Patent Publication Number: US-2022239538-A1

Title: Device beacon for communication management for peer to peer communications

Description:
RELATED APPLICATIONS 
     This application is a continuation application of continuation application of U.S. Patent Application entitled “DEVICE BEACON FOR COMMUNICATION MANAGEMENT FOR PEER TO PEER COMMUNICATIONS”, Ser. No. 16/365,106 and filed on Mar. 26, 2019; which is a continuation application of U.S. Patent Application entitled “DEVICE BEACON FOR COMMUNICATION MANAGEMENT FOR PEER TO PEER COMMUNICATIONS”, Ser. No. 12/267,365 and filed on Nov. 7, 2008; which is related to U.S. Patent Application entitled “DEVICE BEACON FOR HANDOFF MANAGEMENT OF HANDOFFS TO ACCESS NODES”, Ser. No. 12/267,261, and to U.S. Patent Application entitled “DEVICE BEACON FOR HANDOFF MANAGEMENT OF HANDOFFS TO BASE STATIONS”, Ser. No. 12/267,171, both filed on Nov. 7, 2008; all of which are assigned to the assignee hereof, and hereby expressly incorporated by reference. 
    
    
     BACKGROUND 
     The invention relates in general to wireless communication systems and more specifically to device beacon signals in a wireless communication system. 
     Wireless communication systems may include base stations or access nodes establish communication links to portable wireless communication devices. In peer to peer communications, the portable wireless communication devices communicate directly to each other without accessing a base station or access node. Conventional systems, however, are limited in that presence of one wireless communication device is unknown to another device even though communications between the two devices is advantageous or otherwise desired. 
     SUMMARY 
     A wireless communication device transmits a device beacon in accordance with a system timing of a wireless wide area network (WWAN). For one example, the beacon is transmitted relative to WWAN uplink channels of the time-frequency space of the uplink WWAN channel assignment. In response to the reception of the device beacon by another wireless communication device, a peer to peer communication session is established. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a block diagram of a communication system in accordance with an exemplary embodiment of the invention. 
         FIG. 1B  is block diagram of a communication system where the transceiver node is an access node. 
         FIG. 1C  is a communication system where the transceiver node is a mobile wireless communication device. 
         FIG. 2A  is an illustration of an exemplary geographical service area relationship provided by an originating base station and detecting base station where the geographic service area of a detecting base station is within an originating geographic service area of the originating base station. 
         FIG. 2B  is an illustration of an exemplary geographical service area relationship provided by the originating base station and the detecting base station where the geographic service area of a detecting base station overlaps with the originating geographic service area of the originating base station. 
         FIG. 2C  is an illustration of an exemplary geographical service area relationship provided by the originating base station and the detecting base station where the geographic service area of a detecting base station does not overlap with the originating geographic service area of the originating base station. 
         FIG. 3A  is a block diagram of a communication system where the transceiver node is a base station and the beacon is transmitted within the WWAN uplink channel. 
         FIG. 3B  is a block diagram of a communication system where the transceiver node is a base station the beacon is transmitted outside of the WWAN uplink channel. 
         FIG. 4A  is a block diagram of an example of the search message. 
         FIG. 4B  is block diagram of an example of the device proximity. 
         FIG. 5  is flow chart of a method of managing wireless service to a wireless communication device performed at the detecting base station. 
         FIG. 6  is a flow chart of a method of managing communication services to the wireless communication device performed in the system infrastructure. 
         FIG. 7  is block diagram of a communication system where the transceiver node is a WLAN access point and the wireless communication device is a multimode wireless communication device. 
         FIG. 8  is block diagram of a communication system where a device beacon signal is transmitted in a beacon channel that is not a WWAN channel. 
         FIG. 9A  is a block diagram of an example of a wireless communication device n. 
         FIG. 9B  is a block diagram of another example of a wireless communication device invention where the beacon transmitter includes a WWAN uplink transmitter. 
         FIG. 9C  is a block diagram of an example of a multimode wireless communication device where the beacon is transmitted by the WWAN uplink transmitter. 
         FIG. 9D  is a block diagram of an example of another multimode wireless communication device where the beacon is transmitted within a beacon channel that is not a WWAN uplink channel. 
         FIG. 10  is a flow chart of method performed at the wireless communication device where the transceiver node is a base station. 
         FIG. 11  is a flow chart of method performed at the wireless communication device where the transceiver node is a WLAN access point. 
         FIG. 12A ,  FIG. 12B  and  FIG. 12C  are graphical illustrations of exemplary relationships between the device beacon and the frequency-time space of the uplink WWAN channel when the WWAN system utilizes OFDM techniques. 
         FIG. 13A  is a block diagram of a beacon generator connected to a beacon transmitter wherein the device beacon is transmitted within the WWAN uplink channel. 
         FIG. 13B  is a block diagram of a beacon generator connected to a beacon transmitter wherein the device beacon is transmitted outside of the WWAN uplink channel. 
         FIG. 14  is a block diagram of a communication system in accordance with another exemplary embodiment of the invention where at least two wireless communication devices are able to communicate through a peer to peer link. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1A  is a block diagram of a communication system  100  that includes a wide area wireless network (WWAN)  102 , a transceiver node  104 , and a wireless communication device  106 . The WWAN provides wireless communication services to one or more wireless communication devices  106 . The wireless communication device  106 , at least periodically, transmits a device beacon  108  in accordance with a system timing  110  of the WWAN  102 . The transceiver node  104  also obtains the system timing  110 , either wirelessly or through a wired backhaul. A device beacon detector  112  within the transceiver node  104  uses the system timing  110  to monitor device beacon channels and to receive the device beacon  108 . As discussed below, the transceiver node  104  may perform any of several tasks in response to detecting the device beacon  108  where at least some of the tasks may result in establishing communications between the transceiver node  104  and the wireless communication device  106 . 
     The device beacon  108  may be transmitted within a WWAN channel or may be transmitted in a separate frequency band outside of the WWAN frequency band. Where the device beacon  108  is transmitted within a WWAN channel, the device beacon  108  is transmitted within a time slot and frequency that minimizes interference with other communications within the WWAN  102 . As discussed below, a suitable technique for such an arrangement includes performing a subcarrier mapping of the device beacon  108  with the time-frequency space of the uplink WWAN channel assignment for the wireless communication device. Some examples of channels that can be used that are outside the WWAN uplink channels include WLAN channels, WWAN adjacent bands, and channels within unlicensed bands such WiFi and Bluetooth. Also, the wireless communication device may transmit beacons during WWAN idle states and WWAN non-idle states. The device beacon detector  112  is any device that can detect the device beacon  108  when the wireless communication device  106  is sufficiently close to the transceiver node  104  where the particular implementation depends on the type of device beacon  108 . For the examples discussed below, the device beacon detector  112  comprises a receiver configured to receive signals transmitted within the frequency band and with the modulation scheme used to transmit the device beacon  108 . 
     The transceiver node  104  may be any portable, mobile, or fixed communication device that is capable of communicating with the wireless communication device  106  under the appropriate conditions. For one example discussed below with reference to  FIG. 1C , the transceiver node  104  is another wireless communication device that communicates on the WWAN. For the other examples discussed with reference to  FIG. 1B , the transceiver node  104  is an access node providing wireless communication service where the access node may be a base station operating within the WWAN such as a femtocell base station or may be an access point of a wireless local area network (WLAN). 
       FIG. 1B  is a block diagram of the communication system  100  where the transceiver node  104  is an access node  114 . The communication system  100  includes at least one access node  114  and at least one WWAN base station  116  where the access node  114  provides wireless communication service within a geographical service area that is smaller than the geographical service area in which the base station  116  provides wireless service. The communication system  100  may be implemented in accordance with any of numerous technologies and communication standards where the access node  114  may use the same or different standard than used by the base station  116 . Further, the access node  114  may be part of a separate network or may be part of the same network as the base station  116 . The access node  114  may be self-managed or may be managed by the system infrastructure  118  which may also manage the base station  116 . In some examples, the access node  114  is a femtocell base station operating in the same network where the base station  116  operates as a macrocell base station. In another example, the access node  114  is a wireless access point providing wireless service in a wireless local area network (WLAN) and the base station  116  provides service in a wireless wide area network (WWAN) using a different technology and standard than used by the WLAN access point. The access node  114 , therefore, can be any base station, transceiver, or other communication device that provides wireless communication service to a wireless communication device to connect the wireless communication device to other devices and/or a communication network. 
     The system infrastructure  118  is connected to one or more base stations  116  and access nodes  114 . Communications between the base station  116  and wireless communication devices  106  are at least partially managed by the system infrastructure  118  for the example. A controller  120  within the system infrastructure  118  at least includes hardware, software and/or firmware for receiving and sending control messages. The controller  120  may include at least portions of a BSC and a MSC. For the example discussed herein, the controller  120  is the equipment within the communication system  100  that performs wireless device paging functions and generates paging channel messages. 
