Patent Abstract:
A method and system of reachability indication between a wireless device and at least one push server, the method comprising the steps of: sending device status information from the wireless device to the at least one push server; and receiving the status information at the at least one push server; wherein the at least one push server is enabled to selectively start and stop serving the wireless device on the basis of the status information. The method further comprises sending status information to a packet data serving node that stores a list of push servers associated with a wireless device, and having the packet data serving node forward the status information to the push server. The system and method further includes selectively starting and stopping the serving of the wireless device by the push server during a voice call.

Full Description:
RELATED APPLICATIONS 
   The present application is a continuation of U.S. application Ser. No. 10/836,245, filed May 3, 2004, which claims priority from U.S. provisional application Ser. No. 60/468,310 filed 6 May 2003. The contents of U.S. application Ser. No. 10/836,245 and U.S. provisional application Ser. No. 60/468,310 are incorporated herein by reference. 

   BACKGROUND 
   1. Field of the Invention 
   This invention relates to wireless data devices that access a wireless network, and to infrastructures that route packet data traffic between data servers and wireless data devices within the wireless network. The wireless data devices referred herein include Personal Digital Assistants, mobile communication devices, cellular phones, and wireless two-way communication devices that have packet data processing capability and intended to be used in wireless networks. 
   2. Description of the Related Art 
   In a CDMA2000 (1× Code Division Multiple Access) network, the network typically requires a wireless data device to send a power-up registration when powering up. Similarly, the network requires the device to send an explicit power-down registration message when it powers down for any reason. In this way the CDMA2000 network knows that the wireless data device does not require any services and is no longer reachable. 
   For wireless data devices that support push services, there may be one or more push servers running on different networks managed by different entities. These push servers deliver information such as notification, data and multimedia content to the wireless devices via the wireless IP network. The device&#39;s reachability information known to the CDMA2000 network may not be available to the push servers. When a device is not available, the data servers may keep pushing data traffic to an unreachable device, resulting in a waste of network bandwidth and the starvation of available devices. 
   Packet data services are integrated on top of circuit switched services in CDMA2000 networks. Another problem may arise when a wireless data device does not support concurrent data services and voice services. For instance, when the device is in a voice call, it is unable to accept a data call. In this situation, it is desirable that the data servers stop pushing data to the device temporarily. 
   SUMMARY 
   One method which mitigates unnecessary data traffic on the CDMA2000 network includes sending device status information from a wireless data device to its push servers so that the push servers know when to start and when to stop serving the wireless data device. 
   Another solution is to let a wireless data push server register with the packet data serving node (PDSN) and specify the wireless devices that are associated with it. When the PDSN is informed of a change in device status information, it notifies all the registered push servers associated with that wireless data device. 
   Alternatively, the PDSN may gather the push server information automatically by examining the header of incoming packet data designated for a specific wireless data device. 
   After the push servers are notified of the status change of the wireless data devices by the PDSN, the push servers can start or stop pushing data traffic to the wireless networks accordingly. In this way, the data traffic on the wireless network can be reduced to save network resources. 
   The present invention therefore provides a method for reachability indication between a wireless device and at least one push server, the method comprising the steps of: sending device status information from the wireless device to the at least one push server; and receiving the status information at the at least one push server; wherein the at least one push server is enabled to selectively start and stop serving the wireless device on the basis of the status information. 
   The present invention further provides a method for reachability indication between a wireless device and at least one push server, the method comprising the steps of: sending device status information from the wireless device to a packet data serving node; receiving the status information at packet data serving node and sending from the packet serving node a status message to the at least one push server, the status message corresponding to the status information; receiving the status message at the at least one push server; wherein the at least one push server is enabled to selectively start and stop serving the wireless device on the basis of the status information. 
   The present invention still further provides a method for reachability indication between a wireless device and at least one push server, the wireless device being unable to support simultaneous voice and data calls, the method comprising the steps of: sending voice call information from a mobile switching center to a base station controller; sending from the base station controller to a packet data serving node a data status notification; receiving the data status notification at the packet data serving node and sending to the at least one push server status information; and receiving the status information at the at least one push server; wherein the at least one push server is enabled to selectively start and stop serving the wireless device on the basis of the status information. 
   The present invention yet further provides a push server enabled to selectively start and stop serving a wireless device on the basis of received status information, said push server comprising: a transceiver enabled to receive status information about the wireless device; a processor enabled to interpret status information about the wireless device and to start or stop serving the wireless device based on the status information; and a storage subsystem capable of storing the status information for the wireless device. 
