PATENT DOCUMENT

Publication Number: US-8837366-B2
Application Number: US-201213423875-A
Country: US
Kind Code: B2

Title: Method to use network measurements to optimize mobile wireless device performance

Abstract:
Method and apparatus for managing connections and state transitions between a mobile wireless device and a wireless network are described. The mobile wireless device measures network characteristics of radio sectors in the wireless network and saves the measured network characteristics in a database, later retrieving the network characteristics and determining data inactivity timeout values for the radio sector. The mobile wireless device manages connections and state transitions based on the determined data inactivity timeout values. The database of network characteristics is organized by geographic location.

Claims:
What is claimed is: 
     
       1. A method of managing connections between a mobile wireless device and a wireless network when a PDP context is established between the mobile wireless device and the wireless network, the method comprising the mobile wireless device:
 retrieving network timing characteristics of a radio sector of the wireless network from a database; 
 determining, by the mobile wireless device, a data inactivity timeout value for the radio sector based on the retrieved network timing characteristics of the radio sector, the data inactivity timeout value indicating a length of an inactive time period during which no data packets are transmitted by the wireless device to the wireless network; 
 measuring an elapsed time period after transmitting to the wireless network a most recently transmitted data packet; and 
 transmitting a data packet to the wireless network when the elapsed time period exceeds the data inactivity timeout value determined by the mobile wireless device. 
 
     
     
       2. The method as recited in  claim 1 , wherein the data inactivity timeout value determined by the mobile wireless device is less than a timeout period used by the wireless network to release the PDP context between the mobile wireless device and the wireless network. 
     
     
       3. The method as recited in  claim 1 , further comprising the mobile wireless device:
 measuring at least one network timing characteristic of the radio sector of the wireless network; and 
 storing the measured at least one network timing characteristic of the radio sector in the database. 
 
     
     
       4. The method as recited in  claim 3 , further comprising the mobile wireless device:
 maintaining the database of measured network timing characteristics organized by a geographic location identifiers for radio sectors in the database. 
 
     
     
       5. The method as recited in  claim 3 , further comprising the mobile wireless device:
 maintaining the database of measured network timing characteristics organized by a mobile country code (MCC), a mobile network code (MNC) and a radio sector identifier. 
 
     
     
       6. The method as recited in  claim 3 , wherein at least a portion of the database is stored in the mobile wireless device. 
     
     
       7. The method as recited in  claim 3 , wherein at least a portion of the database is stored in a server maintained by the wireless network. 
     
     
       8. The method as recited in  claim 4 , further comprising the mobile wireless device:
 monitoring a physical location of the mobile wireless device by tracking at least one of a global positioning system location of the mobile wireless device, a Wi-Fi access point location, and a radio sector site location of the wireless network; and 
 determining a geographic location identifier for the radio sector based on the monitored physical location of the mobile wireless device. 
 
     
     
       9. A method of managing state transitions in a mobile wireless device connected to a radio sector of a wireless network, the method comprising the mobile wireless device:
 retrieving network state transition timing information of the radio sector of the wireless network from a database; 
 determining, by the mobile wireless device, a network-based data inactivity timeout value for a state transition of the mobile wireless device from a first state to a second state based on the retrieved network state transition timing information of the radio sector of the wireless network; 
 setting a mobile wireless device based data inactivity timeout value to less than the determined network-based data inactivity timeout value for the state transition of the mobile wireless device from the first state to the second state; 
 detecting a time period of data inactivity at the mobile wireless device exceeding the set mobile wireless device based data inactivity timeout value; and 
 transitioning the mobile wireless device from the first state to the second state after detecting the time period of data inactivity at the mobile wireless device. 
 
     
     
       10. The method as recited in  claim 9 , wherein the network based data inactivity timeout value is associated with a state transition from the first state having an active data connection between the mobile wireless device and the wireless network to the second state having no active data connection. 
     
     
       11. The method as recited in  claim 10 , wherein the first state is a CELL_DCH state and the second state is a CELL_FACH state. 
     
     
       12. The method as recited in  claim 9 , further comprising the mobile wireless device:
 measuring network state transition timing information of the radio sector of the wireless network; and 
 storing the measured network state transition timing information of the radio sector in the database. 
 
     
     
       13. The method as recited in  claim 12 , further comprising the mobile wireless device:
 maintaining the database of measured network state transition timing information organized by geographic locations identifier for radio sectors in the database. 
 
     
     
       14. The method as recited in  claim 13 , wherein the geographic location identifier includes at least a mobile county code (MCC), a mobile network code (MNC) and a radio sector identifier. 
     
     
       15. The method as recited in  claim 13 , further comprising the mobile wireless device:
 monitoring a physical location of the mobile wireless device by tracking at least one of a global positioning system location of the mobile wireless device, a Wi-Fi access point location, and a radio sector site location of the wireless network; and 
 determining a geographic location identifier for the radio sector based on the monitored physical location of the mobile wireless device. 
 
     
     
       16. The method as recited in  claim 15 , wherein at least a first portion of the database is stored in a server maintained by the wireless network and a second portion of the database is stored in the mobile wireless device. 
     
     
       17. A mobile wireless device comprising:
 a transceiver to transmit signals to and receive signals from a wireless network; and 
 a processor configured to cause the mobile wireless device to: 
 measure network characteristics of radio sectors of the wireless network in which the mobile wireless device operates; 
 store the measured network characteristics of the radio sectors in a database in the mobile wireless device; 
 retrieve one or more stored network characteristics of a radio sector to which the mobile wireless device is connected from the database; 
 determine, by the mobile wireless device, a network timeout value for the radio sector to which the mobile wireless device is connected based on the retrieved one or more network characteristics of the radio sector; 
 measure a time period of data inactivity during which the mobile wireless device transmits no data packets to the wireless network after transmission of a most recently transmitted data packet; and 
 transmit a dummy data packet to the wireless network when the measured time period of data inactivity exceeds the determined network timeout value and transmit data buffers are empty. 
 
