Enhanced application telephone network

• US 6,493,444 B2
• Filed: 03/16/1999
• Issued: 12/10/2002
• Est. Priority Date: 03/16/1999
• Status: Expired due to Term

• Current Assignee: Broadview Networks Incorporated (Windstream Holdings II LLC)
• Original Assignee: Bell Canada (BCE Incorporated)
• Inventors: Williams, L. Lloyd
• Primary Examiner(s): Smith, Creighton
• Application Number:
  US09/268,843
• Publication Number:
  US 20020071543A1
• Time in Patent Office: 1,365 Days
• Field of Search: 379/219, 379/220.01, 379/221.01, 379/221.08, 379/221.09, 379/221.1
• US Class Current: 379/221.08
• CPC Class Codes: H04Q 2213/13141 Hunting for free outlet, circuit or channel
• CPC Class Codes: H04Q 2213/13176 Common channel signaling, CCS7
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/13345 Intelligent networks, SCP
• CPC Class Codes: H04Q 2213/1338 Inter-exchange connection
• CPC Class Codes: H04Q 2213/13389 LAN, internet
• CPC Class Codes: H04Q 3/0016 Arrangements providing connection between exchanges
• CPC Class Codes: H04Q 3/0037 involving call modelling techniques, e.g. modifications to the basic call state model [BCSM]

Abstract

An enhanced application switched telephone network and a method of completing calls using the network are described. In the enhanced application switched telephone network, every switching office is connected to at least one enhanced ISUP voice-grade trunk. A link set and a route set associated with the enhanced trunk route common channel signaling messages associated with calls directed to the enhanced trunk(s) to a call control node. The call control node is thereby enabled to exercise control over those calls. The advantages include point of origin call control, enhanced application service development, rapid service, deployment and significantly more efficient use of PSTN facilities.

Claims

1. An enhanced application telephone network having switching offices connected by trunk groups and enabled to communicate over a common channel signaling network to exchange call control messages for calls handled by the groups, comprising:

a call control node connected to the common channel signaling network and configured as a virtual node in a switching plane of the enhanced application telephone network;

a database of information used for defining services associated with the selected calls;

the database being queried by the call control node to retrieve call routing information; and

at least one enhanced trunk for handling selected calls connected to each local switching office, the call control node being a virtual switching node logically located between opposite ends of the enhanced trunk so that common channel signaling messages related to the selected calls are delivered to the call control node, and the call control node is thereby enabled to exercise control over the selected calls.

2. A network as claimed in claim 1 wherein each of the switching offices is enabled to overflow regular calls to the at least one enhanced trunk when other trunk groups are not available to handle the regular calls.

3. A network as claimed in claim 2 wherein each of the switching offices comprises translation tables including:

routing table entries to route the selected calls to the at least one enhanced trunk; and

link sets and route sets that direct common channel signaling messages formulated at the switching office for the selected calls to the call control node.

4. A network as claimed in claim 3 wherein the network further comprises a Service Control Point (SCP) for storing service information, including routing information.

5. A network as claimed in claim 4 wherein each of the switching offices is enabled to formulate common channel signaling queries to the SCP for routing information to route the selected calls to the at least one enhanced trunk.

6. A network as claimed in claim 5 wherein the switching office comprises Advanced Intelligent Network (AIN) triggers to permit the selected calls to trigger the common channel signaling queries.

7. A network as claimed in claim 5 wherein the formulation of common channel signaling queries is initiated by the translation tables.

8. A network as claimed in claim 1 wherein the call control node comprises:

a common channel signaling interface for receiving messages from and sending messages to the common channel signaling network;

a memory for storing at least one of the common channel signaling messages;

a memory for storing programs enabling a processor to examine common channel signaling messages received at the common channel signaling interface, generate common channel signaling messages for controlling call connections, tracking calls virtually routed through the call control node, and assessing predefined criteria to determine an action respecting the control of call connections; and

a processor for executing the programs.

9. A network as claimed in claim 1 wherein the call control node is assigned a service switching point code in the common channel signaling network and the call control node appears in the common channel signaling network as a Service Switching Point (SSP).

10. A network as claimed in claim 8 wherein the programs are further enabled to pass on certain common channel signaling messages received at the common channel signaling interface.

11. A network as claimed in claim 10 wherein at least some of the messages passed on are modified before they are transmitted into the common channel signaling network.

12. A network as claimed in claim 11 wherein the messages that are modified are modified only to an extent that the Originating Point Code and the Destination Point Code are changed to appear logically correct at a node that is a recipient of the message.

13. A network as claimed in claim 1 wherein the call control node further includes a connection to a data network not associated with the common channel signaling network.

14. A network as claimed in claim 13 further comprising service resources for providing services in the enhanced application network.

15. A network as claimed in claim 14 wherein the service resources include an Intelligent Peripheral (IP) that is connected to the data network to permit the call control node and the intelligent peripheral to exchange messages over the data network.

16. A network as claimed in claim 14 wherein the database of information used for defining services associated with selected calls is dynamically updated with data included in the common channel signaling messages received from the common channel signaling network and with data contained in messages, from the service resources transmitted through the data network.

17. A network as claimed in claim 14 wherein the call control node is enabled to initiate a call control action requested by a service resource using the data network.

18. A network as claimed in claim 1 wherein the trunk groups are Integrated Services Digital Network User Part (ISUP) trunks, and the at least one enhanced trunk is also an ISUP trunk.

19. A network as claimed in claim 2 wherein the call control node behaves like a Signal Transfer Point (STP) when regular calls are overflowed to the enhanced trunk.

20. A Method for controlling a selected call associated with special services provided in a switched telephone network wherein a caller dials a predetermined sequence of digits for one of the selected calls, comprising steps of:

routing the selected call from an originating switching office that serves the caller to a trunk member that is connected to the originating switching office, the trunk member logically terminating at a call control node that is connected to a common channel signaling network of the switched telephone network;

receiving at the call control node a common channel signaling message from the originating switching office, the common channel signaling message being related to the selected call;

querying a database from the call control node to determine if the selected call is associated with a special service using information in the common channel signaling message;

if it is determined that the selected call is associated with a special service, determining a call treatment option for the call, else forwarding the common channel signaling message to a switching office associated with an opposite end of the trunk member; and

controlling the selected call associated with the special service using at least one common channel signaling message sent to a switching office connected to an end of the trunk member.

21. A method as claimed in claim 20 wherein the step of determining a call treatment option for the call includes determining a terminating number for the selected call.

22. A method as claimed in claim 21 wherein the step of determining a call treatment option for the call further includes determining an availability of the terminating number to receive the call.

23. A method as claimed in claim 21 wherein the step of determining a call treatment option for the call further includes determining whether the selected call should be completed to or blocked from completion to the terminating number.

24. A method as claimed in claim 20 wherein the common channel signaling message used by the call control node to control the selected call is an ISUP Release message with Cause set to Normal Clearing, the Release message being transmitted to the originating switching office.

25. A method as claimed in claim 24 wherein the ISUP Release message includes a Service Activation Parameter (SAP) and a Generic Address Parameter (GAP) to invoke the originating switching office to reroute the selected call without disconnecting the caller.

26. A method as claimed in claim 24 wherein the common channel signaling message used by the call control node is an ISUP IAM message.

27. A method as claimed in claim 24 wherein the ISUP IAM message is transmitted to a switching office connected to a terminating end of the trunk member to advance the call in a forward direction while permitting the call control node to continue to exercise control over the call.