   The present invention further provides a packet data serving node comprising: a processor; a first transceiver interface for communicating with a base station controller and receiving status information for a wireless device; a second transceiver interface for communicating with a network and for transmitting status information for the wireless device; and a data storage subsystem, said data storage subsystem including: a records storage, said records storage storing data associating a wireless device with at least one push server, wherein said records storage is accessible by said processor upon receipt by said first transceiver interface of the status information for the wireless device, allowing the processor to forward the status information to the at least one push server associated with the wireless device. 
   The present invention further provides a base station controller comprising: a processor; a first transceiver interface for communicating with a mobile switching center and receiving voice call information for a wireless device; a second transceiver interface for communicating with a packet data serving node and for transmitting status information for the wireless device; and a data storage subsystem, said data storage subsystem including: a records storage, said records storage storing data indicating whether a wireless device can support concurrent voice and data calls and whether the wireless device is in a voice call; wherein said records storage is accessible by said processor upon receipt by said first transceiver interface of the voice call information for the wireless device, allowing the processor to forward the status information to the packet data switching network. 
   The present invention further provides a wireless data device comprising: a processor, a user interface communicating with the processor for providing input to the wireless data device, a transceiver interface controlled by said processor for communicating with a wireless network, a storage subsystem communicating with said processor and having information about push servers serving said wireless data device, wherein said wireless data device communicates status information to the push servers serving the wireless devices using said transceiver over said wireless network. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of an exemplary CDMA2000 wireless data network system in accordance with the present application and with which the various embodiments of the method of the instant application may cooperate; 
       FIG. 2  is a block diagram of an exemplary wireless data device for use with the method of the present application; 
       FIG. 3  is a block diagram of an exemplary push server for use with the method of the present application; 
       FIG. 4  is a block diagram of an exemplary PDSN for use with the method of the present application; 
       FIG. 5  is a block diagram of an exemplary BSC for use with the method of the present application; 
       FIG. 6  illustrates various embodiments of the techniques of the present application in terms of a flow chart; 
       FIG. 7  illustrates in greater detail the signaling and data flow between the wireless data device, and two push servers in accordance with a first embodiment of a method of the present application; 
       FIG. 8  illustrates in greater detail the signaling and data flow among the wireless data device, PDSN and two push servers in accordance with a second embodiment of the method of the present application; and 
       FIG. 9  is a detailed signal flow diagram illustrating the signaling, voice and data flow among the wireless data device, BSC, MSC, PDSN and push servers in accordance with a third embodiment of the a method of the present application. 
   

   The same reference numerals are used in different Figures to denote similar elements. 
   DETAILED DESCRIPTION 
   Referring to  FIG. 1 ,  FIG. 1  is a block diagram of an exemplary CDMA2000 wireless data network system in accordance with the present application and with which the various embodiments of the method of the instant application may cooperate.  FIG. 1  shows a block diagram of a wireless data device  10 , an exemplary 1× Code Division Multiple Access (CDMA2000) mixed circuit switched and packet switched network  20 , a Public Switched Telephone Network (PSTN)  30 , Internet  40  and push servers  50  with which the instant techniques of this application may cooperate. The wireless data device  10  is preferably a two-way communication device having data and/or voice communication capabilities. 
   CDMA2000 network  20  includes mixed circuit and packet switched components—Base Transceiver Subsystem (BTS)  22  and Base Station Controller (BSC)  24 , a circuit switched only component—Mobile Switching Centre (MSC)  26 , and a packet switched only component—Packet Data Serving Node (PDSN)  28 . 
   Operationally, mobile device  10  communicates wirelessly with BTS  22  and BSC  24  to gain access to circuit switched services provided by MSC  26 , such as voice and short message service (SMS) via PSTN  30 . 
   Mobile device  10  also communicates wirelessly with BTS  22  and BSC  24  to gain access to packet data services provided by PDSN  28 , such as e-mail, wireless application protocol (WAP), and other data services via Internet  40 . 
     FIG. 2  is a block diagram of an exemplary wireless data device for use with the method of the present application. Reference is still made to  FIG. 1  for individual components within wireless network  20 . The wireless data device  10  is preferably a two-way communication device having at least data or data/voice communication capabilities. Where the device  10  is enabled for two-way communications, the device will incorporate a processor  100 , a storage subsystem  102 , a transceiver subsystem  104  and a user interface module  106 . The microprocessor  100  controls the overall operation of the wireless data device. Communication functions, including signaling between wireless data device  10  and wireless network  20 , signaling between wireless data device  10  and push servers  50 , and data/voice communications, are performed through the transceiver subsystem  104 . The microprocessor  100  also interacts with further device subsystems such as the storage subsystem  102  and the user interface module  106 . In CDMA2000 network, signaling between wireless data device  10  and wireless network  20 , for instance, includes power up and power down registrations. Users may command the operation of the wireless data device  10  through the user interface module  106 , for instance power up and power down the wireless data device  10 , making data and/or voice calls. 
