Abstract:
A power management system is described where the handset can enter sleep or hibernation mode for a particular service, when the particular service is either not used or not available. The handset is capable of using the service, even in response to a non-user initiated incoming request for communication. The handset receives the request over the active service. The handset can then check for the availability of the inactive service, activate it, and a selection can be made between them.

Description:
RELATED APPLICATIONS 
     This application claims priority to Application Ser. No. 60/679,936 filed Aug. 16, 2005 by Govindarajan, et. al. The foregoing is incorporated herein by reference for all purposes. 
    
    
     BACKGROUND OF THE INVENTION 
     Wireless radio technology provides both cellular service and wireless local area networks. Cellular service provides both mobile telephone and data services, including Internet access. Wireless local area networks (wi-fi) have traditionally provided data services, as well. The development of the transfer of voice data over a packet-based network, such as the internet, allows voice communications. This is known as Voice over IP (VOIP), which has been used as a substitute for telephone service. 
     A user can use a modern wireless handset to access both cellular service and wi-fi, if they are available. The availability of each of these services depends on the location of the user and the radio coverage for each of these services at the user&#39;s location. When both are accessible, the user has a choice. The user can choose between the wi-fi and cellular service for both data services and between cellular phone service or VOIP. 
     The handsets scan for both cellular service and wi-fi signals. When the handset is out of range for either service, the handset may continue to scan for a signal, or stop scanning for the out of range signal. Continuing to scan for a signal consumes the battery of the handset. 
     By not scanning, the handset misses opportunities when the signal becomes available. For example, a user may travel through a hole in the radio coverage of either the cellular or wi-fi service. If when the handset loses the signal, the handset stops scanning, the handset will miss the signal when the user exits the hole. 
     This circumstance is aggravated when there is a communication attempt initiated by another party, such as an incoming phone call, or request for a chat communication. If the handset is not scanning for either the cellular service, or the wi-fi service, the incoming phone call/request for a chat communication is not received. If the handset is accessing one of the services, for example the cellular service, the handset receives the communication attempt via the cellular service. This can occur, even where the wi-fi service is available. However, handset does not take advantage of this choice. 
     BRIEF SUMMARY OF THE INVENTION 
     A power management system is described where the handset can enter sleep or hibernation mode for a particular service, when the particular service is either not used or not available. The handset is capable of using the service, even in response to a non-user initiated incoming request for communication. The handset receives the request over the active service. The handset can then check for the availability of the inactive service, activate it, and a selection can be made between them. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG. 1  is a diagram of the service options for the handset; 
         FIG. 2  is a state diagram describing the power states of the handset; 
         FIG. 3  describes the signaling for emerging from the cellular on/wi-fi off state to the cellular on/wi-fi on state; 
         FIG. 4  is a flow diagram for emerging from the cellular on/wi-fi off state to the cellular on/wi-fi on state by the handset; 
         FIG. 5  describes the signaling for emerging from the cellular off/wi-fi on to the cellular on/wi-fi on state; 
         FIG. 6  is a flow diagram for emerging from the cellular off/wi-fi on to the cellular on/wi-fi on state by the handset; 
         FIG. 7  is a flow diagram for the provider server; and 
         FIG. 8  is a block diagram for the handset. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a diagram of converged networks providing service for handset  100 . The handset  100  has access to both a cellular network  110  and a wi-fi network  120 . The cellular network  110  provides both cellular telephone and data services, such as Internet access and short message services (SMS) to the handset  100 . The cellular network  110  is generally, but does not have to be, a public land mobile network (PLMN), for example, according to GSM/GPRS (Global System for Mobile Communications and General Packet Radio Services). 
     The cellular network  110  provides access to the public switched telephone network (PSTN), allowing the handset to call and be called by another telephone. The cellular network  110  also provides access to the internet. The handset  100  can then access web servers, conduct chat sessions, and send email using the Internet. The cellular network  110  also includes a provider server  130 . The provider server  130  can be a computer that is linkable to a network. 
     The wi-fi network  120  also provides access to the Internet as well as other data services. The wi-fi network  120  is generally a more localized network, as compared to the cellular network. For example, the wi-fi network  120  can cover a corporate campus or the like, and also provide access to the company computer network. 
     The handset  100  can be a laptop, a palm pilot, a PDA, a blackberry, mobile phone or the like that can wirelessly access the cellular network  110  and the wi-fi network  120 . The handset  100  includes receivers for receiving the radio signals from both the cellular network  110  and the wi-fi network  120 . The receivers scan for signals from the cellular network  110  and the wi-fi network  120 . 
