WO2014056159A1

WO2014056159A1 - System and method of wsn-assisted location services

Info

Publication number: WO2014056159A1
Application number: PCT/CN2012/082711
Authority: WO
Inventors: Zhenhong Li; Fei YIN; Haifeng Wang; Zhi YUAN; Honglin Hu
Original assignee: Broadcom Corporation
Priority date: 2012-10-10
Filing date: 2012-10-10
Publication date: 2014-04-17

Abstract

A method of providing wireless sensor network (WSN)-assisted positioning services comprises receiving a positioning service request from a client, the positioning request identifying at least one target UE located within a WSN comprising a plurality of sensor nodes; transmitting a listening request message to the at least one target UE; receiving a positioning request message from the at least one target UE, the positioning request message containing addresses and received signal quality indicators of at least four WSN sensor nodes acquired by the at least one target UE; computing a 3-D position of the at least one target UE using the addresses and received signal quality indicators of the at least four WSN sensor nodes; and transmitting the 3-D position of the at least one target UE to the client.

Description

SYSTEM AND METHOD OF WSN-ASSISTED LOCATION SERVICES

FIELD

[0001] The present disclosure relates the field of wireless communications, and more particularly to a system and method of WSN-assisted location services.

BACKGROUND

[0002] A wireless sensor network (WSN) consists of spatially-distributed autonomous sensors that are capable of monitoring physical or environmental conditions, such as temperature, sound, pressure, humidity, air quality, etc. and to cooperatively pass the sensor data through the network to a primary node or a gateway node. The more modern networks pass data bi- directionally, which enables more advanced control of sensor communication and activity.

[0003] The wireless sensor network may include hundreds or thousands of sensor nodes deployed in a variety of topologies such as a simple star network to a more complex cluster-tree- topology (multi-hop) configuration. The data propagation technique between the nodes of the network may be by routing, flooding, or other suitable methods. The WSN typically include one or more nodes with more computational, energy, and communication resources. In a typical wireless sensor network, these nodes may act as an information sink, and as a gateway between the sensor nodes and other communication networks. Other special components in routing-based WSNs may include routers that are designed to compute, calculate, and distribute the routing tables.

[0004] The development of wireless sensor networks was motivated by military applications such as battlefield surveillance. Today, such networks are used in many industrial and security applications, such as industrial process monitoring and control, machine monitoring, border surveillance, and other applications. One special application employing wireless sensor networks may be in urban emergency search, rescue, and recovery, such as in firefighting and other public safety situations in which it is vitally important to know the real-time position of each firefighter on the site of a fire. Current location solutions have serious drawbacks in these applications.

[00051 In certain applications such as urban firefighting, the fire scene is often a high-rise structure with multiple floors. These indoor conditions are not suitable for location technologies that use satellite positioning such as Global Positioning System (GPS), GLONASS, and Galileo, due to obstructed satellite signals. The network-assisted GNSS (Global Navigation Satellite System) methods further require the User Equipment (UE) to be equipped with satellite receivers, which are added burden for battery resources. Further, the request and transmission of satellite- assistance data may introduce delay and signaling overhead between the UE and the base station. Most current satellite positioning applications also provide the position solution in terms of longitude and latitude, but not altitude or the height of the target. These 2-D positioning solutions are nearly useless when the site in question is a multi-story structure.

SUMMARY

[0006] A method of providing wireless sensor network (WSN)-assisted positioning services comprises receiving a positioning service request from a client, the positioning request identifying at least one target UE located within a WSN comprising a plurality of sensor nodes; transmitting a listening request message to the at least one target UE; receiving a positioning request message from the at least one target UE, the positioning request message containing addresses and received signal quality indicators of at least four WSN sensor nodes acquired by the at least one target UE; computing a 3-D position of the at least one target UE using the addresses and received signal quality indicators of the at least four WSN sensor nodes; and transmitting the 3-D position of the at least one target UE to the client.

[0007] A method of providing wireless sensor network (WSN)-assisted positioning services comprises receiving from a cellular base station, at a target UE, a listening request message containing a prioritized channel list of radio frequency channels that the target UE should tune to in order to acquire at least four WSN sensor node; listening for at least four WSN sensor nodes' beacon signals transmitted in a radio frequency channel identified in the prioritized channel list; determining received signal quality of the beacon signals of the at least four WSN sensor nodes acquired by the target UE; and transmitting a positioning request message containing addresses and received signal quality indicators of the at least four WSN sensor nodes acquired by the target UE to the cellular base station.