   The present method and application provide for signaling between wireless data device  10  and push servers  50  that includes conveying status information about wireless data device  10  through a Data Active Message  60  and Data Inactive Message  66 . 
   A predetermined set of applications that control basic device operations, including at least data communication applications for example, will normally be installed on the device  10  during manufacture. A set of applications that may be loaded onto the device includes, but is not limited to e-mail, calendar events, appointments, browser and task items. Such applications would have the ability to send and receive data items, via the CDMA2000 network  20  and Internet  40  (not shown), to and from push server  50 . For voice communications, device  10  communicates with PSTN  30  (not shown) via the CDMA2000 network  20 . 
   When the wireless data device  10  powers up, it sends a power up registration to BSC  24 . When the required power up registration has been completed, the wireless data device  10  may send and receive communication signals over CDMA2000 network  20 . 
   When the wireless data device  10  powers down, it sends a power down registration to BSC  24 . When the required power down registration has been completed, the CDMA2000 network  20  stops serving the wireless data device  10 . 
     FIG. 3  is a block diagram of an exemplary push server for use with the method of the present application. The push server  50  incorporates at least one microprocessor  200 , a storage subsystem  202 , and a transceiver subsystem  204 . 
   The microprocessor  200  controls the overall operation of the push server. Microprocessor  200  interacts with storage subsystem  202 , and transceiver subsystem  204 . Communication functions, including signaling between push server  50  and wireless network  20 , signaling between push server  50  and wireless data device  10 , and data communications, are performed through the transceiver subsystem  204 . Signaling between push server  50  and wireless network  20  as well as signaling between push server  50  and wireless data device  10  include, but are not limited to, receiving status information about wireless data device  10 . Further, a Data Active Message  60  and Data Inactive Message  66  are sent to push server  50 . 
   Push server  50  communicates with the wireless network  20  and with wireless data device  10  via Internet  40 , as seen in  FIG. 1 . 
     FIG. 4  is a block diagram of an exemplary PDSN for use with the method of the present application. Operationally it includes at least one processor  300 , a storage subsystem  302 , and two transceiver interfaces  304  and  306 . The first transceiver interface  304  is used to receive status information of wireless data device  10  (not shown). In present the method and application, this includes a Data Active Notification  68  or Data Inactive Notification  72  from BSC  24 . These messages are used to indicate whether the wireless data device  10  will accept data using the Data Active Notification  68 , or will not accept data using the Data Inactive Notification  72 . 
   The second transceiver  306  is used to send information to push server  50 , as seen in  FIG. 1 . Using the present method and application, transceiver  306  can include a Data Active Message  60  or a Data Inactive Message  66  sent to push server  50  via internet  40 , as illustrated in  FIG. 1 . These messages tell push server  50  that wireless data device  10  will accept data (Data Active Message  60 ) or not accept data (Data Inactive Message  66 ). 
   In one embodiment, Storage subsystem  302  stores a system record  308 . Each system record  308  represents all information for one wireless data device  10  and includes a device identifier field  308 B to store identifier information for a wireless data device  10 . Record  308  further preferably includes a device status field  308 D, as well as push server identifier field  308 F for identifying all push servers  50  associated with wireless data device  10 . 
   Processor  300  controls overall operation of PDSN  28 . When a Data Active Notification  68  arrives at transceiver interface  304 , the processor  300  examines its system record  308  stored in storage subsystem  302  and retrieves all of the push server identifiers stored in push server identifier field  308 F associated with the wireless data device  10 , as located based on device identifier field  308 B. Processor  300  sends out Data Active Message  60  to all the push servers  50  (not shown) via transceiver interface  306  and Internet  40  on behalf of wireless data device  10 , after which all push servers may commence serving the wireless data device  10  by pushing data traffic onto wireless network  20 . The device status field  308 D is updated accordingly. 
   Similarly when a Data Inactive Notification  72  arrives at transceiver interface  304 , the processor  300  examines its system record  308  stored in storage subsystem  302  and retrieves all push server identifiers stored in push server identifier field  308 F associated with that wireless data device  10 , as located in device identifier field  308 B. Processor  300  then sends out Data Inactive Message  66  to all push servers  50  via transceiver interface  306  and internet  40  on behalf of wireless data device  10 , after which all push servers may safely cease serving the wireless data device  10  by terminating pushing data traffic onto the wireless network  20 . The device status field  308 D is updated accordingly. 