     
     
       18. The mobile wireless device as recited in  claim 17 , wherein the processor is further configured to cause the mobile wirelss device to:
 maintain the database of measured network characteristics of the radio sectors organized by geographic location identifiers for radio sectors in the database. 
 
     
     
       19. The mobile wireless device as recited in  claim 18 , wherein the processor is further configured to cause the mobile wirelss device to:
 monitor a physical location of the mobile wireless device by tracking at least one of a global positioning system location of the mobile wireless device, a Wi-Fi access point location, and a radio sector site location of the wireless network; and 
 determine a geographic location identifier for the radio sector to which the mobile wireless device is connected based on the monitored physical location of the mobile wireless device. 
 
     
     
       20. The mobile wireless device as recited in  claim 17 , wherein the processor is further configured to cause the mobile wirelss device to:
 maintain the database of measured network characteristics of the radio sectors organized by a mobile country code (MCC), a mobile network code (MNC) and a radio sector identifier. 
 
     
     
       21. The mobile wireless device as recited in  claim 17 , wherein the determined network timeout value is less than a timeout period used by the wireless network to release a PDP context between the mobile wireless device and the wireless network. 
     
     
       22. A computer program product encoded in a non-transitory computer readable medium for managing state transitions in a mobile wireless device connected to a radio sector of a wireless network, the computer program product comprising computer program code, which when executed by a processor, causes the mobile wireless device to:
 retrieve network characteristics of the radio sector of the wireless network to which the mobile wireless device is connected from a database; 
 determine by the mobile wireless device, a network-based data inactivity timeout value for a state transition of the mobile wireless device from a first state to a second state based on the retrieved network characteristics of the radio sector of the wireless network; 
 set a mobile wireless device based data inactivity timeout value to less than the determined network based data inactivity timeout value for the state transition of the mobile wireless device from the first state to the second state; 
 detect a time period of data inactivity at the mobile wireless device exceeding the set mobile wireless device based data inactivity timeout value; and 
 transition the mobile wireless device from the first state to the second state after detecting the time period of data inactivity at the mobile wireless device. 
 
     
     
       23. The computer program product as recited in  claim 22 , wherein the network based data inactivity timeout value is associated with a state transition from the first state having an active data connection between the mobile wireless device and the wireless network to the second state having no active data connection. 
     
     
       24. The computer program product as recited in  claim 23 , wherein the first state is a CELL_DCH state and the second state is a CELL_FACH state. 
     
     
       25. The computer program product as recited in  claim 22 , further comprising computer program code, which when executed by the processor, causes the mobile wireless device to:
 measure network characteristics of the radio sector of the wireless network in which the mobile wireless device operates; 
 store the measured network characteristics of the radio sector in the database.

