Abstract:
A wireless mobile terminal is alerted to the presence of an available Wireless Local Area Network by a communication network, based on the location of the mobile terminal. The mobile terminal alerts a wireless computing device, either via a wired or wireless interface, or by paging the user. Alternatively, the mobile terminal and the wireless computing device may form an integrated unit with interfaces to both the WLAN and the communication network. The wireless computing device initiates a scan for the WLAN, or logs onto the WLAN based on information transmitted to the mobile terminal. When the user is not in the range of a WLAN, the wireless computing device conserves battery power by not scanning for a WLAN. The communication network may additionally be connected to the WLAN for data exchange. The alert criteria may be customized and stored in a subscriber database at the communication network.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates generally to the field of wireless communications and computing, and specifically to a method of notifying a mobile terminal of the availability of a wireless local area network through a communications network, based on the location of the mobile unit.  
           [0002]    Wireless access to communications and information services is a recent and growing trend in the telecommunications and data processing industries. Wireless communications services, such as cellular telephone services, have become ubiquitous and are today used to get wide area access to computer networks such as the Internet. Wireless local access to computer networks are also becoming commonplace, particularly in areas frequented by travelers, such as airport lounges, coffee shops, hotels, and the like. Concurrently, the line between consumer communications devices such as pagers and cellular telephones, and data processing devices such as laptop computers, continue to blur as each incorporates functionality of the other.  
           [0003]    Due primarily to the different bandwidth needs between communications and computing devices, different wireless networks are built and deployed by service providers to address each application. Typically, wireless communication networks span large geographic regions, while wireless computing networks are more limited in geographic extent. Additionally, wireless computing networks are far less extensively deployed than are wireless communications networks in these limited areas. Thus, a number of wireless local access networks are typically subsumed within the coverage area of one or more wireless communications networks.  
           [0004]    Wireless consumer electronics devices—both communications and computing devices—are nearly synonymous with battery-powered mobile devices. The minimization of power dissipation and the maximization of battery life are prime concerns. Many mobile consumer computing devices currently must either continuously search for a wireless local access network, wasting battery power, or alternatively the user may forego the advantages of the wireless local access network if the user is not aware of its presence and availability.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention includes a method of alerting a mobile terminal connected to a wireless communication network of the availability of a wireless local area network. The method comprises determining the location of the mobile terminal; comparing that location with the known location of the wireless local area network; and notifying the mobile terminal of the wireless local area network via the wireless communication network in response to the comparison. The notification may include transferring data regarding the wireless local area network to the mobile terminal.  
           [0006]    The present invention additionally includes a method of a mobile unit accessing a wireless local area network. The method comprises connecting to a wireless communication network operative to determine the location of the mobile unit; receiving from the wireless communication network, in response to the location determination, a notification of the availability of a wireless local area network; and accessing the wireless local area network in response to the notification. The mobile unit may include at least a communication device and a computing device. The two devices may be integrated into a common unit, or may be separate and connected in a data transfer relationship. The data may be transferred between the communication and computing devices via a wired connection such as a wire or optical cable or a wireless connection such as an infrared data link or a BLUETOOTH interface. 
       
    
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0007]    [0007]FIG. 1 is a diagram depicting a wireless communications network and wireless local area networks;  
         [0008]    [0008]FIG. 2 is a diagram depicting the lines of communication between the networks and separate wireless user devices;  
         [0009]    [0009]FIG. 3 is a diagram depicting the lines of communication between the networks and wireless user devices connected by a data transfer interface;  
         [0010]    [0010]FIG. 4 is a diagram depicting the lines of communication between the networks and integrated wireless user devices; and  
         [0011]    [0011]FIG. 5 is a flowchart depicting the method step according to one embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0012]    [0012]FIG. 1 depicts a wireless communication network, indicated generally by the numeral  10 , providing wireless communication services to mobile terminals  60  over a large geographic area. The service area is divided into a plurality of regions or “cells”  12 . A cell  12  may be subdivided into sectors two or more sectors. Each cell  12  typically includes a base station  14  for communicating with mobile terminals  60  within that cell  12 . As used herein, the term “mobile terminal” means any device capable of wireless communications, and may include a cellular radiotelephone; a Personal Digital Assistant (PDA) that combines a cellular radiotelephone with data processing capabilities; or a conventional laptop and/or palmtop computer including a radiotelephone transceiver. Mobile terminals may also be referred to as “pervasive computing” devices.  