     FIG. 5  is a block diagram of an exemplary BSC for use with a further method of the present application. It is applicable when both voice and data capabilities are available on wireless data device  10  but voice and data calls cannot be supported simultaneously. Operationally it includes at least one processor  400 , a storage subsystem  402 , and two transceiver interfaces  404  and  406 . 
   Storage subsystem  402  preferably has a system record  408 . Each system record  408  represents information for one wireless data device  10  and includes a device identifier field  408 B for storing identifiers for wireless data device  10 . System record  408  further preferably includes a device capability indicator field  408 C (to indicate whether the device associated with the device identifier field can support concurrent voice and data calls), a device voice call status field  408 D, as well as device data call status field  408 F. 
   Processor  400  controls the overall operation of BSC  24 . When a Voice Call Notification  76  arrives at transceiver interface  404 , the processor  400  examines its system record  408  stored in storage subsystem  402  and finds out through device capability indicator field  408 C whether voice call and data call can be supported simultaneously at wireless data device  10 . If voice call and data call cannot be supported simultaneously at wireless data device  10 , processor  400  further finds out through data call status field  408 F whether there exist any on-going push services. If at least one on-going push service exists, processor  400  will update voice call status field  408 D, data call status field  408 F and send out a Data Inactive Notification  72  to PDSN  28  via transceiver interface  406 . PDSN  28  may update push server  50  with the new status of wireless data device  10  accordingly as described above with reference to  FIG. 4 . 
   Similarly when a Voice End Notification  84  arrives at transceiver  404 , the processor  400  examines its system record  408  stored in storage subsystem  402  and finds out through device capability indicator field  408 C whether voice call and data call can be supported simultaneously at wireless data device  10 . If device capability indicator field  408 C indicates that voice call and data call cannot be supported simultaneously by device  10 , processor  400  further finds out through data call status filed  408 F whether there existed any on-going push services at the time of the voice call setup. If any of these push data services existed, processor  400  will send out a Data Active Notification  68  to PDSN  28  via transceiver interface  406 . PDSN  28  may update push server  50  with the new status of wireless data device  10  accordingly as described above with reference to  FIG. 4 . Voice call field  408 D and data call field  408 F will be updated accordingly. 
     FIG. 6  illustrates a flow chart of the above embodiments of the present application. If wireless data device  10  does not support voice operations, as identified in step  502 , then data communications are the sole concern, and processing proceeds to step  504 . 
   In step  504  a determination is made about whether the PDSN is incorporated into the present method and application. Without the PDSN being incorporated, the present method and application can be applied between the wireless data device  10  itself and push server  50 , which is described below referring to  FIG. 7 . Conversely, if in step  504  PDSN  28  is incorporated with the present method and application, the wireless data device  10  communicates with PDSN  28 , which in turn communicates with push servers  50 , as detailed below referring to  FIG. 8 . 
   If wireless data device  10  supports both data calls and voice, as found in step  502 , a check in step  506  is made to determine whether wireless data device  10  supports concurrent voice and data calls. If wireless data device  10  does not support concurrent voice calls and data calls, the present method and application allows BSC  24  to communicate status information to PDSN  28 , and push servers  50 , as detailed below in  FIG. 9 . 
   If in step  506  it is determined that wireless data device  10  supports concurrent voice and data calls then push server  50  does not need to cease pushing data calls when the device is active, and the process could end. However, as will be realized by those skilled in the art, the methods of  FIG. 7  or  8  could still be used to disable pushing of data when the wireless data device  10  is turned off or out of radio coverage. 
   Referring now to  FIG. 7 , this Figure illustrates in greater detail the signaling and data flow between wireless data device  10 , and two push servers  52  and  54  in accordance with a first embodiment of a method of the present application. 
   When the wireless data device  10  powers up, it notifies its data active status by sending Data Active Message  60 A and Data Active Message  60 B to push servers  52  and  54  respectively. After receiving Data Active Message  60 A and  60 B, data servers  52  and  54  start serving the wireless data device  10 . For example, user data  62 A and  62 B and server data  64 A and  64 B can be exchanged between wireless data device  10  and push servers  52  and  54  respectively. 
   When the wireless data device  10  powers down, it notifies its data inactive status by sending a Data Inactive Messages  66 A and  66 B to push servers  52  and  54  respectively. After receiving Data Inactive Message  66 A and  66 B, data server  52  and  54  stop serving the wireless data device  10 , preventing user data  62 A and  62 B from flowing in CDMA2000 network  20 . 
