Patent Publication Number: US-2018054699-A1

Title: System and methods to support a cluster of positioning beacons

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of and priority to: U.S. Provisional Patent Application No. 62/377,669 entitled “SYSTEM AND METHODS TO SUPPORT A CLUSTER OF POSITIONING BEACONS,” filed Aug. 21, 2016, and U.S. Provisional Patent Application No. 62/400,073 entitled “SYSTEM AND METHODS TO SUPPORT A CLUSTER OF POSITIONING BEACONS,” filed Sep. 26, 2016. The above-identified applications are assigned to the assignee hereof and incorporated by reference in their entireties. 
    
    
     FIELD 
     The subject matter disclosed herein relates to location determination and more specifically, to techniques to support positioning beacons or transmission points in Terrestrial Beacon Systems (TBS). 
     BACKGROUND 
     It is often desirable to know the location of a mobile device such as a cellular phone. For example, a location services (LCS) client may desire to know the location of a mobile device in the case of an emergency services call from the mobile device or to provide some service to the user of the mobile device such as navigation assistance or direction finding. The terms “location” and “position” are synonymous and are used interchangeably herein. 
     In Observed Time Difference of Arrival (OTDOA) based positioning, a mobile device may measure time differences between signals received from different pairs of base stations. Because positions of the base stations can be known, the observed time differences may be used to calculate the location of the mobile device. To further help location determination, Positioning Reference Signals (PRS) may be provided by a base station (BS) in order to improve OTDOA positioning performance. The measured time difference of arrival of the PRS from a reference cell (e.g. the serving cell) and a neighboring cell is known as a Reference Signal Time Difference (RSTD). Using the RSTD measurements for two (or more usually three) or more neighbor cells, the known absolute or relative transmission timing of each cell, and the known position(s) of BS physical transmitting antennas for the reference and neighboring cells, the position of the mobile device may be calculated. 
     Positioning beacons or transmission points (hereinafter referred to as “TPs”) are sometimes used to provide improved location accuracy in areas with a low density of visible base stations. The positioning beacons can provide additional downlink PRS signals to be measured by a mobile device but may not provide any communication support—e.g. may not support uplink signal reception from a mobile device or other communications services normally associated with a BS. 
     In conventional systems, the improved position accuracy provided by positioning beacons may be offset by the additional cost of the positioning beacons and additional network resources that may be used during positioning beacon operation. For example, backhaul signaling connections and other operations support for positioning beacons in conventional systems may require additional network resources and increase overhead. Thus, systems and methods to lower the cost and improve the configuration and operation of positioning beacons may facilitate deployment of positioning beacons and improve positioning accuracy. 
     SUMMARY 
     In some embodiments, a method on a Transmission Point Controller (TPC) to facilitate User Equipment (UE) location determination may comprise: exchanging a first signaling information with a Positioning Reference Signal Transmission Point (PRS TP) broadcasting a downlink (DL) positioning reference signal (PRS) to the UE, wherein the PRS TP is controlled by the TPC and the broadcasting is based at least in part on the first signaling information; and exchanging a second signaling information with a location server, wherein the second signaling information comprises at least a portion of the first signaling information. PRS TPs are TPs that refrain from broadcasting information to the UE indicating support for uplink signals from the UE. In some embodiments, the TPC may be communicatively coupled to the PRS TP using a local area network (LAN) or a wireless LAN (WLAN). 
     In some embodiments, exchanging the first signaling information may comprise sending the first signaling information to the PRS TP, wherein the first signaling information comprises a common time reference. In some embodiments, the common time reference may be determined based on input from a GPS receiver or a GNSS receiver (e.g. SPS receiver  740 ) coupled to the TPC  140 , wherein the common time reference is a time reference for one of: the Global Positioning System (GPS), or a Coordinated Universal Time (UTC), or a Global Navigation Satellite System (GNSS). In some embodiments, the DL PRS may be for the 3GPP LTE radio access type. 
     In some embodiments, the first signaling information and the second signaling information may each comprise PRS configuration parameters for the PRS TP, an identity of the PRS TP, a location of the PRS TP, or some combination thereof. In some embodiments, the method may further comprise: receiving third signaling information from an Operations and Maintenance (O&amp;M) server communicatively coupled to the TPC; and exchanging the first signaling information with the PRS TP may comprise sending the first signaling information to the PRS TP, wherein the first signaling information comprises a portion of the third signaling information. 
     In some embodiments, the DL PRS may be for the 3rd Generation Partnership Project (3GPP) Long Term Evolution radio access type. In embodiments where the DL PRS is for 3GPP LTE radio access type, the second signaling information may be exchanged using the 3GPP LTE Positioning Protocol A (LPPa). In embodiments where the DL PRS is for 3GPP LTE radio access type, the location server may be an Enhanced Serving Mobile Location Center (E-SMLC) or a Secure User Plane Location (SUPL) Location Platform (SLP). In embodiments where the DL PRS is for the 3GPP LTE radio access type, the TPC may include functionality for a 3GPP evolved NodeB (eNB) or a 3GPP Home eNB. In embodiments where the DL PRS is for the 3GPP LTE radio access type, the TPC may be communicatively coupled to a Mobility Management Entity (MME) using a 3GPP S1 interface or a subset of a 3GPP S1 interface. 
     In another aspect, a Transmission Point Controller (TPC) to facilitate User Equipment (UE) location determination may comprise: a memory and a processor coupled to the memory. The processor may be configured to: perform the exchange of a first signaling information with a Positioning Reference Signal Transmission Point (PRS TP) broadcasting a downlink (DL) positioning reference signal (PRS) to the UE, wherein the PRS TP is controlled by the TPC and the broadcasting is based at least in part on the first signaling information; and perform the exchange of a second signaling information with a location server, wherein the second signaling information comprises at least a portion of the first signaling information. PRS TPs are TPs that refrain from broadcasting information to the UE indicating support for uplink signals from the UE. 
     In a further aspect, a Transmission Point Controller (TPC) to facilitate User Equipment (UE) location determination may comprise: means for exchanging a first signaling information with a Positioning Reference Signal Transmission Point (PRS TP) broadcasting a downlink (DL) positioning reference signal (PRS) to the UE, wherein the PRS TP is controlled by the TPC and the broadcasting is based at least in part on the first signaling information; and means for exchanging a second signaling information with a location server, wherein the second signaling information comprises at least a portion of the first signaling information. PRS TPs are TPs that refrain from broadcasting information to the UE indicating support for uplink signals from the UE. 
     In some embodiments, a non-transitory computer-readable medium for a Transmission Point Controller (TPC) may comprise executable instructions to facilitate location determination for a User Equipment (UE), wherein the executable instructions may configure a processor to: exchange a first signaling information with a Positioning Reference Signal Transmission Point (PRS TP) broadcasting a downlink (DL) positioning reference signal (PRS) to the UE, wherein the PRS TP is controlled by the TPC and the broadcasting is based at least in part on the first signaling information; and exchange a second signaling information with a location server, wherein the second signaling information comprises at least a portion of the first signaling information. PRS TPs are TPs that refrain from broadcasting information to the UE indicating support for uplink signals from the UE. 
     Disclosed embodiments pertain to a method on a Transmission Point (TP) to facilitate location determination for a User Equipment (UE), the method comprising: exchanging a signaling information with a Transmission Point Controller (TPC); broadcasting a downlink (DL) positioning reference signal (PRS) to the UE, wherein the broadcast of the DL PRS is based, at least in part, on the signaling information; and refraining from broadcasting information to the UE indicating support for uplink signals from the UE. In some embodiments, the DL PRS may be for the 3 rd  Generation Partnership Project (3GPP) Long Term Evolution radio access type. In embodiments where the DL PRS is for the 3GPP LTE radio access type, the TPC may include functionality for a 3GPP evolved NodeB (eNB) or a 3GPP Home eNB. 
     In some embodiments, the signaling information may comprise PRS configuration parameters for the TP, an identity of the TP, a location of the TP, or a combination thereof. In some embodiments, exchanging the signaling information with the TPC may comprise receiving the signaling information from the TPC, wherein the signaling information comprises a common time reference. In some embodiments, the common time reference may be a time reference for one of: a Global Positioning System (GPS), or a Coordinated Universal Time (UTC), or a Global Navigation Satellite System (GNSS), and the method may further comprise: synchronizing the broadcast of the DL PRS to the common time reference. 
     In another aspect, a TP to facilitate location determination for a User Equipment (UE) may comprise a memory, a transceiver, and a processor coupled to the memory and the transceiver, wherein the processor is configured to: perform, via the transceiver, the exchange of signaling information with a Transmission Point Controller (TPC); initiate broadcast, via the transceiver, of a downlink (DL) positioning reference signal (PRS) to the UE, wherein the broadcast of the DL PRS is based, at least in part, on the signaling information; and configure the transceiver to refrain from broadcasting information to the UE indicating support for uplink signals from the UE. 
     In a further aspect, a TP to facilitate location determination for a User Equipment (UE) may comprise: means for exchanging a signaling information with a Transmission Point Controller (TPC); means for broadcasting a downlink (DL) positioning reference signal (PRS) to the UE, wherein the broadcast of the DL PRS is based, at least in part, on the signaling information, wherein means for broadcasting refrains from broadcasting information to the UE indicating support for uplink signals from the UE. 
     In some embodiments, a non-transitory computer-readable medium may comprise executable instructions to facilitate location determination for a User Equipment (UE), wherein the executable instructions may configure a processor on a TP to: exchange a signaling information with a Transmission Point Controller (TPC); broadcast a downlink (DL) positioning reference signal (PRS) to the UE, wherein the broadcast of the DL PRS is based, at least in part, on the signaling information; and refrain from broadcasting information to the UE indicating support for uplink signals from the UE. 
     In some embodiments, a method on a location server to determine a location of a user equipment (UE) may comprise: exchanging a first signaling information with a Transmission Point Controller (TPC), wherein the TPC controls at least one Positioning Reference Signal Transmission Point (PRS TP), the at least one PRS TP broadcasting a downlink (DL) Positioning Reference Signal (PRS) to the UE, the broadcast of the DL PRS based at least in part on the first signaling information; sending a second signaling information to the UE, the second signaling information comprising a portion of the first signaling information; receiving a third signaling information from the UE, the third signaling information based on the second signaling information; and determining a location of the UE based, at least in part, on the first signaling information and the third signaling information. PRS TPs are TPs that refrain from broadcasting information to the UE indicating support for uplink signals from the UE. 
     In some embodiments, the first signaling information may comprise PRS configuration parameters for the at least one TP, an identity of the at least one TP, a location of the at least one TP, or some combination thereof. In some embodiments, exchanging a first signaling information with a Transmission Point Controller (TPC) may comprise receiving the first signaling information from the TPC. 
     In some embodiments, the DL PRS may be for the 3 rd  Generation Partnership Project (3GPP) Long Term Evolution radio access type. Further, the first signaling information may be exchanged using the 3GPP LTE Positioning Protocol A (LPPa). In embodiments, where the DL PRS may be for the 3GPP LTE radio access type, the location server is an enhanced serving mobile location center (E-SMLC) or a Secure User Plane Location (SUPL) Location Platform (SLP). In embodiments, where the DL PRS may be for the 3GPP LTE radio access type, the TPC may include functionality for a 3GPP evolved NodeB (eNB) or a 3GPP Home eNB. 
     In embodiments, where the DL PRS may be for the 3GPP LTE radio access type, the second signaling information may be sent and the third signaling information may be received using the 3GPP LTE Positioning Protocol (LPP). Further, the second signaling information may comprise an LPP Provide Assistance Data message, and the third signaling information may comprise an LPP Provide Location Information message, and the location of the UE may be determined based on the 3GPP observed time difference of arrival (OTDOA) position method. 
     In another aspect, a location server to determine a location of a user equipment (UE) may comprise: a memory, and a processor coupled to the memory, wherein the processor is configured to: exchange a first signaling information with a Transmission Point Controller (TPC) controlling at least one Positioning Reference Signal Transmission Point (PRS TP), which broadcasts a downlink (DL) Positioning Reference Signal (PRS) to the UE, wherein the broadcast of the DL PRS is based at least in part on the first signaling information; send a second signaling information to the UE, the second signaling information comprising a portion of the first signaling information; receive a third signaling information from the UE, the third signaling information based on the second signaling information; and determine a location of the UE based, at least in part, on the first signaling information and the third signaling information. PRS TPs are TPs that refrain from broadcasting information to the UE indicating support for uplink signals from the UE. 
     In a further aspect, a location server to determine a location of a user equipment (UE) may comprise: means for exchanging a first signaling information with a Transmission Point Controller (TPC) controlling at least one Positioning Reference Signal Transmission Point (PRS TP), which broadcasts a downlink (DL) Positioning Reference Signal (PRS) to the UE, the broadcast of the DL PRS based at least in part on the first signaling information; means for sending a second signaling information to the UE, the second signaling information comprising a portion of the first signaling information; means for receiving a third signaling information from the UE, the third signaling information based on the second signaling information; and means for determining a location of the UE based, at least in part, on the first signaling information and the third signaling information. PRS TPs are TPs that refrain from broadcasting information to the UE indicating support for uplink signals from the UE. 
     In some embodiments, a non-transitory computer-readable medium may comprise executable instructions to determine a location of a user equipment (UE) wherein the executable instructions may configure a processor to: exchange a first signaling information with a Transmission Point Controller (TPC) controlling at least one Positioning Reference Signal Transmission Point (PRS TP), which broadcasts a downlink (DL) Positioning Reference Signal (PRS) to the UE, the broadcast of the DL PRS based at least in part on the first signaling information; send a second signaling information to the UE, the second signaling information comprising a portion of the first signaling information; receive a third signaling information from the UE, the third signaling information based on the second signaling information; and determine a location of the UE based, at least in part, on the first signaling information and the third signaling information. PRS TPs are TPs that refrain from broadcasting information to the UE indicating support for uplink signals from the UE. 
     The methods disclosed may be performed by one or more of servers including location servers, mobile devices, etc. using LPP, LPPe, LPPa, or other protocols. Embodiments disclosed also relate to software, firmware, and program instructions created, stored, accessed, read, or modified by processors using non-transitory computer readable media or computer readable memory. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an architecture of an exemplary system with TPs capable of providing Location Services to UEs. 
         FIG. 2A  shows the structure of an exemplary LTE subframe sequence with PRS positioning occasions. 
         FIG. 2B  provides a further illustration of an exemplary LTE subframe sequence with PRS positioning occasions. 
         FIG. 3  shows a signaling flow diagram for positioning of a UE according to some disclosed embodiments. 
         FIGS. 4, 5, 6A, and 6B  show flowcharts illustrating an exemplary method of positioning a UE according to some disclosed embodiments. 
         FIG. 7  shows a schematic block diagram illustrating certain exemplary features of a TP controller. 
         FIG. 8  shows a schematic block diagram illustrating a positioning beacon or TP. 
         FIG. 9  shows a schematic block diagram illustrating a location server. 
     