Description:
TECHNICAL FIELD 
     The described embodiments generally relate to methods and apparatuses for optimizing performance of mobile wireless devices. More particularly, the present embodiments describe use of network measurements of network timing characteristics to improve operating performance of mobile wireless devices. 
     BACKGROUND 
     Wireless networks continue to evolve as new communication technologies develop and standardize. A representative wireless network for a wireless network service provider can include support for one or more releases of wireless communication protocols specified by the Third Generation Partnership Project (3GPP) and Third Generation Partnership Project 2 (3GPP2) communication standards organizations. The 3GPP develops wireless communication standards that include releases for Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE) and LTE Advanced standards. The 3GPP2 develops wireless communication standards that include CDMA2000 1×RTT and 1×EV-DO standards. Each wireless communication standard includes operational parameters for wireless network equipment including mobile wireless devices. Some operational characteristics, such as network timing characteristics, can be expressed as a range of values or can be not specified in the wireless communication standard. A mobile wireless device operating in a wireless network can be not informed of specific values for network timing characteristics for the radio sector of the wireless network in which the mobile wireless device is operating. Representative network timing characteristics can include a number of inactivity timeout values that can cause a connection between the wireless network and the mobile wireless device to be released or can transition the mobile wireless device between operating states. In order to optimize operating performance, the mobile wireless device can prefer to transition between different operating states and to establish, maintain and release connections under its own control rather than according to timing determined by the wireless network, at least where the wireless communication standard allows such flexibility. Power consumption by the mobile wireless device can depend on the operating state in which the mobile wireless device operates. By controlling the operating state, the mobile wireless device can conserve power when limited amounts or no data is available for transmission. In addition, a user&#39;s experience in using the mobile wireless device can be affected by responsiveness to user input, and “always on” connections can provide quicker immediate feedback than when connections need be established. Maintaining a connection during brief periods of data inactivity can ensure rapid response when data transmission resumes. Each radio sector (also referred to as a cell) of a wireless network to which a mobile wireless device can be associated or connected can use different values for network timing characteristics. As the actual values can be unknown a priori to the mobile wireless device, there exists a need to measure network timing characteristics and to use the measured characteristics to optimize performance of the mobile wireless device. 
     SUMMARY OF THE DESCRIBED EMBODIMENTS 
     In one embodiment, a method of managing connections between a mobile wireless device and a wireless network is described. The method includes at least the following steps when a PDP context is established between the mobile wireless device and the wireless network. In a first step, the mobile wireless device retrieves network timing characteristics for a radio sector of the wireless network from a database. The mobile wireless device determines a data inactivity timeout value for the radio sector based on the retrieved network timing characteristics of the radio sector. The mobile wireless device measures an elapsed time period after transmitting to the wireless network a most recently transmitted data packet and transmits a data packet to the wireless network when the elapsed time period equals the data inactivity timeout value. In an embodiment, the mobile wireless device maintains the database of measured network timing characteristics organized by a geographic location identifier for the radio sector. 
     In another embodiment, a method of managing state transitions in a mobile wireless device connected to a radio sector of a wireless network is described. The method includes at least the following steps. In a first step, the mobile wireless device retrieves network state transition timing information for the radio sector of the wireless network from a database. The mobile wireless device determines a network based data inactivity timeout value for a state transition of the mobile wireless device from a first state to a second state based on the retrieved network state transition timing information for the radio sector of the wireless network. The mobile wireless device sets a mobile wireless device based data inactivity timeout value less than the determined network based data inactivity timeout value for the state transition of the mobile wireless device from the first state to the second state. After detecting a time period of data inactivity at the mobile wireless device exceeding the set mobile device data inactivity timeout value, the mobile wireless device transitions from the first state to the second state. In an embodiment, the network based data inactivity timeout value is associated with a state transition from the first state having an active data connection between the mobile wireless device and the wireless network to the second state having no active data connection. 
     In a further embodiment, a mobile wireless device including a transceiver and a configurable processor is described. The receiver transmits signals to and receives signals from a wireless network. The processor is configured to measure network characteristics of radio sectors of the wireless network in which the mobile wireless device operates. The processor is also configured to store the measured network characteristics in a database in the mobile wireless device. The processor is further configured to retrieve one or more stored network characteristics of the radio sector to which the mobile wireless device is connected from the database and to determine a network timeout value based on the retrieved network characteristics of the radio sector. The processor is configured to measure a time period of inactivity after transmission of a data packet and to transmit a dummy data packet when the measured time period exceeds the determined network timeout value. In an embodiment, the processor is further configured to monitor the physical location of the mobile wireless device by tracking at least one of a global positioning system location of the mobile wireless device, a WiFi access point location and a radio sector site location of the wireless network and to determine the geographic location identifier of the radio sector based on the monitored physical location of the mobile wireless device. 
     In another embodiment, computer program product encoded in a non-transitory computer readable medium for managing state transitions in a mobile wireless device connected to a radio sector of a wireless network is described. The computer program product in the mobile wireless device includes the following computer program code. Computer program code for retrieving network characteristics for the radio sector of the wireless network from a database. Computer program code for determining a network based data inactivity timeout value for a state transition of the mobile wireless device from a first state to a second state based on the retrieved network characteristics for the radio sector of the wireless network. Computer program code for setting a mobile wireless device based data inactivity timeout value less than the determined network based data inactivity timeout value for the state transition of the mobile wireless device from the first state to the second state. Computer program code for detecting a time period of data inactivity at the mobile wireless device exceeding the set mobile wireless device based data inactivity timeout value. Computer program code for transitioning the mobile wireless device from the first state to the second state after detecting the time period of data inactivity at the mobile wireless device. In an embodiment, the network based data inactivity timeout value is associated with a state transition from the first state having an active data connection between the mobile wireless device and the wireless network to the second state having no active data connection. 
     Although described in terms of a UMTS wireless network, the embodiments disclosed herein can be extended to include GSM networks, CDMA2000 1×/EV-DO networks and LTE/LTE-Advanced networks as well. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The described embodiments and the advantages thereof may best be understood by reference to the following description taken in conjunction with the accompanying drawings. 
         FIG. 1  illustrates components of a generic wireless communication network. 
         FIG. 2  illustrates components of a UMTS wireless communication network. 
         FIG. 3  illustrates components of a CDMA2000 1× wireless communication network. 
         FIG. 4  illustrates components of a LTE wireless communication network. 
         FIG. 5  illustrates a representative architecture for a mobile wireless communication device. 
         FIG. 6  illustrates a state transition diagram for a mobile wireless communication device for a UMTS wireless network. 
         FIG. 7  illustrates a state transition diagram for a mobile wireless communication device for a GSM wireless network. 
         FIG. 8  illustrates a state transition diagram for a mobile wireless communication device for a CDMA2000 1× wireless network. 
         FIG. 9  illustrates a state transition diagram for a mobile wireless communication device for an LTE wireless network. 
         FIG. 10  illustrates a representative method for managing connections between a mobile wireless device and a wireless network. 
         FIG. 11  illustrates a representative method for managing state transitions in a mobile wireless device connected to a radio sector of a wireless network. 
         FIG. 12  illustrates a representative method for maintaining an active connection between a mobile wireless device and a radio sector of a wireless network. 
     