     The wireless communication device  106  transmits a device beacon  108  that is based on timing information  122  received from the base station  116 . Timing information is derived at the wireless communication device by receiving WWAN downlink signals  122  transmitted by the base station  116 . Examples of suitable methods for acquiring WWAN system timing include receiving a sync channel or a sync-type channel. A downlink control signal may be received, for example, and accurate timing derived from the signal. In some circumstances, an early-late gate method is used to derive timing which uses an auto-correlation function. For systems that transmit information in a packetized mode, the synchronization processes may be aided by a sync preamble consisting of a training sequence. These training sequences typically have appropriate cyclic guard intervals. The preambles are periodically transmitted in between data symbols. After acquiring a coarse timing, the wireless communication may implement tracking mode where it tracks/adjusts and maintains the timing information. When the wireless communication device  106  is sufficiently close to the access node  114 , the access node  114  can receive the device beacon  108  transmitted by the wireless communication device  106 . The access node  114 , therefore, at least periodically attempts to receive signals in the designated device beacon channels  124 . As discussed, the device beacon  108  may be transmitted within designated WWAN uplink channels or outside of the WWAN band. At the appropriate times (or continuously), the device beacon detector  112  tunes to the appropriate frequencies and/or uses the appropriate scrambling codes to monitor the device beacon channels  124  where device beacons  108  may be present. The device beacon detector  112 , therefore, is any device that is able to monitor the device beacon channels  124  and determine when a device beacon  108  is present. For the examples discussed herein, the device beacon is deterministically transmitted such that a receiver can easily find and acquire beacon signals as needed. The information defining the device beacon assigned parameters may be broadcasted by the WWAN using control channels. Such broadcasts may be autonomous or in response to a request from a WLAN Access Point or femtocell base station. Examples of beacon parameters include beacon transmission times and periods as well as subcarrier and frequency information. 
     The access node  114  derives the system timing  110  either through a backhaul from the system infrastructure  118  or by monitoring the base station downlink signals  122 . The WWAN downlink signal  122  from the base station  116  to the access node  114  is shown as a dashed line to illustrate that the signal may or may not be received by the access node  114 . Where the access node  114  is femtocell base station, the system timing  110  is typically obtained through backhaul, GPS or the WWAN. In some circumstances where the access node  114  is a WLAN assess point, deriving the timing from WWAN downlink signals  122  may be more efficient than obtaining the system timing directly from the system infrastructure  118 . 
     The reception of the device beacon signal  108  invokes the acquisition of wireless service from the access node  114  by the wireless communication device  106 . In the examples discussed, the access node  114  informs the system infrastructure  118  of the detection after detecting the device beacon  108 . In response, the system infrastructure  118  transmits a search message  126  to the wireless communication device  106  that adjusts the searching scheme used by the wireless communication device  106  to search for alternate wireless service. Where the wireless communication device  106  is a dual mode device searching for a WLAN, for example, the search message  126  may result in an activation of the WLAN receiver to search for WLAN signals. Where the access node  114  is a base station connected on the same cellular network as the base station  116 , the wireless communication device  106  may change search parameters of the searching scheme used to search for alternate base stations in response to the search message  126 . Additional information may be processed by the access node  114  and/or the system infrastructure  118  before messages are transmitted by the system infrastructure  118  and/or the wireless communication device  106 . As discussed below, for example, the capacity of the access node  114  and the bandwidth requirements of the wireless communication device  106  may be evaluated before invoking a handoff to the access node  114 . In some situations, the detection of the device beacon signal may invoke additional procedures or mechanisms. For example, in situations where the access node is not transmitting a pilot signal until services are to be provided, the detection of the beacon invokes the transmission of the pilot signal. 
       FIG. 1C  is a block diagram of the communication system  100  where the transceiver node  104  is a mobile wireless communication device  128 . The mobile wireless communication device  128  is any mobile or portable device that is capable of receiving WWAN downlink signals  130  and may be, for example, a handset, phone, wireless personal digital assistant (PDA), wireless modem, or wireless laptop computer. In some circumstances, the mobile wireless communication device  128  may be capable of communication on the WWAN  102 . In other situations, however, the mobile wireless communication device  128  may include adequate electronics to receive the WWAN downlink signals  122  but may be configured to operate on a different network where the network may use the same or different technology and/or protocol than the WWAN  102 . For example, the mobile wireless communication device  128  may be a WLAN device that operates in accordance with WiFi but that also includes WWAN receiver. Further, the mobile wireless communication device  128  may be a multi-mode wireless communication device such as a dual-mode phone capable of operating within a WWAN and a WLAN. Since both of the wireless communication devices  106 ,  128  receive downlink signals  122 ,  130  from the WWAN base station  116 , the two devices  106 ,  128  both receive system timing information  110  from the WWAN. Accordingly, the system timing  110  is used as a reference for transmitting and receiving the device beacon  108 . 
     After the beacon detecting wireless communication device  128  detects the device beacon  108 , a peer to peer session is established between the wireless communication device  106  and the beacon detecting wireless communication device  128 . Peer to peer communication includes peer to peer communication  132  between the two devices  106 ,  128  without transmitting data through a network. The arrow representing peer to peer communication is shown with dashed lines in  FIG. 1C  to illustrate that the communications  132  are not established until after the device beacon  108  is detected. The peer to peer session may be established using any of several techniques and signaling schemes. For example, a device detection message may be sent to the WWAN which invokes a session establishment message that is transmitted by the WWAN to the wireless communication device  106 . In response to the session establishment message, the wireless communication device  106  transmits and/or receives messages to establish the peer to peer session. In some situations, the beacon detecting wireless communication device  128  sends a message directly to the wireless communication device  106  without using the WWAN. 
       FIG. 2A ,  FIG. 2B  and  FIG. 2C  are depictions of exemplary geographical service area relationships  200 ,  206 ,  208  provided by the WWAN  102  and the transceiver node  104 . A WWAN geographical service area  202  provided by the WWAN base station  116  and a geographic service area  204  provided by the transceiver node  104  may have any of numerous shapes, sizes, and configurations. Accordingly, the clouds representing the service areas generally illustrate the relationships between the service areas and do not necessarily depict the actual shapes of the service areas. Further, the service areas may contain holes of coverage where service is unavailable. In the interest of clarity and brevity, such features are not illustrated in the figures. In  FIG. 2A , the service area  204  of the detecting transceiver node  104  is completely within the service area  202  provided by the WWAN  102 . Such service area relationships  200  often occur where some base stations within the communication system  100  provide smaller service regions such as microcell, picocell, and femtocell configurations. A femtocell arrangement, for example, may include a femtocell base station (transceiver node  104 ) located at a residence where the femtocell is a service area for devices used by device users living at the residence. When the wireless communication devices are outside the service area  204 , service is provided by larger macrocells (e.g. reference base station  116 ). When the authorized wireless communication device is at the residence, however, service is provided by the transceiver node  104  presenting the smaller femtocell service area  204 . Further, the relationship  200  is likely to occur where the transceiver node  104  is a wireless communication device  128 . In such situations, the geographic service area is a geographic area within which another wireless communication device can engage in a per-to-peer communication session with the wireless communication device  128 . Accordingly, in most situations, the service area  204  of the transceiver node  104  will be completely within the service area  202  of the base station  116 . In some situations, however, the service area  204  may be partially overlapping with the service area  202  as shown in  FIG. 2B  or may be non-overlapping but adjacent to the service area  202  as shown in  FIG. 2C . 
       FIG. 3A  is a block diagram of a communication system  300  where the transceiver node  104  (access node  114 ) is a base station  302  such as a femtocell base station, picocell base station, or microcell base station. The system  300  may be implemented using any variety of communication technologies and cell sizes. For the example discussed with reference to  FIG. 3A , the base station  302  provides wireless service within a femtocell and the base station  116  provides service within a macrocell. In the interest of clarity, the base station  302  that detects the device beacon  108  is referred to as the detecting base station  302  and the base station  116  providing the system timing  110  to the wireless communication device  106  is referred to as the reference base station  116 . The base stations  302 ,  116  operate in accordance with OFDM protocols and standards such as IEEE802.16 and 3GPP LTE. Other communication standards and protocols, however, may be used in some circumstances. Examples of other suitable communication standards include CDMA standards such as cdma20001×, 1×EV-DO and W-CDMA, and GSM standards. The term macrocell is used primarily to distinguish this group of diverse technologies from picocells and femtocells that typically have smaller service areas on the order of 100 to 300 feet per base station. Accordingly, the reference base station  116  is any base station that provides wireless communication services within relatively large geographical areas as compared to the geographical service area provided by the base station  302  in the example of  FIG. 3A . The functional blocks of  FIG. 3A  may be implemented using any combination of hardware, software and/or firmware. Two or more of the functional blocks may be integrated in a single device and the functions described as performed in any single device may be implemented over several devices. For example, at least portions of the functions of the system infrastructure  118  and controller  120  may be performed by the base station  116 , a base station controller, or an MSC in some circumstances. 
