KR100730977B1 - Methods and apparatus for re-establishing communication for a wireless communication device after communication loss in the wireless communication network - Google Patents

Abstract

Several related methods and apparatus are disclosed for re-establishing communication for a wireless communication device after communication loss between the wireless device and the wireless communication network. In an illustrative example, the wireless network broadcasts over a control channel identifiers of wireless devices associated with communication losses in the wireless network. After reacquiring signal coverage, the wireless device monitors the control channel to decode each broadcasted identifier and compare it with the wireless device's identifier. Based on the match between the broadcast identifier and the wireless device identifier, the wireless device sends a control message notifying the wireless network of the existence of the wireless device. Otherwise, the wireless device typically refrains from sending control messages to the wireless network. Preferably, communication with the wireless network is re-established without overloading the wireless link with unnecessary traffic.

Wireless device, wireless communication network, communication loss, communication re-establishment, wireless device identifier, control message, overload

Description

METHODS AND APPARATUS FOR RE-ESTABLISHING COMMUNICATION FOR A WIRELESS COMMUNICATION DEVICE AFTER A COMMUNICATION LOSS IN A WIRELESS COMMUNICATION NETWORK}

FIELD This application relates generally to data communication for wireless communication devices, and more particularly, to methods and apparatus for reestablishing communication for a wireless communication device after communication loss in the wireless communication network.

When operating within poor coverage areas of a wireless communication network, such as a wireless packet-switched network, wireless communication devices can only send and receive traffic in sporadic intervals. This breaks down the general concepts of packet-switched data transactions. Conventional approaches, such as simply retrying transmissions using a back-off algorithm, have shown poor reliability or poor use of radio resources, especially for communication from the network to the wireless device. Will effect.

Many known wireless networks use the concept of a wireless device to query data from a server, which is commonly used in most Internet transactions. This includes, for example, requests for web pages and periodic polling of the email server by the email program for new email. In this existing "pull" approach, a typical traffic pattern is the transmission of a wireless device to a network, which involves the network sending a response to the wireless device. If the network is transmitting to a wireless device, the network always does so for a short time after link quality is established. If a transaction fails because of poor coverage, the wireless device or user can wait for coverage to improve and then retry the query. However, it is the wireless device's responsibility to retry the transaction after any such communication problems.

Another communication method uses a "push" method. "Push" means that data is pushed from the network to the wireless device. The conventional Internet concept of periodic polling for new data (such as e-mail messages) may be inappropriate because, for wireless device applications, it is considered too radio intensive. Alternatively, push requires that traffic exchange be initiated from the network side. Many packet-switched wireless networks have provisions for network-initiated traffic.

In one known push approach, the network will attempt to contact the wireless device several times, either by sending a packet directly or by paging the wireless device. This approach will work well for a few retries, but if the majority of devices have pending traffic, the network's ability to contact them can quickly run out without the exchange of any useful traffic. To limit the waste of radio resources attempting to contact wireless devices, a typical network attempts to contact a wireless device only a limited number of times and then suspends the attempt until the device re-announces itself to the network. something to do. As such, the wireless devices may indicate to the network that they have reacquired coverage after a period of out of coverage. This indication informs the network that the network can send back to the wireless device even if the network has already stopped attempting to contact the wireless device. The basic problem with this approach is that without testing the network's ability to receive communication signals transmitted by the wireless device, the wireless device cannot know whether or not its coverage is indeed suitable. However, a test of how well a network receives communication signals from a wireless device can only be reliably determined by actually sending packets to the network. It uses radio resources and is not used very often.

Some networks, such as General Packet Radio Service (GPRS) based networks, force the wireless device to periodically indicate to the network that the wireless device is actually available on the network. However, this also uses radio resources and is therefore performed at relatively long intervals, typically on the order of an hour. Although this periodic transmission will synchronize the view of coverage of the network and the wireless device, the network coverage view between these periodic transmissions to the network can be very different from the coverage view of the wireless device.

Additional issues arise with regard to the use of one or more application servers (eg, an e-mail server) to provide voice and / or data services to wireless devices. Firstly, the application server will lose connection with the wireless device after a loss of communication between the wireless device and the wireless network (eg, out of coverage). If the data connection is not automatically reestablished even after the wireless device has reacquired the appropriate signal coverage, the wireless device may not properly receive subsequent service (s) from the application server. However, once the application server is configured to automatically re-establish a connection with a broken wireless device, this may undesirably flood the connection requests for a wireless device that is still unavailable to the network.

Thus, there is a need for improved methods and apparatus for reestablishing communication for a communication device after communication loss in a wireless communication network.

Several methods and apparatus are disclosed for reestablishing communication for a wireless communication device after communication loss between the wireless device and the wireless communication network.

In one exemplary technique, a wireless network broadcasts over a control channel identifiers of wireless devices associated with communication losses in the wireless network. After reacquiring coverage, the wireless device monitors the control channel to decode and compare each broadcast identifier with the wireless device identifier. Based on the match between the broadcast identifier and the wireless device identifier, the wireless device sends a control message notifying the wireless network of the existence of the wireless device. Otherwise, the wireless device typically refrains from sending any control message to the wireless network. Thus, the wireless network can determine whether the wireless device is out of coverage and control the reestablishment process in a manner that does not overload the wireless link with unnecessary traffic.

In another example technique, communication loss between the wireless device and the wireless network sometimes occurs after a connection between the application server and the wireless device is established. After communication is reestablished between the wireless device and the wireless network, the stored correspondence of identifiers for the application server and the wireless device is used to support automatic connection reestablishment between the wireless device and the application server. For example, after communication is reestablished between the wireless device and the wireless network, the application server may be automatically contacted using its identifier stored in order to reestablish the connection.

In another exemplary technique, after a loss of communication between the wireless device and the wireless network, a plurality of connection requests from the application server to the wireless device are received at the network server. However, the number or rate of connection requests from the application server may be limited during the communication loss by the network server. The number or rate of connection requests may be limited, for example, by using rate limiting or traffic policing techniques.

Preferably, communication to the wireless device is reestablished without overloading the wireless network and / or the wireless link using the methods and apparatus described herein. Other aspects and specifications will become apparent to those skilled in the art upon reviewing the following description of specific embodiments in conjunction with the accompanying drawings.

Embodiments of the present invention will now be described by way of example with reference to the accompanying drawings.

1 is a block diagram of a communication system for communication in a wireless communication network, including a wireless communication device.

2 is a diagram of a wireless communication network having a wireless communication device operating there to communicate data between one or more application servers over a public or dedicated communication network.

3 is a specific structure of a system for communicating with a wireless communication device.

4 is a more detailed example of a wireless communication device for use in a wireless communication network.

5 is a flow chart illustrating a method for reestablishing communication for a wireless communication device after communication loss in a wireless communication network.

6 and 7 are related flow diagrams for explaining another method of reestablishing communication for a wireless communication device.

8 and 9 are related flow diagrams for explaining a method of reestablishing communication for a wireless communication device having one or more application servers.

10 is a flow chart illustrating another method of reestablishing communication for a wireless communication device having one or more application servers.

FIG. 11 is a diagram of a network server used in a network for the method described in connection with FIG. 10.

In the present application, FIGS. 1-4 illustrate various aspects and levels of detail of different network and device configurations that may be used in connection with several different methods and apparatus described with respect to FIGS. 5-11. Indicates.

More specifically, FIG. 1 is a block diagram of a communication system 100 that includes a wireless communication device 102 communicating in a wireless communication network 104. Wireless communication device 102 preferably includes a display 112, a keyboard 114, and possibly one or more user interfaces 116, each of which is connected to a controller 106. Controller 116 is coupled to radio modem 108 and antenna 110.

