WO2011124941A1

WO2011124941A1 - Wireless device assisted self-positioning

Info

Publication number: WO2011124941A1
Application number: PCT/IB2010/000785
Authority: WO
Inventors: Gilles Charbit; Tao Chen
Original assignee: Nokia Corporation; Nokia, Inc.
Priority date: 2010-04-09
Filing date: 2010-04-09
Publication date: 2011-10-13

Abstract

A method for wireless device assisted self-positioning is described. The method includes receiving location information from a first network node. The received location information describes a location of the first network node. Determining a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node is also included in the method. The method also includes storing the currently determined location. The first network node is a different network node from the second network node. The method may also include determining a location of another network node based at least in part on the currently determined location. Apparatus and computer readable media are also described.

Description

WIRELESS DEVICE ASSISTED SELF-POSITIONING

TECHNICAL FIELD:

The exemplary and non-limiting embodiments of this invention relate generally to wireless communication systems, methods, devices and computer programs and, more specifically, relate to wireless device assisted self-positioning.

BACKGROUND:

This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.

The following abbreviations that maybe found in the specification and/or the drawing figures are defined as follows:

3 GPP third generation partnership project

AP access point

CDM code division multiplexing

CRS cell-specific reference signal

DL downlink (eNB towards UE)

DwPTS downlink pilot time slot

eNB E-UTRAN Node B (evolved Node B)

EPC evolved packet core

E-SMLC enhanced serving mobile location center

E-UTRAN evolved UTRAN (LTE)

FDD frequency division duplex (or frequency domain duplexing)

GPS global positioning system

GW gateway

HARQ hybrid automatic repeat request

HeNB home eNB

LTE long term evolution of UTRAN (E-UTRAN) LPP LTE positioning protocol

M2M machine-to-machine

MAC medium access control (layer 2, L2)

MM/MME mobility management/mobility management entity

MTC machine type communications

Node B base station

O&M operations and maintenance

OFDMA orthogonal frequency division multiple access

OTD observed time difference

OTDOA observed time difference of arrival

PDCP packet data convergence protocol

PHY physical (layer 1 , L 1 )

PRS positioning reference signal

P-SCH primary synchronization channels

RLC radio link control

RRC radio resource control

RRM radio resource management

RSTD reference signal time difference

SC-FDMA single carrier, frequency division multiple access

S-GW serving gateway

SRS sounding reference signal

S-SCH secondary synchronization channels

TDD time division duplex (or time domain duplexing)

UE user equipment, such as a mobile station or mobile terminal UL uplink (UE towards eNB)

UTRAN universal terrestrial radio access network

A communication system known as evolved UTRAN (E-UTRAN, also referred to as UTRAN-LTE or as E-UTRA) has been specified within 3 GPP. The DL access technique is OFDMA, and the UL access technique is SC-FDMA. One specification of interest is 3 GPP TS 36.300, V9.2.0 (2010-01), "3rd Generation Partnership Project; Technical Specification Group Radio Access Network; Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Access Network (E-UTRAN); Overall description; Stage 2 (Release 9)".

Figure 1 reproduces Figure 4-1 of 3GPP TS 36.300, and shows the overall architecture of the E-UTRAN system. The E-UTRAN system includes eNBs, providing the E-UTRA user plane (PDCP/RLC/MAC/PHY) and control plane (RRC) protocol terminations towards the UE (not shown). The eNBs are interconnected with each other by means of an X2 interface. The eNBs are also connected by means of an SI interface to an EPC, more specifically to a MME (Mobility Management Entity) by means of a SI MME interface and to a Serving Gateway (SGW) by means of a SI interface. The SI interface supports a many-to-many relationship between MMEs/S-GW and eNBs.

The eNB hosts the following functions:

• functions for RRM: Radio Bearer Control, Radio Admission Control, Connection Mobility Control, Dynamic allocation of resources to UEs in both UL and DL (scheduling);

• IP header compression and encryption of the user data stream;

• selection of a MME at UE attachment;

• routing of User Plane data towards the Serving Gateway;

• scheduling and transmission of paging messages (originated from the MME);

• scheduling and transmission of broadcast information (originated from the MME or O&M); and

• a measurement and measurement reporting configuration for mobility and scheduling.