    
    
     Like numbered entities in different figures may correspond to one another. Different instances of a common type of entity may be indicated by appending a label for the common entity with an additional label. For example, different instances of a TP  110  may be labeled  110 - 1 ,  110 - 2  etc. When referring to a common entity without an extra appended label (e.g. TP  110 ), any instance of the common entity can be applicable. 
     DETAILED DESCRIPTION 
     The terms “device”, “mobile device”, “user equipment” (UE) and “target” are used interchangeably herein and may refer to a device such as a cellular or other wireless communication device, personal communication system (PCS) device, personal navigation device (PND), Personal Information Manager (PIM), Personal Digital Assistant (PDA), laptop, cell phone, smartphone, tablet, tracking device or other suitable mobile device which is capable of receiving wireless communication and/or navigation signals. The terms are also intended to include devices which communicate with a personal navigation device (PND), such as by short-range wireless, infrared, wireline connection, or other connection—regardless of whether satellite signal reception, assistance data reception, and/or position-related processing occurs at the device or at the PND. The term “communicate,” “communicating,” or “communication” as used herein refers to sending/transmission, reception, or relaying of signals by an entity; or some combination of sending/transmission, reception, or relaying. The term “location” (also referred to as a “position”) as used herein may refer to a geodetic location that may comprise coordinates (e.g. latitude, longitude, and possibly altitude) and optionally an expected error or uncertainty for the location. A geodetic location may be absolute (e.g. comprise a latitude and longitude) or may be relative to some other known absolute location. A location may also be civic and comprise a place name, street address or other verbal description or definition. 
       FIG. 1  shows an architecture of an exemplary system  100  with TPs  110  capable of providing Location Services to a UE  120  including the transfer of location assistance data or location information. System  100  may support the transfer of location assistance data and/or location information, using messages such as Long Term Evolution (LTE) Positioning Protocol (LPP) or LPP extensions (LPPe) messages between UE  120  and a Location Server (LS) such as an Enhanced Serving Mobile Location Center (E-SMLC)  155  or another network entity. Further, the LPP A protocol (LPPa) may be used for communication between an LS or E-SMLC  155  and one or more TPCs  140 . In some embodiments, system  100  may include a Terrestrial Beacon System (TBS) (e.g. a network of ground-based transmitters or TPs broadcasting signals for geo-spatial positioning) with wide-area or regional coverage. For example, a TBS may include a number of TPs  110  that each transmit a Positioning Reference Signal (PRS) to support location determination for UEs  120 . 
     The LTE radio access type is described in documents available from an organization known as the 3rd Generation Partnership Project (3GPP). In some embodiments, system  100  may form part of, comprise, or contain an Evolved Packet System (EPS), which may comprise an evolved UMTS Terrestrial Radio Access Network (E-UTRAN) and an Evolved Packet Core (EPC). LPP is well-known and described in various publicly available technical specifications from 3GPP (e.g. 3GPP Technical Specification (TS) 36.355). LPPe has been defined by the Open Mobile Alliance (OMA) (e.g. in OMA TS OMA-TS-LPPe-V1_0) and may be used in combination with LPP such that an LPP message may contain an embedded LPPe message in a combined LPPILPPe message. LPPa is described in the publicly available 3GPP TS 36.455 document. In general, a positioning protocol such as LPP and/or LPPe may be used by an LS to coordinate and control position determination for a UE such as UE  120 . The positioning protocol may define: (a) positioning related procedures that may be executed by the LS and/or UE; and/or (b) communication or signaling exchanged between the UE and LS related to positioning of the UE. In the case of LPPa, the protocol may be used between an LS (e.g. E-SMLC  155 ) and a BS (e.g. eNB  104 ) to enable the LS to request and receive configuration information for the BS (e.g. details of PRS signals transmitted by the BS) and positioning measurements made by the BS of a UE. 
     In  FIG. 1 , one or more of the blocks shown may correspond to logical entities. The logical entities shown in  FIG. 1  may be physically separate, or, one or more of the logical entities may be included in a single physical server or device. The transfer of the location information may occur at a rate appropriate to both UE  120  and the LS or other entity. The logical entities and blocks shown in  FIG. 1  are merely exemplary and the functions associated with the logical entities/blocks may be split or combined in various ways in a manner consistent with disclosed embodiments. 
     System  100  includes an evolved NodeB  104  (also referred to as an eNodeB or eNB), a Mobility Management Entity (MME)  115 , a Gateway Mobile Location Center (GMLC)  145 , an Enhanced Serving Mobile Location Center (E-SMLC)  155 , a Security Gateway  185 , and a Home eNB (HeNB) Gateway  175 . The eNB  104 , MME  115 , E-SMLC  155 , Security Gateway  185  and Home eNB (HeNB) Gateway  175  may be part of a serving network for UE  120 , which may also be a home network for UE  120 , and may be referred to as an Evolved Packet System (EPS). 
     The eNB  104  may be a serving eNB for UE  120  and may function as a base station (BS) supporting LTE wireless access by UE  120  including supporting the transfer of control signaling, voice and/or data between UE  120  and entities such as one or more of MME  115 , E-SMLC  155 , GMLC  145 , and External Client  165 . In some embodiments, eNB  104  may also support transfer of control signaling, voice and/or data between UE  120  and other entities not shown in  FIG. 1  such as a Secure User Plane Location (SUPL) Location Platform (SLP) or other UEs. 
     The MME  115  may be the serving MME for UE  120  and may support attachment and network connection of UE  120 , mobility of UE  120  (e.g. via handover between different network cells) as well as establishing and releasing data and voice bearers on behalf of UE  120 . GMLC  145  may provide access on behalf of an external client (e.g. External Client  165 ) to the location of UE  120 . The External Client  165  may be a web server or remote application that may have some association with UE  120  (e.g. may be accessed by a user of UE  120 ) or may be a server, application or computer system providing a location service to some other user or users which may include obtaining and providing the location of UE  120  (e.g. to enable a service such as friend or relative finder, asset tracking or child or pet location). 
     The E-SMLC  155  may be an LS that supports a control plane location solution enabling a location of a UE (e.g. UE  120 ) with LTE radio access to be obtained. With a control plane (CP) location solution, the signaling used to initiate positioning of a UE  120  and the signaling related to the positioning of UE  120  occur over interfaces of a cellular network and using protocols that support signaling (as opposed to data or voice transfer). In CP positioning, the location server may include or take the form of an E-SMLC such as E-SMLC  155 . The architecture illustrated in  FIG. 1  may support a control plane location solution. 
     With a User Plane (UP) location solution, such as the Secure User Plane Location (SUPL) location solution defined by the Open Mobile Alliance (OMA), signaling to initiate and perform positioning of a UE (e.g. UE  120 ) may be transferred using interfaces and protocols that support transfer of data (and possibly voice and other media). With the SUPL UP location solution, the location server may include or take the form of a SUPL Location Platform (SLP) such as a Home SLP (H-SLP) or emergency SLP (E-SLP). For example, the SLP (not shown in  FIG. 1 ) may be connected to or accessed via the Internet and may communicate with UE  120  via a BS (e.g. eNB  104 ) and one or more other entities such as a Serving Gateway and Packet Data Network Gateway (not shown in  FIG. 1 ). 
     The Security Gateway  185  and HeNB Gateway  175  may be used to support connection of small cells and/or HeNBs (not shown in  FIG. 1 ). The small cells and/or HeNBs are small base stations that support LTE radio access by UEs (e.g. UE  120 ) over a small area (e.g. 100 to 200 meters or less from one side to another) and may connect to the Security Gateway  185  via the Internet and/or via an Internet Service Provider. The Security Gateway  185  may help authenticate the small cells and/or HeNBs and may enable secure communication between the small cells and/or HeNBs and other network entities such as MME  115 . The HeNB Gateway  175  may be combined with the Security Gateway  185  or may be separate and may perform protocol relaying and conversion in order to allow small cells and/or HeNBs connected to Security Gateway  185  to communicate with other entities such as MME  115 . 
     System  100  also includes one or more Space Vehicles (SVs)  180 , which may be part of a Satellite Positioning System (SPS) such as a Global Navigation Satellite System (GNSS). Examples of a GNSS include the Global Positioning System (GPS), Galileo, GLONASS, and Beidou. 
     For simplicity, only one UE  120 , two TP controllers (TPCs)  140 , one eNB  104  and seven TPs  110  are shown in  FIG. 1 . In general, system  100  may comprise several or many UEs  120 , multiple cells served by multiple TPCs  140  and/or multiple eNBs  104 , multiple TPs  110 , and additional logical and/or physical entities. 
     As shown in  FIG. 1 , UE  120  may be capable of receiving wireless communication from TPCs  140 , TPs  110  and/or eNB  104  over an LTE-Uu radio interface  125 . LTE-Uu radio interface  125  may facilitate communication between UE  120  and a TPC  140 , between UE  120  and a TP  110  and between UE  120  and eNB  104 . 
     A TPC  140  may control a number of TPs  110  (e.g. up to 4096 TPs  110  in some implementations) that transmit downlink radio signals (e.g. PRS signals) to assist positioning of UE  120 . As referred to herein, a TP  110  is considered to act as a positioning beacon and to transmit downlink signals (e.g. PRS signals) to assist positioning of UE  120 . A TP  110  may be physically separate from a TPC  140  and is then referred to herein as an “external TP  110 .” For example, each of TPs  110 - 1  to  110 - 7  in system  100  is considered to be an external TP. An external TP  110  may obtain electrical power from any convenient local source such as a building it is attached to or located within, a street light (e.g. if attached to a street light pole) or a nearby local power line and/or may have its own power source such as a solar panel and battery. A TP  110  may also be part of a TPC  140 . For example, a TPC  140  may include a TP  110  and transmit downlink radio signals (e.g. function as an eNB/TPC  140  as described below). A TP  110 , which is part of TPC  140 , is referred to herein as an “internal TP  110 .” 
     A TP  110  (e.g. an external TP  110  that functions as a remote radio head or an internal TP  110 ) may support reception of uplink signals from UE  120  and assist UE  120  to communicate with other entities such as MME  115  or E-SMLC  155 . However, in some embodiments, a TP  110  may not support uplink functionality such as the reception of uplink signals from UE  120  or assisting UE  120  to communicate with other entities such as MME  115  or E-SMLC  155 . A TP  110  that does not support uplink functionality may be referred to as a terrestrial beacon system (TBS) beacon, a TBS TP, a PRS TP, a positioning beacon, a positioning only beacon, a positioning only PRS beacon, a PRS beacon, an eNB beacon, a standalone eNB beacon, or a RAN beacon. Thus, a PRS TP may transmit downlink radio signals (e.g. PRS signals) to UEs but may refrain from broadcasting information to the UE indicating support for uplink signals from the UE. 
     In system  100 , TPs  110 - 1  to  110 - 7  are all considered to be PRS TPs (i.e. the TPs do not support uplink functionality). A TP  110  that does not support reception of uplink signals from UE  120  may refrain from broadcasting information to the UE  120  indicating such support. For example, the TP  110  may refrain from broadcasting one or more of a master information block (MIB), a system information block 1 (SIB1) or a system information block 2 (SIB2) (e.g. as defined in 3GPP TS 36.331 entitled “Radio Resource Control (RRC); Protocol specification,”) for normal support of uplink LTE signals from a UE  120  by an eNB or HeNB. 
     In some embodiments, a TPC  140  may be connected to, and may communicate with, one or more external TPs  110  that are controlled by the TPC  140  using a Local Area Network (LAN), a Wireless LAN (WLAN), or microwave links. For example, as shown in  FIG. 1 , TPC  140 - 1  is connected to external TPs  110 - 1 ,  110 - 2 ,  110 - 3 ,  110 - 4 , and  110 - 5 , while TPC  140 - 2  is connected to external TPs  110 - 6  and  110 - 7 . A LAN may be an Institute of Electrical and Electronics Engineers (IEEE) 802.3x network, for example. A WLAN may be an IEEE 802.11x network. Signaling between a TPC  140  and an external TP  110  may be used by TPC  140  to configure or reconfigure a TP  110 , provide a common timing reference to a TP  110 , and/or to monitor TP  110  operation. For example, TPs  110  may act as PRS TPs and may transmit PRS after being appropriately configured by a TPC  140 . 
     In some embodiments, a TPC  140  may function as both a TPC and as an eNB or HeNB by including functions of an eNB or HeNB, respectively. A TPC  140  that functions as both an eNB and TPC is referred to herein as an eNB/TPC  140  and may also be referred to as an eNB or enhanced eNB. Similarly, a TPC  140  that functions as both an HeNB and TPC is referred to herein as an HeNB/TPC  140  and may be referred to as an HeNB or enhanced HeNB. The term (H)eNB is used herein to refer to an eNB or an HeNB, and the term “(H)eNB/TPC” refers to a TPC that includes functionality for an eNB or HeNB. An (H)eNB/TPC  140  supports the normal functions defined by 3GPP for an (H)eNB such as supporting LTE wireless access and communication on behalf of one or more UEs  120  as well as functioning as a TPC. An (H)eNB/TPC  140  may support normal two way LTE radio access by UE  120  in one or more LTE cells supported by the (H)eNB/TPC  140 . An (H)eNB/TPC  140  may also support downlink PRS transmission from one or more external TPs  110  controlled by the (H)eNBTPC  140  such as TPs  110 - 1  to  110 - 5  in the case of TPC  140 - 1  (when TPC  140 - 1  is an eNB/TPC) or TPs  110 - 6  and  110 - 7  in the case of TPC  140 - 2  (when TPC  140 - 2  is an HeNB/TPC). 
     Each of the cells supported by an (H)eNB/TPC  140  may correspond to a distinct internal TP  110  that is functionally part of the (H)eNB/TPC  140  as described earlier. A internal TP  110  may support one cell for an (H)eNB/TPC  140  and may share an antenna or multiple antenna elements for the (H)eNB/TPC  140  with other internal TPs  110  that are part of the same (H)eNB/TPC  140  and that support other cells for the (H)eNB/TPC  140  (e.g. in the case of an eNB/TPC  140  that supports a number of separate cell sectors). The coverage area(s) of the cell(s) (e.g. for internal TP(s)  110 ) supported by an (H)eNB/TPC  140  and the coverage area(s) for the external TP(s)  110  controlled by the (H)eNB/TPC  140  may or may not overlap. For example, fully overlapping or partially overlapping coverage areas may be useful to increase the number of TPs  110  and eNBs  104  visible to UE  120  at any one location, whereas non-overlapping or partially overlapping coverage areas may be useful to extend the overall coverage area of the (H)eNB/TPC  140  with regards to support of positioning of a UE  120 . It is to be understood that a TPC  140  not designated herein as an (H)eNB/TPC  140  may or may not contain (H)eNB functionality. 
     The Functions of a TPC  140  can include: (i) communicating with one or more external TPs  110  (e.g. via a LAN or WLAN); (ii) configuring and/or reconfiguring downlink (DL) signaling information in external TPs  110  (e.g. information related to transmission of PRS signals); (iii) activating and deactivating external TPs  110 ; (iv) communicating with an LS (e.g. an E-SMLC  155 ) using, for example, LPPa: to allow the LS to request and receive configuration information for internal and/or external TPs  110  controlled by the TPC  140 , or to provide configuration information for internal and/or external TPs to the TPC  140 ; (v) communicating with an Operations and Maintenance (O&amp;M) system or server to receive configuration information for TPs  110 ; (vi) providing timing information to external TPs  110  (e.g. GPS time information obtained using a GPS receiver associated with or co-located with the TPC  140 ); and/or (vii) requesting and obtaining from external TPs  110  downlink (DL) signaling information for TPs  110  (e.g. information related to transmission of PRS signals) and/or other information for the external TPs  110  (e.g. location coordinates of an antenna for a TP  110 ). A TPC  140  that interacts with an external TP  110  as just described (e.g. to configure PRS information for the TP  110 ) or that has an internal TP  110  may be referred to as a controlling TPC  140  or serving TPC  140  for the external or internal TP  110 , respectively, and the TP  110  (whether internal or external) may be referred to as a TP  110  that is controlled by, configured by or associated with the TPC  140 . An (H)eNB/TPC  140  that interacts with an external TP  110  as just described (e.g. to configure PRS information for the TP  110 ) or that has an internal TP  110  may be referred to as a controlling (H)eNB or serving (H)eNB for the external or internal TP  110 , respectively. 
