time a called number is received at the telephone exchange; and

at least one database, the at least one database collectively containing routing information for each ported number in the table at each telephone exchange.

9. A system for providing network-wide number portability as claimed in claim 8 wherein the at least one database is located in each telephone exchange and contains routing information for at least each ported number in the table at the telephone exchange.

10. A system for providing network-wide number portability as claimed in claim 8 wherein a one of the at least one database is located at a Service Control Point (SCP) in the network, the database located at the SCP including routing information for ported numbers listed in a plurality of the tables.

11. A system for providing network-wide number portability as claimed in claim 9 wherein the one of the at least one database at the telephone exchange contains an instruction for directing toll calls to a tandem telephone exchange in the network, and

on identifying a called number associated with a toll call as a ported number using the table at the tandem exchange, the tandem exchange sends a query to the SCP to obtain routing information for forwarding the call to a final destination.

12. A system for providing network-wide number portability as claimed in claim 9 wherein the one of the at least one database at the telephone exchange contains routing information far directing toll calls to a tandem telephone exchange in the network, and

on identifying a called number associated with a toll call as a ported number using the table at the tandem exchange, the tandem exchange searches the one database to obtain routing information for forwarding the call to a final destination.

13. A method of using number portability enhanced routing tables, comprising:

a) receiving a called number associated with a call at a telephone exchange in a network in which any telephone number can be a portable number;

b) determining, each time step (a) arises, whether the called number is a ported number, the step of determining taking place by performing a search of a table at the telephone exchange in the network to locate the called number; and

c) obtaining from at least one database, in response to determining that the called number is a ported number as a result of step (b), a routing option for each ported number in the network to enable the call to reach a final destination in the network, the at least one database collectively containing the routing option for each ported number in the network.

14. A method of using number portability enhanced routing tables as claimed in 13, wherein step (c) includes the steps of:

(d) querying a first database local to the telephone exchange for an instruction in response to determining that the called number is a ported number in step (b); and

(e) obtaining from a second database at a Service Control Point (SCP), based on the instruction in step (d), the routing option for the call.

15. A method of using number portability enhanced routing tables as claimed in 13, further comprising replacing the called number with the routing option, the routing option being another telephone number.

16. A method of using number portability enhanced routing tables as claimed in 13, wherein the call is a toll call, the telephone exchange is a tandem exchange, and further comprising:

f) identifying the called number associated with the toll call as the ported number after searching the table for the called number at the tandem exchange;

g) directing, each time the called number is identified as the ported number pursuant to step (f), the toll call to the final destination in the network.

17. A method of using number portability enhanced routing tables, comprising:

a) receiving a called number associated with a call at one of a plurality of telephone exchanges in a network in which any number in a number plan supported by the network can be a ported number;

b) determining, each time step (a) arises, whether the called number is a ported number, the step of determining taking place by performing a search of a table at the telephone exchange in the network to locate the called number; and

c) obtaining from at least one database, in response to determining that the called number is a ported number from step (b), routing information for each ported number in the network, the at least one database collectively containing routing information for each ported number in the network.

18. A method of using number portability enhanced routing tables as claimed in 17, wherein the call is a toll call, the telephone exchange is a tandem exchange, and further comprising:

d) directing one of a plurality of toll calls to the tandem telephone exchange in the network, the step of directing taking place pursuant to an instruction from the at least one database at the telephone exchange in the network;

e) identifying the called number associated with the toll call as the ported number, the step of identifying taking place after searching the table to locate the called number at the tandem exchange;

f) obtaining routing information from at least one database, the step of obtaining taking place by the tandem exchange sending a query to the SCP;

g) forwarding the called number, identified in step (e), based on the query in step (f), to a final destination.