   The dashed curve lines of  FIG. 7  within push server  52  are meant to indicate that the corresponding signaling and data traffic is between wireless data device  10  and push server  54 , and does not actually flow through push server  52 . 
   An improvement to the method of  FIG. 7  is to have wireless data device  10  only send one message, rather than a message to each of the push servers  50 . This saves battery life of wireless data device  10  and network resources of wireless network  20 . Reference is now made to  FIG. 8 . 
     FIG. 8  illustrates in greater detail the signaling and data flow between wireless data device  10 , PDSN  28  and two push servers  52  and  54  in accordance with a second embodiment of the method of the present application. When the wireless data device  10  powers up it notifies PDSN  28  via BSC  24  with a Data Active Notification  68 . PDSN  28  in turn sends out Data Active Message  60 A and  60 B to push servers  52  and  54 . As one skilled in the art will realize, different number of push servers  50  could exist for wireless data device  10 , and if more push servers exist, Data Active Message  60  will be sent to these push servers as well. 
   As illustrated in  FIG. 4 , push servers  52  and  54  are registered within server identifier field  308 F associated with the wireless device identifier for wireless data device  10  at PDSN  28 . 
   After push servers  52  and  54  receive Data Active Messages  60 A and  60 B respectively, user data  62 A and  62 B and server data  64 A and  64 B can be exchanged between the wireless data device  10  and the push servers  52  and  54  respectively. In CDMA2000 network, Data Active Notification  68  may be associated with a Power Up Registration. 
   Likewise, when wireless data device  10  powers down, PDSN  28  is notified via BSC  24  using a Data Inactive Notification  72 . PDSN  28  then sends out Data Inactive Message  66 A and  66 B to push servers  52 ,  54 . In CDMA2000 network, this Data Inactive Notification  72  may be associated with Power Down Registration. 
   Based on the above, by using the method of  FIG. 8 , wireless data device  10  does not have to send out multiple Data Active Messages and Data Inactive Messages, thereby increasing its battery life, and reducing over the air traffic. 
   As with  FIG. 7 , the dashed lines flowing over push server  52  indicate that the signaling and data traffic is between wireless data device  10  and push server  54 , and does not flow through push server  52 . 
   In some cases it is desirable to further prevent push servers  50  from pushing data during a voice call when wireless data device  10  does not support concurrent voice and data calls. Reference is now made to  FIG. 9 . 
     FIG. 9  illustrates a signal flow diagram showing the signaling, voice and data flow among the wireless data device  10 , BSC  24 , MSC  26 , PDSN  28  and push servers  50  in accordance with a further embodiment of the a method of the present application.  FIG. 9  illustrates the interaction between a voice call and data call when voice and data cannot be supported simultaneously on wireless data device  10 . 
   Initially the wireless data device  10  is in a data (active or dormant) mode of an on-going push service. When a voice call comes in, MSC  26  notifies BSC  24  using Voice Call Notification  76 . BSC  24  realizes that wireless data device  10  is in a data (active or dormant) mode based on system record  408  through data call status field  408 F as outlined above with regards to  FIG. 5 . 
   BSC  24  sends a Data Inactive Notification  72  to PDSN  28 . After receiving Data Inactive Notification  72 , PDSN  28  notifies all push servers  50  that registered with it using a Data Inactive Message  66 . All push servers  50  stop pushing data onto the network for device  10  based on this message. 
   When the voice call ends, MSC  26  sends a Voice End Notification  84  to BSC  24 . BSC  24  then notifies PDSN  28  using a Data Active Notification  68 . After receiving Data Active Notification  68 , PDSN  28  sends out a Data Active Message  60  to all push servers that are associated with wireless data device  10  and registered with PDSN  28 . Push servers can then start exchanging user data  62  and server data  64  with wireless data device  10 . 
   The dashed curve line in MSC  26  indicates that the signaling and data traffic are either between wireless data device  10  and push servers  50  or between BSC  24  and PDSN  28 . They do not flow through push data MSC  26 . 
   The embodiments of  FIGS. 8 and 9  require all push servers  50  desirous of communicating with wireless data device  10  to register with PDSN  28 . In an alternative embodiment, the PDSN may gather push server information automatically by examining the header of each packet data designated for that wireless data device  10 . 
   The embodiments described herein are examples of structures, systems or methods having elements corresponding to elements of the application. This written description may enable those skilled in the art to make and use embodiments having alternative elements that likewise correspond to the elements of the application. The intended scope of the application thus includes other structures, systems or methods that do not differ from the application as described herein, and further includes other structures, systems or methods with insubstantial differences from the application as described herein.

Technology Classification (CPC): 7