    
    
     DETAILED DESCRIPTION OF SELECTED EMBODIMENTS 
     In the following description, numerous specific details are set forth to provide a thorough understanding of the concepts underlying the described embodiments. It will be apparent, however, to one skilled in the art that the described embodiments may be practiced without some or all of these specific details. In other instances, well known process steps have not been described in detail in order to avoid unnecessarily obscuring the underlying concepts. 
     The examples and embodiments provided below describe various methods and apparatuses for managing connections and state transitions in a wireless mobile wireless device connected to a radio sector of a wireless network. Representative embodiments are described for simplicity in relation to a UMTS wireless network; however other implementations of the same methods and apparatuses can apply to mobile wireless devices used in other types of wireless networks. For example, the same teachings could also be applied to a GSM wireless network, a CDMA2000 1×/EV-DO wireless network, and an LTE/LTE-Advanced wireless network or to other wireless networks using voice and packet data wireless communications. In general, the teachings described herein can apply to a mobile wireless device operating in a wireless network based on radio frequency access technology. 
     Wireless communication network deployments continue to evolve as wireless communication network technology advances and new or updated wireless communication protocols are standardized. Circuit switched networks continue to offer voice services, while packet switched networks expand from data oriented services to include a multiplicity of services including video and packet voice. Mobile wireless devices also continue to increase in functionality to supplement voice connections with multimedia internet connectivity and advanced resolution displays in compact form factors. Users can desire both responsiveness and extended battery life from a multi-functional mobile wireless device. For responsiveness, maintaining connections to a wireless network during brief periods of inactivity can provide ready access to internet services. For extended battery life, minimizing power consumption during longer periods of inactivity can conserve stored battery power. Several different timeout mechanisms specified by wireless communication protocols can determine when a wireless network transitions a mobile wireless device from a higher power consumption state to a lower power consumption state, and also when to tear down an active data connection and/or signaling connection in order to reassign scarce radio frequency access resources to other mobile wireless devices. Wireless networks can share radio frequency resources in an access network among multiple mobile wireless devices. As such, active connections between the mobile wireless device and the wireless network can be dropped after a period of data transmission inactivity in order to reallocate the radio frequency resources until required by the mobile wireless device. The user of the mobile wireless device, however, can prefer that the mobile wireless device be immediately responsive when data transmission activity resumes, without any perceptible delay to re-establish connections between the mobile wireless device and the wireless network. Each radio sector within a wireless network can use different timeout values, so the mobile wireless device can not know a priori timeout values of the radio sector to which the mobile wireless device is connection and adjust its behavior accordingly. Instead, the mobile wireless device can observe network characteristics and store values for those observed network characteristics in a database. The database can be organized based on a geographic location or based on a unique network element identifier such that the mobile wireless device can learn and re-use values for network characteristics. With knowledge of network characteristics, such as state transition timing characteristics and connection release timeout values, the mobile wireless device can take actions to provide a balance between responsiveness and power consumption for the user of the mobile wireless device. In a representative embodiment, the mobile wireless device can maintain a connection during brief periods of data inactivity by sending a data packet to the wireless network before a connection release timeout for the radio sector of the wireless network occurs. The mobile wireless device can retrieve a previously measured value for the connection release timeout stored in the database for a current radio sector of the wireless network to which the mobile wireless device is connected. Similarly, when a more extended period of data inactivity can occur, the mobile wireless device can release connections and/or transition from higher power consumption states to lower power consumption states in advance of a timeout for the wireless network based on knowledge of the state transition timing characteristics of the radio sector. Measurements of network characteristics can be stored, retrieved and used to optimize performance of the mobile wireless device when operating within a radio sector of the wireless network. 
     These and other embodiments are discussed below with reference to  FIGS. 1-12 . However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes only and should not be construed as limiting. 
       FIG. 1  illustrates a representative generic wireless communication network  100  that can include multiple mobile wireless devices  102  connected by radio links  126  to radio sectors  104  provided by a radio access network  128 . Each radio sector  104  can represent a geographic area of radio coverage emanating from an associated radio node  108  using a radio frequency carrier at a selected frequency. Radio sectors  104  can have different geometric shapes depending on antenna configuration, such as radiating outward in an approximate circle or hexagon from a centrally placed radio node  108  or cone shaped for a directional antenna from a corner placed radio node  108 . Radio sectors  104  can overlap in geographic area coverage so that the mobile wireless device  102  can receive signals from more than one radio sector  104  simultaneously. Each radio node  108  can generate one or more radio sectors  104  to which the mobile wireless device  102  can connect by one or more radio links  126 . Radio sectors  104  can also be referred to as cells in some wireless networks; however, the description herein will use the generic term “radio sector.” The wireless network  100  can determine network characteristics for each radio sector  104  that can include network timing values, such as for establishing and releasing connections between the mobile wireless device  102  and a radio node  108 . The wireless network  100  can also determine state transition timing mechanisms that can determine when to transition a mobile wireless device  102  connected through the radio sector  104  to the wireless network  100  between different operating states. While the mobile wireless device  102  can have direct knowledge of certain network timing values, such as those that are fixed by a wireless communication standard, other network characteristics can vary over a range of values and/or can be only known through observation and measurement. The mobile wireless device  102  can measure and remember key network characteristics for each radio sector  104  of the wireless network  100  in order to modify its own behavior to provide a balance between responsiveness and power conservation for the user of the mobile wireless device  102 . 