     The reference base station  116  transmits downlink link (forward) signals  122  to, and receives uplink (reverse link) signals  304  from, one or more wireless communication devices to provide wireless communication service. The wireless communication device  106  may be in any of several states while receiving the WWAN downlink signals that provide system timing. The operational states of the wireless communication device  106  may include idle states, dormant states, active states and other traffic and non-traffic states. The wireless communication device  106  generates and transmits the device beacon  108  in accordance with the system timing. The system timing includes at least the timing reference as well as time slot and channel assignment. For the example discussed with reference to  FIG. 3A , device beacon  108  is transmitted at a designated time and channel (subcarrier) within the uplink WWAN time-frequency space. For the example discussed with reference to  FIG. 3B  below, the device beacon  108  is transmitted outside of the uplink channel but in accordance with the WWAN system timing. 
     The system infrastructure  118  includes the controller  120  that may be implemented as a mobile switching center (MSC), a combination of an MSC and base station controllers (BSCs), or other similar communication controllers and/or servers. The controller  120  is connected to the base stations  302 ,  116  through the system infrastructure  118  and manages communications within the system  300 . Although the controller  120  is illustrated as part of the system infrastructure  118 , it may be part of the base station  116  or collocated with the base station  116 . The controller  120  may include, or may be part of, the MSC, BSC or other infrastructure. The controller  120  includes the hardware and software for generating the search message  126  and, for this example, is the same equipment used to generate paging channel messages. 
     A network interface  306  within the detecting base station  302  facilitates communication with an IP network  308  through an access router  310 . The network interface  306  provides packet data communications and facilitates access to the Internet and to an access gateway  312  in the system infrastructure  118  through the access router  310 . In some circumstances the access router  310  may be implemented as part of the network interface and the network interface  306  may directly access the Internet. The access router  310  may be connected to several base stations and provides communication management and control functions to the detecting base station  302 . In some circumstances, the connection between the access gateway  312  and the base station  302  may include a wireless communication link such as satellite communication link or point-to-point microwave link, for example. Also, in some situations, circuit switched connections may be used to connect the detecting base station  302  to the system infrastructure  118 . In a typical arrangement, the detecting base station  302  is connected to the Internet through an Internet Service Provider (ISP) service provided by a digital subscriber line (DSL) or CATV connection. Accordingly, the access router  310  is a DSL modem or cable modem in the typical arrangement. In the example, therefore, the system infrastructure  118  comprises a packet switched core network that includes at least one access gateway  312 . The access gateway  312  is a communication interface that allows the base station  302  to communicate with the system infrastructure  118 . 
     The wireless communication device  106  is any type of communication device that is capable of communicating with the base stations  302 ,  116 . The wireless communication device  106 , sometimes referred to as an access terminal, may be a wireless modem, a personal digital assistant (PDA), cellular telephone, or other such device. Examples of suitable wireless communication devices are provided below. 
     In addition to the functions and features discussed herein, the detecting base station  302  operates in accordance with the communication protocols of the communication system  300  and is a femtocell base station. The detecting base station  302  includes a controller  314 , memory  316 , WWAN transceiver  318 , such as cellular transceiver, and the network interface  306  in addition to other devices and software for performing the functions of the base station  302 . The cellular transceiver  318  includes an uplink receiver  320  and a downlink transmitter  322 . The downlink transmitter  322  transmits WWAN downlink signals  132  to wireless communication devices such as the wireless communication device  106 . 
     In addition to other information, the memory  316  stores communication device identification values corresponding to each wireless communication device  106  that is authorized to receive service from the base station  302 . The communication device identification value may include an electronic serial number (ESN), Mobile station Equipment Identifier (MEID) or International Mobile Subscriber Identity (IMSI) or other unique data identifying the wireless communication device  106 . An example of a group of identification values stored in memory  316  includes a collection of ESNs corresponding to the communication devices of the family members of a household where the base station  302  provides service. The identification values may be stored at the base station  302  using any of numerous techniques. An example of a suitable method of storing the values includes storing the values during an initialization procedure performed when the base station  302  is installed. The identification values may be provided, at least partially, by the core network or the macrocell base station  116 . In some implementations, the identification values may be omitted or the base station  302  may allow communication devices that do not have corresponding identification values stored at the base station  302  to receive service from the base station  302 . 
     During operation, the detecting base station  302  monitors, at least periodically, a device beacon channel  124  which is a wireless channel that may include the device beacon signal  108 . For the example of  FIG. 3A , the device beacon signal  108  is within a sub-carrier time slot. In some circumstances, no other channel is assigned for the other frequencies during the time slot assigned for the device beacon. Such a scenario increases the likelihood of the detecting base station  302  to detect the device beacon signal  108  since all of the device beacon energy is concentrated at a particular frequency with no other concurrently transmitted signals present. The assignment of subcarriers for the beacon is established at the base band frequencies. Accordingly, the actual transmitted signal at the radio frequencies (RF) may include a wideband signal. The device beacon detector  112  is formed by at least portions of the controller  314 , memory  316  and uplink receiver  320 . Since the detecting base station  302  is synchronized with the system infrastructure  118 , the cellular transceiver  318  has adequate system timing information to determine the time slot boundary and the timing of uplink signals. The timing facilitates non-blind beacon detection at the receiver. With appropriate beacon designs, blind detection may also be performed. In some circumstances, the device beacon detector  112  may only search for beacons signals transmitted from wireless communication devices that are authorized to use the detecting base station  302 . An authorized list of serial numbers or other device identifiers are stored in memory  316  at the detecting base station  302 . 
     In response to detecting the device beacon signal  108 , the detecting base station  302  sends a device proximity message  324  to the controller  120  which invokes the reference base station  116  to transmit the search message  126  to the wireless communication device  106 . For this example, the controller  314  determines if the device beacon signal  108  is successfully received at the detecting base station  302 . If the signal can be received, the controller  314  determines that the wireless communication device  106  is sufficiently close to receive service from the base station  302 . In some cases, the device beacon signal may be detected and received even though the wireless communication device  106  is not within the service area of the base station  302 . In these circumstances, the wireless communication device  106  may unsuccessfully attempt to acquire service from the base station  302  after receiving the search message  126  from the reference base station  116 . The controller  314  determines, or at least estimates, the proximity of the authorized wireless communication device  106  to the detecting base station  302  based on one or more characteristics of the uplink signal. In the exemplary embodiment, the detection of an uplink signal from the communication device  106  is sufficient to determine that the communication device  106  is within a proximity range. The proximity is used to determine whether the communication device  106  is possibly within range of the base station  302  and at least possibly able to receive communication service from the base station  302 . Therefore, the controller  314  at least determines whether the communication device  106  is possibly within range of the base station  302 . If the controller  314  determines that the wireless communication device  106  is possibly in range, the device proximity message  324  is sent to the controller  120  in the system infrastructure  118  which results in the transmission of the search message  126  to the wireless communication device  106 . 
     The controller  314  may determine whether to transmit the device proximity message  324  based on factors other than proximity of the wireless communication device  106  or the detection of the device beacon signal  108 . For example, factors may include the available capacity of the detecting base station  302 , core network requirements, required bandwidth of the wireless communication device communications, and availability of other base stations or communication service providers in the area. Accordingly, the base station  302  may not transmit the device proximity message  324  even if the wireless communication device  106  is within range in some circumstances. In some situations, the device proximity message  324  is transmitted every time a wireless communication device  106  is detected by the detecting base station  302  and the system infrastructure  118  determines whether to transmit the search message  126 . 
     The device proximity message  324  is generated by the controller  314  and transmitted through the network interface  306 , through the IP network  308  and/or the access router  310  to the access gateway  312 . The access gateway  312  routes the device proximity message  324  through the system infrastructure  118  to the controller  120 . For the discussed example, the controller  120  is the same equipment that is used to generate paging messages to the wireless communication device  106 . The controller  120  receives the device proximity message  324  and extracts the appropriate information. In response to the device proximity message  324 , the controller  120  generates the search message  126  which is transmitted from the reference base station  116  to the wireless communication device  106 . The search message  126  triggers an adjustment of the wireless communication device searching scheme that the wireless communication device  106  employs for searching for alternate base stations. The wireless communication device  106 , therefore, changes one or more searching parameters of the searching scheme in response to receiving the search message  126 . Any combination of numerous parameters can be adjusted where the adjustments increase the likelihood of the wireless communication device  106  detecting a signal transmitted by the detecting base station  302 . The search message  126  may result in a change in the search scheme to devote more resources to search for an alternate base station or may result in a change in resources to search for the specific detecting base station  302 . In some circumstances, the search message  126  may specifically instruct the wireless communication device  106  to search for the detecting base station  302 . 