In modern communication devices, the controller 106 is implemented as a central processing unit (CPU) that runs the operating system software of a memory component (not shown). The controller 106 generally controls the overall operation of the wireless device 102, while signal processing operations associated with the communication functions are typically performed at the radio modem 108. The controller 106 interfaces with the display device 112 to display received information, stored information, user inputs, and the like. Keyboard 114, which may be a telephone keypad or a full alphanumeric keyboard, typically includes data for storage at wireless device 102, information for transmission to network 104, telephone number for phone call, wireless device 102. Are provided for inputting commands to be executed, and possibly other user inputs.

Wireless device 102 transmits communication signals to and receives communication signals from network 104 via an antenna 110 via a wireless link. The radio modem 108 performs functions similar to those of the base station 120, including, for example, modulation / demodulation and possibly encoding / decoding and encryption / decryption. It is also contemplated that the modem 108 may perform certain functions in addition to the functions performed by the base station 120. It will be apparent to those skilled in the art that the radio modem 108 will be tuned for a given wireless network or networks on which the wireless device 102 will operate.

In wireless device 102, the transmitter in radio modem 108 is typically used or turned on only when it is transmitting to the network, otherwise it is turned off to conserve resources. This intermittnet operation of the transmitter has a significant impact on the power consumption of the wireless device 102. Power to wireless device 102 is typically provided by a limited power source, such as a rechargeable battery, so that device design and operation should minimize power consumption in order to extend battery life or time between power source charging operations. .

As will be apparent from the foregoing, the term "wireless device" is used herein to refer to a wireless mobile communication device. In the embodiment of FIG. 1, the wireless device 102 is a mobile station. Wireless device 102 may be a single device, such as a data communication device, a cellular telephone, a multi-function communication device with data and voice communication functions, a personal digital assistant (PDA) capable of wireless communication, or a computer including an internal modem. It may consist of units. Alternatively, wireless device 102 may be a multi-module unit comprising a plurality of individual components, including but not limited to a computer or other device connected to a wireless modem. In particular, in the wireless device block diagram of FIG. 1, for example, modem 108 and antenna 110 may be implemented as a radio modem unit that may be inserted into a port on a laptop computer. In this case, the laptop computer would include a display 112, a keyboard 114, one or more auxiliary UIs 116, and a controller 106 implemented as the computer's CPU. It may also be possible for a computer or other equipment, typically unable to perform wireless communication, to be connected to a single unit of radio modem 108 and antenna 110, such as one of those described above, and adjusted to assume substantial control. Although only one wireless device 102 is shown in FIG. 1, those skilled in the art will appreciate that many devices, including different types of devices, may be activated or operable at any time within a wireless communication network. . In addition, such wireless device 102 may have one or more predetermined implementations, as described below with respect to wireless device 402 of FIG. 4.

The wireless device 102 communicates in and via the wireless communication network 104. In the embodiment of FIG. 1, the wireless network 104 is a Global Systems for Mobile (GSM) and General Packet Radio Service (GPRS) network. The wireless network 104 includes a base station 120 with an associated antenna tower 118, a Mobile Switching Center (MSC) 122, a Home Location Register (HLR) 132, and a Serving General Packet Radio Service (GPRS) Support Node; 126), and Gateway GPRS Support Node 128 (GGSN). MSC 122 is coupled to a base station 120 and a terrestrial network, such as a Public Switched Telephone Network (PSTN) 124. SGSN 126 is coupled to base station 120 and GGSN 128, which is coupled to a public or dedicated data network 130 (such as the Internet). HLR 132 is coupled to MSC 122, SGSN 126, and GGSN 128.

Base station 120 includes a controller and antenna tower 118 associated therewith and provides wireless network coverage for a given coverage area, commonly referred to as a "cell." Base station 120 transmits communication signals to and from wireless devices in a cell via antenna tower 118. The base station 120 typically modulates these functions under the control of the base station controller, and possibly modulates and possibly encodes and / or encrypts the signals to be transmitted to the wireless device according to certain, usually predetermined, communication protocols and parameters. As. Base station 120 similarly demodulates, possibly decodes and decodes any communication signals received from wireless device 102 in the cell, if necessary. Communication protocols and parameters may vary between different networks. For example, one network may use a different modulation scheme than other networks and may operate at different frequencies.

The wireless link shown in the communication system 100 of FIG. 1 may be configured to include one or more different channels, typically different radio frequency (RF) channels, and related protocols used between the wireless network 104 and the wireless device 102. Express. The RF channel is typically a limited resource that must be conserved due to overall bandwidth limitations and limited battery power of the wireless device 102. Even if traffic is not exchanged, the network is typically adjusted to operate continuously or intermittently, but the wireless device typically operates only when there is traffic to transmit. Conventional "pull" approaches involving inquiry from the device to the network before meaningful information is exchanged are resource intensive and in many cases unsuitable for the wireless network 104.

Those skilled in the art will appreciate that a wireless network in use may include hundreds of cells, each serviced by a separate base station 120 and a transceiver, depending on the overall desired space of network coverage. All base station controllers and base stations can be connected by multiple switches and routers (not shown) controlled by multiple network controllers.

For all wireless devices 102 that are registered with the network operator, both the temporary data (such as the wireless device 102's current location) as well as the temporary data (such as the wireless device 102's current location) are stored in the HLR 132. Are stored in. When there is a voice call to the wireless device 102, the HLR 132 is queried to determine the current location of the wireless device 102. The VLR (Visitor Location Register) of the MSC 122 is responsible for a group of location areas and stores data of wireless devices currently present in its area. This includes permanent wireless device data portions sent from the HLR 132 to the VLR for faster access. However, the VLR of MSC 122 may also allocate and store local data, such as temporary identification information. Optionally, the VLR of MSC 122 can be performed more efficiently through more efficient coordination and functionality of GPRS and non-GPRS services (eg, SGSN 126 and combined GPRS and non-GPRS location updates). , Paging for circuit-switched calls).

As part of the GPRS network, a Serving GPRS Support Node (SGSN) 126 is at the same hierarchical level as the MSC 122 and tracks individual locations of wireless devices. SGSN 126 also performs security functions and access control. Gateway GPRS Support Node (GGSN) 128 provides inter-networking with external packet-switched networks and SGSN (such as SGSN 126) over an IP-based GPRS backbone network. Is connected to the field. SGSN 126 performs authentication and cryptography procedures based on the same algorithms, keys, and criteria as in traditional GSM. In conventional operation, cell selection may be performed automatically by the wireless device 102 or by the base station 120 indicating to the wireless device 102 to select a particular cell. Wireless device 102 notifies wireless network 104 when wireless device 102 reselects another cell or another group of cells, known as a routing area.

To access GPRS services, wireless device 102 first informs wireless network 104 of its presence by performing what is known as a GPRS " attach ". This operation establishes a logical link between the wireless device 102 and the SGSN 126 so that the wireless device 102 can, for example, pages through the SGSN, notifications of input GPRS data, or via GPRS. Enables the receipt of Short Message Service (SMS) messages. In order to transmit and receive GPRS data, wireless device 102 supports activation of packet data addresses that wireless device 102 intends to use. This operation informs the GGSN 128 of the wireless device 102 such that mutual networking with external data networks can occur. User data may be transparently transmitted between wireless device 102 and external data networks, for example, using encapsulation and tunneling. The data packets are equipped with GPRS-specific protocol information and the data packets are transmitted between the wireless device 102 and the GGSN 128.