     In some wireless networks  100 , the mobile wireless device  102  can be connected to more than one radio sector  104  simultaneously. The multiple radio sectors  104  to which the mobile wireless device  102  is connected can come from a single radio node  108  or from separate radio nodes  108  that can share a common radio controller  110 . A group of radio nodes  108  together with the associated radio controller  110  can be referred to as a radio access subsystem  106 . Typically each radio node  108  in a radio access subsystem  106  can include a set of radio frequency transmitting and receiving equipment mounted on an antenna tower, and the radio controller  110  connected to the radio nodes  108  can include electronic equipment for controlling and processing transmitted and received radio frequency signals. The radio controller  110  can manage the establishment, maintenance and release of the radio links  126  that connect the mobile wireless device  102  to the radio access network  128 . The radio controller  110  in the radio access subsystem  106  can thus control some of the network timing characteristics that can be observed, measured and stored in a database by the mobile wireless device  102 . Radio links  126  can be set up and torn down by the radio access subsystem  106  to provide connections for both voice/data services and for signaling between the mobile wireless device  102  and the wireless network  100 . As radio frequency resources provided by the radio access network  128  can be scarce and shared among multiple different mobile wireless devices  102  simultaneously, the wireless network  100  can re-allocate radio resources as required to balance throughput capacity to multiple users of the wireless network  100 . 
     The radio access network  128 , which provides radio frequency air link connections to the mobile wireless device  102 , connects also to a core network  112  that can include a circuit switched domain  122 , usually used for voice traffic, and a packet switched domain  124 , usually used for data traffic. Radio controllers  110  in the radio access subsystems  106  of the radio access network  128  can connect to both a circuit switching center  118  in the circuit switched domain  122  and a packet switching node  120  in the packet switched domain of the core network  112 . The circuit switching center  118  can route circuit switched traffic, such as a voice call, to a public switched telephone network (PSTN)  114 . The packet switching node  120  can route packet switched traffic, such as a “connectionless” set of data packets, to a public data network (PDN)  116 . 
       FIG. 2  illustrates a representative UMTS wireless communication network  200  that can include one or more user equipment (UE)  202  that can communicate with a UMTS terrestrial radio access network (UTRAN)  242  that can connect to a core network (CN)  236 . The UE  202  shown for the UMTS wireless network  200  in  FIG. 2  can be equivalent to the mobile wireless device  102  shown for the generic wireless network  100  in  FIG. 1 . The core network  236  can include a circuit switched domain  238  that can connect the UE  202  to a public switched telephone network (PSTN)  232  and a packet switched domain  240  that can connect the UE  202  to a packet data network (PDN)  234 . The UTRAN  242  can include one or more radio network sub-systems (RNS)  204 / 214  each of which can include a radio network controller (RNC)  208 / 212  and one or more Node-Bs (base stations)  206 / 210 / 216  managed by a corresponding RNC. The RNC  208 / 212  within the UTRAN  242  can be interconnected to exchange control information and manage packets received from and intended for the UE  202 . Each RNC  208 / 212  can handle the assignment and management of radio resources for the cells  244  through which the UE  202  connects to the UMTS wireless network  200  and can operate as an access point for the UE  202  with respect to the core network  236 . The Node-B  206 / 210 / 216  can receive information sent by the physical layer of UE  202  through an uplink and transmit data to UE  202  through a downlink and can operate as an access point of the UTRAN  242  for UE  202 . 
     UTRAN  242  can construct and maintain a radio access bearer (RAB) for communication between UE  202  and the core network  236 . Services provided to a specific UE  202  can include circuit switched (CS) services and packet switched (PS) services. For example, a general voice conversation can be transported through a circuit switched service, while a Web browsing application can provide access to the World Wide Web (WWW) through an internet connection that can be classified as a packet switched (PS) service. To support circuit switched services, the RNC  208 / 212  can connect to the mobile switching center (MSC)  228  of core network  236 , and MSC  228  can be connected to gateway mobile switching center (GMSC)  230 , which can manage connections to other networks, such as the PSTN  232 . To support packet switched services, the RNC  208 / 212  can also be connected to serving general packet radio service (GPRS) support node (SGSN)  224 , which can connect to gateway GPRS support node (GGSN)  226  of core network  236 . SGSN  224  can support packet communications with the RNC  208 / 212 , and the GGSN  226  can manage connections with other packet switched networks, such as the PDN  234 . A representative PDN  234  can be the “Internet” A packet data protocol (PDP) context can be established between the GGSN  226  and the UE  202  to support packet data services between the PDN  234  and the UE  202 . With a PDP context established, an internet protocol (IP) address can be associated with the UE  202 . While data traffic between the UE  202  and the UMTS wireless network  200  can be transmitted in bursts, it can be preferred to maintain the PDP context during brief periods of data inactivity rather than having to re-establish the PDP context when data is available for transfer to/from the UE  202 . By maintaining the PDP context, the IP address associated with the UE  202  can remain constant. 
       FIG. 3  illustrates a representative CDMA2000 1× wireless network  300  that can include elements comparable to those described earlier for the generic wireless network  100  and the UMTS wireless network  200 . Multiple mobile stations  302  can connect to one or more radio sectors  304  through radio frequency links  326 . Each radio sector  304  can radiate outward from a base transceiver station (BTS)  308  that can connect to a base station controller (BSC)  310 , together forming a base station subsystem (BSS)  306 . Multiple base station subsystems  306  can be aggregated to form a radio access network  328 . Base station controllers  310  in different base station subsystems  306  can be interconnected. The base station controllers  310  can connect to both a circuit switched domain  322  that use multiple mobile switching centers (MSC)  318  and a packet switched domain  324  formed with packet data service nodes (PDSN)  320 , which together can form a core network  312  for the wireless network  300 . As with the other wireless networks  100 / 200  described above, the circuit switched domain  322  of the core network  312  can interconnect to the PSTN  114 , while the packet switched domain  324  of the core network  312  can interconnect to the PDN  116 . 