     For the example, the search message  126  is transmitted using the paging channel. Any suitable downlink channel monitored by the wireless communication device  106  during the non-traffic state, however, may be used. The wireless communication device  106  searches for signals transmitted by alternate base stations in accordance with the searching scheme. Alternate base station signals from frequencies and/or technologies different than those by the base station  116  may be searched. The wireless communication device  106  searches for pilot signals although other signals may be searched. For example, the wireless communication device  106  may search for base station beacon signals in some situations. Examples of searching parameters include a total time period for searching, time periods for searching particular frequencies, the frequency of searching, the frequency of searching particular frequencies, the groups of frequencies searched, the portions of channels searched, the receiver settings for searching and type of communication technology. Other searching parameters will be apparent to those skilled in the art based on these teachings. As discussed in further detail below with reference to  FIG. 4A , therefore, the search message  126  includes information that results in an adjustment of one or more of the search parameters. 
     For the present example, device proximity message  324  are sent only in response to receiving device beacon signals  108  from authorized users of the detecting base station  302 . The search message  126  is sent to the wireless communication device  106  in response to receiving the device proximity message  324  at the controller  120 . In some situations, however, additional criteria may be evaluated before sending the device proximity message  324 , the search message  126 , or before sending both. As discussed below, for example, the detecting base station  302  may evaluate one or more parameters to determine the proximity of the wireless communication device  106  to the detecting base station  302  and only send the device proximity message  324  if the calculated proximity is less than a threshold. Also, the controller  120  may evaluate system conditions and refrain from sending the search message  126  if certain system conditions are not met. 
     Examples of data that may be evaluated by the detecting base station  302  include the capacity of the detecting base station  302 , bandwidth requirements of the wireless communication device  106  and a calculated or estimated proximity of the wireless communication device  106  to the detecting base station  302 . Accordingly, the detecting base station  302  may evaluate a characteristic of the device beacon signal  108  to determine whether to transmit the device proximity message  324 . In the example, the reception of the device beacon signal  108  by the UL receiver  320  is sufficient to determine that the wireless communication device  106  is present and that the device proximity message  324  should be transmitted. In other circumstances, other signal characteristics may be evaluated to determine the proximity. Therefore, a characteristic of the device beacon signal  108  may be any of numerous parameters with any of numerous thresholds depending on the particular implementation and the characteristic may be whether the device beacon signal  108  is detectable by the base station receiver  320 . Examples of other characteristics include a signal to noise ratio (SNR), bit error rate (BER), power level, signal propagation time, and presence of particular data. An example of technique for determining the proximity is discussed in U.S. patent application Ser. No. 11/565,266 entitled “APPARATUS, SYSTEM AND METHOD FOR MANAGING WIRELESS LOCAL AREA NETWORK SERVICE TO A MULTI-MODE PORTABLE COMMUNICATION DEVICE”, filed on Nov. 30, 2006, and incorporated by reference in its entirety herein. 
     The device proximity message  324  and search message  126  may have any of numerous relationships and each message may be dependent on the information within, the format of, and/or other characteristics of the other message. For example, the device proximity message  324  and the search message  126  may be the same message in some circumstances. Such a situation occurs where the device proximity message  324  is an SMS message sent directly to the wireless communication device  106  indicating that the device beacon signal  108  transmitted from the device  106  has been detected by the detecting base station  302 . The wireless communication device  106  interprets the device proximity message  324  as a search message  126  indicating that the search parameters should be changed. Transmitting the search message  126  within the paging channel, however, allows for minimizing power consumption since additional resources are not invoked to receive SMS messages. 
     After receiving the search message  126 , the wireless communication device  106  searches for an alternate base station in accordance with the adjusted search scheme. In response to the search message  126 , the wireless communication device  106  activates the appropriate circuitry to receive signals transmitted by the detecting base station  302  such as a beacon pilot signal or communication pilot signals. In most situations, such circuitry is periodically activated in accordance with the search scheme to the reception of the search message and the search message does not directly trigger the activation of the receive circuitry. The adjusted search scheme, however, may result in more frequent activation of the circuitry. The detecting base station  302  generates and transmits a communication pilot signal which provides control and timing information to the wireless communication device  106 . In some circumstances, the detecting base station  302  may refrain from transmitting pilot signals until a wireless communication device  106  is detected and the proximity message  304  is sent. In addition, the detecting base station  302  may transmit a base station beacon pilot signal. After the detecting base station  302  is found by the wireless communication device  106 , the wireless communication device  106  may engage in a handoff procedure where, after a determination that the wireless communication device  106  should be handed off to the detecting base station  302 , the system  300  establishes wireless service to the wireless communication device  106  from the detecting base station  302 . 
       FIG. 3B  is a block diagram of a communication system  350  where the transceiver node  104  (access node  114 ) is a base station  352  such as a femtocell base station, picocell base station, or microcell base station and where the device beacon is transmitted outside of the WWAN uplink frequency band. The system  350  is similar to the system  300  discussed with reference to  FIG. 3A  except that the detecting base station  302  includes a device beacon detector  112  that detects device beacons  108  outside of the WWAN uplink frequency band. For the example of  FIG. 3B , therefore, the wireless communication device  106  transmits a device beacon with a frequency band outside of the WWAN uplink frequency band. Examples of suitable frequency bands include Bluetooth frequency bands and WLAN frequency bands. The device beacon detector  112  includes a receiver that can receive the signals transmitted within the device beacon frequency band. After detecting the device beacon, the base station  302  may perform the functions discussed above with reference to  FIG. 3A . In some situations, detecting base station may not be transmitting or receiving any WWAN signals until after detection of the device beacon  108 . Accordingly, the WWAN pilot signal  132  may be transmitted in response to the detection of the device beacon signal  108 . 
       FIG. 4A  is a block diagram of the search message  126  where the search message  126  is transmitted within a paging channel message  400 . The search message  126  may contain any of several types of information, may have any of numerous formats, and may be transmitted using a variety of channels and signals. For this example, the search message  126  is contained within the message body  402  of a paging channel message  400  in accordance with one or more OFDMA standards. The paging channel is allocated a set of time-frequency bins where each paging channel message  400  includes a header field  404 , a message body  402 , and a cyclic redundancy check (CRC)  406 . 
     For the example, a search message indicator  408  may be included in the header  404 . The header  404  may also include message length information. Typically, length is kept constant for paging messages.]. The search message indicator  408  is any number of bits that indicates to the wireless communication device  106  that the paging message is a search message  126 . The search information includes information related to the search scheme adjustment. In some cases, the search message indicator  408  is sufficient to notify the wireless communication device  106  of a need to adjust the searching scheme and the search information  410  may be omitted. The search information, however, may include any of numerous parameters related to the adjusting the searching scheme. As discussed below in further detail, the search information  410  may include information that identifies one or more base stations that should be searched or frequencies that should be searched. 
     The search message  126  includes information that results in an adjustment of one or more of the search parameters. In some situations, the search message  126  may only indicate that a more robust search should be performed and the wireless communication device  106  adjusts searching resources in response. The search information  410  may be omitted in this case. The search change may be a preprogrammed adjustment or a dynamic adjustment based on other criteria observed by the wireless communication device  106 . For example, if some detection of energy had been recently observed in a particular channel, the adjustment in search parameters may be adjusted to more heavily target resources to searching that particular channel as compared to the resources that would have been applied to the channel if the search message were not received. In an example where the search scheme is preprogrammed that is not based on other criteria, the wireless communication device may search in accordance with a scheme utilized prior to receiving the search message  126  but may increase search times or reduce the periods between searches. 
     The search message  126  may also include search information  410  identifying a group of base stations that may be available. Such an indication may be a specific identifier specifically identifying one or base stations or may be a general identification identifying a group of base stations such as an identifier indicating all authorized femtocell base stations. Since the wireless communication device  106  includes a list of all femtocell base stations that the device is authorized to access, a general identifier will provide sufficient information for identifying specific base stations. 
     In some circumstances, the search message  126  may indicate specific frequencies. A pilot frequency or beacon frequency of the detecting base station  302  may be identified, for example. 