[0008] A wireless communication device for wireless sensor network (WSN)-assisted positioning comprises a transmitter/receiver operable to communicate with a cellular base station and receive beacon signals transmitted by sensor nodes in a WSN; a processor; and at least one memory including program code that, when executed by the processor, causes the wireless communication device to: receive from a cellular base station, at a target UE, a listening request message containing a prioritized channel list of radio frequency channels that the target UE should tune to in order to acquire at least four WSN sensor node; listen for at least four WSN sensor nodes' beacon signals transmitted in a radio frequency channel identified in the prioritized channel list; determine received signal quality of the beacon signals of the at least four WSN sensor nodes acquired by the target UE; and transmit a positioning request message containing addresses and received signal quality indicators of the at least four WSN sensor nodes acquired by the target UE to the cellular base station. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 is a simplified block diagram of an exemplary heterogeneous network including a wireless sensor network deployed in a multi-story building application and in communic tion with a LoCation Service (LCS) center via a cellular network;

[0010] FIG. 2 is another simplified block diagram of an exemplary heterogeneous network including a wireless sensor network in communication with a LoCation Service (LCS) center via a cellular network;

[0011] FIG. 3 is a simplified message flow diagram showing an exemplary WSN-assisted positioning procedure according to the teachings of the present disclosure;

[0012] FIG. 4 is a simplified diagram showing an exemplary REQ-Listenmg message structure according to the teachings of the present disclosure;

[0013] FIG. 5 is a simplified diagram showing an exemplary WSN-Position Request message structure according to the teachings of the present disclosure; and

[0014] FIG. 6 is a simplified block diagram of an exemplary User Equipment according to the teachings of the present disclosure.

DETAILED DESCRIPTION

[0015] FIG. 1 is a simplified block diagram of an exemplary heterogeneous network 10 including a wireless sensor network 12 deployed in a multi-story building and in communication with a LoCation Service (LCS) center 14 via a cellular network 16. The wireless sensor network 12 is operating within a cellular coverage area of a base station or eNodeB (Enhanced Node B) 18. The base station 18 services and is in communication with one or more User Equipment (UE) or mobile wireless communication device 20 and 22 that are also proximately located near a plurality of sensor nodes 24-26 of the wireless sensor network 12 deployed on multiple floors of a building. The UE 22 may operate as a gateway for the sensor nodes 24-26 to transmit data from the wireless sensor network 12 to the servers and databases of the LCS center 14 via the base station 18. Accordingly, the gateway UE 22 is a multi-mode mobile device that incorporates transmit receive interfaces to both the cellular network 16 as well as the wireless sensor network 12. Details of the gateway UE 22 are provided below with references to FIG. 6.

[0016] The wireless sensor network 12 may be configured in a cluster- tree topology (multi-hop) operating in a beacon-enabled mode. The wireless sensor network 12 may include a plurality of sensor nodes 24 in communication with at least one router-sensor node 25, and at least one PAN (Personal Area Network) coordinator node 26. Inter-node communication in the wireless sensor network 12 may be achieved pursuant to suitable communication protocols, such as ZigBee, and the like. ZigBee is a specification for a suite of high level cornmunication protocols based on an IEEE 802 standard for personal area networks. As shown in FIG. 1, each cluster-tree of sensor node is in communication with a PAN coordinator node 26. The PAN coordinator node 26 is a device that provides synchronization and control functions for the sensor nodes in its cluster-tree by transmitting a signal containing synchronization and control information to the sensor nodes. More than one radio frequency channel may be used for inter- node communications. For example, the ZigBee standard specifies operation in the unlicensed 2.4 GHz (worldwide), 915 MHz (Americas and Australia) and 868 MHz (Europe) Industrial, Scientific and Medical (ISM) bands. Sixteen channels are allocated in the 2.4 GHz band, with each channel requiring 5 MHz of bandwidth.