As will be apparent from the above, the term " wireless network " includes fixed network components that are used to facilitate the wireless transmission of information, including RF transceivers, amplifiers, base station controllers, network servers, Servers connected to a network, and the like, but are not limited thereto. Those skilled in the art will appreciate that other network components and networks (eg, the Internet) may be configured to interact with and include other systems and components, including those not explicitly indicated in FIG. 1. There will be. Which portions of the network (or networks) are responsible for certain aspects of the final operation on the wireless link, are not as important as the overall operation generated by the connected components, except as explicitly stated herein not.

2 is a simplified diagram of a wireless network 104 having a wireless device 102 operating there to communicate data between one or more application servers 202 via a public or dedicated communication network 130. The network 130 may be the Internet or may include the Internet and includes a serving network to facilitate information communication between the application servers 202 and the wireless device 102. Although three application servers 202, that is, application servers 204, 206, and 208 are shown in FIG. 2, any suitable number of application servers may be employed in the network. The application servers 202 may provide any suitable voice and / or data service (s), in particular “push” -based services, to the wireless device 102. More specifically, application servers 202 may be, by way of example, an electronic mail (e-mail) service, a wireless application protocol (WAP) service, a short messaging service (SMS) service, or a weather update service, a fortune service, and Provide application-specific services such as stock market services.

3 illustrates a predetermined system architecture for communicating with a wireless communication device. In particular, FIG. 3 shows the basic components of an IP-based wireless data network, such as a GPRS network. The wireless device 100 communicates with a wireless packet data network 145 and may also communicate with a wireless voice network (not shown). The voice network may be associated with, for example, an IP-based wireless network 145 similar to GSM and GPRS networks, or alternatively may be a completely separate network. The GPRS IP-based data network is characterized in that it is a substantial overlay to the GSM voice network. As such, GPRS components may extend existing GSM components, such as base stations 320, or add additional components, such as an enhanced Gateway GPRS Service Node (GGSN) as a network entry point (305). Will need.

As shown in FIG. 3, the gateway 140 may be coupled to an internal or external address resolution component 335 and one or more network entry points 305. Data packets are routed through the network 145 from the gateway 140, which is a source of information to be transmitted to the wireless device 100, by establishing a wireless network tunnel 325 from the gateway 140 to the wireless device 100. Is sent. To form this wireless tunnel 325, a unique network address is associated with the wireless device 100. However, in an IP-based wireless network, network addresses are typically not assigned permanently to a particular wireless device 100, but are dynamically assigned as needed. Thus, to establish the radio tunnel 325, the wireless device 100 obtains a network address and the gateway 140 preferably determines this address.

Network entry point 305 is generally used to multiplex and demultiplex between many gateways, enterprise servers, and bulk connections such as the Internet, for example. As they also wish to focus on externally available wireless network services, there are generally only a few of these network entry points 305. Network entry points 305 typically use some form of address resolution component 335 that supports address assignment and lookup between gateways and wireless devices. In this example, address resolution component 335 is represented as a dynamic host configuration protocol (DHCP), which is one method for providing an address resolution mechanism.

The central embedded component of the wireless data network 345 is the network router 315. Typically, network routers 315 are proprietary to a particular network, but in other ways, they may be configured from commercial standard hardware. The purpose of network routers 315 is to centralize thousands of base stations 320, which are typically implemented in relatively large networks, to a central location for long-haul backlinks to network entry points 305. In some networks, there may be cases where multiple layers of network routers 315 and master and slave network routers 315 exist, but in all these cases the functions are similar. Usually the network router 315 will access the name server 307, which in this case is shown as a dynamic name server (DNS) 307 used on the Internet, to find destinations for routing data messages. Base stations 320 provide wireless links to wireless devices, such as wireless device 100, as described above.

Wireless network tunnels, such as wireless tunnel 325, are opened through wireless network 345 to allocate memory, routing, and address resources needed to forward IP packets. In GPRS, these tunnels 325 are established as part of what are referred to as "PDP contexts" (ie, data sessions). In order to open the wireless tunnel 325, the wireless device 100 must use certain techniques associated with the wireless network 345. Opening such a wireless tunnel 325 may require the wireless device 100 to indicate the domain or network entry point 305 with which the wireless device 100 wishes to open the wireless tunnel 325. have. In this example, the tunnel first arrives at network router 315 which uses name server 307 to determine which network entry point 305 matches the domain provided. Multiple radio tunnels can be opened from one wireless device 100 for redundancy or to access different gateways and services on the network. Once the domain name is found, the tunnel extends to network entry point 305 and the necessary resources are assigned to each of the nodes on the path. The network entry point 305 then assigns an IP address to the wireless device 100 using an address resolution (or DHCP 335) component. After the IP address is assigned to the wireless device 100 and communicated to the gateway 140, information may be transferred from the gateway 140 to the wireless device 100.

The radio tunnel 325 typically has a limited lifetime, depending on the coverage profile and activity of the wireless device 100. The wireless network 145 tears down the wireless tunnel 325 after a period of inactivity or out of coverage, in order to reacquire resources held by the wireless tunnel 325 for other users. something to do. The main reason for this is to regenerate the temporarily reserved IP address for the wireless device 100 when the wireless tunnel 325 is first opened. After the IP address is lost and the wireless tunnel 325 is broken down, the gateway 140 may send an IP data packet to the wireless device 100, whether through TCP (Transmission Control Protocol) or UDP (User Datagram Protocol). You lose all your ability to initiate them.

In this application, an "IP-based wireless network" (which is a particular type of wireless communication network) includes (1) a Code Division Multiple Access (CDMA) network developed and operated by Qualcomm; (2) a General Packet Radio Service (GPRS) network for use with a Global System for Mobile Communications (GSM) network, both developed by the Standards Council of the European Conference of Postal and Telecommunications Administrations (CEPT); And (3) future third-generation (3G) networks such as Enhanced Data rates for GSM Evolution (EDGE) and Universal Mobile Telecommunications System (UMTS). GPRS is a data communication overlay on top of a GSM wireless network. Although specific IP-based wireless networks have been described, it will be appreciated that the communication reestablishment schemes of the present application may be used with any type of suitable wireless packet data network.

Preferred wireless device . 4 is a block diagram of a preferred wireless communication device 402 that may be configured to re-establish communication in accordance with the methods described herein. Wireless device 402 is preferably a two-way communication device having at least voice and data communication functions, including the ability to communicate with other computer systems on the Internet. Depending on the functionality provided by the wireless device 402, the wireless device 402 may be a data messaging device, a two-way pager, a cellular telephone with data messaging functions, a wireless internet appliance, or (with or without phone functions). It may be referred to as a data communication device.

If the wireless device 402 is operated for two-way communication, the wireless device 402 typically includes a receiver 412, a transmitter 414, and one or more antenna elements 416 and 418 (preferably embedded or embedded). Communication subsystem 411, including related components such as local oscillators (413), and a processing module, such as a digital signal processor (420). The communication subsystem 411 is similar to the radio modem 108 and antenna 110 shown in FIG. 1. As will be apparent to those skilled in the communications art, the particular design of the communication subsystem 411 depends on the communication network in which the wireless device 402 will operate.

Network access requirements will also vary depending on the type of network used. For example, in GPRS networks, network access is associated with a subscriber or user of wireless device 402. Thus, GPRS devices require a Subscriber Identity Module (not shown), commonly referred to as a "SIM" card, to operate in a GPRS network. Without a SIM card, the GPRS device will not work perfectly. Local or non-network communication functions (if present) may be operable, but the wireless device 402 will not perform any functions involving communication over the network. On the other hand, in Mobitex and DataTAC networks, this wireless device 402 is registered with the network using a unique identification number associated with each wireless device.

