Method and apparatus for selecting call list numbers based on entry/exit to a WLAN

A wireless communication device (100) includes a transceiver (204) that is operable to communicate with a first wireless communication network (104) and a second wireless communication network (106). The device (100) also includes a memory (216) for storing at least a first destination-device identifier (304) associated with the first wireless communication network (104) and a second destination-device identifier (306) associated with the second wireless communication network (106). The device (100) further includes a controller (210) coupled to the transceiver (204) and the memory (216), for determining whether the device is within coverage of the first wireless communication network (104) and causing only the first destination-device identifier (304) to be selected from the memory (216) if the device is within coverage of the first wireless communication network (104) and causing only the second destination-device identifier (306) to be selected from the memory (216) if the device is outside the coverage of the first wireless communication network (104).

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates in general to seamless multi-network wireless service handoffs and more particularly to automatically switching between destination device contact numbers in a call list based on network coverage type.

2. Description of the Related Art

Wireless Local Area Networks (WLANs) are typically supported by WLAN servers, which may alternatively be referred to as private branch exchanges (PBXs) or enterprise servers. The PBX normally provides a control and switching function for the WLAN and communication units operating therein or users thereof. The WLAN can be an attractive and inexpensive alternative for typical voice services such as telephony or dispatch services and may provide additional amenities such as high-speed wireless Internet and Intranet access as well as other real-time applications that may be more specific to a given enterprise.

Wireless Wide Area Networks (wireless WANs or WANs) such as conventional cellular telephone systems are also known. Such networks provide the advantage of wide area coverage but may not be economically attractive for routine access to wideband or high speed data capabilities, such as are required for certain Internet or Intranet applications. Nevertheless a communication unit that is operating on a WLAN may move beyond the effective service area for the WLAN and thus need support or services from a WAN.

Each network type—WLAN and WAN—provide a unique device identifier to each subscribing device to facilitate location of and connection to each of the wireless devices. WAN networks typically provide 10-digit identifiers, while WLANs typically provide 4-digit identifiers, but may also provide a 10-digit WLAN identifier. Connection of wireless devices through a WLAN typically does not implicate any expense to the users. However, if a first user connects to a second user by utilizing the second user's 10-digit WAN identifier, the second user will be connected through the WAN to the first user, even if both users are within a coverage area of a WLAN. Unlike the WLAN, connection through the WAN typically incurs a per-minute charge. Therefore, if a WLAN connection is available, connection of users through a WAN should be automatically avoided.

Currently, a user of an originating device must consciously consider where the originating device is currently located and where destination device might be located before placing a call. These considerations are burdensome on the originating user, waste time, create extra steps in placing a call, and often result in improper guessing by the originating user, necessitating a second attempt.

SUMMARY OF THE INVENTION

Briefly, in accordance with the present invention, disclosed is a wireless communication device with a transceiver that is able to communicate with a Wide Area Network (WAN) and a Wireless Local Area Network (WLAN). The device has a memory for storing a destination-device identifier associated with the WAN and a destination-device identifier associated with the WLAN. The device also has a controller, coupled to the transceiver and the memory, for determining whether the wireless communication device is within coverage of the WLAN, and for causing only the WLAN destination-device identifier to be selected from the memory if the wireless communication device is within coverage of the WLAN and for causing only the second destination-device identifier to be selected from the memory if the wireless communication device is outside the coverage of the WLAN.

In one embodiment of the present invention, the wireless device has a display coupled to the controller, the display for displaying the selected destination device identifier to a user.

In an embodiment of the present invention, the controller is operable to determine whether the wireless communication device is within coverage of the WLAN, and for causing only the WLAN identifier to be selected from the memory if the wireless communication device is within coverage of the WLAN network and causing only the WAN identifier to be selected from the memory if the wireless communication device is outside the coverage of the WLAN.

In one embodiment of the present invention, the WAN is a carrier network and the WAN identifier is a cellular phone number.

In an embodiment of the present invention, the WLAN is a non-carrier network and the WLAN identifier is a WLAN phone number.