[0017] FIG. 2 is another simplified block diagram of an exemplary heterogeneous network 30 including one or more wireless sensor networks 32 in communication with a LoCation Service (LCS) center 34 via a cellular network 36. As shown in FIG. 2, the wireless sensor networks 32 may be configured in a cluster-tree topology (multi-hop) operating in a beacon-enabled mode. The wireless sensor network 32 may be configured to include multiple sub-networks or WSN areas that have adequate coverage of an area of interest, such as a facility or building, for example. The wireless sensor networks 32 are within a cellular coverage area of a base station or eNodeB 38. The base station 38 services and is in communication with one or more UE 40 and 42 that are in operation within coverage areas of the wireless sensor networks 32. In this example shown in FIG. 2, the UE 40 operates as a gateway between the base station 38 and a wireless sensor network 44, and can transmit data between the wireless sensor network to the LCS center 34. For another wireless sensor network 46, a fixed gateway 48 may serve as the interface node between the base station 38 and the wireless sensor network 46 to relay data to and from the LCS center 34. The wireless sensor networks 32 may include three types of nodes: sensor nodes 50, router-sensor nodes 52, and coordinator nodes 54.

[0018] FIG. 3 is a simplified message flow diagram showing an exemplary WSN-assisted positioning procedure according to the teachings of the present disclosure. The occurrence of an emergency, such as a fire in a multi-story structure, may trigger the need for the WSN-assisted positioning procedure to aid in firefighting and search and rescue efforts. The WSN-assisted positioning procedure may be initiated by a LCS client 60 sending a Positioning Request message 62 to the eNodeB or base station 64 of the cellular network. Alternatively, the request 62 may be transmitted to the Mobility Management Entity (MME) of the LTE access network. A LCS client 60 is a logical functional entity that makes a request to the Public Land Mobile Network (PLMN) to obtain the location information of one or more target UE. In the firefighting example, firefighting personnel carry or wear multi-mode UEs that are operable to interface with both the cellular network and the wireless sensor networks. The LCS client 60 may reside in an entity within the PLMN or external to the PLMN. The LCS client 60 may reside within a UE, at a server, or another location. If the LCS client 60 is external to the PLMN, one or more location service requestors may initiate the WSN-assisted positioning procedure on behalf of the LCS client.

[0019] In response to the Positioning Request message 62, the base station 64 makes a determination as to whether the target UE(s) are capable of using WSN-assisted positioning. The base station 64 may determine whether the target UEs are capable of WSN-assisted positioning by checking each UE's Positioning Capability parameter stored in a database. The base station 64 may further determine the density of sensors in the cell where the target UEs are currently located. In order to arrive at a 3-D position solution (longitude, latitude, and altitude), each UE must be within the listening range of a minimum of four sensors with known locations, which are typically fixed sensors (but could be mobile sensors where their positions are somehow known to the entity computing location solutions). If the target UEs are capable of WSN-assisted positioning, the bases station 64 then sends a REQ-Listening message 66 to each target UE 68 to request that the target UE acquire WSN beacon signals for positioning.

[0020] FIG. 4 is a simplified diagram showing an exemplary REQ-Listening message structure 90 according to the teachings of the present disclosure. The exemplary REQ-Listening message structure 90 may include a header portion 92 and a payload portion 94. The header portion 92 may include a Frame Control parameter 96 and one or more Address parameters 97 for routing puiposes. The payload portion 94 may include a Positioning Type parameter 98 and a Channel Priority List 99. The Positioning Type parameter 98 specifies what type of positioning methodology is requested, and may be enumerated as {WSN-assisted UE 3-D location, NULL}. If the value of the Positioning Type parameter 98 is NULL, it is an indication that positioning methods other than WSN-assisted positioning should be used.

[0021] The Channel Priority List 99 of the exemplary REQ-Listening message structure 90 is a list of radio frequency channels operating in the wireless sensor networks that the target UE is currently located. Using the REQ-Listening message, the target UE may listen for the beacon signals emitted by the sensor nodes in the radio channels identified in the Channel Priority List. The Channel Priority List 99 may be organized as a queue with the channel having the highest number of fixed sensor nodes in the listening area of a target UE at the front of the queue. Thus, the target UE may listen in the radio frequencies identified near the front of the Channel Priority List 99 in order to maximize the number of acquired beacon signals to optimize the 3-D positioning solution. The cellular network may configure the Channel Priority List 99 and adjust its length or content according to the target UE's WSN-assisted positioning capability, service requirements, and other factors. In response to receiving the REQ-Listening message 66, the target UE may send an Acknowledgement (ACK) message 70 back to the base station 64.