         [0013]    Wireless communication network  10  may provide voice services, data services, or both voice and data services. Numerous standards exist for wireless communication networks. Representative standards include Time Division Multiple Access (TDMA) standards such as the Telecommunications Industry Association (TIA)/Electronics Industry Alliance (EIA) standard TIA/EIA-136, or the Global System for Wireless communication (GSM), and Code Division Multiple Access (CDMA) standards such as IS-95, cdma2000, and Wideband CDMA (W-CDMA). While the present invention is explained in the context of a CDMA network and provides examples utilizing features and capabilities specific to that standard, the present invention is not thus limited, and may be implemented by one of skill in the art in a wide variety of wireless communication networks, utilizing analogous features to implement the same or similar functions.  
         [0014]    [0014]FIG. 1 additionally depicts Wireless Local Area Networks (WLANs)  20 . WLANs  20  provide wireless access to high-bandwidth data networks to appropriately equipped wireless computing devices  70 . As used herein, the term “wireless computing device” means a computing device, such as a laptop computer or Personal Digital Assistant (PDA), equipped with a wireless interface for connecting wirelessly with a computer network, such as the Internet or private network, via a wireless access point. WLANs may be implemented according to a variety of protocols and technical standards, such as for example, IEEE 802.11(b) (also known as “Wi-Fi”); the short-range wireless ad hoc network developed and promulgated by Telefonaktiebolaget L. M. Ericsson, known commercially as BLUETOOTH; IEEE 802.11(a); or HiperLAN/2.  
         [0015]    WLANs  20  are characterized by high bandwidth data communications, and have a limited service coverage area. WLANs  20  may be deployed for private use within offices, universities, laboratories, and the like, and for public use in airport lounges, coffee shops, hotels, and the like. WLANs  20  may additionally be deployed over wider areas, such as a university campus, or several city blocks. Two or more WLANs  20  may be interconnected to provide high-bandwidth data communications over a metropolitan area. The areas covered by WLANs  20  typically form islands surrounded by areas with no such service. These islands are commonly referred to as “hot spots.” 
         [0016]    WLANs  20  may be provided by the same service provider as the wireless communication network  10 . Alternatively, WLANs  20  may be provided by independent service providers, such as Wireless Internet Service Providers (WISPs) or site operators. User access to the WLANs  20  may be restricted, such as for example, by subscription with only subscribed users granted access, or open to the general public, either on a pay-per-use basis or without billing, such as to induce customers to patronize an establishment. The particulars of access to WLANs  20 , and billings therefore, are not germane to the present invention and are not further discussed herein.  
         [0017]    Users of wireless computing devices  70  may prefer to access WLANs  20  whenever possible for network connectivity, such as Internet access, and for high-bandwidth data transfers. However, the radio frequency interfaces in wireless computing devices  70  may consume a great deal of power when constantly or periodically searching for an active WLAN  20  connection, dramatically reducing battery life.  
         [0018]    The present invention provides a method of notifying subscribers to a wireless communication network  10  of WLAN availability when the user is in the vicinity of a WLAN  20 . The wireless communication network  10  tracks the current location of a mobile terminal  60  associated with the user and sends a notification to the subscriber via the mobile terminal  60  when there is a WLAN in the vicinity of the user&#39;s current location. The mobile terminal  60  may be integrated with a wireless computing device  70  to form an integrated mobile unit with two interfaces. Alternatively, the mobile terminal  60  and wireless computing device  70  may comprise two separate devices. In the latter case, the wireless computing device  70  may have a first WLAN interface (such as an IEEE 802.11(b) interface) for communicating with the WLAN  20  and a second interface (such as a BLUETOOTH radio interface) for communicating with the mobile terminal  60 . If the mobile terminal  60  and wireless computing device  70  are part of an integrated mobile unit, the mobile unit may automatically activate a WLAN interface responsive to the notification from the wireless communication network  10  and begin searching for the WLAN. If the mobile terminal comprises a separate device, the mobile terminal may forward the notification from the mobile terminal  60  to the wireless computing device  70  via the second interface, which may in turn activate its WLAN interface. If there is no interface between the mobile terminal  60  and the wireless computing device  70 , the user may manually activate wireless computing device  70  and/or the WLAN interface in the wireless computing device  70 . The present invention allows the wireless computing device an/or WLAN interface to be placed in an inactive mode when there is no WLAN available and awakened only when the wireless computing device  70  is in the vicinity of a WLAN, thus conserving battery power.  