     When the handset  100  is out of range for either service, the handset powers down in a manner that maintains its readiness to wake up. This preserves battery power and saves energy. The handset  100  can be in four different power states: 
     a. Cellular Awake/Wi-fi Awake 
     b. Cellular Awake/Wi-fi Asleep 
     c. Cellular Asleep/Wi-fi Awake 
     d. Cellular Asleep/Wi-fi Asleep 
       FIG. 2  is a state diagram describing the power states of the handset. In state a, the handset  100  scans for signals from both the cellular network  110  and the wi-fi network  120 . For a variety of reasons, the signals that the handset  100  receives may fade. For example, the handset  100  may move to an area where the signal from either of the networks is weak or non-existent. 
     If the signals from cellular network  110  or wi-fi network  120  fades to less than some threshold signal strength, the cellular network  110  is no longer accessible by the handset  100 . After a period of time, the handset  100  stops scanning for a signal from the cellular network  110  or wi-fi network  120 . When the handset  100  stops scanning for the signal from the cellular network  110 , the handset  100  enters state c (arrow  205 ). When the handset  100  stops scanning for the signal from the wi-fi network  120 , the handset enters state b (arrow  210 ). From states b and c, where the handset  100  stops scanning for the signal from the other network  110 , or  120 , the handset  100  enters state d (arrow  215 ). In state d, the handset  100  polls the services at regular time intervals. Although the handset  100  stops scanning in states b, c, and d, the handset  100  is ready to resume both cellular  110  and wi-fi services  120  where such services are available. The existence of certain conditions cause the handset  100  to check for the availability of a particular service. Where the particular service is found, the handset  100  changes states. 
       FIG. 3  is a signal diagram for emerging from the cellular on/wi-fi off state to the cellular on/wi-fi on state as shown in  FIG. 2 , arrow  220 . The handset  100  maintains access to the cellular services  110 , but does not scan for signals from the wi-fi service  120 . 
     The handset  100  checks for the availability of the wi-fi service  120  responsive to a variety of conditions. Some of the conditions may be user-initiated. Examples of user-initiated conditions are placement of an outbound call, initiation of a chat request, accessing a web page, or sending an email. When one of these conditions occur, the handset  100  polls (arrow  305 ) for a wi-fi signal. 
     If the wi-fi signal is available, the handset  100  establishes a wi-fi connection (arrow  310 ). Upon establishing the wi-fi connection, the handset  100  transmits a signal (arrow  315 ) that informs the provider server  130  of its access to wi-fi services  120  over the wi-fi network. The signal provides information, such as the handset  100  IP address, and other information, such as user preferences, signal strength of the wi-fi, and the amount of battery power for the handset  100 . 
     If the wi-fi signal is available, the handset  100  compares the cellular service  110  to the wi-fi service  120  according to certain metrics. These metrics include (but are not limited to):
         a. Costs—the cost of each of the services. The cheaper service is preferred.   b. Power Consumption—the amount of power consumed by each service. The less power hungry service is preferred.   c. Quality of Services—how suitable the service is for the communication.   d. Signal Strength—the strength of the signal received.   e. User Preferences
 
Based on the comparison of a combination of these metrics, the handset  100  selects between the cellular service  110  and the wi-fi service  120 . For the data services, such as chat request, web page access, or sending an email, the handset  100  can use either the cellular service  110  (arrow  320 ) or the wi-fi service  120  (arrow  325 ) to access the Internet. For the outgoing call, the handset  100  can either use the wi-fi service for VOIP, or the cellular service  110 .
       

     The handset  100  also checks for the availability of the wi-fi services  120  in response to non-user initiated events. These events can include, for example, an incoming phone call, email, or chat request. The provider server  130  receives the incoming communication, and routes the communication through the cellular network  110  to the handset  100 . The cellular network  110  transmits a control signal (arrow  330 ) to the handset  100 . 
     The handset  100  polls the wi-fi network  120  (arrow  305 ) to determine if wi-fi services are available. If the wi-fi services  120  are available, the handset  100  registers with the wi-fi services  120 . Additionally, the handset  100  sends a signal (arrow  315 ) over the wi-fi network  120  to the provider server  130 , informing the provider server  130  of its IP address, and other information. 
     The handset  100  or provider server  130  compares the cellular service  110  and the wi-fi service  120  according to the aforementioned metrics and selects either the cellular network  110  or the wi-fi service  120  and selects one. If the handset  100  selects the service, the handset  100  sends a selection signal (arrow  315 ) to the provider server  130 . The provider server  130  can route the communication through the cellular network  110  (signal  325 ) or the wi-fi network  120  (signal  320 ). 
     Referring now to  FIG. 4 , there is illustrated a flow diagram for emerging from the cellular on/wi-off state to the cellular on/wi-fi on state by the handset  100 . At  405 , an event occurs at the handset  100 . The event can either be receiving a command for a user-initiated action, or receiving a notification of a non-user initiated communication. Upon the occurrence of the event, at  410  the handset  100  polls the wi-fi service  120 . If at  415 , the wi-fi service is available, the handset  100  registers with the wi-fi service at  420 , notifies the provider server  130  at  425 , and compares the cellular service  110  to the wi-fi service  120  according to the certain metrics at  430 . At  435 , the handset  100  communicates using the selected service. If at  415 , the wi-fi service is unavailable, the handset communicates using the cellular service  110  at  440 . 