     The wireless communication device  106  extracts the information from the search message  126  and adjusts the searching scheme in accordance with search message  126 . The adjustment may include any of numerous parameter changes where some examples include adjusting one or more of the following: frequencies searched, channels searched, period between searches, period between searches of specific frequencies, time period of search, time period for search at specific frequencies, search offsets, location of starting search in the search-space, and searcher receiver settings. In circumstances where the wireless communication device  106  searches for service from a system utilizing a different communication technology and universal searcher is used, similar parameters may be adjusted. Where a new searcher is invoked for the alternate technology base station, the parameters may also include the timing of the activation of the new searcher. 
       FIG. 4B  is block diagram of a device proximity message  324  that includes a message identifier  452 , and a device identifier  454 . In some cases, proximity data  456  may also be included. The proximity data  456  is illustrated with dashed lines to indicate that this feature is optional. The device proximity message  324  may have any of numerous formats and may be sent using any suitable signaling method. The message identifier  452  includes any combination of data that indicates to the controller  120  that the message  450  is a device proximity message  324 . Accordingly, the message identifier  452  may be a single bit flag in some circumstances. The device identifier  454  includes data that identifies the wireless communication device  106  that has been detected by the detecting base station  302 . One example of a device identifier  454  is a device serial number. 
       FIG. 5  is flow chart of a method of managing wireless service to a wireless communication device  106  performed at the detecting base station  302 . The method may be performed by any combination of hardware, software and/or firmware. The order of the steps discussed below may be varied and one or more steps may be performed simultaneously in some circumstances. In the exemplary embodiment, the method is performed, at least in part, by executing code on the controller  314  in the detecting base station  302 . 
     At step  502 , the wireless channel that may contain a device beacon signal  108  is monitored. The uplink receiver  320  attempts to demodulate and/or decode incoming signals within the wireless communication channel. The WWAN system timing is applied to receive the monitor the beacon channels. In this example, the uplink receiver  320  is tuned to decode any uplink signals  304  transmitted from any of the communication devices  106  in the user list stored in memory  316 . The long code masks derived with the device identification values are applied to incoming signals until an incoming device beacon signal  108  is detected. 
     At step  504 , it is determined whether a device beacon signal  108  has been detected. In this example, the controller  314  determines that device beacon signal has been received if an incoming uplink signal can be decoded and determined to be a beacon signal transmitted from an authorized wireless communication device  106 . If a device beacon signal  108  has been received, the method continues at step  506 . Otherwise, the method returns to step  502  to continue monitoring the device beacon channel. 
     At step  506 , it is determined whether the device proximity message  324  should be transmitted. In some situations, step  506  can be omitted and the device proximity message  324  may be transmitted when the device beacon signal  108  is detected. This procedure is discussed with reference to  FIG. 8 . In other situations, however, additional processing or communication is invoked before the device proximity message  324  is transmitted. For example, system conditions of the detecting base station  302 , other base stations, the core network, and/or alternate networks can be evaluated to determine whether a handoff to the detecting base station  302  is desired. An example of such a procedure is discussed with reference to  FIG. 9 . If it is determined that the device proximity message  324  should be transmitted, the method continues at step  508 . Otherwise, the method returns to step  502 . In some circumstances, a response may be sent to the beacon-transmitting wireless communication device. An ACK may be sent, for example, with an appropriate message that assists the wireless communication device in finding the detecting-device. This ACK-message can be transmitted in WWAN or WLAN frequency or any other frequency (pre-defined)]. 
     At step  508 , the device proximity message  324  is sent to the system infrastructure. The device proximity message  324  at least identifies the wireless communication device  106  and indicates that the wireless communication device  106  may be within, or near, the service area of the detecting base station  302 . 
       FIG. 6  is a flow chart of a method of managing communication services to the wireless communication device  106  performed in the system infrastructure  118 . The method may be performed by any combination of hardware, software and/or firmware. The order of the steps discussed below may be varied and one or more steps may be performed simultaneously in some circumstances. In this example, the method is performed, at least in part, by executing code on the controller  120  in the system infrastructure  118 . 
     At step  602 , the device proximity message  324  is received from the detecting base station  302 . As described above, the device proximity message  324  is sent through the IP network  308  and routed through the access gateway  312  to the controller  120 . The controller  120  extracts information from the device proximity message  324  which includes at least information identifying the wireless communication device  106 . 
     At step  604 , it is determined whether the search message  126  should be transmitted to the wireless communication device  106 . The controller  120  may evaluate any number of factors in accordance with known techniques for managing handoffs and communication resources in determining whether to transmit the search message. In some circumstances, the threshold may be relatively low and the controller  120  determines to send the search message  126  solely in response to receiving the device proximity message  324 . In other circumstances, the controller  120  may apply the same criteria as used to determine whether to handoff a device from one base station to another. Some examples of criteria that may be evaluated by the controller  120  include bandwidth requirements, capacity of the base stations, QoS levels priority levels, and costs. If the controller  120  determines that the search message  126  should be sent, the procedure continues at step  606 . Otherwise, the method returns to step  602 . 
     At step  606 , the search message  126  is generated and transmitted to the wireless communication device  106 . The controller  120  generates a search message  126  in accordance with page messaging techniques. As discussed above, the search message  126  includes information for adapting the search parameters of the base station searching scheme used by the wireless communication device  106 . When the invoking the changes contained in the search message  126 , the wireless communication device  106  increases the likelihood of detecting the base station  302  in a shorter time than if the changes are not made. The search message  126  is transmitted from the reference base station  116 . 
       FIG. 7  is a block diagram of a communication system  700  where the transceiver node  104  is a WLAN access point  702  and the wireless communication device  106  is a multimode wireless communication device  704 . The system  700  may be implemented using any variety of communication technologies and cell sizes. For the example discussed with reference to  FIG. 7 , the WLAN access point  702  provides WLAN wireless service within a WLAN service area and the base station  116  provides cellular service within a macrocell. The WLAN access point  702  operates in accordance with a WLAN protocol such as WiFi protocol. The functional blocks of  FIG. 7  may be implemented using any combination of hardware, software and/or firmware. Two or more of the functional blocks may be integrated in a single device and the functions described as performed in any single device may be implemented over several devices. For example, at least portions of the functions of the access router  310  may be performed by the base station network interface  306  within the WLAN access point  702  in some circumstances. 
     The base station  116  transmits downlink (forward link) signals  122  to, and receives uplink (reverse link) signals  304  from, one or more wireless communication devices to provide wireless communication service. The multimode wireless communication device  704  may be in any of several states while receiving the WWAN downlink signals that provide system timing. The wireless communication device states may include idle states, dormant states, active states and other traffic and non-traffic states. The wireless communication device  704  generates and transmits the device beacon in accordance with the system timing and a time and channel assignment. For the example discussed with reference to  FIG. 7 , the device beacon  108  is transmitted at a designated time and channel within the uplink WWAN time-channel space. As discussed below with reference to  FIG. 8 , the device beacon may be transmitted outside the WWAN channels by the multimode wireless communication device in some circumstances. 
     A WLAN transceiver  706  within the WLAN access point  702  facilitates wireless interface with one or more multimode wireless communication devices  704 . The WLAN transceiver  706  includes a WLAN receiver  708  for receiving WLAN uplink signals and a WLAN transmitter  710  for transmitting WLAN downlink signals in accordance with the WLAN protocol. 
     The multimode wireless communication device  704  is any type of communication device that is capable of communicating with the WLAN access point and at least receiving WWAN downlink signals from the base station  116 . For the example of  FIG. 7 , the multimode wireless communication device  704  is capable of receiving, at least non-simultaneously, wireless service from both the WWAN and WLAN systems. The wireless communication device  704 , sometimes referred to as an access terminal, may be a wireless modem, a personal digital assistant (PDA), cellular telephone, or other such device. 
     The system infrastructure  118  includes the controller  120  that may be implemented as a mobile switching center (MSC), a combination of an MSC and base station controllers (BSCs), or other similar communication controllers and/or servers. The controller  120  is connected to the base station  116  through the system infrastructure  118  and manages communications at least on the WWAN system. A network interface  306  within the WLAN access point  702  facilitates communication with an IP network  308  through an access router  310 . The network interface  306  provides packet data communications and facilitates access to the Internet and to an access gateway  312  in the system infrastructure  118  through the access router  310 . In some circumstances the access router  310  may be implemented as part of the network interface  306  and the network interface  306  may directly access the Internet. The access router  310  may be connected to several access points. In some circumstances, the connection between the access gateway  312  and the access point  702  may include a wireless communication link such as satellite communication link or point-to-point microwave link, for example. Also, in some situations, circuit switched connections may be used to connect the access point  702  to the system infrastructure  118 . In a typical arrangement, the WLAN access point  302  is connected to the Internet through an Internet Service Provider (ISP) service provided by a digital subscriber line (DSL) or CATV connection. Accordingly, the access router  310  is a DSL modem or cable modem in the typical arrangement. In the example, therefore, the system infrastructure  118  comprises a packet switched core network that includes at least one access gateway  312 . The access gateway  312  is a communication interface that allows the access point  702  to communicate with the system infrastructure  118 . The WLAN access point receives system timing information form the WWAN through the network interface for this example. In some situations, a WWAN downlink receiver  716  can be used to intercept WWAN downlink signals to derive the system timing. The block representing the WWAN DL RX  716  is shown within dashed lines to indicate that the WWAN DL RX  716  is optional. 