         [0019]    [0019]FIG. 2 illustrates an exemplary communication environment in which the present invention may be used. In FIG. 2, the user has two separate communication devices—a mobile terminal  60  for communicating with a first wireless communication network, such as a TIA/EIA/IS-2000 network  10 , and a separate wireless computing device  70  for communicating with a second wireless communication network  20 , such as WLAN  20 . The mobile terminal  60  includes a radio interface  62 , generally known as the A interface in the TIA/EIA/IS-2000 standards, for communicating with the wireless communication network  10 . Wireless communication network  10  connects the mobile terminal  60  to the PSTN and may additionally connect the mobile terminal to a packet data network, such as the Internet  40 . The mobile terminal  60  may further comprise a positioning receiver, such as a GPS receiver, for receiving signals from a GPS satellite  50  and determining its current location. The wireless computing device  70  includes an interface, such as an 802.11(b) compliant interface, for communicating with the WLAN  20 , which serves as an access point to the Internet  40  or other packet data network. The WLAN  20  may, for example, implement the IEEE 802.11(b) protocol.  
         [0020]    The user may be roaming within the service area of the wireless communication network  10  and may want to know when a WLAN  20  is available. To alert a user that he or she is within range of a WLAN  20  (or to directly alert the user&#39;s computing device, as described below), the wireless communication network  10  must determine the user&#39;s location, which for the purposes of the present invention may be taken as the location of the user&#39;s mobile terminal  60 . In one embodiment, the location of a mobile terminal  60  may simply comprise the cell  12  within which the mobile terminal  60  is located, as indicated by the base station  14  that is serving the mobile terminal  60 . For example, referring to FIG. 1, the mobile terminal  60  in a cell  12  which at least partially overlaps the coverage area of a WLAN  20  would be alerted to search for the WLAN  20 , even though the mobile terminal  60  may not actually be within the coverage area of WLAN  20 . For example, a mobile terminal  60  located anywhere in cell B, C, D, or F would be alerted to search for a WLAN  20 , which my result in many unsuccessful searches by mobile terminals  60  within these cells but outside of the coverage area of a WLAN  20 . The location of a mobile terminal  60  may be determined with greater specificity in a sectored cell, such as cell D. For example, as depicted in FIG. 1, mobile terminal  60  may only be alerted to the presence of WLAN  20  when it is being serviced within sector D 1  and might not be so alerted in sectors D 2  and D 3 . In one embodiment of the present invention, wherein the determination of the location of a mobile terminal  60  is simply an identification of the cell  12  or sector in which the mobile terminal  60  is operating, the alert transmitted by the wireless communication network  10  if a WLAN  20  is available in the cell  12  or sector (as described more fully below) may comprise a message broadcast to all mobile terminals  60  in the relevant cell  12  or sector.  
         [0021]    While location of a mobile terminal  60  at the granularity of a cell  12  or sector allows the wireless computing device  70  to save power by not unnecessarily searching for WLANs  20  outside of a cell  12  or sector where a WLAN  20  is present, the wireless computing device  70  may still consume battery power unnecessarily searching for WLANs  20  when it is within the indicated cell  12  or sector but outside of the coverage area of the WLANs  20 . A wide variety of techniques are known in the wireless communication arts for more precisely determining the location of a mobile terminal  60  within the wireless communication network  10 , any of which may be advantageously applied to the present invention. For example, the relative signal strengths, signal propagation delay, phase shift, or the like of signals transmitted by the mobile terminal  60  to three or more base stations  14  may be compared to triangulate or more precisely locate the position of the mobile terminal  60 . The mobile terminal  60  may include a positioning receiver and processing circuit for receiving satellite navigation signals from a satellite  50  or terrestrial antenna, and determining its position therefrom, transmitting that position information to the communication network  10 . One example of such a satellite navigation system is the U.S. Global Positioning System (GPS). The mobile terminal  60  may determine its position from GPS signals independently, or alternatively, it may receive assistance data, such as satellite ephemeris data or approximate location, from the communication network  10 . A wide variety of systems and methods for determining and tracking the precise location of mobile terminals  60  within a wireless communication network  10  have been developed to support location-based services such as advertising and emergency call point-of-origin reporting. These systems and methods are known in the art, and may be advantageously applied to the present invention.  