Positioning support in LTE Rel-9 was specified with an explicit focus on emergency call applications in macro cells. Enhanced LTE positioning was discussed in RAN2. The widespread use of positioning applications in 3G systems may make the market for non- regulatory applications in LTE more abundant. Moreover, the accelerating interest for LTE in aspects such as machine-to-machine communications create many use cases in which positioning will only become more important. See further: R2-101582, "Proposed WI on LTE positioning enhancements", RAN2#69, Feb. 2010.

Machine communications have become a major topic in recent discussions on wireless systems applications. Machine applications may be used for many purposes (e.g., smart homes, smart metering, fleet management, remote healthcare, access network operation management, etc.). In January 2009, ETSI started work in a new Technical Committee (ETSI TC M2M) to specify M2M requirements and to develop an end-to-end high level architecture for machine systems. In September 2009, 3 GPP TSG RAN decided to open a new Study Item on 'RAN Improvements for Machine-type Communications'. See further: RP-090991 , "New SI proposal: RAN Improvements for Machine-type Communications", RAN#45 Sept 09.

According to RAN2#69, there should be ways to assist a node, such as a home eNB (HeNB) to position itself in order to determine whether the HeNB is allowed to transmit at its current location, and to enable location determining of any UE accessing the HeNB in the case that direct positioning of the UE is not possible. Further, positioning assistance for a HeNB should be enabled by allowing the HeNB to make use of LPP to obtain its own position using any known positioning methods for a normal UE. Similarly to HeNB, there may also be need for self-positioning of machine nodes. The HeNBs and machine nodes may be considered to be relatively fixed wireless nodes that may be

1) used as positioning anchors for LTE positioning protocol, where the UE can detect PRS from the wireless nodes for OTDOA positioning; and/or

2) used by the application layer with knowledge of their location, e.g., where the wireless nodes are medical sensors for heath monitoring and emergency service.

Additionally, HeNBs and machine nodes may not have the same positioning capabilities as an UE, for example, the node may not be able to receive a GPS signal or be able receive PRS signals for OTDOA positioning. Individuals setting up their HeNB access point and/or companies installing machine nodes with wireless modules (e.g. LTE, LTE-Advanced) may perform a one-off GPS measurement during the installation and log the GPS coordinates in a database available for the network or the application layer. However, such approaches require user intervention. Additionally, if the machine node is subsequently moved, new GPS coordinates would need to be measured and entered.

Recent FCC requirements in the US state that 67% of users are to be located within 50 m (approx. within five samples accuracy with Fs=32.72 MHz); and 98% within 150 m (or 15 samples). However, this may not be sufficient in heavily populated areas. Therefore, if fixed wireless nodes such as HeNBs or other machine nodes are used for positioning of UEs, their location should be known to the enhanced serving mobile location center (e- SLMC) with as good an accuracy as can practically be achieved. Otherwise, the wireless node position error will unsatisfactorily increase the UE position error.

Various techniques exist for determining the location of a device, for example, observed time difference of arrival (OTDOA), positioning using the global positioning system (GPS), etc. In OTDOA, the location of a UE maybe triangulated using knowledge of the transmit timings of nearby network cells and their geographical locations.

An OTDOA principle is illustrated in Figure 5. The UE 210 reports observed time difference (OTD) relative to the serving eNB 220 timing. Based on the OTD, the UE 210 determines its distance from the serving eNB 220. The UE 210 provides a measurement report to the serving eNB 220 based on the OTD. The location of UE 210 is then determined using the measurement report and knowledge of the location of the eNB 220.

A positioning reference signal (PRS) pattern may have been agreed prior to transmission. OTDOA uses μβ-ΐενεΐ network synchronization, which may require expensive technology, for example, GPS (Field-Proven CDMA2000 BTS lxRTT AFLT with synch accuracy of ±3 μ≤ ); and/or IEEE 1588 Standard for a Precision Clock Synchronization (where an eNBs measures round trip time (RTT) to local routers and iteratively adjusts their clock timing in a coordinated fashion). OTDOA is a Release 9 feature requiring UE implementation. See further: Rl -092213, WF on RANI concept for OTDOA, Ericsson, Alcatel-Lucent, Nokia, Nokia Siemens Networks, Qualcomm Europe, LG, Samsung, Huawei, Motorola, Pantech & Curitel; and R 1-092963, "PRS Pattern design", Qualcomm, ranl#58Bis, Aug 09.