[0022] Using the information in the Channel Priority List 99, the target UE listens for

WSN beacon signals (block 72) from at least four fixed sensor nodes. The acquired beacon signals may include the sensor nodes' Addresses, {Add], Add , ·■-, Add_n), n > 4. The Address parameter of a sensor node may incorporate the node's identifier. Alternatively, a node's Address may incorporate the node's 3-D position. Each target UE further determines the Received Signal Strength Indicator (RSSI) measurement of the beacon signaling from each sensor node, where RSSI is an indication of the power level being received by the UE antenna.:

[0023] RSSI values of 57V,-: RSSL = RSSI{SNi,UE)

[0024] RSSI values: RSSI - {RSSIi, RSSh,..., RSSL} , where n > 4. [0025] In the above equations, n is the number of sensor nodes within the listening range and acquired by the target UE., SN, is the sensor node i, and RSSIi is the RSSI value of the signal from SNj to UE. RSSI measurement is one method that may be used by the UE to estimate its distance to the WSN sensor nodes. Other quality parameters such as Link Quality Indication (LQI) that provides an indication of the quality of the data packets received by the UE, and other suitable metrics may be used.

[0026] The target UE then sends a WSN-Positioning Request (PR) message 76 to the base station 64, which forwards the information to the E-SMLC (Evolved Serving Mobile Location Center) node 80. FIG. 5 is a simplified diagram showing an exemplary WSN-PR message structure 100 according to the teachings of the present disclosure. The WSN-PR message structure 100 includes a header portion 102 and a payload portion 103. The header portion 102 includes a Frame Control parameter 104 and Addressing fields 105. The payload portion 103 includes a Positioning Type parameter 106 that is indicative of the methodology used to determine the positioning solution. For example, the Positioning Type parameter 106 would specify WSN-assisted positioning in this instance. Additionally, the payload portion 103 includes the RSSI information 108 of each sensor node that the target UE acquired. The E- SMLC 80 may look up the position of each sensor node using the node address or identifier in a look-up table, database, etc. In yet another alternate embodiment, the address of a node may incorporate the 3-D location information of the node. Using the RSSI values of at least four sensor nodes, the E-SMLC 80 determines the 3-D position of the target UE, LUE (LVE , LU , L_VE ^Z), using the known 3-D positions of the sensor nodes:

[0027] RSSI = {RSSI}, RSSI₂, RSSI - D = {d_h d₂, d„}, where n > 4.

[0028] (V - L_sm ^x)² + (V ~ L_sm ^yf + (L_UE ^: - L_SN f = d,² [0029] (L '_tUE

[0032]

[0034] The E-SMLC 80 then forwards the computed UE 3-D position to the base station (eNodeB/MME) 64, which further forwards the solution to the LCS client 60 (WSN-PR message 88) and/or the target UE 68 (WSN-PR message 86). The cellular network may further update its databases with the current location of the target UE.

[0035] In the exemplary firefighting scenario, the 3-D position solution of the target UE which may be worn or carried by a firefighter is relayed to the incident commander at a fire scene. Having the real-time 3-D location of each UE carried or worn by a firefighter yields many important advantages. For example, the incident commander is able to obtain a much improved assessment of current firefighter status, can more easily deploy and move firefighters around the scene to fight fire more effectively, and can quickly pinpoint the location of a firefighter to provide back-up or rescue efforts.

[0036] FIG. 6 is a simplified block diagram of an exemplary multi-mode User Equipment (UE) or wireless communication device 120 configured or arranged to perform WSN-assisted positioning according to the teachings of the present disclosure. The UE 120 may include a processor 122, a transceiver 124, a transmit/receive element 126, and may further include a speaker/microphone 108, a keypad 130, a display/touchpad 132, non-removable memory 134, removable memory 136, a power source 138, an optional global positioning system (GPS) chipset 140, and other peripherals 142. [0037] The processor 122 may be a general purpose processor, a special purpose processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 122 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the UE 120 to operate in a wireless environment. The processor 122 is configured to execute a number of communication protocols such as those pursuant to the 3 GPP standards. The processor 122 may further be operable to execute a WSN Media Access Control (MAC) protocol for communication with the sensor nodes in the WSN. The processor 122 is coupled to the transceiver 124, which is coupled to the transmit/receive element 126. While FIG. 6 depicts the processor 122 and the transceiver 124 as separate components, it should be appreciated that the processor 122 and the transceiver 124 may be integrated together in an electronic package or chip.