       FIG. 4  illustrates a representative Long Term Evolution (LTE) wireless network  400  architecture designed as a packet switched network exclusively. A mobile terminal  402  can connect to an evolved radio access network  422  through radio links  426  associated with radio sectors  404  that emanate from evolved Node B&#39;s (eNodeB)  410 . The eNodeB  410  includes the functions of both the transmitting and receiving base stations (such as the Node B  206  in the UMTS network  200  and the BTS  308  in the CDMA2000 network  300 ) as well as the base station radio controllers (such as the RNC  212  in the UMTS network  200  and the BSC  310  in the CDMA2000 network  300 ). The equivalent core network of the LTE wireless network  400  is an evolved packet core network  420  including serving gateways  412  that interconnect the evolved radio access network  422  to public data network (PDN) gateways  416  that connect to external internet protocol (IP) networks  418 . Multiple eNodeB  410  can be grouped together to form an evolved UTRAN (eUTRAN)  406 . The eNodeB  410  can also be connected to a mobility management entity (MME)  414  that can provide control over connections for the mobile terminal  402 . 
       FIG. 5  illustrates select elements of a mobile wireless device  102 . The mobile wireless device  102  can include a transceiver  504  that can process signals according to one or more wireless communication protocols. The transceiver  504  can be connected to a processor  502  that can provide higher layer functions, such as requesting establishment and release of connections for various resident application services. The processor  502  can also measure, analyze, store and retrieve network characteristics in a database to determine actions to take in order to optimize performance of the mobile wireless device  102 . While depicted as a single block in  FIG. 5 , the processor  502  can also be divided among multiple elements, such as among an application processor that can execute applications that can interact with the user of the mobile wireless device  102  and a baseband processor that can encode and decode signals that can interface with the wireless network  100  through the transceiver  504 . The transceiver  504  can provide the lower layer functions that can support the transport of data for the higher layer services ordered by the processor  502 . The transceiver  504  can be connected to a first antenna  506  and a second antenna  508  that can transmit and receive signals according to the one or more wireless communication protocols. The use of multiple antennas for certain wireless communication protocols can provide improved performance (e.g. higher data rates and/or better immunity to noise/interference) compared to a single antenna configuration. For example, a multiple input multiple output (MIMO) scheme can be used for mobile terminals  402  connected to the LTE wireless network  400 . 
       FIG. 6  illustrates a state transition diagram  600  having several states for a radio resource control (RRC) portion of a protocol stack for a UE  202  operating in a UMTS wireless network  200 . The UE  202  can be in an unconnected UTRAN IDLE state  612  or in a UTRA RRC connected state  610 , and the UTRA RRC connected state  610  can include several different states. In the UTRAN IDLE state  612 , the UE  202  can request an RRC connection to establish radio resources for communication between the UE  202  and the UMTS wireless network  200  whenever data is available to exchange between UE  202  and the UTRAN  242  in the wireless network  200 . The UE  202  can establish the RRC connection when an application in the UE  202  requires a connection to send data or to retrieve data from the UMTS wireless network  200 . The UE  202  can also establish the RRC connection when initiating a mobile originated voice connection or completing a mobile terminated voice connection. When the UE  202  has sent a request to the UTRAN  242  to establish a radio connection, the UTRAN  242  can choose a state for the RRC connection between the UE  202  and the wireless network  200 . The UTRA RRC connected state  610  can include four separate states for the UE  202 : a CELL_DCH state  606 , a CELL_FACH state  608 , a CELL_PCH state  604  and a URA_PCH state  602 . Each of these separate states  602 / 604 / 606 / 608  for the UTRA RRC connected state  610  can provide different capabilities for connections between the UE  202  and the wireless network  200  and can also consume different amounts of power from a battery in the UE  202 . 
     From the UTRAN IDLE state  612 , UE  202  can transition initially to the CELL_FACH state  608 , in which UE  202  can make an initial data transfer to the UMTS wireless network  200 , subsequent to which the UMTS wireless network  200  can determine which of the states  602 / 604 / 606 / 608  in the UTRA RRC connected state  610  to use for continued data transfer between the UE  202  and the UMTS wireless network  200 . The wireless network  200  can move UE  202  into the Cell Dedicated Channel (CELL_DCH) state  606  or keep UE  202  in the Cell Forward Access Channel (CELL_FACH) state  608 . In CELL_DCH state  606 , a dedicated channel can be allocated to UE  202  for both uplink and downlink to exchange data. The CELL_DCH state  606 , with a dedicated physical channel allocated to UE  202 , can typically consume more battery power from UE  202  than the other states of the UTRA RRC connected state  610 , and significantly more battery power than the IDLE state  612 . Alternatively, rather than place the UE  202  in the CELL_DCH state, UTRAN  242  can maintain UE  202  in a CELL_FACH state  608 . In a CELL_FACH state  608  no dedicated channel can be allocated to UE  202 . Instead, common channels can be used to send signaling in relatively small bursts of data. However, UE  202  can continue to monitor common channels in the CELL_FACH state  608 , and therefore the UE  202  can consume more battery power than in select alternative states, namely CELL_PCH state  604  and URA_PCH state  602 , as well as compared to UTRAN IDLE state  612 . While the UTRAN IDLE state  612  can consume the least amount of power, the UE  202  can require a connection establishment  614  when data is available for transfer with the wireless network  200 . As such, the user of the UE  202  can in some cases detect a delay for data transfer as the UE  202  transitions from the UTRAN IDLE state to the UTRA RRC connected state  610 . For short periods of data inactivity, the user of the UE  202  can prefer to keep the UE  202  in the UTRA RRC connected state  610  rather than transition to the UTRAN IDLE state  612 . For longer periods of data inactivity, however, conserving battery power can be preferred and a state having lower power consumption than the CELL DCH  606  state can be preferred. 
       FIG. 7  illustrates a state transition diagram  700  for a mobile wireless device  102  operating in a GSM/GPRS network. Transitions between a GSM/GPRS connected state  702  and a GSM/GPRS idle state  704  can occur when establishing and releasing connections  706  between the mobile wireless device  102  and the wireless network  100 . 