The present invention also includes a method for selecting a device identifier from a call list. The method includes the steps of determining a network providing communication service to an originating wireless device; searching a memory coupled to the originating wireless device, the memory containing at least a WLAN identifier associated with a WLAN network and a WAN identifier associated with a WAN network; and selecting only one of the identifiers based on the network providing communication service to the originating wireless device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The present invention relates to a method and apparatus for implementing automatically alternating groups of wireless-device identifiers in a call list404(seeFIG. 4) when transitioning coverage between two networks. In particular, the present invention enables a wireless device100to automatically detect if it is within the coverage of a WLAN. The wireless device100then automatically edits its call list404to either display a 4-digit WLAN identifier of other devices in the WLAN service coverage or to automatically place a call using the WLAN identifier, so that the originating user can only call another device by using the WLAN identifier and thereby avoid incurring any service-provider charges. In some WLANs, a 10-digit identifier is assigned to a particular device, or both a 4-digit and a 10-digit identifier are assigned and may be used. In one embodiment of the present invention used in a WLAN with two identifiers, both identifiers are shown to the originating user for selection. In another embodiment, one of the numbers is automatically dialed when the originating user selects the destination user's name from the call list404.

Alternatively, the present invention removes the WLAN identifiers from the call list404if the originating wireless device is out of the coverage of a WLAN. Removing the WLAN identifiers simplifies the call process. Removing the WLAN identifiers from the list of choices eliminates the need for a caller to navigate around the WLAN identifiers to get to the WAN identifier or accidentally selecting the WLAN identifiers. In addition, many cellular subscription plans include free “mobile-to-mobile” or “in-network” calling to subscribers of the same cellular service. By calling the destination device using the 10-digit WAN identifier, the free mobile-to-mobile minutes may be utilized.

The present invention can be utilized for situations in which a wireless device100moves between control areas of various networks, such as carrier networks and non-carrier networks. Carrier networks operate on cellular networks or Wide Area Networks (WAN) and, generally, are controlled by cellular carriers including, but not limited, to Cingular Wireless, Sprint PCS, Metro PCS, Verizon Wireless, and Tmobile Wireless. Carrier networks typically employ an analog-based air interface and/or one or more digital-based air interfaces. Digital-based air interfaces utilize digital communication technologies including, but not limited to, Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Global System for Mobile Communications (GSM), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access-3rd Generation (CDMA2000), and the like.

Non-carrier networks operate on wireless networks and, generally, are not controlled by cellular carriers. Non-carrier networks employ a wireless local area network (WLAN) based air interface including, but not limited to, IEEE 802.11 supported by the Institute of Electrical and Electronics Engineers, Inc., Wi-Fi supported by the Wireless Ethernet Compatibility Alliance, Bluetooth™ supported by the Bluetooth SIG, Inc., HomeRF supported by the HomeRF Working Group Inc., and the like.

The communication units or devices that operate within these networks have wireless communication capabilities, such as IEEE 802.11, Bluetooth, or Hiper-Lan and the like that preferably utilize CDMA, frequency hopping, OFDM or TDMA access technologies and one or more of various networking protocols, such as TCP/IP (Transmission Control Protocol/Internet Protocol), UDP/IP (User Datagram Protocol/IP), IPX/SPX (Inter-Packet Exchange/Sequential Packet Exchange), Net BIOS (Network Basic Input Output System) or other protocol structures.

The following drawings will be helpful in understanding the present invention. Turning now toFIG. 1, a diagram of one embodiment of the present invention is shown where communication establishment and handover is accomplished between two networks: a WAN and a WLAN. For this illustration, a wireless device100at a first position102is within a coverage area103of and may establish a call using a carrier network (WAN)104. The device100may also move to a second position108within radio coverage109of a non-carrier network (WLAN)106and establish a call on the WLAN106. However, the wireless device100at the second position108may establish a call using the WLAN106and, thereafter, “handover” the call to the WAN104after the wireless device100moves to the first position102within radio coverage of the WAN104. The “handover” function provides a relatively invisible transition to the user. Once the device begins to move out of range of the WLAN, a call is placed to the WAN. The device has two calls in process at this time. Once communication via the WAN is fully established, the WLAN call is terminated and the device switches lines without any input from the user. If the user moves back into the coverage of the WLAN, the call will be moved back into the coverage of the WLAN. Typically, the user is unaware of any of these transitions. Of course, although a carrier network and a non-carrier network are represented inFIG. 1, the present invention may also be utilized for communication between two carrier networks and between two non-carrier networks.