       FIG. 5  is a signal diagram for emerging from the cellular off/wi-fi on state to the cellular on/wi-fi on state as shown in  FIG. 2 , arrow  230 . The handset  100  maintains access to the wi-fi services  120 , but does not scan for signals from the cellular services  110 . When the handset  100  accesses the wi-fi services  120 , the handset  100  sends a notification ( 502 ) to the provider server  130 . The notification  502  includes the IP address for the handset  100 , and other information, such as user preferences, signal strength of the wi-fi, and the amount of battery power for the handset  100 . 
     The handset  100  checks for the availability of the cellular service  110  responsive to a variety of conditions. Some of the conditions may be user-initiated. Examples of user-initiated conditions are placement of an outbound call, initiation of a chat request, accessing a web page, or sending an email. When one of these conditions occur, the handset  100  polls (arrow  505 ) for a cellular signal. 
     If the cellular signal is available, the handset  100  establishes a connection (arrow  510 ) with the cellular network  110 . If the cellular signal is available, the handset  100  compares the cellular service  110  to the wi-fi service  120  according to certain metrics. 
     Based on the comparison of a combination of these metrics, the handset  100  selects between the cellular service  110  and the wi-fi service  120 . For the data services, such as chat request, web page access, or sending an email, the handset  100  can use either the cellular service  110  (arrow  520 ) or the wi-fi service  120  (arrow  525 ) to access the Internet. For an outgoing call, the handset  100  can either use the wi-fi service  120  for VOIP, or the cellular service  110 . 
     The handset  100  also checks for the availability of the cellular services  110  in response to non-user initiated events. These events can include, for example, an incoming phone call, email, or chat request. The provider server  130  receives the incoming communication, and routes the communication through the wi-fi network  120  to the handset  100 . As noted above, the provider server  130  is aware of the handset  100  IP address from signal  502 . The wi-fi network  120  transmits a control signal (arrow  530 ) to the handset  100 , informing the handset  100  of the incoming communication. 
     The handset  100  polls the cellular network  110  (arrow  505 ) to determine if cellular services  110  are available. If the cellular services  110  are available, the handset  100  registers with the cellular services  110 . The provider server  130  compares the cellular service  110  and the wi-fi service  120 , using the information provided to it from signal  502 , according to the metrics and selects either the cellular network  110  or the wi-fi service  120 . Alternatively, the handset  100  makes the comparison and selection, and informs the provider server. The provider server  130  can route the communication through the cellular network  110  (arrow  540 ) or the wi-fi network  120  (arrow  550 ). 
     Referring now to  FIG. 6 , there is illustrated a flow diagram for emerging from the cellular on/wi-off state to the cellular on/wi-fi on state by the handset  100 . At  605 , an event occurs at the handset  100 . The event can either be receiving a command for a user-initiated action, or receiving a notification of a non-user initiated communication. Upon the occurrence of the event, at  610  the handset  100  polls the cellular service  110 . If at  615 , the cellular service  110  is available, the handset  100  registers with the cellular service at  620 , notifies the provider server  130  at  625 , and compares the cellular service  110  to the wi-fi service  120  according to the certain metrics at  630 . At  635 , the handset  100  communicates using the selected service. If at  615 , the cellular service  110  is not available, the handset  100  communicates using the wi-fi service at  640 . 
     Referring now to  FIG. 7 , there is illustrated a flow diagram for the provider server  130 . At  705 , the provider server  130  receives an incoming communication request. At  710 , the provider server  130  attempts to locate the handset  100  in both the cellular network  110  and the wi-fi network  120 . 
     If the handset  100  at  715  is only available in one of the networks, the provider server  130  notifies the handset  100  in the available network of the incoming request for communication. At  720  the provider server  130  receives a notification from the handset  100  indicating whether the handset  100  was able to establish connection with the other network, and if so, its location in the other network. At  725 , the provider  130  receives a signal from the handset  100  indicating the preferred network. At  730 , the provider server  130  sends the incoming request for communication to the handset  100  over the selected network. 
       FIG. 8  is a block diagram of the handset  100 . The handset  100  includes receiver(s) Rx for receiving radio signals from the cellular service  110  and the wi-fi service  120 , transmitter(s) Tx for transmitting radio signals to the cellular service  110  and the wi-fi service  120 , a keyboard  825 , a microphone  830 , speaker  835 , processor  840 , a memory  845 , a screen  847 , and a battery  850 . The memory  845  can store software that is run by the processor  840  that controls the handset  100  as has been described. 
     The foregoing section and figures describe the present invention by way of example. The present invention is not limited by the foregoing examples. Although cellular and wi-fi services are used as examples, other services can also be used. The examples can be modified in a variety of ways without departing from the scope of the present invention. Therefore, the present invention includes all embodiments falling within the scope of the following claims.