     For the example of  FIG. 7 , the device beacon signal  108  is transmitted within a WWAN uplink channel and the device beacon detector  112  is formed, at least partially by a WWAN receiver  718 , a controller  714  and a memory  712 . The WWAN receiver  718  is at least periodically tuned to the appropriate WWAN uplink channel in accordance with the system timing to monitor the device beacon channels. 
     In addition to other information, the memory  712  stores communication device identification values corresponding to each communication device  704  that is authorized to receive service from the access point. The communication device identification value may include an electronic serial number (ESN), Mobile station Equipment Identifier (MEID) or International Mobile Subscriber Identity (IMSI) or other unique data identifying the wireless communication device  704 . In some implementations, the identification values may be omitted or the access point  702  may allow communication devices that do not have corresponding identification values stored at the access point  702  to receive service from the access point  702 . 
     During operation, the access point  702 , monitors, at least periodically, a device beacon channel  124  which is a wireless channel that may include the device beacon signal  108 . For the example of  FIG. 7 , the device beacon signal is transmitted within a sub-carrier time slot. In some circumstances, the time slot is not assigned for any other communications for any frequency. Although the device beacon detector  112  is formed by at least portions of the controller  714 , memory  712  and WWAN receiver  718 , separate hardware and/or software may be sued to implement the device beacon detector in some cases. Since the WLAN access point receives the WWAN system timing from the system infrastructure  118 , the WWAN receiver  718  has adequate system timing information to determine the time slot boundary and the timing of uplink signals. In some circumstances, the device beacon detector  112  may only search for beacons signals transmitted from wireless communication devices that are authorized to use access point as mentioned above. An authorized list of serial numbers or other device identifiers are stored in memory  712  at the WLAN access point. 
     In response to detecting the device beacon signal  108 , the WLAN access point  702  sends a device proximity message  324  to the controller  120  which invokes the base station  116  to transmit the search message  126  to the wireless communication device  106 . The controller  714  determines if the device beacon signal  108  is successfully received at the WLAN access point  702 . If the signal can be received, the controller  714  determines that the wireless communication device  106  is sufficiently close to receive service from the access point  702 . The controller  714  determines, or at least estimates, the proximity of the authorized wireless communication device  106  to the access point  702  based on one or more characteristics of the uplink signal. In the exemplary embodiment, the detection of an uplink signal from the communication device  106  is sufficient to determine that the communication device  106  is within a proximity range. The proximity is used to determine whether the communication device  106  is possibly within range of the WLAN access point and at least possibly able to receive communication service from the WLAN access point. Therefore, the controller  714  at least determines whether the communication device is possibly within range of the access point  702 . If the controller determines that the wireless communication device is possibly in range, the device proximity message  324  is sent to the controller  120  in the system infrastructure  118  which results in the transmission of the search message  126  to the wireless communication device  106 . 
     The controller  714  may determine whether to transmit the device proximity message  324  based on factors other than proximity of the wireless communication device  106  or the detection of the device beacon signal  108 . For example, factors may include the available capacity of the access point, core network requirements, required bandwidth of the wireless communication device communications, and availability of other, access points, base stations or communication service providers in the area. Accordingly, the access point  702  may not transmit the device proximity message  324  even if the wireless communication device  106  is within range in some circumstances. In some situations, the device proximity message  324  is transmitted every time a wireless communication device is detected by the access point and the system infrastructure  118  determines whether to transmit the search message  126 . 
     The device proximity message is generated by the controller  714  and transmitted through the network interface  306 , through the IP network  308  and/or the access router  310  to the access gateway  312 . The access gateway  312  routes the device proximity message through the system infrastructure  118  to the controller  120 . For the discussed example, the controller  120  is the same equipment that is used to generate paging messages to the wireless communication device  106 . The controller  120  receives the device proximity message and extracts the appropriate information. In response to the device proximity message  324 , the controller  120  generates the search message  126  which is transmitted from the base station  116  to the wireless communication device  106 . The search message  126  triggers an adjustment of the wireless communication device searching scheme that the wireless communication device  106  employs for searching for access points. In the example of  FIG. 7 , the multimode wireless communication device  704  activates a WLAN receiver to search for WLAN signals. In some circumstances, the search message  126  may specifically instruct the wireless communication device  704  to search for the access point and/or provide specific frequencies, channels or other information to assist the device  704  to search for the access point. For the example, the search message  126  is transmitted using the paging channel. Any suitable downlink channel monitored by the wireless communication device  704 , however, may be used. 
     For the present example, the device proximity message  324  is sent in response to receiving device beacon signal  108  from an authorized user of the access point  702 . The search message  126  is sent to the wireless communication device  106  in response to receiving the device proximity message  324  at the controller  120 . In some situations, however, additional criteria may be evaluated before sending the device proximity message  324 , the search message  126 , or before sending both. As discussed above, for example, the access point  702  may evaluate one or more parameters to determine the proximity of the wireless communication device  106  to the access point and only send the device proximity message  324  if the calculated proximity is less than a threshold. Also, the controller  120  may evaluate system conditions and refrain from sending the search message  126  if certain system conditions are not met. 
     Examples of data that may be evaluated by the access point  702  include the capacity of the access point, bandwidth requirements of the wireless communication device  106  and a calculated or estimated proximity of the wireless communication device  106  to the access point  702 . Accordingly, the access point  702  may evaluate a characteristic of the device beacon signal  108  to determine whether to transmit the device proximity message  324 . In the example, the reception of the device beacon signal  108  by the WWAN UL receiver  320  is sufficient to determine that the wireless communication device  704  is present and that the device proximity message should be transmitted. In other circumstances, other signal characteristics may be evaluated to determine the proximity. Therefore, a characteristic of the device beacon signal  108  may be any of numerous parameters with any of numerous thresholds depending on the particular implementation and the characteristic may be whether the device beacon signal  108  is detectable by the WWAN receiver  718 . Examples of other characteristics include a signal to noise ratio (SNR), bit error rate (BER), power level, signal propagation time, and presence of particular data. An example of technique for determining the proximity is discussed in U.S. patent application Ser. No. 11/565,266 entitled “APPARATUS, SYSTEM AND METHOD FOR MANAGING WIRELESS LOCAL AREA NETWORK SERVICE TO A MULTI-MODE PORTABLE COMMUNICATION DEVICE”, filed on Nov. 30, 2006, and incorporated by reference in its entirety herein. 
     After receiving the search message, the wireless communication device  704  searches for an access point in accordance with the adjusted search scheme. In response to the search message, the wireless communication device  704  activates the appropriate circuitry to receive signals transmitted by the access point  702  such as a beacon pilot signal or communication pilot signals. Such circuitry is activated in response to reception of the search message. After the access point  702  is found by the wireless communication device  704 , the wireless communication device  704  may engage in a handoff procedure where, after a determination that the wireless communication device  704  should be handed off to the access point, the system  700  establishes wireless service to the wireless communication device  704  from the access point  702 . Hence, data and control communication is made through communication channel  720  between the wireless communication device  704  and the access point  702 . 
       FIG. 8  is block diagram of a communication system  800  where device beacon signal is transmitted in a beacon channel  124  that is not a WWAN channel. The access point  802  includes a device beacon detector  812  that is not a WWAN receiver. Any of numerous frequencies and channels can be used for the beacon channel where the beacon channel is based on the WWAN system timing. The beacon may be transmitted in unlicensed frequency bands in some circumstances. The beacon may be transmitted in accordance existing beacon transmissions within 802.11 (WiFi) systems. Beacon transmissions are part of power conversation used by systems such as 802.11. In some circumstances, the timing of these beacon transmissions could be a function of WWAN system timing (assuming WLAN is aware of WWAN timing as well). The system timing provides a reference for the wireless communication device  804  and the WLAN access point  802  to use in sending and receiving the device beacon signal  108 . The system timing can be applied to establish a designated time for transmitting the beacon even though the actual channel is not a WWAN channel. 