       FIG. 8  illustrates a state transition diagram  800  between states in a CDMA2000 1×/EV-DO wireless network  300 . A mobile station  302  in the CDMA2000 1×/EV-DO wireless network  300  can be in a 1×RTT/EV-DO idle state  804  and can establish and release connections  806  to transition between the 1×RTT/EV-DO idle state  804  and the 1×RTT/EV-DO connected state  802 . 
       FIG. 9  illustrates a state transition diagram  900  between states in an LTE/LTE-Advanced wireless network  400 . A mobile terminal  402  in the LTE/LTE-Advanced wireless network  400  can be in an E-UTRAN idle state  904  and can establish and release connections  906  to transition between the E-UTRAN idle state  904  and the E-UTRAN connected state  902 . 
     For each of the state transition diagrams  600 / 700 / 800 / 900  illustrated in  FIGS. 6-9 , the associated wireless network can determine when to transition a mobile wireless device  102  between the states in the state transition diagrams  600 / 700 / 800 / 900 . The timeout values used for the state transitions can be not known to the mobile wireless device  102 ; however, the mobile wireless device  102  can measured network characteristics and store the measured values to later use to determine when state transitions can occur. The mobile wireless device  102  can use the measured network characteristics in combination with knowledge of internal status (e.g. state of internal data buffers) to improve operating performance of the mobile wireless device  102 . In a representative embodiment, the mobile wireless device  102  can determine that no additional data remains to be sent, and the mobile wireless device  102  can conserve power by switching to a lower power consuming state earlier than would occur when waiting for the wireless network  100  to determine a data timeout has occurred. In another representative embodiment, the mobile wireless device  102  can prefer to maintain a connection with the wireless network  100  by sending “dummy” data packets in the absence of having other data packets to send and before a network data inactivity timeout can occur. The “dummy” data packets can “keep alive” the connection between the wireless network  100  and the mobile wireless device  102 , so that a data connection, signaling connection, PDP context, or other connection required to transmit and receive data by the mobile wireless device  102  is already established when additional data is ready for transfer. 
       FIG. 10  illustrates a representative method of managing connections between the mobile wireless device  102  and the wireless network  100 . While the method is described for a generic wireless network  100 , the same method can equally apply to the UMTS wireless network  200 , the CDMA1×/EV-DO wireless network  300  and the LTE wireless network  400 . When connected to the radio sector  104  of the wireless network  100 , in step  1002 , the mobile wireless device  102  retrieves a network timing characteristic for the radio sector  102  from a database. The database is located in the mobile wireless device  102  or in the wireless network infrastructure. In step  1004 , the mobile wireless device  102  determines a data inactivity timer value for the radio sector  1004  based on the retrieved network timing characteristic. In a representative embodiment, the retrieved network timing characteristic is a timeout interval for the radio sector  104  of the wireless network  100 . In an embodiment, the retrieved network timing characteristic is measured by the mobile wireless device  102  during a previous connection (or during the current connection) and stored in the database for retrieval later by the mobile wireless device  102 . The data inactivity timeout value for the radio sector  102  of the wireless network  100  is determined based on the retrieved network timing characteristic. In an embodiment, the determined data inactivity timeout value is less than the timeout period used by the wireless network  100  to release a packet data protocol (PDP) context between the mobile wireless device  102  and the wireless network  100 . In step  1006 , the mobile wireless device  102  measures an elapsed time period after transmitting a most recent data packet. After transmitting each data packet, the mobile wireless device  102  can measure an inactivity time period when no data packets are received or sent. In an embodiment, the mobile wireless  102  can measure data inactivity time periods only after sending a data packet that empties a transmit data buffer. In step  1008 , the mobile wireless device  102  transmits a data packet to the wireless network  100  when the measured elapsed time period exceeds the data inactivity timeout value. The data packet can be a “dummy” data packet solely sent to maintain data activity without any “real” data included or can be an “actual” data packet containing “real” data. As a result of the mobile wireless device  102  transmitting the data packet, the wireless network  100  will detect data activity from the mobile wireless device  102  and thereby reset its own data inactivity timeout mechanisms that could otherwise trigger a change of state for the mobile wireless device  102  or release a connection between the mobile wireless device  102  and the wireless network  100 . In an embodiment, by maintaining a PDP context between the mobile wireless device  102  and the wireless network  100 , an IP address can be sustained for packet data transmission between the mobile wireless device  102  and the wireless network  100  during brief periods of data inactivity. 
     In a representative embodiment, the mobile wireless device  102  organizes the database of measured network timing characteristics based on a geographic location identifier for the radio sector  104 . The geographic location identifier can be used by the mobile wireless device  102  to associate the radio sector  104  in which the mobile wireless device  102  is currently connected to the wireless network  100  with appropriate stored network timing characteristics in the database. In a representative embodiment, the database of measured network timing characteristics are organized by a combination of a mobile country code (MCC), a mobile network code (MNC) and a radio sector  104  identifier (e.g. cell ID). In a representative embodiment, the mobile wireless device  102  monitors its physical location by tracking at least one of a global positioning system (GPS) location of the mobile wireless device  102 , a WiFi access point location and a radio sector  104  (cell) site location. The geographic location identifier associated with the radio sector  104  in the database of measured network timing characteristics can be determined based on the monitored physical location of the mobile wireless device  102 . 