When the necessary network registration or activation procedures have been completed, the wireless device 402 can send and receive communication signals over the network. Signals received by the antenna 416 over the network are input to the receiver 412, which is a typical receiver function such as signal amplification, frequency downconversion, filtering, channel selection, and the like, and in the example shown in FIG. A / D (analog-to-digital) conversion may be performed. More complex communication functions such as demodulation and decoding may be performed in the DSP 420 due to A / D conversion of the received signal. In a similar manner, signals to be transmitted are also processed by the DSP 420, including, for example, modulation and encoding. These DSP-processed signals are input to transmitter 414 for digital-to-analog (D / A) conversion, frequency up-conversion, filtering, amplification, and transmission via a communication network by antenna 418. DSP 420 not only processes communication signals, but also provides receiver and transmitter control. For example, the gains applied to the communication signals at the receiver 412 and the transmitter 414 may be adaptively controlled by automatic gain control algorithms implemented in the DSP 420.

The wireless device 402 is an implementation of the controller 106 of FIG. 1 and includes a microprocessor 438 that controls the overall operation of the wireless device 402. Communication functions, including at least data and voice communication, are performed via communication subsystem 411. Microprocessor 438 also includes display 422, flash memory 424, random access memory (RAM) 426, auxiliary input / output (I / O) subsystems 428, serial port 430, It also interacts with additional device subsystems such as keyboard 432, speaker 434, microphone 436, short-range communications subsystem 440, and any other device subsystems that are generally represented as 442. . Some of the subsystems shown in FIG. 4 perform communication-related functions, while other subsystems may provide “resident” or on-device functions. In particular, some subsystems, such as, for example, the keyboard 432 and the display 422, may include communications-related functions and calculators or task lists, such as entering text messages for transmission over a communications network. It can be used for both device-resident functions. The operating system software used by the microprocessor 438 is preferably stored in permanent storage, such as flash memory 424. Alternatively, the permanent storage device may be a read-only memory (not shown) or ROM. It may be a similar storage element. Those skilled in the art will also appreciate that the operating system, specific device applications, or portions thereof may be temporarily loaded into volatile storage, such as RAM 426. Loss of received communication signals, detected signal log, and contact log may also be stored in RAM 426.

Microprocessor 438 is preferably capable of executing software applications at wireless device 402 in addition to its operating system functions. Certain sets of applications that control basic device operations, including at least data and voice communication applications (such as a network re-establishment scheme), will typically be installed in the wireless device 402 during its manufacture. Preferred applications that can be loaded on the wireless device 402 include organizing and managing user related data items, including but not limited to e-mail, calendar events, voice mails, appointments, and task items. It may be a personal information manager (PIM) application with the ability to do so. Naturally, one or more memory storage devices may be used in the wireless device 402 to facilitate storage of PIM data items.

Such a PIM application preferably has the ability to send and receive data items via a wireless network. In a preferred embodiment, the PIM data items are corresponding data items of a wireless device user stored in and / or associated with the host computer system that are seamlessly integrated, synchronized, and updated over the wireless network. , In conjunction with these items, forms a mirrored host computer on the wireless device 402. This is particularly desirable when the host computer system is an office computer system of a wireless device user. Additional applications may also be loaded into the wireless device 402 via the network, auxiliary I / O subsystem 428, serial port 430, short range communication subsystem 440, or any other suitable subsystem 442. It may be installed in the RAM 426 or, preferably, not shown (not shown) by the user for execution by the microprocessor 438. Such application installation compatibility increases the functionality of the wireless device 402 and may provide enhanced on-device functions, communication-related functions, or both. For example, secure communication applications can allow e-commerce functions and other such financial transactions to be performed using the wireless device 402.

In the data communication mode, received signals, such as text messages or web page downloads, will be processed by input to the communication subsystem 411 and microprocessor 438. Microprocessor 438 will preferably further process the signal for output to display 422 or, alternatively, to auxiliary I / O device 428. A user of the wireless device 402 may use the keyboard 432 with the display 422 and possibly the auxiliary I / O device 428 to configure data items, such as e-mail messages, for example. Keyboard 432 is preferably a full alphanumeric keyboard and / or telephone keypad. The so configured items may be transmitted by the communication subsystem 411 through the communication network.

In the case of voice communication, the overall operation of the wireless device 402 is substantially similar except that the received signals will be output to the speaker 434 and the signals for transmission will be generated by the microphone 436. Other voice or audio I / O subsystems, such as the voice message recording subsystem, may be implemented on the wireless device 402. It may be desirable for the voice or audio signal output to be primarily realized through the speaker 434, but in some instances, during a voice call, to provide an indication of the calling party's identification information or other voice call related information. Display 422 may be used.

Serial port 430 of FIG. 4 is typically implemented in a personal digital assistant (PDA) type communication device where synchronization with a user desktop computer is an optional but desirable component. Serial port 430 allows a user to set preferences via an external device or software application, and by providing information or software downloads to the wireless device 402, rather than via a wireless communication network. Extend the functions of the wireless device 402. Another download path may be used to load the encryption key onto the wireless device 402 via a direct, secure and reliable connection, for example, providing secure device communication.

Short-range communication subsystem 440 is an additional optional component that provides communication between the wireless device 402 and different systems or devices, which need not necessarily be similar devices. For example, subsystem 440 may include an infrared device and associated circuits and components, or a Bluetooth ^™ communication module, for providing communication with similarly-operated systems and devices. Bluetooth ^™ is a registered trademark of Bluetooth SIG, Inc.

5 is a flow chart illustrating one method for re-establishing communication for a wireless communication device. Such methods may be used in the components shown and described above in connection with FIGS. FIG. 5 relates in particular to a method registered with a wireless communication network and used by a wireless communication device for operating in a wireless communication network and for monitoring and receiving radio frequency (RF) signals via a control channel.

Beginning at start block 502 of FIG. 5, the wireless device tests whether the current RF frequency or channel being monitored is suitable for communication (step 504). Such testing may be performed, for example, by testing whether a received signal strength indication (RSSI) is above or below a predetermined threshold. For example, if the RSSI is below a certain threshold, the RF frequency or channel is inappropriate. If the RF frequency or channel is suitable when tested in step 504, the wireless device continues to operate normally in the wireless network. However, if the RF frequency or channel is inadequate when tested in step 504, the wireless device enters a first mode of scan operation in which the wireless device searches for a new RF frequency or channel for communication (step 506). In the first mode of this scan operation, the wireless device may scan several possible other RF frequencies or channels to identify an available or "best" signal.

If this new signal is not found immediately when tested in step 508, the wireless device tests whether a timeout has occurred in step 510 and then continues searching for a new RF frequency or channel in step 506. However, if a new signal is found when tested in step 508, the wireless device immediately attempts to re-establish communication with the wireless network (step 512). The wireless device can perform step 512 by sending a control message informing the wireless network of the existence of the wireless device. The method then begins at step 504 and repeats after step 512.

The control message sent in step 512 is an update message that is any message sent by the wireless device suitable for use in notifying and / or updating the status of the wireless device to the network, although the message may have other purposes that may be different. Can be. For example, in GPRS, the update message may be a location area update message or a routing area update message. As another example, the update message may be a message for transmitting user data. This message allows the wireless network to receive an indication of communication-reestablishment between the wireless device and the wireless network.