     Operation of the WLAN access point  802  is as described above with reference to  FIG. 7  except that the device beacon detector  812  does not include a WWAN receiver. Accordingly, system timing is applied to the receiver (not shown) within the device beacon detector  812  to monitor the appropriate beacon channels for device beacons. The system timing may be derived from information sent through the backhaul or may be derived by intercepting WWAN downlink signal  122 . The WWAN receiver  716  is shown with dashed lines to illustrate that the receiver is optional. As discussed above with respect to  FIG. 7 , the WLAN access point  802  includes a memory  712  and a controller  714  which accomplish the pertinent tasks performed in the WLAN access point  702 . After the access point  802  is found by the wireless communication device  804 , the wireless communication device  804  may engage in a handoff procedure where, after a determination that the wireless communication device  804  should be handed off to the access point, the system  800  establishes wireless service to the wireless communication device  804  from the access point  802 . Hence, data and control communication is made through communication channel  720  between the wireless communication device  804  and the access point  802 . 
       FIG. 9A  and  FIG. 9B  are block diagrams of examples of wireless communication devices  900 ,  910  suitable for use as a wireless communication device  106  and  FIG. 9C  and  FIG. 9D  are block diagrams of examples of multimode wireless communication devices  920 ,  930  suitable for use as multimode wireless communication devices  704 . The functional blocks of each of the communication devices shown in  FIG. 9  A,  FIG. 9B ,  FIG. 9C  and  FIG. 9D  may be implemented using any combination of hardware, software and/or firmware. Two or more of the functional blocks may be integrated in a single device and the functions described as performed in any single device may be implemented over several devices. For example, at least portions of the functions of the beacon generator  902  may be implemented by the controller  904  in some circumstances. 
     The wireless communication device  900  includes at least a beacon generator  902 , a controller  904 , a beacon transmitter  906 , and a WWAN downlink receiver  908 . As discussed below the beacon transmitter  906  may include a WWAN transmitter or may include another type of transmitter depending on the channel used for beacon transmission. The WWAN downlink receiver  908  receives WWAN downlink signal that include WWAN system timing information. The controller derives the system timing information from the signals and the beacon generator applies the WWAN system timing to generate a device beacon. The device beacon is transmitted by the beacon transmitter  906 . 
       FIG. 9B  is a block diagram of a wireless communication device  910  where the beacon transmitter includes a WWAN uplink transmitter  912 . For the example of  FIG. 9B , a WWAN transceiver  914  provides an interface to the WWAN. The WWAN transceiver  914  includes the WWAN uplink transmitter  912  and the WWAN downlink receiver  908 . The transceiver  914  transmits and receives WWAN signals to facilitate wireless communication with the WWAN. The beacon generator  902  applies the system timing derived from received WWAN signals to generate a device beacon signal that is transmitted within a WWAN uplink channel that is used as the beacon channel. For the examples of  FIG. 9B ,  FIG. 9C  and  FIG. 9D , the wireless communication device also includes a memory  916 . In some cases, the memory is part of the controller. In addition to storing other information and code, the memory stores code, that when run on the controller, manages the functions described herein. 
       FIG. 9C  is a block diagram of multimode wireless communication device  920  where the beacon is transmitted by the WWAN uplink transmitter. In addition to the functional blocks described above, the multimode wireless communication also includes a WLAN transceiver  926  for communicating with a WLAN. The WLAN transceiver includes a WLAN UL transmitter  922  for transmitting WLAN signals and a WLAN downlink receiver  924  for receiving WLAN signals. The multimode wireless communication device, therefore, may access both the WWAN and the WLAN for communication services. The WWAN signals may be received in any state and provide the WWAN system timing that is applied to generate and transmit the device beacon signal in a WWAN uplink channel designated for device beacons. 
       FIG. 9D  is a block diagram of multimode wireless communication device  930  where the beacon is transmitted within a beacon channel that is not a WWAN uplink channel. The WWAN signal timing derived from the received WWAN signals is applied to generate the device beacon. The device beacon is transmitted through a beacon channel by a beacon transmitter that may include the WLAN uplink transmitter in some circumstances. In some circumstances, the beacon may be transmitted through separate beacon transmitter through a beacon channel that is not a WWAN or WLAN channel. Such beacon channel may be a Bluetooth channel, for example. In order to illustrate that a separate beacon transmitter is not required when the beacon is transmitted through the WLAN transmitter, the beacon transmitter is shown with dashed lines. 
       FIG. 10  is a flow chart of method performed at the wireless communication device where the transceiver node  104  is a base station  302 . The method is performed, at least partially, by executing code on the controller  904  in the wireless communication device  106 . 
     At step  1002 , WWAN downlink signals are received from a WWAN base station  116 . The signals are any signals that provide WWAN system timing information and may be received during any of several states of the wireless communication device  106  including idle (non-traffic) and active (traffic) states. As discussed above, examples of WWAN signals including system timing information include downlink control signals. 
     At step  1004 , the system timing is derived from the WWAN signals. Typically, the receiver first synchronizes to the time slot boundaries. After achieving synchronization, the receiver detects and decodes information using knowledge about the frame-structure of WWAN downlink signals. 
     At step  1006 , the device beacon signal is transmitted. The device beacon signal is generated and transmitted in accordance with the system timing. The beacon generator applies the system timing and any required scaling to generate a sequence that is mapped to a subcarrier channel of the WWAN uplink frequency-time space. 
     At step,  1008 , the search message  126  is received. In accordance with known techniques, the wireless communication device periodically monitors the downlink paging channels to receive control messaging from the system infrastructure  118  during traffic and non-traffic states. The search message  126  is received and deciphered to extract the information related changes to the search parameters. 
     At step  1010 , the changes included in the search message are applied to the search scheme of the wireless communication. 
     At step  1012 , the newly applied search parameters are applied in searching for an alternate base station. The wireless communication device  106  tunes the WWAN downlink receiver in accordance to the searching scheme to search for a pilot signal transmitted from the detecting base station  114  (such as a femtocell base station  302 ). In some circumstances, the wireless communication device  106  may search for beacons or other signals transmitted from the femtocell base station  302 . 
     At step  1014 , it is determined whether the base station  302  has been detected. If a signal from the base station  302  is detected, the method continues at step  1016 , where a handoff procedure is performed. The procedure may include an analysis to determine whether a handoff should be performed. A handoff is initiated in accordance with known techniques. Otherwise, the method continues at step  1018 . 
     At step  1018 , it is determined whether a new search message is being transmitted. If so, the method returns to step  1008  to receive the new search message. Otherwise, the method returns to step  1012  to continue searching for the femtocell base station. 
       FIG. 11  is a flow chart of method performed at the wireless communication device where the transceiver node  104  is a WLAN access point  702 ,  802 . The method is performed, at least partially, by executing code on the controller  904  in the wireless communication device  106  ( 920 ,  930 ). 
     At step  1102 , WWAN downlink signals are received from a WWAN base station  116 . The signals are any signals that provide WWAN system timing information and may be received during any of several states of the wireless communication device  106  including idle (non-traffic) and active (traffic) states. Examples of WWAN signals including system timing information include downlink control signals 
     At step  1104 , the system timing is derived from the WWAN signals. Typically, the receiver first synchronizes to the time slot boundaries. After achieving synchronization, the receiver detects and decodes information using knowledge about the frame-structure of WWAN downlink signals. 
     At step  1106 , the device beacon signal is transmitted. The device beacon signal is generated and transmitted in accordance with the system timing. The beacon generator applies the system timing and any required scaling to generate a sequence that is mapped to a subcarrier channel of the WWAN uplink frequency-time space. In some circumstances, the beacon signal may be transmitted within a beacon channel that is not a WWAN uplink channel. 
     At step,  1108 , the search message  126  is received. In accordance with known techniques, the wireless communication device periodically monitors the downlink paging channels to receive control messaging from the system infrastructure  118  during traffic and non-traffic states. For this example, the search message indicates that the WLAN receiver should be activated to search for signals transmitted by the WLAN access point. 
     At step  1110 , the WLAN receiver is activated in response to receiving the search message. Accordingly, the wireless communication device  106  searches for the WLAN access point. In some circumstances, the wireless communication device  106  may search for beacons or other signals transmitted from the WLAN access point  702 ,  802 . 
     At step  1112 , it is determined whether WLAN access point  702 ,  802  has been detected. If a signal from the WLAN access point  702 ,  802  is detected, the method continues at step  1114 , where a handoff procedure is performed and a handoff is initiated in accordance with known techniques. Otherwise, the method continues at step  1116 . 
     At step  1116 , it is determined whether a new search message is being transmitted. If so, the method returns to step  1108  to receive the new search message. Otherwise, the method returns to step  1110  to continue searching for the femtocell base station. 