Each network includes a plurality of transceivers for communicating with the wireless device100, an intercommunication component for communicating between networks, and an interoperable arrangement for communicating between the plurality of transceivers and the intercommunication component. As shown inFIG. 1, the carrier network104may include a plurality of base stations110, a Mobile Switching Center (“MSC”)112, and a cellular access network114communicating between the base stations and the MSC112. The non-carrier network106may include a plurality of access points116, a media gateway118, and a wireless access network120, that may alternatively be referred to as Private Branch Exchange (PBX), enterprise server, media gateway controller (MGC) and so on. The wireless access network120allows communication between the access points116and the media gateway118. The networks104,106communicate with each other via the MSC112and the media gateway118.

As stated above, the present invention enables a wireless device100to operate seamlessly between networks without regard to the air interface technology utilized by the wireless device100for wireless communications. It is important to understanding the present invention to note that a bearer channel established between stations and/or devices is always established through a media gateway, whether the call is initiated from a carrier network to a non-carrier network, from a non-carrier network to a carrier network, from a non-carrier network to another non-carrier network, or from a carrier network to another carrier network. Also, one or more of the wireless devices100engaged in the call are assigned a telephone number associated with each network, for example, one number for a carrier network and another number for a non-carrier network. For the present invention, wireless devices100that are assigned multiple numbers will be capable of handover regardless of the call originator and network of call initiation.

It is also important to understand that, because all calls are routed through the media gateway118, each handover of a mobile wireless device100between networks is a “make before break” soft handover, and control of each handover is implemented by the media gateway118without intervention or control by the carrier network104. Thus, SS7or other control signaling, as utilized by traditional switching systems, is not required to accomplish the goals of the present invention. For example, in reference toFIG. 1, the present invention does not require SS7or other control signaling to be communicated between the MSC112and the media gateway118.

Stated another way, the media gateway of the present invention does not handover control of a communication with a wireless device100to a carrier network. Instead, the media gateway retains control of the communication as the wireless device100re-locates from one network to another network. In particular, when a mobile wireless device100and a remote wireless device have a call that is directed through the media gateway, the media gateway has one connection to the mobile wireless device100and another connection to the remote wireless device. Herein, the connection between the media gateway and the mobile wireless device100shall be referred to as a first call leg. The media gateway then establishes a second call leg with the mobile wireless device100so that the first and second call legs exist concurrently, hands over the communication from the first call leg to the second call leg, and disconnects the first call leg after handover has been completed. By retaining control of the communication with the mobile wireless device100, the media gateway is capable of handover without intervention or control by a carrier network. As will be explained in detail below, the wireless devices100are cognizant of which wireless network they are and are not connected through (determining that the device is either within coverage or outside of the coverage of a particular wireless network) and, according to one aspect of the present invention, can make configuration adjustments accordingly.

Referring now toFIG. 2, a simplified block diagram of a wireless communication unit100that is capable of facilitating a handover of an ongoing communication with the wireless communication unit100from a first to a second wireless communication network will be discussed and described. The communication unit100is generally known, thus the known functions and structure of such devices will not be described in detail other than as related to the inventive principles and concepts disclosed and discussed below. The communication unit100includes an antenna202or antenna structure that operates to couple radio frequency signals between a transceiver204and the first or second network104,106. For example, radio signals that are transmitted from the WAN104or WLAN106, such as respectively, by the base stations (WAN transceiver)110or the access points (WLAN transceiver)116are absorbed by the antenna202and coupled to a receiver, that is part of the transceiver204.