If no new signal is found in step 508 before the timeout occurs in step 510, the wireless device enters a second mode of scan operation in which the wireless device searches for a new RF frequency or channel again (step 514). If a new signal is found when tested at step 516, the wireless device attempts to re-establish communication with the wireless network immediately at step 512, as described above. However, if no new signal is found immediately in step 516, the wireless device enters the sleep mode of operation for a predetermined time (step 518).

During the sleep mode, the wireless device cuts power to its main circuit parts (e.g., the controller and receiver or portions thereof). The predetermined time of sleep mode covers a plurality of consecutive reception times that would otherwise have caused the wireless device to operate its receiver and controller. After the predetermined time expires, the circuit is reactivated and the wireless device again searches for a new RF frequency or channel. Thus, the search in the second mode of operation is performed periodically after the wireless device wakes up in the sleep mode of operation.

Alternatively, a wireless device, such as a cellular mobile station, operates in a cellular communication network and detects whether the signal strength for signals from the cellular communication network is below a predetermined threshold. The cellular mobile station then scans the signals from one or more additional cellular communication networks in response to detecting that the signal strength of the signals is below a predetermined threshold. While signals from one or more additional networks are still unsuitable for communication, the cellular mobile station transmits, at regular intervals (periodically), a control message informing the cellular communication network of the presence of the cellular mobile station. Periodic transmission of such control messages may occur in short intervals, eg every 20 seconds to every 3 minutes.

6 and 7 are related flow diagrams for explaining another method of reestablishing communication for a wireless communication device. Such methods may also be used for the components shown and described above in connection with FIGS. FIG. 6 relates in particular to a method used in a fixed network infrastructure, and FIG. 7 relates in particular to a related method used by a wireless communication device. In order to provide an initial context for the method, a wireless communication device is registered and operating in a wireless communication network. However, sometimes during operation, communication loss occurs between the wireless device and the wireless network. For example, the wireless device may be moved to an area where the wireless network can no longer properly receive wireless signals from the wireless device. Communication loss is defined to include any harmful signals, channels, or decoding conditions (or combinations thereof) that interfere with communication such that information cannot be properly transmitted or received.

Beginning at start block 602 of FIG. 6, the network receives an indication indicating communication loss associated with the wireless device (step 604). In practical implementations, the network may receive a number of such indications for a number of different wireless devices associated with this communication loss. Based on one of a number of different methods adopted between the wireless device and the wireless network, communication loss can be determined. As an example, "keep-alive" messages may be sent periodically between the wireless device and the wireless network every predetermined period, in which case communication loss occurs when the network fails to receive a keep-alive message within the predetermined period. So that the network receives an indication that indicates a loss of communication. Preferably, the method is a predetermined process that provides some hysteresis, so short-range losses such as simple signal fades (eg, on the order of 1 to 90 seconds) are ignored. Thus, very simple communication losses (such as those encountered when passing through large obstacles or driving through tunnels or underground parking lots) do not need to trigger into the network an indication that a communication loss is being experienced.

However, if an indication is received indicating a communication loss for the wireless device, the network adds the wireless device identifier to the list of wireless communication devices associated with the communication losses in the wireless network (step 606). The identifier may, for example, be unique to the wireless device, such as a Mobile Identification Number (MIN), Temporary MIN (TMIN), International Mobile Subscriber Identity (IMSI), Mobile Subscriber ISDN Number (MSISDN), or Internet Protocol (IP) address. May be any suitable identifier.

Communication may be re-established for some wireless communication devices in the wireless network. In this case, the network receives an indication that communication re-establishment has occurred between the wireless device and the wireless network (step 608). For example, if "keep-alive" messages are typically sent between a wireless device and a wireless network every predetermined period, the network receives a keep-alive message from the wireless device after failing to receive keep-alive messages for a period of time. can do. Alternatively, this indication may be in the form of a control message or an update message sent by the wireless device, as described above.

Upon receiving an indication of communication re-establishment, the network deletes the associated wireless device identifier from the list of wireless devices associated with the communication losses (step 610). The network also checks for each wireless device in the list whether the timer associated with the wireless device has expired (step 612). The timer may be initially set for an appropriate amount of time for each wireless device as each wireless device is added to the list, in some applications a 10-15 minute timer may be suitable, for example. If a timeout occurs for the wireless device, the associated identifier for the wireless device is deleted from the list (step 614). Since the wireless device is now available for communication, the network may also check whether any messages are pending for this wireless device and immediately send it to the wireless device.

Next, the network broadcasts the identifiers of the resources over the wireless network (step 616). Identifiers may be broadcast, for example, over a control channel of the network. For example, system information messages carried over Broadcast Control Channel (BCCH), Packet Broadcast Control Channel (PBCCH), BCCH and PBCCH, Periodic Route Area Update procedure, or page request and response protocol. Any suitable control channel and / or control information communication means can be used, such as the use of.

The method of FIG. 6 repeats starting again at step 604 where new indications of communication losses and reestablishments are received and identifiers are added to and deleted from the list. Thus, broadcasts for identifiers on the list occur regularly in the network, and preferably occur periodically (eg every 90-180 seconds).

Reference will now be made to FIG. 7 for the wireless device method associated with FIG. 6. Beginning at start block 702 of FIG. 7, a communication loss occurs between the wireless device and the wireless network (step 704). As mentioned above, communication loss is defined to include any harmful signal, channel, or decoding condition (or combination thereof) that prevents communication from being transmitted or received properly. At this point, steps 604 and 606 of FIG. 6 are used to add this wireless device identifier to the list of wireless devices associated with the communication losses.

However, after some time, communication between the wireless device and the wireless network is re-established (step 706 of FIG. 7). Accordingly, the wireless device is tuned to the control channel of the wireless network to receive signals and decode identifiers for the list of unavailable wireless devices broadcast by the wireless network (step 708). This list is a list of wireless device identifiers associated with communication losses of the wireless network, broadcasted at step 616 of FIG. 6. For each decoded identifier, a comparison is made between the wireless device identifier and the decoded identifier (step 710 of FIG. 7).

In step 712, if a match occurs between the tested identifiers, the wireless device transmits a control message notifying the wireless network of the presence of the wireless device (step 714). As mentioned above, the control message may be an update message, which is any message sent by the wireless device that is used to notify and / or update the status of the wireless device to the network, although the message may have a different other purpose. have. For example, in GPRS, the update message may be a Location Update Request message or a Routing Area Update Request message. As another example, the update message may be a message for transmitting user data. This message causes the wireless network to receive an indication of reestablishing communication between the wireless device and the wireless network.

In step 712, if a match does not occur between one of the broadcast identifiers and the wireless device identifier, the wireless device refrains from sending a control message to the wireless network. The method of FIG. 7 is repeated when another communication loss is experienced between the wireless device and the wireless network.

Advantageously, communication can be re-established between the wireless devices and the wireless network in a controlled manner that does not overload the wireless link, especially with unnecessary traffic. The control message from the wireless device typically does not need to be sent unless the wireless device identifier is broadcast by the wireless network. If a wireless device experiences a communication loss and its identifier is not present in the list broadcast by the wireless network, there is no reason to send a control message since the wireless device is not considered unavailable or lost by the wireless network.

8 and 9 are flow charts for explaining other methods of re-establishing communication for a wireless communication device, which use one or more application servers for communication with the wireless device. Such methods may use the devices and networks shown and described above with respect to FIGS. 8 is particularly referred to in conjunction with FIG. 2 as to a method used within a fixed network infrastructure.