In cell-specific reference signal (CRS)-based home eNB (HeNB) synchronization to macro layer eNB in TDD networks, the macro layer configures more OFDM symbols than the HeNB in a DwPTS field of a special time slot. This allows the HeNB to track macro layer eNB cell-specific reference signal (CRS) in DwPTS during its relatively larger guard period without additional impact on its normal transmission. The HeNB can perform initial synchronization to the macro eNB by first detecting the P-SCH and S-SCH to determine the symbol timing, radio frame timing and eNB cell ID. Although this method may allow synchronization of the TDD HeNB, it may not be used for self-positioning of the HeNB. See further: R4-092746, "Text Proposal for TDD HeNB synchronization with macro layer eNB", Nokia, NSN, RAN4#52, Aug. 09 What is needed is a practical and accurate self-positioning of HeNB/machine nodes.

SUMMARY

The below summary section is intended to be merely exemplary and non-limiting. The foregoing and other problems are overcome, and other advantages are realized, by the use of the exemplary embodiments of this invention.

In a first aspect thereof an exemplary embodiment of this invention there is provided a method for wireless device assisted self-positioning. The method includes receiving location information from a first network node. The received location information describes a location of the first network node. Determining a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node is also included in the method. The method also includes storing the currently determined location. The first network node is a different network node from the second network node.

In a further aspect thereof an exemplary embodiment of this invention there is provided an apparatus for wireless device assisted self-positioning. The apparatus includes at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform actions. The actions include to receive location information from a first network node. The received location information describes a location of the first network node. To determine a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node is also included in the actions. The actions also include to store the currently determined location. The first network node is a different network node from the second network node.

In an additional aspect thereof an exemplary embodiment of this invention there is provided a computer readable medium for wireless device assisted self-positioning. The computer readable medium is tangibly encoded with a computer program executable by a processor to perform actions. The actions include receiving location information from a first network node. The received location information describes a location of the first network node. Determining a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node is also included in the actions. The actions also include storing the currently determined location. The first network node is a different network node from the second network node.

In a further aspect thereof an exemplary embodiment of this invention there is provided an apparatus for wireless device assisted self-positioning. The apparatus includes means for receiving location information from a first network node. The received location information describes a location of the first network node. Means for determining a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node is also included in the apparatus. The apparatus also include means for storing the currently determined location. The first network node is a different network node from the second network node. BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other aspects of exemplary embodiments of this invention are made more evident in the following Detailed Description, when read in conjunction with the attached Drawing Figures, wherein:

Figure 1 reproduces Figure 4-1 of 3 GPP TS 36.300, and shows the overall architecture of the E UTRAN system.

Figure 2 shows a simplified block diagram of exemplary electronic devices that are suitable for use in practicing various exemplary embodiments of this invention.

Figure 3 shows a more particularized block diagram of an exemplary user equipment such as that shown at Figure 2.

Figure 4 shows a simplified block diagram of additional exemplary electronic devices that are suitable for use in practicing various exemplary embodiments of this invention.

Figure 5 shows the overall architecture of the OTDOA principle.

Figure 6 shows a simplified overall architecture of exemplary electronic devices that are suitable for use in practicing various exemplary embodiments of this invention.

Figures 7a-7d illustrate various UE-assisted self-positioning error distributions for the wireless nodes practicing various exemplary embodiments of this invention.

Figure 8 depicts a signaling diagram that illustrates the operation of another exemplary method in accordance with various exemplary embodiments of this invention.

Figure 9 is a logic flow diagram that illustrates the operation of another exemplary method, and a result of execution of computer program instructions embodied on a computer readable memory, in accordance with various exemplary embodiments of this invention.

DETAILED DESCRIPTION

Various exemplary embodiments in accordance with this invention are related to LTE positioning, machine-to-machine (M2M) communications, home eNBs (HeNB), integration of wireless sensors and sensor networks with cellular networks, and location positioning. Uses of various exemplary embodiments provide accurate self-positioning of network nodes (e.g., HeNB, machine nodes and other temporarily fixed wireless nodes). Before describing in further detail various exemplary embodiments in accordance with this invention, reference is made to Figure 2 for illustrating a simplified block diagram of various electronic devices and apparatus that are suitable for use in practicing exemplary embodiments of this invention.

In the wireless system 230 of Figure 2, a wireless network 235 is adapted for communication over a wireless link 232 with an apparatus, such as a mobile communication device which may be referred to as a UE 210, via a network access node, such as a Node B (base station), and more specifically an eNB 220. The network 235 may include a network control element (NCE) 240 that may include the MME/SGW functionality shown in Figure 1 , and which provides connectivity with a network, such as a telephone network and/or a data communications network (e.g., the internet 238).