       FIG. 11  illustrates a representative method of managing state transitions in the mobile wireless device  102  connected to the radio sector  104  of the wireless network  100 . The method includes at least the following steps. In step  1102 , the mobile wireless device  102  retrieves network state transition timing information for the radio sector  104  from a database. In step  1104 , the mobile wireless device  102  determines a network based data inactivity timer value for the radio sector  104  of the wireless network  100  for a state transition from a first state to a second state based on the retrieved network state transition timing information. In step  1106 , the mobile wireless device  102  sets a mobile device based data inactivity timeout value to less than the determined network based data inactivity timeout value. In step  1108 , the mobile wireless device  102  detects a time period of data inactivity between the mobile wireless device  102  and the wireless network  100  that exceeds the set mobile device based data inactivity timeout value. In step  1110 , the mobile wireless device transitions from the first state to the second state. As a result of the steps outlined for the method in  FIG. 11 , the mobile wireless device  102  transitions from the first state to the second state more quickly than waiting for the wireless network  100  to determine to perform the state transition. In a representative embodiment, the first state represents a state with an active data connection between the mobile wireless device  102  and the wireless network  100 , while the second state represents a state having no active data connection between the mobile wireless device  102  and the wireless network  100 . In another representative embodiment, the first state is the CELL_DCH state  606  and the second state is the CELL_FACH state  608 . In another representative embodiment, the first state is a state for the mobile wireless device  102  having a highest amount of power consumption (among the possible states for the mobile wireless device  102  using the wireless communication protocol supported by the wireless network  100 ), while the second state is a state having a lower power consumption than the first state. In an embodiment, the first state is one of the UTRA RRC connected states  610 , and the second state is the UTRAN IDLE  612  state. 
     The method  1100  illustrated in  FIG. 11  can be extended to include the mobile wireless device  102  measuring at least one network state transition timing information of the radio sector  104  of the wireless network  100  and storing the measured network state transition timing information of the radio sector  104  in the database. The database can be organized by a geographic location identifier for the radio sector  104 , for example including an MCC, an MNC and a radio sector (cell) ID. The mobile wireless device  102  can monitor its physical location by tracking one or more of a GPS location, locations of nearby WiFi access points and locations of the radio sector sites (cell sites). The mobile wireless device  102  can use the monitored geographic location identifiers to determine the geographic location identifier for the radio sector stored in the database. In an embodiment, at least a first portion of the database is stored in a database maintained by the wireless network  100  and a second portion of the database is stored in the mobile wireless device  102 . The mobile wireless device  102  can update the locally stored database in the mobile wireless device  102  by downloading select information from the remotely stored database in the wireless network  100 . Maintaining only a portion of the database locally in the mobile wireless device  102  can limit the amount of memory required in the mobile wireless device  102  to provide information for the method  1100 . The mobile wireless device  102  can also retrieve database information from another mobile wireless device  102  through a peer to peer wireless transfer mechanism using a short range wireless communication technology, e.g. Bluetooth, Infrared (IRDA) and Near Field Communication (NFC) or a medium range wireless communication technology, e.g. WiFi. Database information can be then shared between multiple mobile wireless communication devices by a single user or group of users. 
       FIG. 12  illustrates another method  1200  to manage connections of the mobile wireless device  102  in the wireless network  100 . In step  1202 , the mobile wireless device measures one or more network characteristics of the radio sectors  104  of the wireless network  100  in which the mobile wireless device  102  operates. In step  1204 , the mobile wireless device  102  stores the measured network characteristics in a database in the mobile wireless device  102  for later retrieval. The database in the mobile wireless device  102  can contain measured network characteristics for multiple radio sectors  104  of the wireless network  100 . The multiple radio sectors  104  can include a subset of all radio sectors  104  visited by the mobile wireless device  102 , e.g. a subset of most recently visited radio sectors  104  or a subset of most frequently visited radio sectors  104 . In step  1206 , the mobile wireless device  102  retrieves one or more of the stored network characteristics for a current radio sector  104  in which the mobile wireless device  102  is currently operating. In step  1208 , the mobile wireless device  102  determines a network timeout value based on the retrieved one or more network characteristics of the current radio sector  104 . In step  1210 , the mobile wireless device  102  measures a time period of data inactivity at the mobile wireless device  102  after transmitting a data packet through the radio sector  104  of the wireless network  100 . In an embodiment, the mobile wireless device  102  measures data inactivity after the most recently transmitted data packet. In another embodiment, the mobile wireless device  102  measures data inactivity after the most recently transmitted data packet only when transmit data buffers for the mobile wireless device  102  are empty. In step  1212 , the mobile wireless device  102  transmits a dummy data packet to the wireless network  100  when the measured time period of data inactivity exceeds the determined network timeout value. The determined network timeout value in step  1208  can be less than an actual network timeout value, and thus when sending the dummy packet to the wireless network  100 , the mobile wireless device  102  can forestall the wireless network  100  detecting a timeout based on data inactivity with the mobile wireless device  102 . The mobile wireless device  102  can thus keep a connection, such as a PDP context, alive with the wireless network  100 , even when the mobile wireless device  102  has no actual data to send. 
     The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. 
     The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not target to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings. 
     The advantages of the embodiments described are numerous. Different aspects, embodiments or implementations can yield one or more of the following advantages. Many features and advantages of the present embodiments are apparent from the written description and, thus, it is intended by the appended claims to cover all such features and advantages of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, the embodiments should not be limited to the exact construction and operation as illustrated and described. Hence, all suitable modifications and equivalents can be resorted to as falling within the scope of the invention.

Metadata:
Filing Date: 20120319
Publication Date: 20140916
Grant Date: 20140916
Priority Date: 20120319
Inventors: LI LI
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W64/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W76/32", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W64/00", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/02", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W76/25", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/32", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W76/25", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/02", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 49157514