To provide an initial context for the method of FIG. 8, a wireless communication device is first registered and operated in a wireless communication network and communicates data to and from one or more application servers. However, sometimes during operation, communication loss occurs between the wireless device and the wireless network. Communication loss is defined to include any harmful signal, channel, or decoding condition (or a combination thereof) that prevents communication from being transmitted or received properly. For example, the wireless device may be moved to an area where the wireless network can no longer properly receive wireless signals from the wireless device. Due to the communication loss between the wireless device and the wireless network, a connection and communication loss between the wireless device and the application server occurs. In practical implementations, a number of different wireless devices may be operating in conjunction with a number of different application servers, where, over time, a number of connection and communication losses may occur.

As an illustrative example, the wireless device 102 of FIG. 2 may initially be registered and operating with the wireless network 104 and may be receiving data from the application server 204 over a connection (eg, a TCP / IP connection). have. Over time, a communication loss occurs between the wireless device 102 and the wireless network 104, thereby interrupting the connection between the wireless device 102 and the application server 204. Without the methods described herein, the application server 204 may place a heavy burden on the wireless network 104 with continued connection attempts to the wireless device 102 while the wireless device 102 is unavailable. Alternatively, the application server 204 may not be configured to automatically attempt to re-establish a connection with the wireless device 102 once communication has been re-established between the wireless device 102 and the wireless network 104. It may not.

Beginning at the start block 802 of FIG. 8, the network server stores the storage space for a list of identifiers of application servers associated with identifiers of wireless devices for which connections and / or data communication have already been established or pending therebetween. Maintain (step 804). For example, the list may store the wireless device 102 identifier of FIG. 2 with respect to the identifier of the application server 204 for which data communication has already been established between them. Such a list may be referred to as a "check-in" list. The identifiers used may be any suitable identifier that uniquely identifies the wireless device and application server. The identifier for the wireless device may be, for example, a Mobile Identification Number (MIN), a Temporary MIN (TMIN), an International Mobile Subscriber Identity (IMSI), a Mobile Subscriber ISDN Number (MSISDN), or an Internet Protocol (IP) address. , The identifier for the application server may be, for example, an application server name. Each association to the identifiers may be entered or added to the list at any time during the establishment or maintenance of the connection between the wireless device and the application server. Alternatively, each association may be entered or added to the list only when or after the connection or data communication between the wireless device and the application server is disrupted or interrupted.

Once communication is re-established between the wireless device and the wireless network, the stored identifier of the application server associated with the wireless device is used to re-establish connection and data communication between the application server and the wireless device (step 806). For example, a network server may be a contact server that contacts an application server using an application server identifier to allow it to re-establish connection and data communications. As another example, an individual contact server may request and receive application server identification information by querying the network server using the identifier of the wireless device, in which case the contact server then contacts the application server to establish connection and data. Communication can be re-established. As shown in FIG. 8, the method is repeated over and over so that multiple wireless devices can be served in the same manner. Preferably, the method and stored list of FIG. 8 is maintained on an existence server, such as the presence server 134 of FIG. 1, which may be communicatively connected in the network as shown.

9 is a flow diagram of a preferred, more detailed embodiment, illustrating the method of FIG. 8. Beginning at start block 902, an indication is received indicating a loss of communication between the wireless device and the wireless network (step 904). In response to the communication loss, the identifiers of the application servers are stored in a list associated with the identifiers of the wireless devices for which connection and / or data communications between them have been established or pending (step 906). If an indication for re-establishing communication between the wireless device and the wireless network is received (step 908), the identifier of the application server is used to re-establish connection and data communication between the application server and the wireless device (step 910). For example, to enable an application server to reestablish a connection with a wireless device, the application server is contacted using application server identification information (eg, application server name). The identifiers for the application server and the wireless device are then deleted from the stored list (step 912). The method starts over at step 904 and repeats continuously. Although the method of FIG. 9 is described above with respect to a single wireless device in a network, in practical implementation, the method is performed in connection with a plurality of wireless devices and a plurality of application servers in the network. Preferably, the method and stored list of FIG. 9 are maintained on an existence server, such as the presence server 134 of FIG. 1, which may be communicatively connected in the network, as shown.

Preferably, the method described in connection with FIGS. 8 and 9 provides for automatic communication reestablishment for a wireless device without overloading the wireless network with subsequent multiple connection attempts from application servers.

10 is another method for re-establishing communication for a wireless communication device having one or more application servers. The method can be used in the systems shown and described above with respect to FIGS. 10 is particularly referred to in conjunction with FIG. 2 as to a method used within a fixed network infrastructure.

To provide an initial context for the method of FIG. 10, a wireless communication device is first registered and operated in a wireless network and communicates data to and / or from one or more application servers. However, sometimes during operation, communication loss occurs between the wireless device and the wireless network. Communication loss is defined to include any harmful signal, channel, or decoding condition (or a combination thereof) that prevents communication from being transmitted or received properly. For example, the wireless device may be moved to an area where the wireless network can no longer properly receive wireless signals from the wireless device. Due to the communication loss between the wireless device and the wireless network, a connection and communication loss between the wireless device and the application server occurs. In practical implementations, a number of different wireless devices may operate in conjunction with a number of different application servers, where, over time, a number of connection and communication losses may occur.

As an illustrative example, the wireless device 102 of FIG. 2 may initially register and operate with the wireless network 104 and receive data from the application server 204 over a connection (eg, a TCP / IP connection). have. Over time, a communication loss occurs between the wireless device 102 and the wireless network 104, thereby interrupting the connection between the wireless device 102 and the application server 204. Without the methods described herein, the application server 204 may place a heavy burden on the wireless network 104 with subsequent connection attempts to the wireless device 102 while the wireless device 102 is unavailable, or otherwise. As such, after communication is re-established between wireless device 102 and wireless network 104, application server 204 may not be configured to automatically attempt to re-establish connection with wireless device 102. .

Beginning at start block 1002 of FIG. 10, the server receives a plurality of connection requests from the application server to the wireless device for a predetermined time after communication loss between the wireless device and the wireless network (step 1004). The server receives these connection requests, but limits the number or rate of requests that occur during communication loss between the wireless device and the wireless network. The server can achieve this using, for example, rate limiting techniques or traffic polishing techniques. The method is completed starting again at step 1004, but repeated for additional communication losses for the wireless device as well as the multiple wireless devices.

Rate limiting and traffic polishing techniques are currently used to manage the volume and speed at which traffic enters the service provider's core transport network. As is evident in the current application of FIG. 10, these techniques are used to manage the volume and / or speed at which connection requests from application servers enter the network to facilitate data communication between the application server and the wireless devices. . This is particularly desirable when performed while there is a communication loss between the wireless device and the wireless network.

In the block diagram of FIG. 11, some device components from FIG. 2 are shown, including application servers 202, wireless device 102, and base station 120. Also shown in FIG. 11 is a server 1102 that limits the number and / or rate of connection requests from application servers 202 that are allowed to pass through a wireless network. Server 1102 receives these connection requests via router 1104. Connection request limiting techniques are performed while there is a communication loss between at least the wireless device 102 and the wireless communication network including the base station 120.

In one embodiment, server 1102 is part of the SGSN of the wireless network. Alternatively, server 1102 may be part of the GGSN of the wireless network. In another embodiment, the server 1102 may be part of both SGSN and GGSN of the wireless network.

To perform these techniques, server 1102 includes at least queue 1106 and coordination component 1108. In one embodiment, server 1102 is capable of network congestion by placing connection requests in queue 1106 with a “shaper” (ie, coordination component 1108) at the head of queue 1106. A traffic shaping technique may be performed to reduce the number of traffic shaping techniques. This technique mitigates connection request flows and adjusts the speed and volume of requests coming into the network. At least two basic traffic-shaping, rate-limiting techniques that can be used: (1) traffic-mitigation techniques; And (2) long-term average traffic rate-shaping techniques.