The UE 210 includes a controller, such as a computer or a data processor (DP) 214, a computer-readable memory medium embodied as a memory (MEM) 216 that stores a program of computer instructions (PROG) 218, and a suitable wireless interface, such as radio frequency (RF) transceiver 212, for bidirectional wireless communications with the eNB 220 via one or more antennas.

The eNB 220 also includes a controller, such as a computer or a data processor (DP)

224, a computer-readable memory medium embodied as a memory (MEM) 226 that stores a program of computer instructions (PROG) 228, and a suitable wireless interface, such as RF transceiver 222, for communication with the UE 210 via one or more antennas. The eNB 220 is coupled via a data/control path 234 to the NCE 240. The path 234 may be implemented as the S 1 interface shown in Figure 1. The eNB 220 may also be coupled to another eNB via data/control path 236, which may be implemented as the X2 interface shown in Figure 1.

The NCE 240 includes a controller, such as a computer or a data processor (DP) 244, a computer-readable memory medium embodied as a memory (MEM) 246 that stores a program of computer instructions (PROG) 248.

Figure 3 illustrates further detail of an exemplary UE in both plan view (left) and sectional view (right), and the invention may be embodied in one or some combination of those more function-specific components. At Figure 3 the UE 210 has a graphical display interface 320 and a user interface 322 illustrated as a keypad but understood as also encompassing touch-screen technology at the graphical display interface 320 and voice- recognition technology received at the microphone 324. A power actuator 326 controls the device being turned on and off by the user. The exemplary UE 210 may have a camera 328 which is shown as being forward facing (e.g., for video calls) but may alternatively or additionally be rearward facing (e.g., for capturing images and video for local storage). The camera 328 is controlled by a shutter actuator 330 and optionally by a zoom actuator 332 which may alternatively function as a volume adjustment for the speaker(s) 334 when the camera 328 is not in an active mode.

Within the sectional view of Fig. 3 are seen multiple transmit/receive antennas 336 that are typically used for cellular communication. The antennas 336 maybe multi-band for use with other radios in the UE. The operable ground plane for the antennas 336 is shown by shading as spanning the entire space enclosed by the UE housing though in some embodiments the ground plane may be limited to a smaller area, such as disposed on a printed wiring board on which the power chip 338 is formed. The power chip 338 controls power amplification on the channels being transmitted and/or across the antennas that transmit simultaneously where spatial diversity is used, and amplifies the received signals. The power chip 338 outputs the amplified received signal to the radio-frequency (RF) chip 340 which demodulates and downconverts the signal for baseband processing. The baseband (BB) chip 342 detects the signal which is then converted to a bit-stream and finally decoded. Similar processing occurs in reverse for signals generated in the apparatus 210 and transmitted from it.

Signals to and from the camera 328 pass through an image/video processor 344 which encodes and decodes the various image frames. A separate audio processor 346 may also be present controlling signals to and from the speakers 334 and the microphone 324. The graphical display interface 320 is refreshed from a frame memory 348 as controlled by a user interface chip 350 which may process signals to and from the display interface 320 and/or additionally process user inputs from the keypad 322 and elsewhere. Certain embodiments of the UE 210 may also include one or more secondary radios such as a wireless local area network radio WLAN 337 and a Bluetooth® radio 339, which may incorporate an antenna on-chip or be coupled to an off-chip antenna. Throughout the apparatus are various memories such as random access memory RAM 343, read only memory ROM 345, and in some embodiments removable memory such as the illustrated memory card 347. The various programs 218 are stored in one or more of these memories. All of these components within the UE 210 are normally powered by a portable power supply such as a battery 349.

Figure 4 shows a simplified block diagram of exemplary machine node that is suitable for use in practicing various exemplary embodiments of this invention. The node 410 includes a controller, such as a computer or a data processor (DP) 414, a computer- readable memory medium embodied as a memory (MEM) 416 that stores a program of computer instructions (PROG) 418, and a suitable wireless interface, such as radio frequency (RF) transceiver 412, for bidirectional wireless communications with an eNB 220 (not shown), another node 410 and/or a UE 210 via one or more antennas. Node 410 may be embodied in various devices, for example, household electronics, refrigerators, vehicles, a home eNB (HeNB), etc.