     The use of a TPC  140  or (H)eNB/TPC  140  to control (or serve) a plurality of TPs  110  (e.g. up to 256 or 4096 TPs  110 ) may reduce the complexity of external TPs  110  and/or the cost of deploying external TPs  110 . For example, an external TP  110  may support communication with one TPC  140  or one (H)eNB/TPC  140  (e.g. using a LAN or WLAN). This may enable an external TP  110  to operate without an Internet connection and a public IP address, without supporting a GPS or other GNSS receiver, and/or without other standalone capability to autonomously obtain an accurate common time reference, which may reduce external TP  110  cost and complexity. In addition, when a TPC  140  or (H)eNB/TPC  140  provides an accurate common time reference (e.g. GPS time or other GNSS time) to an external TP  110 , the external TP  110  may be enabled to operate at a location (e.g. a basement or deep inside a building) where common time signals (e.g. GPS signals) cannot be received or cannot be accurately received (e.g. without an impairment to an ability to transmit synchronized signals such as synchronized PRS signals). In some embodiments, TPs  110  associated with a TPC  140  may serve (e.g. transmit DL PRS signals that can be received and measured in) multiple cells, a single cell or some portions of a cell. 
     A TPC  140  may interface with MME  115  either using a direct link or via a security gateway and possibly a Home eNodeB (HeNB) gateway. When a direct link is used, a TPC  140  (e.g. TPC  140 - 1  in  FIG. 1 ) that does not include eNB functionality may communicate with the MME  115  via a subset of the normal 3GPP S1 interface defined in 3GPP TS 36.413 entitled “S1 Application Protocol (S1AP),” for use between an MME and eNB. When a direct link is used, an eNB/TPC  140  (e.g. TPC  140 - 1  in  FIG. 1 ) that includes eNB functionality may communicate with the MME  115  via S1 interface  105 , which may be the normal 3GPP S1 interface defined in 3GPP TS 36.413 for use between an MME and eNB. When a link via a security gateway  185  and optionally via an HeNB gateway  175  is used, a TPC  140  (e.g. TPC  140 - 2  in  FIG. 1 ) that does not include HeNB functionality may access MME  115  similarly to or the same as an HeNB or small cell (e.g. using an Internet connection to access the security gateway  185 ) but using a subset of the 3GPP S1 interface. An HeNBITPC  140  that includes HeNB functionality may access MME  115  the same as an HeNB or small cell (e.g. using the full 3GPP S1 interface). 
     In OTDOA based positioning, the UE  120  may measure time differences, referred to as Reference Signal Time Differences (RSTDs), between signals (e.g. PRS signals) transmitted by different pairs of eNBs and TPs. For example, the UE  120  may measure an RSTD between a PRS signal transmitted by eNB  104  and a PRS signal transmitted by TP  110 - 1 , between a PRS signal transmitted by TP  110 - 1  and a PRS signal transmitted by TP  110 - 2 , and % or between a PRS signal transmitted by eNB  104  and a PRS signal transmitted by some other eNB (not shown in  FIG. 1 ). Typically, either one cell supported by an eNB  104  or one TP  110  will be used as a reference TP (or reference cell) and will be common to all the RSTD measurements made by the UE  120  (in the sense that each RSTD measurement may provide a time difference between a signal transmitted by the reference cell or reference TP and a signal transmitted by another neighbor eNB  104  or neighbor TP  110 ). The RSTDs may be used in conjunction with the known positions of eNBs/TPs to calculate the position of UE  120 . The calculation may be performed by the UE  120  (e.g. if E-SMLC  155  provides the known positions to UE  120 ) or by the E-SMLC  155  (e.g. if UE  120  provides the measured RSTDs to E-SMLC  155 ). 
     To obtain acceptable positioning information, some or all of eNBs  104 , (H)eNB/TPCs  140  and/or TPs  110  participating in OTDOA may be synchronized (e.g. to within 50 ns or better). Synchronization may ensure that common signal markers (e.g. the start of a new set of LTE radio frames, the start of an LTE subframe and/or the start a set of consecutive PRS subframes) are transmitted by an eNB  104 , (H)eNB/TPC  140  and/or a TP  110  at exactly or almost exactly the same time or with precisely known time differences. In some embodiments, TPCs  140  and (H)eNB/TPCs  140  may have access to a GPS Clock, GPS timing, and/or to a GPS or other GNSS SV  180 , to facilitate synchronization. For example, a TPC  140  or (H)eNB/TPC  140  may contain a GPS receiver or GNSS receiver with access to an outdoor (or indoor) antenna and may receive, measure and decode signals from one or more SVs  180  and thereby, as is well known in the art, obtain an accurate absolute time reference (such as GPS time, Coordinated Universal Time (UTC) or a time for another GNSS which may be accurate to 50 nanoseconds (ns) or better in some embodiments). In some embodiments, time synchronization information (e.g. GPS time, GNSS time, or UTC time) may be provided to TPs  110  by a TPC  140  by sending signaling information to TPs  110  that includes a time reference such as using, for example, the Internet Network Time Protocol (NTP), IEEE 1588 Precision Time Protocol (PTP) and/or an ITU-T Synchronous Ethernet. 
     In some embodiments, a TPC  140  may communicate with MME  115  over S1 interface  105 . MME  115  may support location sessions in association with a location server such as E-SMLC  155  to provide location services for UE  120  using a CP location solution as previously described. In some embodiments, MME  115  and E-SMLC  155  may communicate over a 3GPP SLs interface  130  (e.g. as defined in 3GPP TS 29.171 entitled “LCS Application Protocol (LCS-AP) between the Mobile Management Entity (MME) and Evolved Serving Mobile Location Centre (E-SMLC); SLs interface”). UE  120  may exchange location related messages (e.g. LPP and/or LPP/LPPe messages) with the E-SMLC  155  to obtain or support location services. The location related messages may be transferred between UE  120  and E-SMLC  155  via eNB  104  and MME  115  when UE  120  is served by eNB  104  or via an (H)eNB/TPC  140  and MME  115  when UE  120  is served by eNB or HeNB functionality supported by the (H)eNB/TPC  140 . 
     In some embodiments, E-SMLC  155  may determine a (network based or UE assisted) location of UE  120 . E-SMLC  155  may use measurements of radio signals such as Positioning Reference Signals (PRS), which may be provided by a UE  120 , to help determine the location of the UE  120 . In some embodiments, MME  115  may communicate with Gateway Mobility Location Center (GMLC)  145  over a 3GPP SLg interface  135  (e.g. as defined in 3GPP TS 29.172 entitled “Evolved Packet Core (EPC) LCS Protocol (ELP) between the Gateway Mobile Location Centre (GMLC) and the Mobile Management Entity (MME); SLg interface”). 
     In some embodiments, GMLC  145  may provide an interface to one or more External Clients  165  as previously described. GMLC  145  may include functionality to support various location services (e.g. such as obtaining the location of UE  120  from MME  115  and sending the location to External Client  165 ). GMLC  145  may forward positioning requests related to UE  120  and received from External Client  165  to an MME  115 , serving UE  120 , over SLg interface  135 . GMLC  145  may also forward location estimates for UE  120 , received from MME  115 , to External Client  165 . 
     In some embodiments, TPC  140 - 2  in  FIG. 1  (or some other TPC  140 ) may be coupled to an Operations &amp; Maintenance (O&amp;M) server  195 , which may provide and manage configuration of TPC  140 - 2  and/or TPs  110  controlled by TPC  140 - 2 . In some embodiments, TPC  140 - 2  and O&amp;M server  195  may be coupled over the Internet. In some embodiments, TPC  140 - 2  may also, or may instead, be coupled to MME  115  through a Security Gateway  185  as previously described. Security Gateway  185  and TPC  140 - 2  may further be coupled over the Internet. Further, Security Gateway  185  may be coupled to (or combined with) an HeNB Gateway  175  and enable TPC  140 - 2  to access MME  115  (via Security Gateway  185  and HeNB gateway  175 ) in the same manner as an HeNB or small cell, which may avoid the need for a direct link between TPC  140  and MME  115  and thereby reduce the operational cost of deploying TPC  140 - 2  and TPs  110 - 6  and  110 - 7 . HeNB Gateway  175  may also be coupled to MME  115  and communicate with MME  115  using an S1 interface. 
       FIG. 2A  shows the structure of an exemplary LTE subframe sequence with PRS positioning occasions. In  FIG. 2A , time is represented horizontally (e.g. on an X axis) with time increasing from left to right, while frequency is represented vertically (e.g. on a Y axis) with frequency increasing (or decreasing) from bottom to top. As shown in  FIG. 2A , downlink and uplink LTE Radio Frames  210  are of 10 ms duration each. For downlink Frequency Division Duplex (FDD) mode, Radio Frames  210  are organized into ten subframes  212  of 1 ms duration each. Each subframe  212  comprises two slots  214 , each of 0.5 ms duration. 
     In the frequency domain, the available bandwidth may be divided into uniformly spaced orthogonal subcarriers  216 . For example, for a normal length cyclic prefix using 15 KHz spacing, subcarriers  216  may be grouped into a group of 12 subcarriers. Each grouping, which comprises 12 subcarriers  216 , in  FIG. 2A , is termed a resource block and, in the example above, the number of subcarriers in the resource block may be written as N SC   RB =12. For a given channel bandwidth, the number of available resource blocks on each channel  222 , which is also called the transmission bandwidth configuration  222 , is indicated as N RB   DL    222 . For example, for a 3 MHz channel bandwidth in the above example, the number of available resource blocks on each channel  222  is given by N RB   DL =15. 
     In the LTE architecture illustrated in  FIG. 1 , a TP  110  may transmit a PRS (i.e. a DL PRS) such as the PRS exemplified in  FIG. 2A  and (as described later)  FIG. 2B , which may be measured and used for UE (e.g. UE  120 ) position determination. Since transmission of a PRS by a TP  110  is directed to all UEs within radio range, a TP  110  can also be considered to broadcast a PRS. A TP  110  that does not support all the normal transceiver functions of an eNB but that transmits (or broadcasts) a PRS signal may be called a terrestrial beacon system (TBS) beacon, a TBS TP, a PRS TP, a positioning beacon, a positioning only beacon, a positioning only PRS beacon, a PRS beacon, an eNB beacon, a standalone eNB beacon, or a RAN beacon. As outlined above, a PRS TP may transmit downlink radio signals (e.g. PRS signals) to UEs but may refrain from broadcasting information to the UE indicating support for uplink signals from the UE. 
     In general, TP  110 , as used herein, refers to all entities in a Radio Access Network (RAN) that transmit PRS to assist in positioning of one or more target UEs  120  and that may or may not support other functions such as providing wireless access (e.g. for voice and data connectivity) to one or more UEs  120 . Further, an eNB beacon, standalone eNB beacon and RAN beacon may be particular examples of a positioning beacon. In some embodiments, TPs  110  may provide additional LTE/PRS coverage for indoor locations—e.g. may support functions of an eNB or of a remote radio head for an eNB. In some embodiments, a TP  110  may act as a standalone beacon that can transmit a PRS signal to support positioning of UEs and may also transmit information needed to support UE acquisition and measurement of the PRS such as an LTE master information block (MIB) and one or more LTE system information blocks (SIBs) but may not transmit or receive data or control information to support normal LTE access by UEs (e.g., may not support wireless access by UEs for the purpose of sending and receiving voice and data). As outlined above, a TP  110  may be coupled to a TPC  140  over a LAN or WLAN. 
     A PRS, which has been defined in 3GPP Long Term Evolution (LTE) Release-9 and later releases, may be transmitted by TPs  110  after appropriate configuration by a TPC  140  and/or by O&amp;M server  195 . A PRS may be transmitted in special positioning subframes that are grouped into positioning occasions. For example, in LTE, a PRS positioning occasion can comprise a number N PRS  of consecutive positioning subframes where the number N PRS  may be between 1 and 160 (e.g. may include the values 1, 2, 4 and 6 as well as other values). The PRS positioning occasions for a TP  110  may occur periodically at intervals, denoted by a number T PRS , of millisecond (or subframe) intervals where T PRS  may equal 5, 10, 20, 40, 80, 160, 320, 640, or 1280. As an example,  FIG. 2A  illustrates a periodicity of positioning occasions where N PRS  equals 4 and T PRS  is greater than or equal to 20. In some embodiments, T PRS  may be measured in terms of the number of subframes between the start of consecutive positioning occasions. 
     Within each positioning occasion, a PRS may be transmitted with a constant power. A PRS can also be transmitted with zero power (i.e., muted). Muting, which turns off a regularly scheduled PRS transmission, may be useful when PRS signals between different cells overlap by occurring at the sane or almost the same time. In this case, the PRS signals from some cells may be muted while PRS signals from other cells are transmitted (e.g. at a constant power). Muting may aid signal acquisition and RSTD measurement by UEs  120  for PRS signals that are not muted by avoiding interference from PRS signals that have been muted. Muting may be viewed as the non-transmission of a PRS for a given positioning occasion for a particular cell or TP. Muting patterns may be signaled to UE  120  using bit strings. For example, in a bit string signaling a muting pattern, if a bit at position j is set to “0”, then UE  120  may infer that the PRS is muted for a j th  positioning occasion. 
     To further improve hearability of PRS, positioning subframes may be low-interference subframes that are transmitted without user data channels. As a result, in ideally synchronized networks, PRSs may receive interference from other cell PRSs with the same PRS pattern index (i.e., with the same frequency shift), but not from data transmissions. The frequency shift, in LTE, for example, is defined as a function of a PRS ID for a cell or TP (denoted as ID   PRS ) or as a function of a Physical Cell Identifier (PCI) (denoted as N ID   cell ) if no PRS ID is assigned, which results in an effective frequency re-use factor of 6. 
     To improve hearability of a PRS further (e.g. when PRS bandwidth is limited such as with only 6 resource blocks corresponding to 1.4 MHz bandwidth), the frequency band for consecutive PRS positioning occasions (or consecutive PRS subframes) may be changed in a known and predictable manner via frequency hopping. In addition, a TP  110 , or a cell supported by an eNB  104  or a TPC  140  with eNB or HeNB functionality, may support more than one PRS configuration, where each PRS configuration comprises a distinct sequence of PRS positioning occasions with a particular number of subframes (N PRS ) per positioning occasion and a particular periodicity (T PRS ). Further enhancements of a PRS may also be supported by a TPC  140 , TP  110 , and/or eNB  104 . 
     OTDOA assistance data is usually provided to a UE  120  by a location server (e.g. E-SMLC  155 ) for a “reference cell” and one or more “neighbor cells” or “neighboring cells” relative to the “reference cell.” For example, the assistance data may provide the center channel frequency of each cell, various PRS configuration parameters (e.g. N PRS , T PRS , muting sequence, frequency hopping sequence, PRS ID, PRS bandwidth), a cell global ID and/or other cell related parameters applicable to OTDOA. In the case of a TP  110  that acts as a positioning only beacon, a neighbor cell or reference cell may be equated to the TP  110  with the same or similar assistance data being provided. 
     PRS positioning by UE  120  may be facilitated by including the serving cell for the UE  120  in the OTDOA assistance data (e.g. with the reference cell indicated as being the serving cell). OTDOA assistance data may also include “expected RSTD” parameters, which provide the UE  120  with information about the RSTD values the UE  120  is expected to measure at its current location between the reference cell and each neighbor cell together with an uncertainty of the expected RSTD parameter. The expected RSTD together with the uncertainty define a search window for the UE  120  within which the UE  120  is expected to measure the RSTD value. OTDOA assistance information may also include PRS configuration information parameters, which allow a UE  120  to determine when a PRS positioning occasion occurs on signals received from various neighbor cells relative to PRS positioning occasions for the reference cell, and to determine the PRS sequence transmitted from various cells in order to measure a signal Time of Arrival (TOA) or RSTD. 
     Using the RSTD measurements, the known absolute or relative transmission timing of each cell, and the known position(s) of eNB  104  and TP  110  physical transmitting antennas for the reference and neighboring cells, the UE  120 &#39;s position may be calculated. The RSTD for a cell “k” relative to a reference cell “Ref,” may be given as (TOA k −TOA Ref ). TOA measurements for different cells may then be converted to RSTD measurements (e.g. as defined in 3GPP TS 36.214 entitled “Physical layer; Measurements”) and sent to the location server (e.g. E-SMLC  155 ) by the UE  120 . Using (i) the RSTD measurements, (ii) the known absolute or relative transmission timing of each cell, and (iii) the known position(s) of eNB  104  and TP  110  physical transmitting antennas for the reference and neighboring cells, the UE  120 &#39;s position may be determined. 
       FIG. 2B  illustrates further aspects of PRS transmission for a cell supported by an eNB  104  or for a TP  110 .  FIG. 2B  shows how PRS positioning occasions are determined by a System Frame Number (SFN), a cell specific subframe offset (Δ PRS ) and the PRS Periodicity (T PRS )  220 . Typically, the cell specific PRS subframe configuration is defined by a “PRS Configuration Index” I PRS  included in the OTDOA assistance data. The PRS Periodicity (r PRS )  220  and the cell specific subframe offset (Δ PRS ) (e.g. as shown in  FIG. 2B ) are defined based on the PRS Configuration Index I PRS , in 3GPP TS 36.211 entitled “Physical channels and modulation,” as exemplified in Table 1 below. 
     