Signals that are amplified by and coupled from the transceiver204, specifically a transmitter (WLAN transmitter or WAN transmitter), to the antenna202are radiated or transmitted or sent to the access point116or base110station according to known WLAN technologies, such as 802.11 and others earlier mentioned or according to known WAN technologies, such as known cellular networks. The transceiver204will be configurable to support simultaneous air interfaces with multiple communication networks according to the conventions and protocols of each or may alternatively further include one or more of a WLAN transceiver206and WAN transceiver208for such purposes as will be appreciated by those of ordinary skill. The transceiver204or respective receivers and transmitters are inter coupled as depicted and interactively operate with and are controlled by a controller210to provide to, or accept or receive from, the controller210, voice traffic or data messages or signals corresponding thereto such as in packet data form.

Accordingly, the transceiver204, as controlled by, and in cooperation with, the controller210and functions thereof, provide the communication unit, or wireless device,100with multi or dual operating mode capability. More particularly, the communication unit100is capable of registering with and obtaining service from the first (WAN) and the second (WLAN) communication network104and106, respectively. The controller can operate to determine whether the wireless device100is within coverage or outside the coverage of a particular wireless network in many different ways, as should be obvious to those of ordinary skill in the art in view of the present discussion. For example, and without limitation, some transceivers204use a received signal strength indication (RSSI) signal to indicate whether the wireless device100is in coverage of a wireless network. As another example, and without limitation, a signal coding scheme such as used for CDMA type wireless communication systems can be received and decoded by a transceiver204to indicate whether the wireless device100is in coverage. As a third example, and without limitation, a wireless device100may utilize a location detection means to detect the location of the wireless device in a geographic area. A location detection means may include use of a GPS receiver or other signal receiver that indicates location of the wireless device100within a geographic area. The location of the wireless device100in a geographic area may be used to determine whether the wireless device is within coverage or outside of the coverage of a wireless network. Other equivalent forms of determination of in-network or outside-of-network coverage for the wireless device100should be obvious to those of ordinary skill in the art in view of the present discussion.

The controller210is coupled to and generally operates in a known manner with a user interface212. The user interface212is known and typically includes, for example, audio transducers, such as an earphone or speaker and microphone, a display, and a keypad. The transceiver and user interface are each inter coupled and the controller210provides overall operational command and control for the communication unit100.

The controller210is essentially a general-purpose processor and, preferably, includes a processor214and an associated memory216. The processor214is, preferably, a known processor based element with functionality that will depend on the specifics of the air interfaces with the first and the second network as well as various network protocols for voice and data traffic. The processor214will operate to encode and decode voice and data messages to provide signals suitable for the transceiver, a transducer, or further processing by the controller210. The processor214may include one or more generally available microprocessors, digital signal processors, and other integrated circuits depending on the responsibilities of the controller210with respect to signal processing duties or other unit features that are not relevant here.

In any event, the controller210also includes the memory216that may be, for example, a combination of known RAM (Random Access Memory), ROM (Read-Only Memory), EEPROM (Electrically Erasable Programmable ROM) or magnetic memory. The memory216is used to store among various other items or programs etc., an operating system or software and data218, such as the call list404, for execution or use by the processor214. This operating software218when executed by the processor214will result in the processor performing the requisite functions of the communication unit100such as interfacing with the user interface212and transceiver204or transmitting and receiving devices.

The memory216further includes call processing routines not specifically shown for supporting voice and data calls that will be appreciated by one of ordinary skill and that will vary depending on air interface, call processing, and service provider or network specifics.

Additionally, packet data processes220are provided for formulating appropriate packets for transport according to the specifics of the communication networks. Furthermore various data is provided in the memory, specifically unit information222including identification information to identify the communication unit100and call information224. Collectively this information can be used to identify a particular unit and a particular call.

A further memory location226is used to store device, system, or user specified information. One example of such information is a call list used to facilitate communication to other devices100within the network or within other networks to which the originating device is not a member. This information can also be stored in other locations in memory216or other memories that are a part of the wireless device100or are external to the wireless device100.

Referring now toFIG. 3, a portion of memory location226is shown in tabular organization, although the memory does not necessarily have any required organizational structural format. The memory location226includes a name field302, a first WAN identifier304, such as a cellular telephone number, a WLAN identifier306, and an optional extra field or fields308for storing alternate contact numbers, such as a public switched telephone number, a fax number, or others. The memory location226can include many other fields and values and can be used to store all information pertaining to a remote user and/or that user's communication device.