The bidirectional wireless communications with another node 410 and/or a UE 210 may occur via a data/control path 430, for example, M2M communication. An UE 210 (and/or various nodes 410) may receive communications from additional devices (not shown) via a data/control path 450, for example, data/control path 232, GPS signal, etc.

At least one of the PROGs 218, 228, 248 and 418 is assumed to include program instructions that, when executed by the associated DP, enable the device to operate in accordance with exemplary embodiments of this invention, as will be discussed below in greater detail.

That is, various exemplary embodiments of this invention maybe implemented at least in part by computer software executable by the DP 214 of the UE 210; by the DP 224 of the eNB 220; by the DP 244 of the NCE 240; and/or by the DP 414 of the node 410, or by hardware, or by a combination of software and hardware (and firmware).

The UE 210, the eNB 220 and node 410 may also include dedicated processors, for example location determining module 215, location determining module 225 and location determining module 415.

In general, the various embodiments of the UE 210 can include, but are not limited to, cellular telephones, personal digital assistants (PDAs) having wireless communication capabilities, portable computers having wireless communication capabilities, image capture devices such as digital cameras having wireless communication capabilities, gaming devices having wireless communication capabilities, music storage and playback appliances having wireless communication capabilities, Internet appliances permitting wireless Internet access and browsing, as well as portable units or terminals that incorporate combinations of such functions.

The computer readable MEMs 216, 226, 246 and 416 may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The DPs 214, 224, 244 and 414 may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on a multicore processor architecture, as non-limiting examples. The wireless interfaces (e.g., RF transceivers 212, 222 and 412) may be of any type suitable to the local technical environment and may be implemented using any suitable communication technology such as individual transmitters, receivers, transceivers or a combination of such components.

Processors 338, 340, 342, 344, 346 and 350, if embodied as separate entities in a UE 210 or eNB 220, may operate in a slave relationship to the main processor 214, 224, which may then be in a master relationship to them. Embodiments of this invention are most relevant to the (fill in here where the invention might likely be embodied; query the inventors), though it is noted that other embodiments need not be disposed there but may be disposed across various chips and memories as shown or disposed within another processor that combines some of the functions described above for Figure 3. Any or all of these various processors of Fig. 3 access one or more of the various memories, which may be on-chip with the processor or separate therefrom. Similar function-specific components that are directed toward communications over a network broader than a piconet (e.g., components 336, 338, 340, 342-345 and 347) may also be disposed in exemplary embodiments of the access node 220, which may have an array of tower-mounted antennas rather than the two shown at Fig. 3.

Note that the various chips (e.g., 338, 340, 342, etc.) that were described above maybe combined into a fewer number than described and, in a most compact case, may all be embodied physically within a single chip.

In an exemplary method in accordance with this invention, a wireless node 410, an enhanced serving mobile location center (E-SLMC), performs coordinates a self- positioning method for a wireless node 410 with the assistance of a UE 210. The E-SLMC may be embodied in the self-positioning wireless node 410, in a separate wireless node 410, e.g., an HeNB, or in another network node, e.g., NCE 240.

The UE 210 is asked by the E-SLMC to determine whether there are nearby wireless nodes and to use them for OTDOA positioning. The E-SLMC may also indicate the list of wireless node identities (WNI) of the wireless nodes via signaling.

Next, the UE 210 reports a connected status to the wireless nodes, e.g., eNB 220, various other wireless nodes 410, etc. The report may include a WNI and measurements such as reference signal received power (RSRP) for each network node. Based on these measurements, the E-SLMC may use a location for the UE 210 to determine the location of the wireless node 410. A location of the UE 210 may be obtained by OTDOA positioning based on observed time difference (OTD) of neighbor eNB 220 relative to the serving eNB 220 timing. The location of the serving eNB 220 and neighbor eNB 220 is known to the E- SLMC. The location of UE 210 is then determined using the measurement report and knowledge of the location of the serving eNB 220 and neighbor eNB 220.

The E-SLMC may repeatedly ask the same UE 210 and/or other UE 210 for these measurement reports based on their connected status to the wireless node 410 over a relatively long-term period, T_sp, (e.g. a few hours/days).