       FIG. 12A ,  FIG. 12B  and  FIG. 12C  are graphical illustrations of exemplary relationships  1200 ,  1250  between the device beacon  108  and the frequency-time space  1202  of the uplink WWAN channel when the WWAN system utilizes OFDM techniques. The uplink WWAN channels are divided in time and frequency to allocate channels for wireless communication device uplink transmissions. The carriers are divided in time to provide subcarriers  1206  that are assigned to the different wireless communication devices.  FIG. 12A ,  FIG. 12  B and  FIG. 12C  are provided for general illustrative purposes and implementations may use different numbers of channels and subcarriers. For the example of  FIG. 12A , the device beacon is transmitted within the WWAN uplink channel where the beacon signal is at an assigned subcarrier and no other subcarriers are assigned during the beacon transmission time period  1204 . In  FIG. 12  B, some or all of the subcarriers within the beacon transmission time period  1204  may include data or control information. In other arrangements, some or all of the subcarriers  1208  within the device beacon transmission period  1204  may be assigned for data or control signaling. The subcarriers that may include data within the beacon transmission period  1204  are illustrated with boxes containing “x”s in  FIG. 12B . 
       FIG. 12C  is a graphical illustration of an example where the device beacon is transmitted outside to the WWAN uplink channel. The device beacon is transmitted at a first frequency during a beacon time period and at a second frequency during a second beacon transmission time period. The first beacon frequency and the second beacon frequency are not within the WWAN uplink channel. The device beacon, however, is transmitted in accordance with the WWAN system timing. Accordingly, the device beacon transmission period  1204  coincides with subcarrier timing of the WWAN uplink channel. 
       FIG. 13A  is a block diagram of a beacon generator  902  connected to a beacon transmitter wherein the device beacon is transmitted within the WWAN uplink channel. The beacon generator  902  may be implemented with any combination of hardware, software, and/or firmware. The blocks shown in  FIG. 13A  represent functions and may not be performed by distinct hardware blocks. Accordingly, two or more of the functional blocks may be integrated in a single device and the functions described as performed in any single device may be implemented over several devices or processes. For the example of  FIG. 13A , the device beacon is transmitted within the WWAN uplink channel and the beacon transmitter is the WWAN uplink transmitter  912 . The description of  FIG. 13A  may be applied to different types of OFDM systems by modifying the transmitter chain in accordance with known techniques. For example, the beacon generator maybe used in a Single-Carrier FDMA (SC-FDMA) system by appropriately processing the signals using Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) stages at the transmitter and receiver, respectively. 
     A pilot signal  1302 , such as baseband bit string, is multiplexed with a beacon message  1304  in a multiplexer  306 . The beacon message consists of pre-determined data with a preamble (for acquisition) and/or a repeatable sequence. The beacon message may also include information such at the location of the device  106  or a transmission power level as well as other information related to the communication device  106 . The resulting multiplexed signal is scrambled with a pseudorandom sequence  1308  in a mixer  1310 . Typically, a scrambling sequence is unique to a specific wireless communication device but other types of sequences (pseudo-unique) are also possible. The mixer  1308  is an exclusive OR (XOR) circuit in this example. A subcarrier mapping engine  1312  maps the scrambled beacon and other data  1314  into the WWAN uplink channel using the WWAN system timing  110 . In accordance with known techniques, a subcarrier bit and power allocator  1316  generates the OFDM signal my managing the subcarrier mapping engine  1312  and adaptive modulator  1318  which applies BPSK, QPSK, M-QAM or other suitable symbols. Channel condition feedback provided by a receiver is typically applied by the subcarrier bit and power allocator  1316  to select a different modulation order and power level per subcarrier. In some circumstances, however, the beacon can be transmitted with a pre-determined (fixed) modulation order and power level. 
     The mapped and processed subcarriers are transmitted by the beacon transmitter which, in this case, is the WWAN uplink transmitter  912 . The WWAN uplink transmitter  912  includes an OFDM transmission processor  1320  and a radio frequency transmitter  1322 . Accordingly, the WWAN uplink signal including the data and device beacon is transmitted in accordance with OFDM techniques in this example. 
       FIG. 13B  is a block diagram of a beacon generator  902  where the device beacon is transmitted outside of the WWAN uplink channel. The beacon message  1304  is scrambled with the PN generator sequence  1308  in the mixer  1308 . The WWAN system timing  110  is applied to the beacon transmitter  932  to generate and transmit the beacon in accordance with the WWAN system timing. The beacon transmitter  932 , includes appropriate modulation and amplification circuitry as well as timing circuitry to control transmission timing. For example, a switching function can be applied to the scrambled sequence to align the device beacon transmission period with one or more WWAN uplink subcarriers. The beacon is transmitted by aligning the uplink frame transmitted to the WWAN base station. A simple switch can be turned on at the same time or at an early/late time-offset relative to the beginning of the uplink frame. Perfect synchronization is not required to receive the beacon. The reference timing increases the successful detection of that beacon detector. In some circumstances the beacon can be time-aligned using a local clock where the local clock is synchronized with the WWAN system timing. The clock is used for triggering transmissions and an early or late offset may be applied as needed. Therefore, even though the device beacon signal is transmitted at a frequency other than an uplink WWAN frequency, the beacon signal has a position in time that is based on the WWAN system timing. 
       FIG. 14  is block diagram of a communication system  1400  where at least two wireless communication devices are able to communicate through a peer to peer link. The wireless communication devices  1402 ,  1404  each include at least a peer to peer interface  1406  and a WWAN downlink receiver  1408 . In some circumstances, one or more of the devices  1402 ,  1404  may be a multimode wireless communication device and the WWAN downlink receiver  1408  may be part of a WWAN transceiver that also includes a WWAN uplink transmitter (not shown). The peer to peer interface is a WLAN transceiver in this example. The peer to peer link, however, may utilize other communication technologies, frequencies, and protocols in some circumstances and the peer to peer interfaces may be something other than WLAN transceivers. At least one of the devices  1402  includes a beacon generator  902  and at least one includes beacon detector  112 . Accordingly,  FIG. 14  illustrates an example where the transceiver node  104  is the wireless communication device  1404  and the other wireless communication device  1402  is the wireless communication device  106  of  FIG. 1A . The wireless communication device  1404  is, therefore, also an example of the wireless communication device  128  of  FIG. 1C . 
     Each wireless communication device  1402 ,  1404  includes a controller  1414 ,  1424 , a WWAN receiver  1408  and memory  1416 ,  1426 . The controller  1414  ( 1424 ) is any electronics, processor, microprocessor or processor arrangement that manages the functions described herein as well as facilitating the overall functionality of the wireless communication device  1402  ( 1404 ). The memory  1416 ,  1426  is any combination of RAM and/or ROM devices that can store code, ID values and other parameters, values, and data for facilitating the described tasks. 
     For the example of  FIG. 14 , the device beacon signal  108  is transmitted within the WLAN channel. The beacon generator  902  generates the beacon signal that is transmitted by the WLAN uplink transmitter  1422  in the peer to peer interface. The device beacon detector  112  in the wireless communication device  1404  is formed by the controller  1414 , memory  1416  and WLAN uplink receiver  1428 . Each wireless communication device  1402 ,  1404  includes a WWAN downlink receiver  1408  configured to at least receive WWAN downlink signals that provide WWAN system timing information  110 . Where the device beacon  108  is transmitted using a channel other than a WLAN channel, the beacon generator and beacon detector are implemented in accordance with the required frequency, channel and protocols of the beacon channel. 
     After detecting the device beacon signal  108 , the wireless communication device  1404  invokes a communication to the wireless communication device  1402 . For this example, the wireless communication device  1404  generates and transmits an acknowledgement message  1420  to the wireless communication device  1402 . The acknowledgement message  1420  is transmitted using a WLAN channel. In some circumstances, an acknowledgement message may be sent through the WWAN system. Further, a device proximity message may be sent to the WWAN communication system and the WWAN communication system may notify the wireless communication device  1402  that the beacon was detected by sending, for example, a search message. The devices  1402 ,  1404  establish a peer to peer communication link after communications are exchanged in response to the detection of the device beacon signal. Accordingly, the detection of the device beacon signal initiates a peer to peer link establishment procedure. After the peer to peer link is established, the system  1400  establishes wireless service between the wireless communication devices  1402  and  1404 . Hence, data and control communication is made utilizing WLAN downlink receiver  1430  and uplink transmitter  1422  of the wireless device  1402  in communicating with the WLAN downlink transmitter  1432  and uplink receiver  1428  of the wireless device  1404 . 
     Clearly, other embodiments and modifications of this invention will occur readily to those of ordinary skill in the art in view of these teachings. The above description is illustrative and not restrictive. This invention is to be limited only by the following claims, which include all such embodiments and modifications when viewed in conjunction with the above specification and accompanying drawings. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims along with their full scope of equivalents.