[0038] The transmit/receive element 126 is configured to transmit wireless signals to or receive signals from the air interface. As noted above, the UE 120 may have multi-mode communication capabilities. Thus, the transceiver 124 may include multiple transceivers for enabling the UE 120 to communicate via multiple RATs (Radio Access Technologies), such as UTRA and IEEE 802.11 (commonly called WiFi), for example. The transmit/receive element 126 is operable to communicate with, for example, a cellular network base station as well as sensor nodes in WSNs. The transmit/receive element 126 may be an antenna configured to transmit and/or receive RF (radio frequency) signals. In another embodiment, the transmit/receive element 126 may be an emitter/detector configured to transmit and/or receive IR (infrared), UV (ultra-violet), visible light signals, and/or a combination thereof. It will be appreciated that the transmit/receive element 126 may be configured to transmit and/or receive any combination of wireless signals. In addition, although the transmit/receive element 106 is depicted in FIG. 6 as a single element, the UE 120 may include any number of transmit/receive elements 126. More specifically, the UE 120 may employ MIMO (multiple input multiple output) technology. Thus, in one embodiment, the UE 120 may include two or more transmit/receive elements 126 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface. The transceiver 124 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 126 and to demodulate the signals that are received by the transmit/receive element 126.

[0039] The processor 122 of the UE 120 may be coupled to, and may receive user input data from, the speaker/microphone 128, the keypad 130 (virtual or hardware), and/or the display/touchpad 132 (e.g., a liquid crystal display (LCD) display unit or organic light- emitting diode (OLED) display unit). The processor 122 may also output user data to the speaker/microphone 128, the keypad 130, and/or the display/touchpad 132. In addition, the processor 122 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 124 and/or the removable memory 126. The non-removable memory 124 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 136 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 122 may access information from, and store data in, memory that is not physically located on the UE 120, such as on a server or a home computer (not shown). The non-removable memory 134 and/or the removable memory 136 are configured to store a myriad types of data, including computer program instmctions, control data, status data, and user data (e.g., text, images, video, audio, music, emails, records, documents, and files).

[0040] The processor 122 may receive power from the power source 138, and may be configured to distribute and/or control the power to the other components in the UE 120. The power source 138 may be any suitable device for powering the UE 120. For example, the power source 138 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like. The processor 122 may also be coupled to the GPS chipset 140, which may be configured to provide location information (e.g., longitude, latitude, and altitude) regarding the current location of the UE 120. In addition to, or in lieu of, the information from the GPS chipset 140, the UE 120 may receive location information over the air interface from a base station and/or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the UE 120 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment. The processor 122 may further be coupled to other peripherals 142, which may include one or more software, firmware, and/or hardware modules that provide additional features, functionality and/or wired or wireless connectivity. For example, the peripherals 142 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and/or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth.RTM. module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, and the like.

[0041] When referred to herein, User Equipment or UE includes but is not limited to a mobile station, a fixed or mobile subscriber unit, a pager, a cellular telephone, a smartphone, a personal digital assistant (PDA), a computer, a laptop, a portable device, or any other type of user device capable of transmitting and/or receiving wireless signals and operating in a wireless environment. When referred to herein, the terminology "base station" includes but is not limited to a Node-B, an evolved Node-B (eNodeB), a site controller, an access point (AP), or any other type of interfacing device capable of operating in a wireless environment.

[0042] The features of the present invention which are believed to be novel are set forth below with particularity in the appended claims. However, modifications, variations, and changes to the exemplaiy embodiments described above will be apparent to those skilled in the art, and the system and method described herein thus encompass such modifications, variations, and changes and are not limited to the specific embodiments described herein.

[0043] GLOSSARY

[0044] 3 GPP Third Generation Partnership Project

[0045] eNodeB Enhanced Node B

[0046] E-SMLC Evolved Serving Mobile Location Center

[0047] E-UTRAN Evolved Universal Terrestrial Radio Access Network

[0048] GNSS Global Navigation Satellite System

[0049] GPS Global Positioning System

[0050] GSM Global System for Mobile Communications

[0051] ISM Industrial, Scientific and Medical

[0052] LCS LoCation Service

[0053] LTE Long Term Evolution

[0054] MME Mobility Management Entity

[0055] PAN Personal Area Network [0056] PLMN Public Land Mobile Network

[0057] RSSI Received Signal Strength Indicator

[0058] UE User Equipment

[0059] WSN Wireless Sensor Network

Claims

WHAT IS CLAIMED IS:

1. A method of providing wireless sensor network (WSN)-assisted positioning services, comprising:

receiving a positioning service request from a client, the positioning request identifying at least one target UE located within a WSN comprising a plurality of sensor nodes;

transmitting a listening request message to the at least one target UE;

receiving a positioning request message from the at least one target UE, the positioning request message containing addresses and received signal quality indicators of at least four WSN sensor nodes acquired by the at least one target UE;

computing a 3-D position of the at least one target UE using the addresses and received signal quality indicators of the at least four WSN sensor nodes; and

transmitting the 3-D position of the at least one target UE to the client.