The E-SLMC may determine the wireless node's location as a running average of UE locations. The running average may be based on (i) connected status; and/or (ii) RSRP. In a simple embodiment, the N best UE measurements (for example, those UEs with the highest RSRP measured from the wireless node CRS transmissions) will be used to determine the location of a given connected wireless node 410 during T_sp. In a further embodiment, a weighted running average of the UE measurements (for example, indoor UEs with relatively high RSRP measured from the wireless node CRS transmissions will be given a higher weight that outdoor UEs with typically a lower RSRP due to outside wall path loss) will be used to determine the location of a given connected wireless node 410 during T_sp.

Additionally, the E-SMLC may request a position-known UE 210 to measure OTD from two position-known wireless nodes and the self-positioned wireless node. If the calculated position for the device sufficiently matches the previously established position of the UE 210, it may be deemed that the self-positioned wireless node is positioned with enough accuracy. For example, this can be simply determined if the difference between the two positions is relatively small, e.g., within a few tens of meters. If the difference is deemed too large, more samples for self-positioning may be gathered in order to reassess the determined location for the self-positioned wireless node.

Once the UE-assisted self-positioning procedure is complete (for example, with a sufficiently small difference in positions), the network may use the wireless nodes as anchors for UE positioning to allow a more accurate UE OTDOA positiomng (for example, as compared to using neighbor cell eNB) due to their relative closeness and likely higher positioning reference signal (PRS) hearability.

As non-limiting examples, the UEs may perform RSTD measurements from these positioning anchors in an explicit way (e.g., wireless nodes WNIs are indicated via e- SLMC signaling in case the wireless node is a machine) or in an implicit way (e.g., using a CSG flag in SIB 1 and PCI indicated via e-SLMC signaling in case the wireless nodes is an HeNB). Wireless nodes, such as HeNBs or machine nodes (e.g. fixed smart meters or boilers), may be used as positioning anchors. These nodes may start transmitting PRSs to allow RSTD measurements by an UE for positioning, e.g., OTDOA positioning, after they have completed a UE-assisted self-positioning procedure. The node may also need to perform DL synchronization to another node, for example, a macro eNB.

The wireless nodes may be synchronized to the macro eNB in order to align its DL timing to that of the eNB. If nearby wireless nodes also align their DL timing to the same eNB, the M2M device is approximately synchronized to the nearby wireless nodes (e.g., synchronized Rx from the eNB and Tx to the cellular device using DL resources in TDD mode). The synchronized wireless nodes may also be able to receive RRC configuration and MAC signaling for DL allocation (e.g., control data for its operational parameters) and UL allocation (e.g., broadcasting of position reference signals to the cellular device).

The synchronization of the wireless node to a macro eNB can also be based on a closed loop method. After DL synchronization is achieved, the wireless node may send a message to the macro eNB in order to get a timing advance command, for example using a RACH. The wireless node may then advance its DL cell timing accordingly. A similar idea was proposed for TDD relay. See further: R4- 100708, CMCC, "Considerations on Backhaul Interference and Synchronization for Relay", RAN4#54, Feb 2010.

Using a typical short-range transmission for the wireless node signals (e.g., using P/S- SCH, CRS), the measuring UE will usually be relatively close, e.g., typically within a few tens of meters and within the FCC 911 requirements: 67% of emergency calls within 50 meters; 95% of emergency calls within 150 meters.

Further, given that a few UEs may connect to the wireless node over a period of time

(or the same UE may connect multiple times), the wireless node location error variance will be reduced when the wireless nodes is not moved to a different location.

In case of a location change, the UE-assisted self-positioning of the wireless node could be restarted. Such a location change may be assumed if the wireless node is powered off and on (including an initial access procedure to a macro eNB). Alternatively, the self- location procedure may be repeated with some periodicity in order to check that the wireless node's location has not changed significantly.

The wireless node may also restrict which UEs are used for self-positioning. A UE may measure the RSRP based on reference signals sent by the wireless node and report these measurements to the wireless node. The UEs measuring the strongest RSRP may be used for the self-positioning of the wireless nodes. This ensures that the UE measurements which are closest to the wireless node are used and measurements which are further away are ignored, thereby increasing the accuracy of the self-positioning. A UE-assisted self-positioning machine algorithm was simulated with 1 , 3, 6, 10, 50, and 100 UEs within 30 meters of the wireless nodes. This predicts practical scenarios where the UEs can measure reference signals from HeNB or machine nodes typically within a few tens of meters. The UE location is assumed to be known by the network. An (x,y) catersian coordinate system is used for the modeling of the positions of the wireless node and the measuring the UEs. The position error for the x and y coordinates is modeled by a Gaussian distribution based on the FCC requirements - i.e. 67% within 50 meters and 98% within 150 meters.