       
         
           
               
               
               
             
               
                 TABLE 1 
               
               
                   
               
               
                   
                 PRS periodicity 
                 PRS subframe offset 
               
               
                 PRS configuration Index 
                 T PRS   
                 Δ PRS   
               
               
                 I PRS   
                 (subframes) 
                 (subframes) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
            
               
                  0-159 
                 160 
                 I PRS   
               
               
                 160-479 
                 320 
                 I PRS  − 160  
               
               
                  480-1119 
                 640 
                 I PRS  − 480  
               
               
                 1120-2399 
                 1280 
                 I PRS  − 1120 
               
               
                 2400-2404 
                 5 
                 I PRS  − 2400 
               
               
                 2405-2414 
                 10 
                 I PRS  − 2405 
               
               
                 2415-2434 
                 20 
                 I PRS  − 2415 
               
               
                 2435-2474 
                 40 
                 I PRS  − 2435 
               
               
                 2475-2554 
                 80 
                 I PRS  − 2475 
               
            
           
           
               
               
               
            
               
                 2555-4095 
                 Reserved 
               
               
                   
               
            
           
         
       
     
     A PRS configuration is defined with reference to the System Frame Number (SFN) of a cell that transmits PRS. PRS instances, for the first subframe of the N PRS  downlink subframes comprising a first PRS positioning occasion, may satisfy: 
       (10× n   f   +└n   s /2┘−Δ PRS )mod  T   PRS =0,  (1)
 