2. The method of claim 1, wherein transmitting a listening request message to the at least one target UE comprises transmitting a prioritized list of radio frequency channels that the at least one target UE should tune to in order to acquire at least four WSN sensor nodes.

3. The method of claim 1, wherein receiving a positioning request message from the at least one target UE comprises receiving the addresses and Received Signal Strength Indicators (RSSI) of the at least four WSN sensor nodes acquired by the at least one target UE.

4. The method of claim 1, wherein computing a 3-D position of the at least one target UE comprises looking up the 3-D locations of the at least four acquired WSN fixed sensor nodes.

5. The method of claim 1, wherein computing a 3-D position of the at least one target UE comprises determining the 3-D locations of the at least four acquired WSN sensor nodes from the addresses of the nodes.

6. The method of claim 1, wherein transmitting a listening request message to the at least one target UE comprises transmitting a positioning type parameter specifying WSN- assisted positioning.

7. The method of claim 1, wherein receiving a positioning request message from the at least one target UE comprises receiving a positioning type parameter specifying WSN-assisted positioning.

8. A method of providing wireless sensor network (WSN)-assisted positioning services, comprising:

receiving from a cellular base station, at a target UE, a listening request message containing a prioritized channel list of radio frequency channels that the target UE should tune to in order to acquire at least four WSN sensor node;

listening for at least four WSN sensor nodes' beacon signals transmitted in a radio frequency channel identified in the prioritized channel list; determining received signal quality of the beacon signals of the at least four WSN sensor nodes acquired by the target UE; and transmitting a positioning request message containing addresses and received signal quality indicators of the at least four WSN sensor nodes acquired by the target UE to the cellular base station.

9. The method of claim 8, further comprising receiving a 3-D position of the target UE determined using the addresses and received signal quality indicators of the at least four acquired WSN sensor nodes.

10. The method of claim 8, wherein transmitting a positioning request message to the cellular base station comprises transmitting the addresses and Received Signal Strength Indicators (RSSI) of the at least four WSN sensor nodes acquired by the at least one target UE.

11. The method of claim 8, wherein receiving a listening request message comprises receiving a positioning type parameter specifying WSN-assisted positioning.

12. The method of claim 8, wherein transmitting a positioning request message comprises transmitting a positioning type parameter specifying WSN-assisted positioning.

13. A wireless communication device for wireless sensor network (WSN)-assisted positioning, comprising:

a transmitter/receiver operable to communicate with a cellular base station and receive beacon signals transmitted by sensor nodes in a WSN; a processor; and

at least one memory including program code that, when executed by the processor, causes the wireless communication device to:

receive from a cellular base station, at a target UE, a listening request message containing a prioritized channel list of radio frequency channels that the target UE should tune to in order to acquire at least four WSN sensor node;

listen for at least four WSN sensor nodes' beacon signals transmitted in a radio frequency channel identified in the prioritized channel list;

determine received signal quality of the beacon signals of the at least four WSN sensor nodes acquired by the target UE; and

transmit a positioning request message containing addresses and received signal quality indicators of the at least four WSN sensor nodes acquired by the target UE to the cellular base station.

14. The wireless communication device of claim 13, wherein the memory further includes program code that further causes the wireless communication device to receive a 3-D position of the target UE detennined using the addresses and received signal quality indicators of the at least four acquired WSN sensor nodes.

15. The wireless communication device of claim 13, wherein the memory further includes program code that further causes the wireless communication device to transmit a positioning request message to the cellular base station comprises transmitting the addresses and Received Signal Strength Indicators (RSSI) of the at least four WSN sensor nodes acquired by the at least one target UE.

16. The wireless communication device of claim 13, wherein the memory further includes program code that further causes the wireless communication device to receive a listening request message comprises receiving a positioning type parameter specifying WSN- assisted positioning.

17. The wireless communication device of claim 13, wherein the memory further includes program code that further causes the wireless communication device to transmit a positioning request message comprises transmitting a positioning type parameter specifying WSN-assisted positioning.