         [0022]    Once the wireless communication network  10  has determined the location of a mobile terminal  60 , that location may be compared to the known location and extent of WLANs  20 . the location of the WLAN  20  may be stored in various databases and other information resources within the communication network  10 . If the mobile terminal  60  is within a predetermined range of one or more WLANs  20  (for example, as measured from the center of the WLAN), the communication network  10  may notify the mobile terminal  60  of that fact via a transmission through the communication network  10 . Within the predetermined range, the mobile terminal  60  may be located within the coverage area serviced by the WLAN  20  or may be approaching such coverage area. In either case, the notification is desirable to bring the wireless computing device  70  out of an inactive state, to begin searching for WLAN  20 . In one embodiment, this notification may be as simple as a paging message sent to the mobile terminal  60 , causing the mobile terminal  60  to signal the user, such as by emitting a predefined “beep.” Alternatively, or in addition, the wireless communication network  10  may send the mobile terminal  60  a brief text message, such as for example, “WLAN DETECTED.” The communication network  10  may send the text message to the mobile terminal  60  using a defined protocol, such as the Short Message Service (SMS), which is displayed to the user. The user may then manually enable the wireless computing device  70  to search for a WLAN  20 .  
         [0023]    As shown in FIG. 3, both the mobile terminal  60  and wireless computing device  70  may be equipped with a second interface  74  for communicating with one another. The second interface  74  may comprise a wireless interface, such as a radio interface (e.g., BLUETOOTH interface) or infrared interface, or a wire or optical cable interface. In the embodiment of FIG. 3, the wireless communication network  10  determines the location of the user, which may comprise cell identification or ranging as described above, or may comprise receiving location information directly from the mobile terminal  60 , that calculates its location from satellite signals received from the GPS system  50 . If the user&#39;s location corresponds to the known service area of a WLAN  20 , as stored in a database accessible to the wireless communication network  10 , the network  10  sends an alert to the mobile terminal  60 . This alert may include data, such as the carrier frequency of the WLAN  20 , which can be sent utilizing in-band signaling within a SMS message. The signaling protocols could also be modified to enable such information to be transmitted to the mobile terminal  60  as a control message. The mobile terminal  60  may then signal the wireless computing device  70  (e.g., via a BLUETOOTH message) via interface  74 , causing the wireless computing device  70  to power-up or otherwise enable its WLAN interface  72  to establish wireless data communication with the WLAN  20 . The information signal sent to the mobile terminal  60  may simply indicate the availability of a WLAN  20 , causing the computing device  70  to search for the WLAN  20 . Alternatively, the information signal may include the carrier frequency of the WLAN  20 , and/or various information such as the WLAN  20  system operator, access policies and protocols, services available, billing information, and the like. In this embodiment, the enabling of the WLAN interface  72  on the wireless computing device  70  is completely automatic with respect to the user. As the user moves into range of a WLAN  20 , the wireless computing device  70  enables its WLAN interface  72  and connects to the WLAN  20 . As the user moves out of the range of a WLAN  20 , the wireless computing device  70  shuts down its WLAN interface  72 , such as by placing the circuit(s) in “sleep” mode, thus conserving battery power and compute resources.  
         [0024]    [0024]FIG. 4 shows a third exemplary embodiment of the invention. In the embodiment shown in FIG. 4, the mobile terminal  60  is integrated with the wireless computing device  70  to form an integrated mobile unit with at least two wireless interfaces  72  and  76 . The first wireless interface  72  is a WLAN interface and the second interface is a TIA/EIA/IS-2000 interface. The wireless computing device  70  communicates with the WLAN  20  via the WLAN interface  72  and communicates directly with the wireless communication network  10  via the second interface  76 . In this embodiment, the mobile computing device  70  may place the first wireless interface  72  in an inactive mode when it is outside the range of a WLAN  20 . As the mobile computing device moves closer to a WLAN  20 , the wireless communication network  10  sends a notification to the wireless computing device  70 , which is received via the second interface  76 . The notification may take any of the forms described above, but preferably includes information to facilitate establishing a connection with the WLAN  20 . Upon receiving the notification form the wireless communication network  10 , the wireless computing device  70  wakens its WLAN interface  72 , begins searching for the WLAN  20 , and establishes a connection if a WLAN  20  is found. Alternatively, the user may be prompted before connecting with the WLAN  20 .  