     where, 
     n f  is the SFN with 0≦n f ≦1023, 
     n s  is the slot number within the radio frame defined by n f  with 0≦n s ≦19, 
     T PRS  is the PRS periodicity, and 
     Δ PRS  is the cell-specific subframe offset. 
     As shown in  FIG. 2B , the cell specific subframe offset Δ PRS    252  may be defined in terms of the number of subframes transmitted starting from System Frame Number 0, Slot Number 0  250  to the start of the first (subsequent) PRS positioning occasion. In  FIG. 2B , the number of consecutive positioning subframes  218  (Npp) equals 4. 
     In some embodiments, when UE  120  receives a PRS configuration index I PRS  in the OTDOA assistance data for a particular cell or TP  110 , UE  120  may determine the PRS periodicity T PRS  and PRS subframe offset Δ PRS  using Table 1. The UE  120  may then determine the radio frame, subframe and slot when a PRS is scheduled in the cell (e.g. using equation (1)). The OTDOA assistance data may be determined by E-SMLC  155  and includes assistance data for a reference cell, and a number of neighbor cells, wherein any neighbor cell and/or the reference cell may correspond to (e.g. may be supported by) a TP  110 . 
     Typically, PRS occasions from all cells in a network that use the same frequency are aligned in time and may have a fixed known time offset relative to other cells in the network that use a different frequency. In SFN-synchronous networks, all eNBs  104  and TPs  110  may be aligned on both frame boundary and system frame number. Therefore, in SFN-synchronous networks all cells supported by eNBs  104  and all TPs  110  may use the same PRS configuration index for any particular frequency of PRS transmission. On the other hand, in SFN-asynchronous networks all eNBs  104  and TPs  110  may be aligned on a frame boundary, but not system frame number. Thus, in SFN-asynchronous networks the PRS configuration index for each cell may be configured separately by the network so that PRS occasions align in time. Synchronization of an external TP  110  in an SFN-synchronous network (e.g. to align both frame boundaries and SFNs with other cells and TPs  110 ) or SFN-asynchronous network (e.g. to align frame boundaries with other cells and TPs  110 ) may be assisted by an accurate common time reference provided to the TP  110  by a controlling TPC  140  for the TP  110  as described previously herein. 
     UE  120  may determine the timing of the PRS occasions of the reference and neighbor cells for OTDOA positioning, if UE  120  can obtain the cell timing (e.g., SFN or Frame Number) of at least one of the cells (e.g. the reference cell). The timing of the other cells and TPs  110  may then be derived by UE  120 , for example based on the assumption that PRS occasions from different cells and TPs  110  overlap. 
     In a typical macro-cell scenario, the PRS configuration parameters such as the number of consecutive positioning subframes, periodicity, muting pattern, etc. may be configured by the network and may be signaled to UE  120  by E-SMLC  155  as OTDOA assistance data. However, in instances where PRS is transmitted by TPs  110  and configured by TPCs  140 , information pertaining to PRS configuration information for TPs  110  may not be available to E-SMLC  155 . For example, TPs  110  may be configured locally by TPCs  140  with PRS parameters and TP  110  locations, and PRS configuration information of TPs  110  may not be available to E-SMLC  155 . In such a case, E-SMLC  155  may send a message (e.g. an LPPa message) to a TPC  140  to request PRS configuration information and other information (e.g. antenna locations) for the TPs  110  controlled by the TPC  140  and the TPC  140  may return a message (e.g. an LPPa message) containing the requested information. A TPC  140  may in turn receive the PRS configuration information and other information from O&amp;M server  195 . In certain other instances, an E-SMLC  155  may be configured (e.g. by O&amp;M server  195 ) with PRS configuration information and other information for the TPs  110  controlled by a TPC  140  and may send the PRS configuration information and other information for the TPs  110  to the TPC  140  (e.g. in an LPPa message) to enable the TPC  140  to configure PRS transmission in the controlled TPs  110 . 
     Referring to  FIG. 1 , in some embodiments, when UE  120  requests OTDOA assistance data, or during a positioning session involving TPCs  140  and/or TPs  110 , E-SMLC  155  may communicate with a TPC  140  via MME  115  to send to the TPC  140 , or receive from the TPC  140 , PRS configuration information and possibly other information (e.g. antenna locations and/or timing information) for TPs  110  controlled by the TPC  140 . In some embodiments, the communication between E-SMLC  155  and TPCs  140  may use the LPPa protocol, which may be transported transparently through MME  115 . In some embodiments, PRS configuration information pertaining to TPs  110  and the locations of TPs  110  may be provided to E-SMLC  155  in LPPa messages by a TPC  140  that controls the TPs  110 . For example, E-SMLC  155  may request PRS configuration parameters for TPs  110 - 1  to  110 - 5  from TPC  140 - 1  in an LPPa OTDOA Information Request message. In some embodiments, TPC  140 - 1  may respond to the LPPa OTDOA Information Request message from E-SMLC  155  with an LPPa OTDOA Information Response message. In some embodiments, the LPPa OTDOA Information Response message may include PRS configuration information and locations for TPs  110  (e.g. one or more ofTPs  110 - 1 - 110 - 5 ). 
     In some embodiments, E-SMLC  155  may also request and obtain PRS configuration information and other information for TPs  110  (e.g. using LPPa) from TPCs  140  that attach to MME  115  the same as or similar to a small cell or HeNB. For example in the case of TPC  140 - 2 , MME  115  may send messages (e.g. LPPa messages) to, and receive messages (e.g. LPPa messages) from, TPC  140 - 2  through: (a) MME  115  and Security Gateway  185 , or (b) MME  115 , HeNB Gateway  175 , and Security Gateway  185 . For example, the PRS Configuration and location information for TPs  110 - 6  and  110 - 7  provided by TPC  140 - 2  may be relayed to E-SMLC  155  over the Internet through (a) Security Gateway  185  and MM E  115 , or (b) M M E  115 , HeNB Gateway  175 , and Security Gateway  185 . 
     In some embodiments, upon (or some time after) receipt of the PRS configuration information and locations and other information for TPs  110 , E-SMLC  155  may provide OTDOA assistance data to a UE  120  whose location is needed. In some embodiments, E-SMLC  155  may provide the OTDOA assistance data to UE  120  using the LPP protocol. For example, E-SMLC  155  may provide the OTDOA assistance data to UE  120  using an LPP Provide Assistance Data message. An LPP Provide Assistance Data message may include OTDOA assistance data such as PRS parameters (e.g. PRS bandwidth, PRS code, frequency, muting, PRS subframe configuration) for a reference cell, neighboring cells including TPs  110  that may correspond to the reference cell and/or some or all neighboring cells. 
     In some embodiments, after providing the OTDOA assistance data E-SMLC  155  may further send an LPP Request Location Information message to UE  120 . In some embodiments, an LPP Request Location Information message may be used to request RSTD measurements from UE  120 . For example, for a UE assisted mode of OTDOA positioning, UE location determination by E-SMLC  155  may be based, in part, on RSTD measurements obtained by, and sent to E-SMLC  155  by, UE  120 . In some embodiments, an LPP Request Location Information message may include: information elements such as the type of location information desired; a desired accuracy for any location estimates or measurements; a response time and/or the location determination method (e.g. OTDOA) to be used. 
     In some embodiments, a UE  120  may obtain RSTD measurements requested by the E-SMLC  155  using assistance data provided by E-SMLC  155  (e.g. in an earlier LPP Provide Assistance Data message from E-SMLC  155 ). Further, UE  120  may, within the specified response time, send the obtained RSTD measurements in an LPP Provide Location Information message to E-SMLC  155 . An LPP Provide Location Information message may include information elements such as one or more of RSTD measurements, quality metrics associated with the RSTD measurements, an identity of the reference cell (or reference TP  110 ) used for measuring the RSTDs, a quality metric related to TOA measurements for the reference cell (or reference TP  110 ), and a neighbor cell measurement list including identities of the measured neighbor cells, and/or measured TPs  110 , for which RSTD measurements are provided. 
     Based on the measurements received from UE  120  in an LPP Provide Location Information message, E-SMLC  155  may determine a location of UE  120  and provide the location information to MME  115 , which may relay the information to External Client  165  through GMLC  145 . 
       FIG. 3  shows a signaling flow  300  illustrating entities and message flows for positioning according to some disclosed embodiments. In  FIG. 3 , for simplicity, only two TPs ( 110 - 1  and  110 - 2 ) and one TPC ( 140 - 1 ) are shown. However, the message flows shown are also applicable to the other TPs coupled to TPC  140 - 1  and to other TPCs (e.g. TPC  140 - 2 ). For example, TPC  140 - 2  may be substituted for (or included in addition to) TPC  140 - 1  and TPs  110 - 6  and  110 - 7  may be substituted for (or included in addition to) TPs  110 - 1  and  110 - 2 . 
     In some embodiments, at stage  310 , TPC  140 - 1  may configure TP  110 - 1  and/or TP  110 - 2  with PRS parameters for PRS transmission (e.g. may provide PRS bandwidth, carrier frequency, coding, subframe configuration, muting pattern). The PRS parameters may have been configured at some previous time in TPC  140 - 1  by an O&amp;M server  195  (not shown in  FIG. 3 ) or by E-SMLC  155 . TPC  140 - 1  may additionally, or instead, provide timing information to TP  110 - 1  and/or TP  110 - 2  at stage  310 . For example, TPC  140 - 1  may send signaling information to TP  110 - 1  and/or TP  110 - 2  that includes an accurate common time reference (e.g. for GPS time, a GNSS time or UTC time), which may have been obtained by TPC  140 - 1  using a GPS or GNSS receiver which may, in some embodiments, be coupled to an outdoor antenna. Alternatively, or in addition, at stage  310 , TPC  140 - 1  may request and obtain from TP  110 - 1  and/or TP  110 - 2  PRS parameters for PRS transmission by TP  110 - 1  and/or TP  110 - 2 , respectively, and/or other information for TP  110 - 1  and/or TP  110 - 2  such as the location coordinates of an antenna for each of TP  110 - 1  and/or TP  110 - 2 , respectively. 
     In some embodiments, at stage  315 , MME  115  may receive a request from External Client  165  (not shown in  FIG. 3 ) for a location of UE  120 . In some embodiments, the location request at stage  315  may be forwarded to MME  115  by GMLC  145  (not shown in  FIG. 3 ). 
     In some embodiments, at stage  320 , MME  115  may forward the location request received at stage  315  to E-SMLC  155  (e.g. using an LCS Application Protocol (LCS-AP) Location Request message). 
     Upon receipt of the location request from MME  115  at stage  320 , E-SMLC  155  may send an LPPa OTDOA Information Request to TPC  140 - 1  at stage  325  requesting PRS configuration parameters and/or other information (e.g. location coordinates) for TPs  110  (and cells) controlled by TPC  140 - 1  (e.g. one or more of TPs  110 - 1 - 110 - 5 ). 
     At stage  330 , TPC  140 - 1  may respond to the LPPa OTDOA Information Request received from E-SMLC  155  at stage  325  with an LPPa OTDOA Information Response message. The LPPa OTDOA Information Response message may include PRS configuration parameters, TP identities, location information and/or other information for TPs  110  controlled by TPC  140 - 1  (e.g. one or more of TPs  110 - 1 - 110 - 5 ) such as providing for each controlled TP  110 , the location coordinates of an antenna for the TP  110 , PRS parameters defining PRS transmission from the TP  110 , a DL carrier frequency, and an identity (ID) for the TP  110  such as a TP ID, a physical cell ID (PCI), a cell portion ID and/or a PRS ID or virtual PCI ID. 
     A TP ID may be a non-unique identity (e.g. an integer between 0 and 4095) assigned to an internal or external TP  110  by an O&amp;M server  195 , TPC  140 - 1  or by E-SMLC  155 . A PRS ID may be a value (e.g. an integer between 0 and 4095) used by a TP  110  to determine a coding sequence and/or a frequency or set of frequencies used by the TP  110  to transmit a PRS. A physical cell ID may be a non-unique value (e.g. an integer between 0 and 503) used to identify an LTE cell (e.g. for an internal TP  110 ) or an external TP  110  within some local area. The local area may include external TPs  110  and/or LTE cells (e.g. associated with internal TPs  110 ) for which RSTD measurements can be obtained by UE  120  for some reference cell. TPC  140 - 1  may have previously obtained the information returned in the LPPa OTDOA Information Response message sent at stage  330  from an O&amp;M server  195  and/or from TPs  110 - 1  and  110 - 2  at stage  310 . 
     In some embodiments, at stage  335 , E-SMLC  155  may send OTDOA assistance data to UE  120  using the LPP protocol (or LPP/LPPe combined protocol). For example, E-SMLC  155  may send the OTDOA assistance data to UE  120  in an LPP Provide Assistance Data message. The LPP Provide Assistance Data message may include OTDOA assistance data such as assistance data for a reference cell (e.g. PRS parameters and a reference cell ID), PRS parameters and IDs for neighboring TPs  110  (e.g. TP  110 - 1  and TP  110 - 2 ), and PRS configuration parameters for cells supported by neighboring eNBs  104  (not shown in  FIG. 3 ). Some or all of the OTDOA assistance data may comprise PRS configuration parameters and IDs for TPs  110  received from TPC  140 - 1  at stage  330 . The ID for each TP  110  may comprise a TP ID (e.g. an integer between 0 and 4095), a PRS ID (e.g. an integer between 0 and 4095) and/or a physical cell ID (e.g. an integer between 0 and 503). 
     In some embodiments, at stage  340 , after providing the OTDOA assistance data at stage  335 , E-SMLC  155  may further send an LPP (or LPP/LPPe) Request Location Information message to UE  120 . In some embodiments, the LPP Request Location Information message may be used to request OTDOA RSTD measurements from UE  120 . In some embodiments, the LPP Request Location Information message may include: information elements such as the type of location information desired; a desired accuracy for any location estimates/measurements; and/or a response time and/or the location determination method to be used. For example, the LPP Request Location Information message may specify that OTDOA is to be used by UE  120 . 
     In some embodiments, at stage  345 , UE  120  may measure PRS signals transmitted by TPs  110 - 1  and  110 - 2 , other TPs  110 , and/or other neighbor cells for other eN Bs  104  and obtain the RSTD measurements requested at stage  340  using the OTDOA assistance data received from E-SMLC  155  at stage  335 . Further, at stage  350 , UE  120  may, within the specified response time, send the UE determined RSTD measurements in an LPP (or LPP/LPPe) Provide Location Information message to E-SMLC  155 . The LPP Provide Location Information message may include information elements such as one or more of: (i) RSTD measurements for TPs  110  (e.g. TPs  110 - 1  and  110 - 2 ) and other neighbor cells obtained at stage  345 ; (ii) the identities of the TPs  110  for which RSTD measurements are provided; (iii) the identities of other neighbor cells measured by UE  110 ; (iv) quality metrics associated with the RSTD measurements provided; (v) an identity of the reference cell (or reference TP  110 ) used for the RSTD measurements; (vi) a quality metric related to the TOA measurements from the reference cell; and/or (vii) a neighbor cell measurement list including information (e.g. RSTD measurements and TP  110  and/or cell identities as already mentioned) for measured neighbor cells. 
     Based on the measurements received from UE  120  at stage  350  in the LPP Provide Location Information message and on other information (e.g. previously configured locations of eNB  104  antennas and/or information for TP  110 - 1  and TP  110 - 2 , such as PRS configuration parameters and locations of antennas, received at stage  330 ), E-SMLC  155  may determine a location of UE  120  at stage  355 . The location determination at stage  355  may be based on the OTDOA position method. For example, E-SMLC may determine a geodetic location of UE  120  that may comprise coordinates (e.g. latitude, longitude, and possibly altitude) and optionally an expected error or uncertainty for the location. 
     In some embodiments, at stage  360 , E-SMLC  155  may return the location information to MME  115 , which may relay the location information to External Client  165  (e.g. through GMLC  145 ) at stage  365 . 
       FIG. 4  shows a flowchart of an exemplary method  400  of locating a user equipment (e.g. UE  120  in system  100 ) by a Transmission Point Controller (e.g. TPC  140  in system  100 ). In some embodiments, method  400  may be performed by a TPC  140  (e.g. TPC  140 - 1  or TPC  140 - 2  in system  100 ), an eNB/TPC  140  or an HeNB/TPC  140 . 