FIG. 4is an illustration of one embodiment of a display400, as is included in the user interface212. The display400is used to allow a user of a wireless device100to interact with portions of the software and hardware comprising the device. One such use of the display is to select destination devices to which a communication link is desired. The wireless devices100are generally identified by the name of their user, although this is not always the case. The display inFIG. 4shows a search screen402where the call list404of names is displayed. A name can be selected by typing the characters via a keypad or by scrolling down to the proper name and pressing a button to select the name. Traditionally, once a name is selected, the display400changes to a further screen, such as that shown inFIG. 5, where a list of available contact numbers is displayed.FIG. 5shows three available numbers for John Jones. The first entry502is a typical 10-digit WAN identifier that can be used to connect to a second user via a carrier network. The second entry504is a WLAN 4-digit identifier that can be used to connect to the second user through an enterprise server or others, as previously described. The third entry506shown inFIG. 5is an exemplary third contact number that may include a telephone number of a non-cellular communication device, such as a wired telephone.

In one embodiment of the present invention, the wireless device100, through logic residing in memory216considers the network in which the originating wireless device resides at the time a call is initiated. The originating wireless device100then makes configuration adjustments accordingly. Specifically, if the originating wireless device100is within the coverage of a WLAN, it would be highly advantageous to be connected through the WLAN to the destination device to take advantage of the increased bandwidth of the WLAN and avoid the usage costs of the WAN. Therefore, in one embodiment of the present invention, the destination user's WAN identifier, such as the first entry502, is not displayed on the originating device's display when the call is being initiated. As a result, the originating caller will automatically be linked to the recipient through the WLAN identifier without any further input by the user. If the destination device is also under the coverage of the WLAN, the call will be free to the users. If the destination device is not under (is outside) the coverage of the WLAN, the WLAN will automatically forward the call to the destination device using the destination device's WAN identifier.

In one embodiment, once a name is selected, as shown inFIG. 4, a call is immediately initiated through the either WLAN or WAN, depending on the location of the originating device100, without any further input from the call-initiating user. In other embodiments, a screen is shown that displays only the entry associated with the network currently available to the originating device100, such as shown inFIG. 6. InFIG. 6, display screen600displays the WLAN identifier602, which is selectable by the call-initiating user to initiate a call. This embodiment requires an additional step from the call-initiating user; however, other stored information can still be obtained, such as for example, through an options soft button604on the display600. In this embodiment, the call-initiating user can override the automatic number selection and initiate a call through the WAN or any other number instead.

If the originating device100is in the coverage of a WAN only, it is advantageous not to display a destination device's WLAN identifier, or identification number. In this case, the originating device100automatically hides the destination device's WLAN identifier from the call-initiating user. As in the example given above, once the destination user name is selected, the call can be immediately initiated without further user input. Alternatively, as shown inFIG. 7, the destination device's 10-digit WAN identifier702can be displayed on the screen700. This embodiment requires an additional step from the call-initiating user; however, other stored information can still be obtained, such as for example, through an options soft button704on the display700. During a handover stage, where the device is receiving coverage of both networks, the device can, in one embodiment of the present invention, display and make available both the WLAN identifier and the WAN identifier to a user. In another embodiment, if the originating device100is receiving coverage by the WLAN, a call will always be placed through the WLAN.

FIG. 8shows a flow diagram illustrating a preferred operation of the wireless device100. The process begins at step800and moves directly to step802where a user uses the originating device100and selects a destination device to place a call. The originating wireless device, in step804, determines whether it is within coverage of a WLAN or a WAN only. If the device is within coverage of a WLAN, the flow moves to step806, where the originating device immediately initiates a call to the destination device using the destination device's WLAN identifier. If, in step804, it is determined that the originating device is within coverage of a WAN only, the device immediately initiates a call, in step808, to the destination device using the destination device's WAN identifier. It should be noted that in step804, if it is determined that the originating device is within coverage of both a WLAN and WAN simultaneously, the originating device immediately initiates a call to the destination device using the destination device's WLAN identifier. If the destination device is not within (is outside) the coverage of the WLAN, the WLAN will forward the call to the WAN to connect the devices.