The UE-assisted self-positioning error distribution for the wireless nodes based on 10,000 wireless node connections with the wireless node positioned in (0,0) coordinate point in space is shown in Figure 7 for - (a) 1 UE; (b) 3 UEs; (c) 10 UEs; (d) 50 UEs. The results show that with 3 UE measurements used (e.g., those UEs connected to wireless node with sufficient wireless node RSRP measured), two-thirds of the wireless node position may be estimated within 50 meters or so, and almost all within 100 meters. Further, with 10 UE measurements, two-thirds of the wireless node position may be estimated within 30 meters or so, and almost all within 50 meters. Even better accuracy may be achieved with larger number of UEs, as shown on Figure 7(d).

In the simulated scenarios, the UEs do not have to be different devices, rather the OTDOA positioning is performed several times at different OTDOA time intervals. This may correspond to the case when a UE or several UEs in the home or close to the home are asked to perform an OTDOA positioning procedure several times within a UE-assisted self-positioning procedure over a few hours/days in order to determine the wireless node position. The UE(s) may be moving during that time. Hence, the proposed method allows accurate positioning of the wireless nodes. The HeNB may assist the RSTD measurements in the UE for OTDOA positioning. The

HeNBs can transmit PRS for RSTD-measurements to the UE as part of the LTE Positioning Protocol. See further: TS 36.355, "LTE Positioning Protocol", v9.0.0, Dec.09.

Machine node PRS transmissions may be used for RSTD measurements in the UE for OTDOA positioning. The machine node to cellular device connection may be implemented by using some of the cellular DL channel resources. This can be done by configuration of subframes in the LTE DL signal structure and indicated by an eNB to all cellular devices and machine nodes. The eNB may also indicate to the cellular device (e.g., with machine node GW capability) the DL resource blocks it should monitor in order to find possible signals from the machine nodes.

Whenever the cellular device is in the vicinity of a machine node, and successfully receives data in the predetermined DL resources blocks (including all preceding data reception related steps, e.g., synchronization), it forwards the data to the eNB, or alternatively sends a predetermined message to the eNB.

Figure 6 illustrates how the eNB, cellular device, and the machine operate. Cellular device (e.g., a UE 210 acting as a M2M GW) is connected to cellular network access point (e.g. an eNB 220) using cellular FDD UL and DL signals. The eNB 220 is connected to a machine/sensor 410 using cellular FDD DL signals. Connection from the machine node 410 to the cellular device 240 is · unidirectional using FDD DL resources. Multiple machines/sensors 410 may also communicate with each other using FDD DL resources operating with TDD duplexing principle.

The machine nodes maybe asked by the e-SLMC via the eNB to transmit PRS to allow a nearby UE to make PRS-based RSTD measurements. The e-SLMC may also signal to the UE both the machine ID and when the machine node is expected to transmit the PRS during the OTDOA measurement interval. Self-positioned wireless nodes may be used to transmit positioning reference signals (PRS) on the DL (e.g., as a normal eNB). Based on the wireless node PCI, UEs within coverage may prioritize measurements from these machine nodes for OTDOA positioning for higher accuracy (due to their relative closeness). Additionally, this information may be used by application layer programs, e.g., for out-of-care patients monitoring.

Further, over-the-air UE-assisted self-positioning methods for the wireless nodes may be more practical way than A-GPS fix measurement and reporting. These measurements may not necessarily be possible indoor and may require an expensive GPS receiver. Various methods in accordance with the invention, may solve positioning problems due to a potential difficulty in measuring OTD from a serving macro eNB and/or a neighbor eNBs due to PRS hearability and implementation/cost considerations. Figure 8 depicts a signaling diagram that illustrates the operation of another exemplary method in accordance with various exemplary embodiments of this invention. As shown, eNB 220 (e.g., an HeNB) and UE 210 are in communication. At 810, eNB 220 transmits a request for the UE 210 to provide location information.

The UE 210 performs measurements in order to determine its location at 820. This may be done using any available location methods available to the UE 210, for example, OTDOA using eNBs, GPS, etc., at 820.

Then, at 830, the UE 210 sends its location information to the eNB 220. The location information may be a determined location for the UE 210 or information sufficient to determine the location of the UE 210, e.g., measured OTDs and the sources of the signals. The location information may also include a strength measurement of a signal (e.g., an RSRP) sent from the wireless node 410 and received at the UE 210.