     At block  410 , the TPC (e.g. TPC  140 ) exchanges first signaling information with at least one Positioning Reference Signal Transmission Point (PRS TP) (e.g. TP  110 ), where the at least one PRS TP broadcasts a downlink (DL) positioning reference signal (PRS) to the UE (e.g. UE  120 ), where the at least one PRS TP is controlled by the TPC and where the broadcasting is based at least in part on the first signaling information. The at least one PRS TP also refrains from broadcasting information to the UE indicating support for uplink signals from the UE. In some embodiments, the TPC (e.g. TPC  140 ) may send information to the at least one PRS TP to configure the at least one PRS TP (e.g. TP  110 ) to refrain from broadcasting information to the UE (e.g. UE  120 ) indicating support for uplink signals from the UE, wherein the information sent to the at least one PRS TP forms part of the first signaling information. In some embodiments, the at least one PRS TP (e.g. TP  110 ) may refrain from broadcasting information to the UE (e.g. UE  120 ) indicating support for uplink signals from the UE based on information received from the TPC (e.g. TPC  140 ), wherein the information received from the TPC forms part of the first signaling information. 
     In an embodiment, the at least one PRS TP may be an external PRS TP  110  (e.g. any of TPs  110 - 1  to  110 - 7 ). In an embodiment, block  410  may correspond to stage  310  in signaling flow  300 . The DL PRS may be a PRS for the 3GPP OTDOA position method for LTE access by the UE (e.g. as described in relation to  FIGS. 2A and 2B ). 
     At block  420 , the TPC (e.g. TPC  140 ) exchanges second signaling information with a location server, where the second signaling information comprises at least a portion of the first signaling information. In an embodiment, the location server may be an E-SMLC (e.g. E-SMLC  155  in system  100 ) or a SUPL SLP. In an embodiment, block  420  may correspond to stage  325  and/or stage  330  in signaling flow  300 . 
     In an embodiment, the first signaling information comprises an accurate common time reference and the TPC (e.g. TPC  140 ) sends the first signaling information to the at least one PRS TP (e.g. TP  110 ) at block  410 . The accurate common time reference may be a time reference for the Global Positioning System (GPS), Coordinated Universal Time (UTC) or a Global Navigation Satellite System (GNSS) and the TPC may determine the accurate common time reference using a GPS receiver or a GNSS receiver. The TPC (e.g. TPC  140 ) may send (or transfer) the accurate common time reference to the at least one PRS TP (e.g. TP  110 ) using the Internet Network Time Protocol (NTP), IEEE 1588 Precision Time Protocol (PTP) and/or Synchronous Ethernet. The at least one PRS TP may use the accurate common time reference to synchronize DL PRS transmission to the common time (e.g. in order to support an SFN-synchronous network or SFN-asynchronous network). 
     In an embodiment, the first signaling information exchanged at block  410  and the second signaling information exchanged at block  420  may each comprise one or more of: PRS configuration parameters for the at least one PRS TP (e.g. PRS bandwidth, PRS coding, PRS periodicity, number of subframes per PRS positioning occasion, PRS muting); an identity for the at least one PRS TP (e.g. a TP ID, PRS ID and/or PCI); a location for the at least one PRS TP (e.g. the location of an antenna for the at least one PRS TP); or some combination of the above information. 
     In an embodiment, the TPC (e.g. TPC  140 ) may receive third signaling information from an Operations and Maintenance (O&amp;M) server (e.g. O&amp;M server  195 ), where the first signaling information comprises at least part of the third signaling information and is sent by the TPC to the at least one PRS TP (e.g. TP  110 ) at block  410 . For example, the third signaling information may comprise PRS configuration parameters for the at least one PRS TP, an identity for the at least one PRS TP (e.g. a TP ID, PRS ID and/or PCI), and/or a location for the at least one PRS TP. 
     In an embodiment, the TPC (e.g. TPC  140 ) is connected to the at least one PRS TP (e.g. TP  110 ) using a local area network (LAN) or a wireless LAN (WLAN). 
     In an embodiment, the DL PRS that is broadcast by the at least one PRS TP (e.g. TP  110 ) is for the 3rd Generation Partnership Project (3GPP) Long Term Evolution radio access type and may support OTDOA positioning. In this embodiment: (i) the second signaling information may be exchanged using the 3GPP LTE Positioning Protocol A (LPPa); (ii) the location server may be an E-SMLC (e.g. E-SMLC  155  in system  100 ); (iii) the TPC (e.g. TPC  140 ) may include functionality for a 3GPP eNB or 3GPP HeNB; and/or (iv) the TPC may be connected to an MME (e.g. MME  115  in system  100 ) using a 3GPP S1 interface or a subset of a 3GPP S1 interface. In the case that the second signaling information is exchanged using LPPa, the TPC (e.g. TPC  140 ) may receive an LPPa OTDOA Information Request message from the location server (e.g. E-SMLC  155 ) requesting OTDOA related information for TPs (e.g. internal and/or external TPs  110 ) controlled by the TPC as in stage  325  of signaling flow  300 , and the TPC may return an LPPa OTDOA Information Response message to the location server as in stage  330  of signaling flow  300  that includes information for the at least one PRS TP controlled by the TPC such as PRS configuration parameters, a TP ID and/or a TP location. 
       FIG. 5  shows a flowchart of an exemplary method  500  of locating a user equipment (e.g. UE  120  in system  100 ) by a Transmission Point (e.g. TP  110 ). In some embodiments, method  500  may be performed by an external TP  110  and/or by a PRS TP  110  (e.g. any of TPs  110 - 1  to  110 - 7  in system  100 ). 
     At block  510 , the TP (e.g. TP  110 ) exchanges signaling information with a Transmission Point Controller (e.g. TPC  140 - 1  or TPC  140 - 2  in system  100 ). In some embodiments, block  510  may correspond to stage  310  in signaling flow  300 . 
     At block  520 , the TP (e.g. TP  110 ) broadcasts (or transmits) a downlink (DL) positioning reference signal (PRS) to the UE (e.g. UE  120 ), where the broadcasting is based at least in part on the signaling information exchanged at block  510 . 
     In some embodiments, at block  530 , the TP may refrain from broadcasting (or transmitting) information to the UE indicating support for uplink signals from the UE (e.g. UE  120 ). In some embodiments, at block  530 , the TP (e.g. TP  110 ) may be configured (e.g. by TPC  140  and/or TP  110 ) to indicate that the TP does not support uplink signals from the UE (e.g. UE  120 ). In some embodiments, the TP (e.g. TP  110 ) may indicate a lack of support for uplink signals from the UE (e.g. UE  120 ) by refraining from broadcasting information to the UE indicating support for uplink signals from the UE. For example, the TP may refrain from broadcasting an LTE MIB, SIB1, and/or SIB2 message to the UE. In some embodiments, the TP (e.g. TP  110 ) may refrain from broadcasting information to the UE (e.g. UE  120 ) indicating support for uplink signals from the UE based on information received from the TPC (e.g. TPC  140 ), wherein the information received from the TPC forms part of the signaling information. In some embodiments, the TP (e.g. TP  110 ) may send information to the TPC indicating that the TP refrains from broadcasting information to the UE indicating support for uplink signals from the UE, wherein the information sent to the TPC forms part of the signaling information. 
     In an embodiment, the signaling information may comprise an accurate common time reference and is received by the TP (e.g. TP  110 ) from the TPC (e.g. TPC  140 ). The TP (e.g. TP  110 ) may receive the accurate common time reference from the TPC (e.g. TPC  140 ) using the Internet Network Time Protocol (NTP), IEEE 1588 Precision Time Protocol (PTP) and/or Synchronous Ethernet. The TP (e.g. TP  110 ) may use the accurate common time reference to synchronize the DL PRS broadcast at block  520  to the common time reference (e.g. in order to support an SFN-synchronous network or SFN-asynchronous network). The accurate common time reference may be a time reference for the Global Positioning System (GPS), Coordinated Universal Time (UTC) or a Global Navigation Satellite System (GNSS) and may have been obtained by the TPC (e.g. TPC  140 ) using a GPS receiver or a GNSS receiver. The TP (e.g. TP  110 ) may synchronize the broadcast of the DL PRS to the accurate common time reference. For example, the TP may align the transmission of the start of each new LTE radio frame with a 10 ms time boundary for the common time reference and/or may align the transmission of a PRS positioning occasion to an interval of time, according to the common time reference, during which other TPs (e.g. other TPs  110 ) that are synchronized to the common time reference are also broadcasting a PRS positioning occasion. 
     In an embodiment, the signaling information in block  510  may comprise one or more of: PRS configuration parameters for the TP (e.g. PRS bandwidth, PRS coding, PRS periodicity, number of subframes per PRS positioning occasion, PRS muting, PRS frequency hopping); an identity for the TP (e.g. a TP ID, PRS ID and/or PCI); a location for the TP (e.g. the location of an antenna for the TP); or some combination of the above information. In this embodiment, the TP (e.g. TP  110 ) may receive the signaling information from the TPC (e.g. TPC  140 ) at block  510  and the TPC may receive the signaling information from an Operations and Maintenance (O&amp;M) server (e.g. O&amp;M server  195  in system  100 ). Alternatively in this embodiment, the TP (e.g. TP  110 ) may be pre-configured with the signaling information and may send the signaling information to the TPC (e.g. TPC  140 ) at block  510 . 
     In an embodiment, the TP is connected to the TPC using a local area network (LAN) or a wireless LAN (WLAN). 
     In an embodiment, the DL PRS broadcast at block  520  is for the 3GPP LTE radio access type and may enable measurement of an OTDOA RSTD by the UE between the DL PRS broadcast at block  520  by the TP and a DL PRS broadcast by some other TP  110  or eNB  104 . In this embodiment, the TPC may include functionality for a 3GPP eNB or HeNB. 
       FIG. 6A  shows a flowchart of an exemplary method  600  of locating a user equipment (e.g. UE  120  in system  100 ) by a location server (e.g. an E-SMLC or a SUPL SLP). In some embodiments, method  600  may be performed by E-SMLC  155  in system  100 . 
     In some embodiments, at block  610 , the location server exchanges first signaling information with a Transmission Point Controller (TPC) (e.g. TPC  140 - 1  or TPC  140 - 2  in system  100 ) controlling at least one Positioning Reference Signal Transmission Point (PRS TP), where the at least one PRS TP broadcasts a downlink (DL) positioning reference signal (PRS) to the UE, and where the broadcasting is based at least in part on the first signaling information. The at least one PRS TP may refrain from broadcasting information to the UE (e.g. a MIB, SIB1 or SIB2) indicating support by the at least one PRS TP for uplink signals from the UE. The at least one PRS TP may correspond to an external TP  110  in system  100  (e.g. any of TPs  110 - 1  to  110 - 7 ). In an embodiment, block  610  may correspond to stages  325  and  330  in signaling flow  300 . 
     At block  620 , the location server (e.g. an E-SMLC or a SUPL SLP) sends or initiates transmission of second signaling information to the UE (e.g. UE  120 ), where the second signaling information includes at least part of the first signaling information. In an embodiment, block  620  may correspond to stage  335  in signaling flow  300 . 
     At block  630 , the location server (e.g. an E-SMLC or a SUPL SLP) may receive third signaling information from the UE (e.g. UE  120 ), where the third signaling information is based on the second signaling information. In an embodiment, block  630  may correspond to stage  350  in signaling flow  300 . 
     At block  640 , the location server (e.g. an E-SMLC or a SUPL SIP) may determine a location for the UE (e.g. UE  120 ) based at least in part on the first signaling information and the third signaling information. In an embodiment, block  640  may correspond to stage  355  in signaling flow  300 . 
     In an embodiment, the first signaling information exchanged at block  610  may comprise one or more of: PRS configuration parameters for the at least one PRS TP (e.g. PRS bandwidth, PRS coding, PRS periodicity, number of subframes per PRS positioning occasion, PRS muting, PRS frequency hopping); an identity for the at least one PRS TP (e.g. a TP ID, PRS ID and/or a PCI); a location for the at least one PRS TP (e.g. a location of an antenna for the at least one PRS TP); or some combination of the above information. In this embodiment, the first signaling information may be received by the location server from the TPC (e.g. TPC  140 ) at block  610 —e.g. following a request sent by the location server to the TPC at block  610  requesting information for TPs (e.g. TPs  110  and/or PRS TPs  110 ) controlled by the TPC. 
     In an embodiment, the TPC, with which the first signaling information is exchanged at block  610 , is connected to the at least one PRS TP using a local area network (LAN) or a wireless LAN (WLAN). 
     In an embodiment, the DL PRS broadcast by the at least one PRS TP is for the 3GPP LTE radio access type. In this embodiment, the first signaling information may be exchanged using the 3GPP LTE Positioning Protocol A (LPPa). For example the location server may send an LPPa OTDOA Information Request message to the TPC to request OTDOA related information for TPs (e.g. internal and/or external TPs  110  and/or PRS TPs  110 ) controlled by the TPC as at stage  325  of signaling flow  300 , and the TPC may return an LPPa OTDOA Information Response message to the location server as at stage  330  of signaling flow  300  that includes information for the least one PRS TP controlled by the TPC such as PRS configuration parameters, a TP ID and/or a TP location. In this embodiment, the TPC may include functionality for a 3GPP eNB or a 3GPP HeNB (e.g. the TPC may be an eNB/TPC  110  or HeNB/TPC  110  in system  100 ). In this embodiment, the second signaling information may be sent at block  620  and the third signaling information may be received at block  630  using the 3GPP LPP protocol or using LPP/LPPe. 
     When the second signaling information is sent at block  620  and the third signaling information is received at block  630  using LPP or LPP/LPPe, the second signaling information may comprise an LPP Provide Assistance Data message (e.g. as at stage  335  in signaling flow  300 ), and the third signaling information may comprise an LPP Provide Location Information message (e.g. as at stage  350  in signaling flow  300 ). The location server may further determine the location for the UE at block  640  based at least in part on the 3GPP OTDOA position method. 
       FIG. 6B  shows a flowchart of an exemplary method  650  of locating a user equipment (e.g. UE  120  in system  100 ) by a location server (e.g. an E-SMLC or a SUPL SLP). In some embodiments, method  650  may be performed by E-SMLC  155  in system  100 . 
     In some embodiments, at block  660 , the location server exchanges first signaling information with a Transmission Point Controller (TPC) (e.g. TPC  140 - 1  or TPC  140 - 2  in system  100 ) controlling at least one Positioning Reference Signal Transmission Point (PRS TP), wherein the first signaling information comprises information defining aspects of downlink (DL) PRS broadcasting by the PRS TP. The at least one PRS TP may refrain from broadcasting information to the UE (e.g. a MIB, SIB  1  or SIB2) indicating support by the at least one PRS TP for uplink signals from the UE. The at least one PRS TP may correspond to an external TP  110  in system  100  (e.g. any of TPs  110 - 1  to  110 - 7 ). In an embodiment, block  660  may correspond to stages  325  and  330  in signaling flow  300 . 
     At block  670 , the location server (e.g. an E-SMLC or a SUPL SLP) sends or initiates transmission of second signaling information to the UE (e.g. UE  120 ), where the second signaling information includes at least part of the first signaling information. In an embodiment, block  670  may correspond to stage  335  in signaling flow  300 . 
     At block  680 , the location server (e.g. an E-SMLC or a SUPL SLP) may receive third signaling information from the UE (e.g. UE  120 ), where the third signaling information is based on the second signaling information. In an embodiment, block  680  may correspond to stage  350  in signaling flow  300 . 
     At block  690 , the location server (e.g. an E-SMLC or a SUPL SIP) may determine a location for the UE (e.g. UE  120 ) based at least in part on the first signaling information and the third signaling information. In an embodiment, block  690  may correspond to stage  355  in signaling flow  300 . 
     In an embodiment, the first signaling information exchanged at block  660  may comprise one or more of: PRS configuration parameters for the at least one PRS TP (e.g. PRS bandwidth, PRS coding, PRS periodicity, number of subframes per PRS positioning occasion, PRS muting, PRS frequency hopping); an identity for the at least one PRS TP (e.g. a TP ID, PRS ID and/or a PCI); a location for the at least one PRS TP (e.g. a location of an antenna for the at least one PRS TP); or some combination of the above information. In this embodiment, the first signaling information may be received by the location server from the TPC (e.g. TPC  140 ) at block  660 —e.g. following a request sent by the location server to the TPC at block  660  requesting information for TPs (e.g. TPs  110  and/or PRS TPs  110 ) controlled by the TPC. 
     In an embodiment, the TPC, with which the first signaling information is exchanged at block  660 , is connected to the at least one PRS TP using a local area network (LAN) or a wireless LAN (WLAN). 