Traffic mitigation techniques remove bursts to present a constant stream of requests to the network, and are generally implemented using what are referred to as "leaky bucket" algorithms. In this case, the adjustment component 1108 may be referred to as a leaky bucket queue adjuster. Long-term average traffic rate-shaping techniques allow bursts of a certain size and present a burst-adjusted stream of requests to the network and are typically implemented using what is called a "token bucket" algorithm. In this case, the coordination component 1108 may be referred to as a token bucket queue coordinator.

The server 1102 may perform a traffic polishing technique that examines the connection requests and causes the connection requests to be discarded or marked if they exceed certain limits. The traffic polishing function uses the token bucket algorithm as described above, in which case the queue 1106 is replaced with a connection request discard / marking function. If the polishing function determines that the particular request is within a predetermined limit, the request is entered into the network. If the polishing function determines that the request is beyond a certain limit, the request is immediately missed ("hard" polishing) or entered into the network but marked as being out of certain limits ("soft" polishing).

Although any suitable means may support the provision of the techniques of FIGS. 10 and 11, these techniques are preferably performed with the Access Point Name (APN) information of the network. The APN is an identifier that identifies an access point of an external network and can be used for billing purposes. More specifically, the APN is used to notify SGSN which GGSN to use and to inform the GGSN which external data network to use. A typical APN has two parts: (1) an APN network identifier; And (2) an APN operator identifier. The APN network identifier identifies the external network being accessed (eg, equivalent to a domain name on the Internet). The APN operator identifier is optional and identifies the network used for roaming. A subscriber may request a particular APN when it has an APN set in the HLR or when the PDP context is activated.

According to the present technology, the APN (or related) field may be used to convey a limit on the number or rate of connection requests for each subscriber from the application server. In this case, the server uses the APN (or related) field to extract the access request restrictions for the subscriber and implement the technique accordingly. Advantageously, the methods and apparatus described in connection with FIGS. 10 and 11 provide communication re-establishment for a wireless device without overloading the wireless network with subsequent multiple connection attempts from application servers.

Final comments . As such, several related methods and apparatus have been described for re-establishing communication for a wireless communication device after a communication loss between the wireless device and the wireless communication network. In one technique, a method includes receiving an indication indicating a loss of communication between a wireless device and a wireless network; Based on receiving an indication indicative of a communication loss, adding an identifier of the wireless device to the list of unavailable wireless devices in the wireless network; And broadcasting the identifiers of the list in the wireless network. In a wireless device, the method includes decoding the broadcast identifiers of the list for wireless communication devices that are unavailable in the wireless network after a communication loss; Comparing each broadcasted identifier with an identifier of the wireless device; And sending a control message notifying the wireless network of the presence of the wireless device based on a match between the broadcast identifier and the wireless device identifier. Otherwise, the wireless device typically refrains from sending control messages to the wireless network.

In another technique, a method for re-establishing a connection between an application server operating in a wireless communication network and a wireless communication device includes storing an identifier of an application server associated with an identifier of the wireless device; Receiving an indication indicating a loss of communication between the wireless device and the wireless network; And providing a stored association to the identifiers of the application server and the wireless device to support connection re-establishment between the wireless device and the application server. The identifier of the application server is used to contact the application server and support connection re-establishment. The method includes a data storage medium; Computer instructions stored on a data storage medium; And a computer processor that executes computer instructions, the computer instructions storing identifiers of application servers in association with identifiers of wireless communication devices for which data communication has been established or pending therebetween; It is for providing an identifier of an application server to support re-establishing a connection between the application server and the wireless communication device after communication is re-established between the wireless device and the wireless communication network.

As another technique, a method for facilitating communication re-establishment between a wireless communication device and an application server may include receiving a plurality of connection requests from the application server to the wireless device after a communication loss between the wireless device and the wireless communication network; And limiting the number or rate of connection requests from the application server during communication loss between the wireless device and the wireless network. The number or rate of connection requests may be limited, for example, using rate limiting techniques or traffic polishing techniques. The server may be used to facilitate re-establishment of communication and may include a data storage medium; Computer instructions stored on a data storage medium; And a computer processor executing computer instructions, the computer instructions receiving a plurality of connection requests from an application server after a communication loss between the wireless device and the wireless communication network; For limiting the number or rate of connection requests from an application server during communication loss between a wireless device and a wireless network.

Yet another technique, a method of re-establishing communication includes operating an wireless communication device in a cellular communication network; Detecting that the signal strength for signals from the cellular communication network is below a predetermined threshold; Scanning for signals from one or more additional cellular communication networks; And periodically transmitting a control message informing the cellular communication network of the presence of the cellular mobile station while signals from one or more additional cellular communication networks are unsuitable for communication. The cellular mobile station includes a receiver; telautograph; An antenna coupled to the receiver and the transmitter; One or more processors coupled to the receiver and the transmitter, wherein the one or more processors operate to detect that the signal strength of signals from the cellular communication network is below a predetermined threshold; In addition, operate to scan signals from one or more additional cellular communication networks based on the detection that the signal strength is below a predetermined threshold; While signals from one or more additional cellular communication networks are inadequate for communication, it additionally operates to periodically send a control message via the transmitter informing the cellular communication network of the presence of a cellular mobile station.

As another final technique, a method that operates to re-establish communication between a wireless device and a wireless communication network may include receiving radio frequency (RF) signals from the wireless communication network during communication therewith; Detecting that the signal strength of the RF signals is no longer suitable for communication; Scanning to identify a new RF signal for communication; If a new RF signal is not identified by the scanning operation, periodically scanning to identify a new RF signal for communication; And if a new RF signal is identified, sending a control message to re-establish communication. The wireless communications apparatus includes a receiver for receiving RF signals from a wireless communications network during wireless communication therewith; A signal strength detector for detecting signal strength of RF signals; telautograph; And one or more processors coupled to the receiver and the transmitter, wherein the one or more processors determine based on the signal strength detector that the RF signals are no longer suitable for communication; Enter the wireless device into a first scan mode for identifying a new RF signal for communication; If a new RF signal is not identified in the first scan mode, enter the wireless device into a second periodic scan mode to identify a new RF signal for communication; Once the new RF signal is identified, it operates to cause the transmitter to send a control message to re-establish the communication.

The above-described embodiments of the present invention are merely examples. Alternatives, modifications, and variations to the specific embodiments may be made by those skilled in the art without departing from the scope of the present invention as defined only by the claims appended hereto.