         [0025]    The manner in which the wireless communication network  10  alerts the mobile terminal  60  of the presence of WLAN  20 , and the information communicated to the mobile terminal  60 , may vary according to a user-specific profile, for example stored in a subscriber database in the communication network  10  such as the Home Location Register (HLR), as is well known to those of skill in the art. For example, such a database may indicate the WLAN  20  systems to which the user subscribes, or billing charges the user is willing to incur. The database may also indicate the manner in which the user&#39;s mobile terminal  60  is to be notified, which may vary among users depending on their equipment and its capacities. In this manner, each user may customize the location-based alerts to available WLAN  20 , and their automatic connection thereto, along a wide variety of parameters.  
         [0026]    In one embodiment, in addition to alerting the mobile terminal  60  of the presence of a WLAN  20  in response to the location of the mobile terminal  60 , the wireless communication network  10  may communicate with the WLAN  20  directly, such as across an IP interface  15 . The communication network  10  may receive data from the WLAN  20  concerning its operation, access, billing, available services, and the like for comparison to the user&#39;s preferences stored in a subscriber database, and/or for transmission to the user. The communication network  10  may also transfer information regarding the user to the WLAN  20 , such as the user&#39;s identification, enabling the WLAN  20  to access the user&#39;s email or perform other data processing in anticipation of the user registering with the WLAN  20 .  
         [0027]    Those of skill in the art will readily recognize that the configuration depicted in FIGS.  2 - 4  is representative only. In particular, the communication network  10  may communicate with the WLAN  20  in a variety of ways, such as through an SS7 signaling network, across a dedicated T1/E1 trunk, through the Internet  40 , or the like. Similarly, the link  15  between the communication network  10  and the WLAN  20  may be omitted altogether, as may be the case if the respective service providers are separate business entities with no cooperative agreement or data-sharing protocol in place. In such a case, the communication network  10  may simply alert the mobile terminal  60  to the presence of the WLAN  20 , and allow the wireless computing device  70  to search for the WLAN  20  and perform all login and authentication procedures.  
         [0028]    A flowchart depicting a method implemented in wireless communication network  10  of alerting a mobile terminal  60  or wireless computing device  70  to the presence of a WLAN  20 . Initially, the wireless communication network  10  determines the location of the mobile terminal  60  or wireless computing device  70  (block  100 ). This may be through cell or sector identification, ranging, triangulation, or other technique as described above, or may simply comprise receiving location information from the mobile terminal  60  or wireless computing device  70 , such as from a GPS receiver integrated therein. The current location of the mobile terminal  60  or wireless computing device  70  is compared with the known locations and extent of WLANs  20  to determine whether the mobile terminal  60  or wireless computing device  70  is within the proximity of, or within the coverage area of, a WLAN  20  (block  102 ). If not, no alert is sent, and control returns to block  100  to monitor the location of the mobile terminal  60  or wireless computing device  70 . If the mobile terminal  60  or wireless computing device  70  is determined to be within a predetermined range of a WLAN  20 , the wireless communication network  10  sends a notification to the mobile terminal  60  or wireless computing device  70 , such as by a page, text message, in-band signaling data transfer, or the like, as described above (block  104 ). The response of the mobile terminal  60  or wireless computing device  70  will depend upon the configuration of the user&#39;s mobile devices. If the notification is received by a mobile terminal  60  without an interface to the wireless computing device, the mobile terminal  60  may simply alert the user by beeping, turning on an indicator, or displaying a text message on a display. If the mobile terminal  60  has an interface for communicating with a wireless computing device  70 , the mobile terminal  60  may send a message to the wireless computing device  70  (block  106 ). The wireless computing device  70  may also receive the notification directly form the wireless communication network  10  if the wireless computing device is equipped with a network interface  76 . In the latter two cases, the wireless computing device  70  may activate its WLAN interface  72 , begin searching for the WLAN  20 , and establish a connection with the WLAN  20  (block  108 ) if a WLAN  20  is found. Control then returns to block  100 , where the communication network  10  continues to monitor the location of the wireless computing device  70 .  
         [0029]    Although the present invention has been described herein with respect to particular features, aspects and embodiments thereof, it will be apparent that numerous variations, modifications, and other embodiments are possible within the broad scope of the present invention, and accordingly, all variations, modifications and embodiments are to be regarded as being within the scope of the invention. The present embodiments are therefore to be construed in all aspects as illustrative and not restrictive and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.