     In an embodiment, the DL PRS broadcast by the at least one PRS TP is for the 3GPP LTE radio access type. In this embodiment, the first signaling information may be exchanged using the 3GPP LTE Positioning Protocol A (LPPa). For example the location server may send an LPPa OTDOA Information Request message to the TPC to request OTDOA related information for TPs (e.g. internal and/or external TPs  110  and/or PRS TPs  110 ) controlled by the TPC as at stage  325  of signaling flow  300 , and the TPC may return an LPPa OTDOA Information Response message to the location server as at stage  330  of signaling flow  300  that includes information for the least one PRS TP controlled by the TPC such as PRS configuration parameters, a TP ID and/or a TP location. In this embodiment, the TPC may include functionality for a 3GPP eNB or a 3GPP HeNB (e.g the TPC may be an eNB/TPC  110  or HeNB/TPC  110  in system  100 ). In this embodiment, the second signaling information may be sent at block  670  and the third signaling information may be received at block  680  using the 3GPP LPP protocol or using LPP/LPPe. 
     When the second signaling information is sent at block  670  and the third signaling information is received at block  680  using LPP or LPP/LPPe, the second signaling information may comprise an LPP Provide Assistance Data message (e.g. as at stage  335  in signaling flow  300 ), and the third signaling information may comprise an LPP Provide Location Information message (e.g. as at stage  350  in signaling flow  300 ). The location server may further determine the location for the UE at block  690  based at least in part on the 3GPP OTDOA position method. 
     The embodiments and examples of the method and techniques so far described (e.g. in relation to  FIGS. 1-6B  above) have generally assumed that positioning is used for a UE  120  with LTE wireless access to some EPS serving network (e.g. to an eNB  104  and MME  115  in an EPS). However, the method and techniques may be applicable to other types of wireless access by a UE  120  such as using LTE Advanced (LTE-A) or the New Radio (NR) and Fifth Generation (5G) wireless access types being developed by 3GPP. Thus, for example, the method and techniques may be applicable to position methods similar to or the same as OTDOA, where time difference measurements similar to or the same as RSTDs, or other measurements, are obtained by a UE  120  based on downlink signals received and measured from TPs  110 . The TPs  110  may be controlled by a TPC  140  and the downlink signals may conform to a different radio access type such as LTE-A, NR, or 5G. In addition, the method and techniques may be applicable to other downlink position methods, such as Enhanced Cell ID (ECID), in which a UE  120  obtains measurements of downlink signals transmitted by TPsl  10  controlled by a TPC  140 . 
       FIG. 7  shows a schematic block diagram illustrating certain exemplary features of a TPC  140  such as TPC  140 - 1  or TPC  140 - 2  in system  100 . The TPC  140  may support the methods and techniques described herein with respect to  FIGS. 1-6B . The TPC  140  may further be an eNB/TPC, HeNB/TPC or a TPC  140  that does not include eNB or HeNB functionality. 
     In some embodiments, TPC  140  may, for example, include one or more processor(s)  702 , memory  704 , a transceiver  710  (e.g., a wireless and/or wireline network interface), and (as applicable) an SPS receiver  740 , which may be operatively coupled with one or more connections  706  (e.g. buses, lines, fibers, links, etc.) to a non-transitory computer-readable medium  720  and memory  704 . The SPS receiver  740  may comprise a GPS receiver or GNSS receiver, and may be enabled to receive signals associated with one or more SPS resources such as one or more Earth orbiting Space Vehicles (SVs)  180 , which may be part of a satellite positioning system (SPS) such as a GNSS. SVs  180 , for example, may be in a constellation of a Global Navigation Satellite System (GNSS) such as the US Global Positioning System (GPS), the European Galileo system, the Russian GLONASS system, or the Chinese BeiDou system. In accordance with certain aspects, the techniques presented herein are not restricted to global systems (e.g., GNSS) for SPS. For example, the techniques provided herein may be applied to or otherwise enabled for use in various regional systems, such as, e.g., Quasi-Zenith Satellite System (QZSS) over Japan, Indian Regional Navigational Satellite System (IRNSS) over India, and/or various augmentation systems (e.g., an Satellite Based Augmentation System (SBAS)) that may be associated with or otherwise enabled for use with one or more global and/or regional navigation satellite systems. 
     By way of example but not limitation, an SBAS may include an augmentation system(s) that provides integrity information, differential corrections, etc., such as, e.g., Wide Area Augmentation System (WAAS), European Geostationary Navigation Overlay Service (EGNOS), Multi-functional Satellite Augmentation System (MSAS), GPS Aided Geo Augmented Navigation or GPS and Geo Augmented Navigation system (GAGAN), and/or the like. Thus, as used herein an SPS may include any combination of one or more global and/or regional navigation satellite systems and/or augmentation systems, and SPS signals may include SPS, SPS-like, and/or other signals associated with such one or more SPS. In some embodiments, SPS receiver  740  may receive GPS or other GNSS Clock and correction information to facilitate synchronization with other TPCs  140 . For example, SPS receiver  740  may enable TPC  140  to determine an accurate common time reference (e.g. for GPS, GNSS or UTC time) which may be transferred to one or more TPs  110  controlled by TPC  140 . For example, clock synchronization and timing information may be provided to TPs  110  by TPC  140  for PRS transmission. 
     Transceiver  710  may, for example, include a transmitter  712  enabled to transmit one or more signals over one or more types of wireless and/or wireline communication networks and communication links, and a receiver  714  to receive one or more signals transmitted over the one or more types of wireless and/or wireline communication networks and communication links. For example, transceiver  710  may transmit and receive LTE signals to/from UEs  120 . Further, transceiver  710  may transmit and receive signals to one or more TPs  110  via a WLAN or LAN. In addition, transceiver  710  may transmit and receive signals to and from an MME  115  (e.g. via a 3GPP S1 interface) and/or to an E-SMLC  155 . Transceiver  710  may be coupled to a communications interface  745  which may format and encode messages and signals (e.g. LPPa messages) transmitted by transceiver  710  and decode and interpret messages and signals (e.g. LPPa messages) received by transceiver  710 . 
     Processor(s)  702  may be implemented using a combination of hardware, firmware, and software. In some embodiments, processor(s)  702  may include OTDOA Assistance Data component  716 , which may process LPPa or other requests for OTDOA assistance information related to PRS configuration of TPs  110  configured by TPC  140  and/or location information of TPs  110  coupled to TPC  140 . In some embodiments, processor(s)  702  may include TP control/PRS configuration component  718 , which may exchange signaling with TPs  110  controlled by TPC  110  in order to configure or retrieve information (e.g. PRS configuration parameters) in or from TPs  110  and/or provide an accurate common time reference to TPs  110 . In some embodiments, processor(s)  702  and/or OTDOA Assistance Data component  716  may perform some or all of method  400  and portions of signaling flow  300 . In some embodiments, processor(s)  702 /OTDOA Assistance Data component  716  may store and provide current PRS configuration information for TPs  110  coupled to TPC  140  (e.g. using the LPPa protocol). 
     When TPC  140  serves as an eNB or HeNB (i.e. is an eNB/TPC  140  or HeNB/TPC  140 ), processor(s)  702  may provide appropriate eNB or HeNB functionality. When TPC  140  serves as a TPC, processor(s)  702  and/or TP control/PRS configuration component  718  may provide appropriate functionality to configure TPs  110  with PRS transmission information, control TPs  110 , and/or monitor TP  110  performance. In some embodiments. TPC  140  may serve as both an eNB or HeNB and a TPC. In some embodiments, TPC  140  may be able to communicate with E-SMLC  155  and/or MME  115  using LPPa messages. In some embodiments, when serving as an eNB or HeNB, TPC  140  may also relay LPP messages between UE  120  and E-SMLC  155 . 
     In some embodiments, TPC  140  and/or one or more of: processor(s)  702 , OTDOA Assistance Data component  716 , or TP Control/PRS Configuration component  718  may facilitate location determination for a UE  120  as outlined further below. In some embodiments, a first signaling information may be exchanged with a PRS TP  110  controlled by TPC  140  (e.g. using transceiver  710  or communications interface  745 ), wherein the PRS TP  110  broadcasts a downlink (DL) positioning reference signal (PRS) to UE  120 , and where the broadcasting of the DL PRS signal is based on the first signaling information. As outlined previously, PRS TP  110  refrains from broadcasting information to UE  120  indicating support for uplink signals from UE  120 . Exchanging the first signaling information may comprise sending the first signaling information to the PRS TP  110 , wherein the first signaling information comprises a common time reference. In some embodiments, the common time reference may be determined based on input from a GPS receiver or a GNSS receiver (e.g. SPS receiver  740 ) coupled to the TPC  140 , wherein the common time reference is a time reference for one of: the Global Positioning System (GPS), or a Coordinated Universal Time (UTC), or a Global Navigation Satellite System (GNSS). In some embodiments, the DL PRS may be for the 3GPP LTE radio access type. 
     Further, in some embodiments, a second signaling information may be exchanged by TPC  140  (e.g. using communications interface  745 ) with a location server, wherein the second signaling information comprises at least part of the first signaling information. In some embodiments, the first signaling information and the second signaling information may each comprise PRS configuration parameters for the PRS TP  110 , an identity of the PRS TP  110 , a location of the PRS TP  110 , or some combination thereof. In embodiments where the DL PRS may be for the 3GPP LTE radio access type, the second signaling information may be exchanged using the 3GPP LTE Positioning Protocol A (LPPa). 
     In some embodiments, TPC  140  may receive third signaling information from an Operations and Maintenance (O&amp;M) server communicatively coupled to the TPC; and when exchanging the first signaling information with the PRS TP  110  may send the first signaling information to the PRS TP  110 , where the first signaling information comprises a portion of the third signaling information. 
     In some embodiments, the TPC  140  may be communicatively coupled to the PRS TP  110  using a Local Area Network (LAN) or a Wireless LAN (WLAN). In embodiments where the DL PRS may be for the 3GPP LTE radio access type, the location server may be E-SMLC  155  or an SLP. When the DL PRS is for the 3GPP LTE radio access type, TPC  140  may include functionality for a 3GPP eNB or a 3GPP HeNB. Further, in some embodiments, TPC  140  may be communicatively coupled to an MME (e.g. MME  115 ) using a 3GPP S1 interface or a subset of a 3GPP S1 interface. 
     In some embodiments, TPC  140  may include one or more antennas  784 , which may be internal or external to TPC  140 . Antennas  784  may be used to transmit and/or receive signals processed by transceiver  710  and/or SPS receiver  740 . In some embodiments, antennas  784  may be coupled to transceiver  710  and SPS receiver  740 . 
     The methodologies described herein may be implemented by various means depending upon the application. For example, these methodologies may be implemented in hardware, firmware, software, or any combination thereof. For a hardware implementation, the processor(s)  702 , OTDOA Assistance Data component  716  and/or TP Control/PRS Configuration component  718  may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or a combination thereof. 
     For a firmware and/or software implementation, the methodologies may be implemented with microcode, procedures, functions, and so on that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software code may be stored in a non-transitory computer-readable medium  720  or memory  704  that is coupled to and executed by processor(s)  702 . Memory may be implemented within the processor unit or external to the processor unit. As used herein the term “memory” refers to any type of long term, short term, volatile, nonvolatile, or other memory and is not to be limited to any particular type of memory or number of memories, or type of media upon which memory is stored. 
     If implemented in firmware and/or software, the functions may also be stored as one or more instructions or program code  708  on a non-transitory computer-readable medium, such as medium  720  and/or memory  704 . Examples include computer-readable media encoded with a data structure and computer-readable media encoded with a computer program  708 . For example, the non-transitory computer-readable medium including program code  708  stored thereon may include program code  708  to: support provision of configuration information for TPs  110  (e.g. PRS parameters and location information) to other entities including E-SMLC  155 ; support LPPa; and/or support PRS configuration and control of TPs  110 , etc. 
     Non-transitory computer-readable media  720  includes physical computer storage media. A storage medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, such non-transitory computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code  708  in the form of instructions or data structures and that can be accessed by a computer; disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media. 
     Memory  704  may represent any data storage mechanism. Memory  704  may include, for example, a primary memory and/or a secondary memory. Primary memory may include, for example, a random access memory, read only memory, etc. While illustrated in this example as being separate from processor(s)  702 , it should be understood that all or part of a primary memory may be provided within or otherwise co-located/coupled with processor(s)  702 . Secondary memory may include, for example, the same or similar type of memory as primary memory and/or one or more data storage devices or systems, such as, for example, a disk drive, an optical disc drive, a tape drive, a solid state memory drive, etc. 
     In certain implementations, secondary memory may be operatively receptive of, or otherwise configurable to couple to a non-transitory computer-readable medium  720 . As such, in certain example implementations, the methods and/or apparatuses presented herein may take the form in whole or part of a computer-readable medium  720  that may include computer implementable instructions  708  stored thereon, which if executed by at least one processor(s)  702  may be operatively enabled to perform all or portions of the example operations as described herein. Computer readable medium  720  may be a part of memory  704 . 
     Reference is now made to  FIG. 8 , which is a schematic block diagram illustrating a TP  110  such as any of TPs  110 - 1  to  110 - 7  in system  100 . TP  110  may be configured to support any of the methods and techniques described herein in  FIGS. 1-6B . TP  110  may be an external TP  110  and/or a PRS TP  110 . 
     In some embodiments, TP  110  may communicate with a controlling TPC  140  over a Local Area Network (LAN) or Wireless LAN (WLAN) through a network interface, which may comprise transceiver  810  and/or communications interface  890 . TP  110  may act as positioning beacon and may transmit PRS (e.g. using transceiver  810 ) after being appropriately configured by a controlling TPC  140 , HeNB/TPC  140  or eNB/TPC  140 . 
     TP  110  may transmit a PRS, which may be measured and used for UE position determination. TP  110  may also be called a positioning beacon, eNB beacon, standalone or eNB beacon. In general, TP  110 , as used herein, refers to any entity in a RAN that transmits PRS to assist in positioning of one or more target UEs  120  (based on configuration by a TPC  140 ) and that may or may not support other functions such as providing wireless access (e.g. for voice and data connectivity) to one or more UEs  120 . Further, an eNB beacon and standalone eNB beacon may be particular examples of a positioning beacon. In some embodiments, TP  110  may provide additional LTE/PRS coverage for indoor locations. In some embodiments, TP  110  may act as a standalone beacon that can transmit a PRS signal to support positioning of UEs and may also transmit information needed to support UE acquisition and measurement of the PRS such as an LTE master information block (MIB) and one or more LTE system information blocks (SIBs) but may not transmit or receive data or control information to support normal LTE access by UEs (e.g., may not support wireless access by UEs  120  for the purpose of sending and receiving voice and data). 
     In some embodiments, TP  110  may include, for example, one or more processor(s)  802 , memory/storage  854 , communications interface  890  (e.g., a wireline and/or wireless network interface), which may be operatively coupled with one or more connections  856  (e.g., buses, lines, fibers, links, etc.). In certain example implementations, some portion of TP  110  may take the form of a chipset, and/or the like. 
     Communications interface  890  may include support for a variety of wired (or wireline) communication interfaces that support wired transmission and/or reception and, if desired, may additionally or alternatively support transmission and reception of one or more signals over one or more types of wireless communication networks such as LTE radio links, WLANs or microwave links. Communication over a WLAN with TPC  140  may be supported, in part, by transceiver  810 , which may comprise transmitter  812  and receiver  814 . 