Claims (54)

A method for reestablishing communication for a wireless communication device in a wireless communication network after a communication loss between the wireless communication network and the wireless communication device, the method comprising: Receiving an indication indicating a loss of communication between the wireless device and a wireless network; Based on receiving an indication indicative of the communication loss, adding the wireless device identifier to a list of unavailable wireless devices in the wireless network; And Causing the identifiers of the list to be broadcast in the wireless network. The method of claim 1, Receiving an indication that communication has been reestablished between the wireless device and a wireless network; And Based on receiving an indication that the communication has been re-established, deleting the wireless device identifier from the list. 2. The method of claim 1, wherein causing the identifiers of the list to be broadcast further comprises causing the identifiers of the list to be regularly broadcast. 2. The method of claim 1, wherein causing identifiers of the list to be broadcast further comprises causing identifiers of the list to be broadcast over a control channel of the wireless network. 2. The method of claim 1, further comprising deleting the wireless device identifier from the list after expiration of a predetermined time. The method of claim 1, In the wireless communication device, After the communication loss, receiving signals from the wireless network; Decoding identifiers of the list, broadcast from the wireless network; Comparing each broadcast identifier with the wireless device identifier; And Based on a match between the broadcast identifier and the wireless device identifier, sending a control message to notify the wireless network of the presence of the wireless device. The method of claim 1, wherein the wireless network comprises a cellular communication network. In a wireless communication network, a method for re-establishing communication with a wireless communication network after communication loss between the wireless communication network and a wireless communication device, the method comprising: After the communication loss, decoding broadcast identifiers of the list for unavailable wireless communication devices of the wireless network; Comparing each broadcast identifier with the wireless device identifier; And Based on a match between the broadcast identifier and the wireless device identifier, sending a control message to notify the wireless network of the existence of the wireless device. 9. The method of claim 8, further comprising refraining from sending the control message to the wireless network, other than in the case of matching. 9. The method of claim 8, wherein decoding the broadcast identifiers further comprises decoding the broadcast identifiers over a control channel of the wireless network. 10. The method of claim 8, wherein the broadcast identifiers comprise one of identification numbers and IP addresses. 10. The method of claim 8, wherein the wireless device comprises a cellular mobile station. receiving set; telautograph; An antenna coupled to the receiver and the transmitter; And One or more processors coupled to the receiver and the transmitter, The one or more processors, Decode broadcast identifiers of unavailable wireless communication devices of the wireless communication network, Compare each broadcast identifier with the wireless device identifier, Based on a match between the broadcast identifier and the wireless device identifier, wherein a control message informing the wireless network of the presence of the wireless device is operative to be transmitted via the transmitter. 14. The wireless communications apparatus of claim 13, wherein, except in the case of matching, the one or more processors typically operate to refrain from sending any control message to the wireless network. 14. The wireless communications apparatus of claim 13, further comprising a cellular mobile station. 14. The wireless communications apparatus of claim 13, wherein the one or more processors are further operative to decode identifiers broadcast over a control channel of the wireless network. The apparatus of claim 13, wherein the broadcast identifiers include one of identification numbers and IP addresses. In a wireless communication device, after a communication loss with a wireless communication network, re-establishing communication with the wireless communication network, the method comprising: Monitoring a control channel of the wireless network; Decoding broadcast identifiers of unavailable wireless communication devices of the wireless network; Comparing each broadcast identifier with the wireless device identifier; And Based on a match between the broadcast identifier and the wireless device identifier, a control message is sent to the wireless network to notify the wireless network of the existence of the wireless device. Refraining from transmitting. A cellular communication system comprising a cellular network infrastructure, The cellular network infrastructure, Receive indications of communication losses with one or more cellular mobile stations; Add identifiers of the one or more cellular mobile stations associated with communication losses to a list; Allow identifiers in the list to be broadcast periodically through the cellular network infrastructure, Each of the one or more cellular mobile stations,   Decode the broadcasted identifiers; Compare each broadcast identifier with an identifier of the cellular mobile station; And based on a match between the broadcast identifier and the cellular mobile station identifier, a control message informing the cellular network infrastructure of the existence of the cellular mobile station. 20. The method of claim 19, wherein if there is no match between the broadcast identifier and the cellular mobile station identifier, then each cellular mobile station is typically further operative to refrain from sending any control message to the cellular network infrastructure. , Cellular communication system. A method of re-establishing a connection between an application server operating in a wireless communication network and a wireless communication device, the method comprising: Storing an identifier of the application server in association with an identifier of the wireless device; Receiving an indication indicating a loss of communication between the wireless device and the wireless network; Receiving an indication that communication has been reestablished between the wireless device and the wireless network; And Providing a stored association for identifiers of said application server and said wireless device to support reestablishing a connection between said wireless device and said application server. 22. The method of claim 21, wherein storing the identifier is performed after receiving an indication indicating the communication loss. 22. The method of claim 21, wherein storing the identifier is performed prior to receiving an indication indicating the communication loss. 22. The method of claim 21, wherein storing the identifier of the application server further comprises storing an application server name of the application server. 22. The method of claim 21, further comprising contacting the application server to support the connection reestablishment using an identifier of the application server. A method of reestablishing data communication between an application server and a wireless communication device from communication loss between a wireless device and a wireless communication network, the method comprising: Storing identifiers of application servers in association with identifiers of wireless communication devices with which data communication is established or pending; And After communication is reestablished between the wireless communication device and the wireless communication network, Supporting a reestablishment of a connection between an application server and the wireless device using a stored association between the application server identifier and the wireless device identifier. 27. The method of claim 26, further comprising contacting the application server using the application server identifier to support the connection reestablishment. 27. The method of claim 26, wherein the application server identifier comprises an application server name. As a server, Data storage media; Computer instructions stored on the data storage medium; And A computer processor for executing the computer instructions, The computer instructions, Storing identifiers of application servers in association with identifiers of wireless communication devices for which data communication is established or pending; And after communication is re-established between the wireless device and a wireless communication network, providing an identifier of the application server to support re-establishing a connection between the application server and the wireless communication device. 30. The server of claim 29, wherein a computer processor executing computer instructions for providing the identifier is used to contact the application server to re-establish a connection between the application server and the wireless device. 30. The computer program product of claim 29, wherein a computer processor for executing the computer instructions is also used to contact the application server using the identifier to support data communication reestablishment between the application server and the wireless device. server. delete delete delete delete delete delete delete delete delete delete delete delete delete delete As a cellular mobile station, receiving set; telautograph; An antenna coupled to the receiver and the transmitter; And One or more processors coupled to the receiver and the transmitter, The one or more processors, Operate to detect that a signal strength of signals from a cellular communication network is below a predetermined threshold, Based on detecting that the signal strength is below a predetermined threshold, operative to scan signals from one or more additional cellular communication networks, And while the signals from the one or more additional cellular communication networks are ineligible for communication, periodically sending through the transmitter a control message informing the cellular communication network of the presence of the cellular mobile station. A wireless communication device, comprising: re-establishing communication between the wireless device and a wireless communication network, the method comprising: Receiving radio frequency (RF) signals from a wireless communication network during communication; Detecting that the signal strength of the RF signals is no longer suitable for communication; Scanning to identify a new RF signal for communication; If a new RF signal is not identified by the scanning step, periodically scanning to identify a new RF signal for communication; And If a new RF signal is identified, sending a control message to re-establish the communication. 48. The method of claim 47, wherein the detecting comprises identifying that a received signal strength indicator (RSSI) is below a predetermined threshold. 48. The method of claim 47, further comprising typically refraining from transmitting the control message until a new RF signal is identified. 48. The method of claim 47, further comprising entering a sleep mode between periods of the periodic scan step. 48. The method of claim 47 wherein the control message comprises an update message. A wireless communication device, A receiver for receiving radio frequency (RF) signals from a wireless communications network during wireless communications with a wireless network; A signal strength detector for detecting signal strength of the RF signals; telautograph; And One or more processors coupled to the receiver and the transmitter, The one or more processors, Based on the signal strength detector, determine that the RF signals are no longer suitable for communication, Enter the wireless device into a first scan mode to identify a new RF signal for communication, If a new RF signal is not identified in the first scan mode, the wireless device enters a periodic second scan mode to identify a new RF signal for communication, And if a new RF signal is identified, causing the transmitter to send a control message to re-establish the communication. 53. The wireless communications apparatus of claim 52, wherein the one or more processors typically refrain from causing the transmitter to transmit the control message until a new RF signal is identified. 53. The wireless communications apparatus of claim 52, wherein the one or more processors enter the wireless device into a sleep mode of stage between periods of periodic scanning of the periodic second scan mode.

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