Patent Publication Number: US-8542677-B1

Title: System and method for enhanced domain availability notification

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 13/470,939, filed May 14, 2012, entitled SYSTEM AND METHOD FOR ENHANCED DOMAIN AVAILABILITY NOTIFICATION, now U.S. Pat. No. 8,428,052, issued Apr. 23, 2013, the specification of which is incorporated herein in its entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to the provision of network availability information, and more particularly to the use of a notification provided from a Voice Call Continuity application server within the IMS domain to provide realtime information with respect to network availability. 
     BACKGROUND 
     The Voice Call Continuity (VCC) specification describes how a voice call can be maintained as a mobile device moves between a circuit switch network and a packet switch network. Within a standard VOIP call, the operation of the mobile devices are controlled by the IP infrastructure. However, within the VCC specification, calls to and from a mobile device in a circuit switch domain may become attached and detached from the IP domain. As the handset becomes attached and detached from wireless access points, such as a Wi-Fi hotspot, a notification is provided of the radio conditions to a VCC platform within the network from the handset. This enables circuit switch and IP switch callings to be originated and terminated in a transparent manner such that the call path is automatically transferred between domains. The points at which these calls become connected and disconnected would be of interest to a network service provider because they provide indications of dead spots or weaknesses within the network. Some manner for providing realtime information with respect to this information that is causing the mobile device to switch between the IP network and circuit switch network would be of great benefit to the service provider in the control and operation of their networks. 
     SUMMARY 
     The present invention as disclosed and described herein, in one aspect thereof, comprises a method for providing IP network information to a network service provider receives at a voice call continuity application server an indication that a call to a mobile device has been dropped by the IP network and transmits information relating to the dropped call from the voice call continuity application server to a monitoring system of the network service provider. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding, reference is now made to the following description taken in conjunction with the accompanying Drawings in which: 
         FIG. 1  illustrates the manner in which notifications are presently provided when a user equipment is dropped from an IP network; 
         FIG. 2  is a flow diagram describing the manner in which location information may be automatically exported to a monitoring system responsive to a dropped IP call; 
         FIG. 3  illustrates the communications links established when an IP call is dropped according to the method of  FIG. 2 ; 
         FIG. 4  more particularly illustrates the manner for providing an automatic notification to a monitoring system responsive to the dropping of an IP call; and 
         FIG. 5  illustrates the manner for including location information within a PANI header. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, wherein like reference numbers are used herein to designate like elements throughout, the various views and embodiments of a system and method for enhanced domain availability notification are illustrated and described, and other possible embodiments are described. The figures are not necessarily drawn to scale, and in some instances the drawings have been exaggerated and/or simplified in places for illustrative purposes only. One of ordinary skill in the art will appreciate the many possible applications and variations based on the following examples of possible embodiments. 
     Referring now to the drawings, and more particularly to  FIG. 1 , there is illustrated the various communications links and messages established responsive to the dropping of a Voice over IP call by an IP network. The user equipment  102  initially establishes the basis for an IP connection with the IP network  106  over a link  104 . Additionally, the user equipment  102  establishes the basis for a connection with the circuit switch network  108  over a link  110 . Calls will then be carried out over the IP network  106  until a problem with the IP network connection is detected. Upon the necessity for dropping an IP based call, the user equipment  102  transmits an SMS message  112  to the Voice Call Continuity application server  114  to notify the application server of the necessity to change to a circuit switched connection. The VCC application server  114  transmits information  116  back to the IP network  106  enabling the handoff of the call from the IP network  106  to the circuit switch network  108  in a seamless fashion. 
     Referring now to  FIG. 2 , there is illustrated the manner in which additional information may be provided to a service provider monitoring system  202  that will enable the information provided by the user equipment  102  to be provided to the monitoring system  202  in realtime and provide network coverage information that may be utilized by a system provider to improve network performance. The user equipment  102  establishes an IP link  104  with the IP network  106  and provides the information necessary for establishing the circuit switched link  110  with the circuit switch network  108 . The user equipment  102  may comprise a mobile telephone, personal data assistant, tablet computer, portable laptop computer or any other type of portable communications device. Upon occurrence of a situation causing the IP based call to be dropped by the user equipment  102 , information  112  is transmitted to the Voice Call Continuity application server  114  indicating dropping of the call by the IP network  106 . The VCC application server  114  transmits information  116  back to the IP network  106  providing for the handoff of the call between the IP network  106  and the circuit switched network  108 . Additionally, the VCC application server  114  will transmit location information  204  relating to the user equipment  102  to the monitoring system  202  such that this information may be used by the service provider to provide realtime information with respect to the network coverage areas associated with the user equipment  102 . The service provider may then use the information to improve and update network performance. 
     Referring now to  FIG. 3 , there is illustrated a flow diagram describing the manner in which the remote monitoring system is provided with information related to the calls being dropped by the IP network. Initially, the user equipment  102  loses IP network coverage at a particular location at step  302 . Responsive to the loss of the IP network coverage, the user equipment  102  is switched to the circuit switched domain at step  304 . The user equipment  102  sends an SMS message to the VCC application server at step  306  notifying the VCC application server  114  of the switch to the circuit switched domain. The VCC application server  114  receives at step  308  the SMS message from the user equipment  102  and determines the last known PANI header of the user equipment at step  310 . Utilizing the location information stored within the last known PANI header at the VCC application server  114 , the location information within the PANI header is exported at step  312  to the network provider monitoring system and this information may then be used by the network provider to track network coverage areas and improve or update network performance. 
     Referring now to  FIG. 4 , there is provided a more detailed description of the manner for notifying the remote monitoring system when an IP based call is dropped. When the user loses IP network coverage at step  402 , the user equipment  102  switches to the client domain at step  404 . The user equipment  102  generates an SMS message including the PANI header from the user equipment at step  406 . The configuration of the PANI header is more particularly illustrated in  FIG. 5 , which shows the PANI header  502  having the location information  504  embedded someplace therein. The user equipment  102  transmits the SMS message at step  408  to the VCC application server  114 . The VCC application server  114  receives the SMS message at step  410  and extracts the location information at step  412  from the PANI header  502  within the SMS message. The SMS message can additionally include RF related information that will aid the service provider in optimization of the network. For example, signal strength that was reported to the user equipment  102  immediately before the call was dropped or neighboring cell information. This extracted location information  504  from the PANI header  502  is exported at step  414  to the remote monitoring system  202  of the system provider. The system provider may use this information with respect to the locations at which IP based calls are being dropped to control and improve various system operations within their IP network. 
     It will be appreciated by those skilled in the art having the benefit of this disclosure that this system and method for enhanced domain availability notification provides realtime network information which may be valuable to a network service provider. It should be understood that the drawings and detailed description herein are to be regarded in an illustrative rather than a restrictive manner, and are not intended to be limiting to the particular forms and examples disclosed. On the contrary, included are any further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments apparent to those of ordinary skill in the art, without departing from the spirit and scope hereof, as defined by the following claims. Thus, it is intended that the following claims be interpreted to embrace all such further modifications, changes, rearrangements, substitutions, alternatives, design choices, and embodiments.