     Communications interface  890  may also support communication with TPC  140  over wired networks. In some embodiments, communications interface  890  may receive clock or timing synchronization information from TPC  140 , such as an accurate common time reference (e.g. for GPS, GNSS or UTC time), for accurate (e.g. synchronized) transmission of PRS signals. In one embodiment, communications interface  890  may comprise network interface cards, input-output cards, chips and/or ASICs that implement one or more of the communication functions performed by TP  110 . 
     In some embodiments, communications interface  890  may interface with a TPC  140  to obtain a variety of network configuration related information, such as PRS configuration information and/or timing information used by TP  110 . Processor(s)  802  and/or PRS generation component  816  may use some or all of the received information to generate PRS signals, which may be transmitted using transceiver  810  and antennas  884  in a manner consistent with disclosed embodiments. 
     Processor(s)  802  may be implemented using a combination of hardware, firmware, and software. In some embodiments, processor(s)  802  may include PRS generation component  816  to generate PRS signals for transmission. In some embodiments, processor(s)  802  may represent one or more circuits configurable to perform at least a portion of a data signal computing procedure or process related to the configuration and generation of PRS signals by TP  110 . 
     In some embodiments, TP  110  and/or one or more of: processor(s)  802  or PRS generation component  816  may perform methods to facilitate location determination for a User Equipment (UE)  120  as outlined further below. In some embodiments, TP  110  may exchange a signaling information with a TPC  140 . Further, TP  110  may broadcast a downlink (DL) positioning reference signal (PRS) to the UE  120 , wherein the broadcast of the DL PRS may be based on the signaling information; and may refrain from broadcasting information to UE  120  indicating support for uplink signals from UE  120 . In some embodiments, the DL PRS may be for the 3GPP LTE radio access type. In embodiments where the DL PRS may be for the 3GPP LTE radio access type, the TPC  140  may include functionality for a 3GPP evolved NodeB (eNB) or a 3GPP Home eNB. 
     In some embodiments, the signaling information may comprise PRS configuration parameters for the TP  110 , an identity of the TP  110 , a location of the TP  110 , or a combination thereof. Further, exchanging the signaling information with the TPC  140  may comprise receiving the signaling information from the TPC  140 , wherein the received signaling information may comprise information obtained from an Operations and Maintenance (O&amp;M) server (e.g. O&amp;M  195 ). 
     In some embodiments, exchanging the signaling information with TPC  140  may comprise receiving the signaling information from TPC  140 , wherein the signaling information comprises a common time reference. The common time reference may be a time reference for one of: the Global Positioning System (GPS), or a Coordinated Universal Time (UTC), or a Global Navigation Satellite System (GNSS), and TP  110  may further synchronize the broadcast of the DL PRS to the common time reference. 
     In some embodiments, the TP  110  may be communicatively coupled to the TPC  140  using a local area network (LAN) or a wireless LAN (WLAN) (e.g. via transceiver  810  and/or communications interface  890 ). 
     The methodologies described herein in flow charts and message flows may be implemented by various means depending upon the application. For example, these methodologies may be implemented in hardware, firmware, software, or any combination thereof. For a hardware implementation, the processor(s)  802  and/or PRS generation component  816  may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or a combination thereof. 
     For a firmware and/or software implementation, the methodologies may be implemented with micro-code, procedures, functions, and so on that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software may be stored in memory storage  854 , which may support the use of non-transitory computer-readable media including removable media. Program code may be resident on non-transitory computer readable media and/or memory/storage  854  and may be read and executed by processor(s)  802 . 
     Memory may be implemented within processor(s)  802  or external to processor(s)  802 . As used herein the term “memory” refers to any type of long term, short term, volatile, nonvolatile, or other memory and is not to be limited to any particular type of memory or number of memories, or type of media upon which memory is stored. For example, memory/storage  854 , which may include non-transitory computer-readable media, may include program code to receive PRS configuration information and/or to generate PRS for transmission in a manner consistent with disclosed embodiments. In addition, TP  110  may receive wired, wireless, or network signals indicative of instructions and data. The instructions and data may be configured to cause processor(s)  802  to implement PRS configuration and/or PRS transmission. 
     Memory/storage  854  may represent any data storage mechanism. Memory/storage  854  may include, for example, a primary memory and/or a secondary memory. Primary memory may include, for example, a random access memory, read only memory, non-volatile RAM, etc. While illustrated in this example as being separate from processor(s)  802 , it should be understood that all or part of a primary memory may be provided within or otherwise co-locatedcoupled with processor(s)  802 . Secondary memory may include, for example, the same or similar type of memory as primary memory and/or storage such as hard disk drives, optical disc drives, tape drives, a solid state memory drive, etc. 
     In certain implementations, secondary memory may be operatively receptive of, or otherwise configurable to couple to a non-transitory computer-readable medium. As such, in certain example implementations, the methods and/or apparatuses presented herein may take the form in whole or part of a removable media drive that may include non-transitory computer readable medium with computer implementable instructions stored thereon, which if executed by at least one processor(s)  802  may be operatively enabled to perform all or portions of the example operations as described herein. 
     Reference is now made to  FIG. 9 , which is a schematic block diagram illustrating a location server (LS)  900 . Location server  900  may correspond to a SUPL SLP or to an E-SMLC such as E-SMLC  155  in system  100 . In some embodiments, location server  900  may perform some or all of the methods and techniques described herein associated with  FIGS. 1-6B . 
     In some embodiments, location server  900  may include, for example, one or more processor(s)  902 , memory  904 , storage  960 , and communications interface  990  (e.g., a wireline and/or wireless network interface) and computer-readable medium  920 , which may be operatively coupled with one or more connections  906  (e.g., buses, lines, fibers, links, etc.). In certain example implementations, some portion of location server  900  may take the form of a chipset, and/or the like. 
     Communications interface  990  may include a variety of wired and wireless connections that support wired transmission and/or reception and, if desired, may additionally or alternatively support transmission and reception of one or more signals over one or more types of wireless and/or wireline communication networks. Communications interface  990  may also include interfaces for communication with various other computers and peripherals. For example, in one embodiment, Communications interface  990  may comprise network interface cards, input-output cards, chips and/or ASICs that implement one or more of the communication functions performed by location server  900 . In some embodiments, communications interface  990  may also interface with cellular network entities to obtain or provide a variety of network configuration related information, such as information for TPs  110 , Location Requests for UEs  120 , OTDOA assistance information for UEs  120 . The information may be obtained from and/or sent to UEs  120 , TPCs  140  and/or other network entities. 
     Communications interface  990  may make use of the LPPa protocol defined in 3GPP TS 36.455 or a modification of this protocol to obtain (or provide) PRS configuration information, timing and/or other information from (or to) a TPC  140 . The information may also be sent to a UE  120  using the LPP or LPP/LPPe protocol. Processor(s)  902  may request and receive PRS configuration information for TPs  110  and location information for TPs  110  using LPPa from a TPC  140 . Further, processor(s)  902  may use some or all of the information (e.g.) to generate OTDOA assistance data for UEs  120 , which may be transmitted using LPP or LPP/LPPe in a manner consistent with disclosed embodiments. 
     Processor(s)  902  may be implemented using a combination of hardware, firmware, and software. In some embodiments, processor(s)  902  may generate OTDOA assistance information for UEs  120 , compute the location of a UE  120  based on OTDOA RSTD measurements obtained and provided by UE  120 , etc. In some embodiments, processor(s)  902  may generate the OTDOA assistance information as Long Term Evolution (LTE) Positioning Protocol (LPP) or LPP extensions (LPPe) messages. In some embodiments, processor(s)  902  may represent one or more circuits configurable to perform at least a portion of a data signal computing procedure or process related to the operation of location server  900 . 
     In some embodiments, LS  900  and/or one or more of: processor  902 , OTDOA Assistance Data component  916 , or Location Determination component  918  may determine a location of a UE  120  as outlined further below. For example, LS  900  and/or processor  902  may exchange a first signaling information with a TPC  140  (e.g. using communications interface  990 ), where the TPC may control at least one PRS TP, where the PRS TP broadcasts a downlink (DL) Positioning Reference Signal (PRS), based at least in part on the first signaling information, to the UE  120 . As outlined previously, PRS TPs may refrain from broadcasting information to UE  120  indicating support for uplink signals from UE  120 . In some embodiments, the first signaling information may comprise PRS configuration parameters for the at least one PRS TP, an identity of the at least one PRS TP, a location of the at least one PRS TP, or some combination thereof. In some embodiments, exchanging a first signaling information with a Transmission Point Controller (TPC)  140  may comprise receiving the first signaling information from the TPC  140 . In some embodiments, the DL PRS may be for the 3GPP LTE radio access type. Further, in some embodiments, the first signaling information may be exchanged using the 3GPP LTE Positioning Protocol A (LPPa). Further, in embodiments where the DL PRS may be for the 3GPP LTE radio access type, the TPC  140  may include functionality for a 3GPP evolved NodeB (eNB) or a 3GPP Home eNB. 
     Further, in some embodiments, LS  900  and/or processor  902  may send a second signaling information to UE  120  (e.g. using communications interface  990 ), where the second signaling information may comprise a portion of the first signaling information. Further, LS  900  and/or processor  902  may receive a third signaling information from the UE (e.g. using communications interface  990 ), where the third signaling information may be based on the second signaling information. In embodiments where the DL PRS may be for the 3GPP LTE radio access type, the second signaling information may be sent and the third signaling information may be received using the 3GPP LTE Positioning Protocol (LPP). For example, the second signaling information may comprise an LPP Provide Assistance Data message, and the third signaling information may comprise an LPP Provide Location Information message. 
     A location of UE  120  may then be determined by the LS  900  (e.g. by processor(s)  902  or location determination component  918 ) based on the first signaling information and the third signaling information. In embodiments where the DL PRS may be for the 3GPP LTE radio access type, the second signaling information may comprise an LPP Provide Assistance Data message, the third signaling information may comprise an LPP Provide Location Information message, and/or the location of the UE may be determined based on the 3GPP observed time difference of arrival (OTDOA) position method. 
     The methodologies described herein in flow charts and message flows may be implemented by various means depending upon the application. For example, these methodologies may be implemented in hardware, firmware, software, or any combination thereof. For a hardware implementation, the processor(s)  902  may be implemented within one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, micro-controllers, microprocessors, electronic devices, other electronic units designed to perform the functions described herein, or a combination thereof. 
     For a firmware and/or software implementation, the methodologies may be implemented with microcode, procedures, functions, and so on that perform the functions described herein. Any machine-readable medium tangibly embodying instructions may be used in implementing the methodologies described herein. For example, software may be stored in storage  960  and/or on removable media drive  970 , which may support the use of non-transitory computer-readable media. Program code  908  may be resident on non-transitory computer readable media  920  or memory  904  and may be read and executed by processor(s)  902 . Memory may be implemented within processor(s)  902  or external to processor(s)  902 . As used herein the term “memory” refers to any type of long term, short term, volatile, nonvolatile, or other memory and is not to be limited to any particular type of memory or number of memories, or type of media upon which memory is stored. 
     If implemented in firmware and/or software, the functions may be stored as one or more instructions or code  908  on a non-transitory computer-readable medium  920  and/or memory  904 . Examples include computer-readable media encoded with a data structure and computer-readable media encoded with a computer program. For example, non-transitory computer-readable medium  920  including program code  908  stored thereon may include program code to support LPPa, LPP, PRS configuration information processing, generation of OTDOA assistance information, location determination based on RSTD measurements, and interfacing with one or more network entities in a manner consistent with disclosed embodiments. 
     Non-transitory computer-readable media  920  includes a variety of physical computer storage media. A storage medium may be any available medium that can be accessed by a computer. By way of example, and not limitation, such non-transitory computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store desired program code in the form of instructions or data structures and that can be accessed by a computer, disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Other embodiments of non-transitory computer readable media include flash drives, USB drives, solid state drives, memory cards, etc. Combinations of the above should also be included within the scope of computer-readable media. 
     Memory  904  may represent any data storage mechanism. Memory  904  may include, for example, a primary memory and/or a secondary memory. Primary memory may include, for example, a random access memory, read only memory, non-volatile RAM, etc. While illustrated in this example as being separate from processor(s)  902 , it should be understood that all or part of a primary memory may be provided within or otherwise co-located/coupled with processor(s)  902 . Secondary memory may include, for example, the same or similar type of memory as primary memory and/or storage  960  such as hard disk drives, optical disc drives, tape drives, a solid state memory drive, etc. In some embodiments, storage  960  may comprise one or more databases that may hold information pertaining to various entities in system  100  (e.g. eNB  104 , TPCs  140 , TPs  110 ) and/or the broader cellular network. In some embodiments, information in the databases may be read, used, and/or updated by processor(s)  902  during various computations, including storing capabilities of UE  120 , capabilities of location server  900 , generating OTDOA assistance data, computing a location of UE  120 , etc. 
     In certain implementations, secondary memory may be operatively receptive of, or otherwise configurable to couple to a non-transitory computer-readable medium  920 . As such, in certain example implementations, the methods and/or apparatuses presented herein may take the form in whole or part of a removable media drive  970  that may include non-transitory computer readable medium with computer implementable instructions stored thereon, which if executed by at least one processor(s)  902  may be operatively enabled to perform all or portions of the example operations as described herein. Computer readable medium  920  may also be a part of memory  904 . 
     Although the present disclosure is described in connection with specific embodiments for instructional purposes, the disclosure is not limited thereto. Various adaptations and modifications may be made to the disclosure without departing from the scope. Therefore, the spirit and scope of the appended claims should not be limited to the foregoing description.