This procedure may be repeated a number of times over a span of time (e.g., hours/days). Based on the location information received, a location for the wireless node 410 may be determined, for example, as an average of locations determined for the UE 210.

Once a sufficient quantity of location information has been received (for example, at least ten), the UE 210 is asked to perform measurements in order to determine its location based at least in part on signaling from the wireless node 410, at 840.

At 850, the UE 210 performs the location determination based at least in part on the wireless node 410 (for example, using OTDOA where the wireless node provides one of the RPSs). The UE 210 also performs measurements in order to determine its location using signals other than those from the wireless node 410.

At 860, the UE 210 sends the two sets of location information to the eNB 220.

The difference between two locations may be used in order to determine whether the location for the wireless node is sufficiently accurate. If sufficient accuracy is achieved (for example, the difference is below a given threshold), the wireless node 410 may be used for location determining procedures. If the difference is considered too large, the procedure (e.g., 810 - 830) may be repeated additional times and the accuracy rechecked.

In an alternative method, the eNB 220 also operates as the wireless node 410. Therefore, the location determined for the wireless node 410 is the location of the eNB 220 (e.g., an HeNB).

Based on the foregoing it should be apparent that the exemplary embodiments of this invention provide a method, apparatus and computer program(s) to provide wireless device assisted self-positioning.

Figure 9 is a logic flow diagram that illustrates the operation of a method, and a result of execution of computer program instructions, in accordance with the exemplary embodiments of this invention. In accordance with these exemplary embodiments a method performs, at Block 910, a step of receiving location information from a first network node, where the received location information describes a location of the first network node. At Block 920, a currently determined location for a second network node is determined based at least in part on the received location information and a previously determined location for the second network node. The first network node is a different network node from the second network node. The currently determined location is stored in memory at Block 930.

The various blocks shown in Figure 9 may be viewed as method steps, and/or as operations that result from operation of computer program code, and/or as a plurality of coupled logic circuit elements constructed to carry out the associated function(s).

In an exemplary embodiment in accordance with this invention, a method is provided for wireless device assisted self-positioning. The method includes receiving (e.g., by a receiver) location information from a first network node. The received location information describes a location of the first network node. Determining (e.g., by a processor) a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node is also included in the method. The method also includes storing (e.g., in a memory) the currently determined location. The first network node is a different network node from the second network node.

In a further exemplary embodiment of the method above, the method also includes sending a request for location information to the first network node. Receiving the location information is performed in response to sending the request.

In an additional exemplary embodiment of any one of the methods above, determining a currently determined location includes averaging the received location information and the previously determined location. Averaging may include taking a weighted average.

In a further exemplary embodiment of any one of the methods above, the location information is associated with a RSRP and where averaging includes averaging location information associated with a plurality N strongest RSRPs. N may be at least five.

In an additional exemplary embodiment of any one of the methods above, the location information includes at least three OTD and where determining the currently determined location for a second network node is performed based on OTDOA positioning.

In a further exemplary embodiment of any one of the methods above, the method also includes: sending a first request for first location information to the first network node, where the first request instructions the first network node to generate the first location information based at least in part on signals from the second network node; sending a second request for second location information to the first network node, where the second request instructions the first network node to generate the second location information not based on signals from the second network node; receiving the first location information and the second location information; determining a first location for the first network node based on the first location information and the currently determined location; determining a second location for the first network node based on the second location information; and determining a difference between the first location and the second location. The method may also include determining whether to use the second network node when determining a location of another network node based at least in part on the difference between the first location and the second location.

In an additional exemplary embodiment of any one of the methods above, the method also includes determining a location of another network node based at least in part on the currently determined location.

In a further exemplary embodiment of any one of the methods above, where determining the currently determined location for the second network node is performed in response to the second network node being activated. In an additional exemplary embodiment in accordance with this invention, an apparatus is provided for wireless device assisted self-positioning. The apparatus includes at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform actions. The actions include to receive location information from a first network node. The received location information describes a location of the first network node. To determine a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node is also included in the actions. The actions also include to store the currently determined location. The first network node is a different network node from the second network node.

In a further exemplary embodiment of the apparatus above, the actions also include to send a request for location information to the first network node. Receiving the location information is performed in response to sending the request.

In an additional exemplary embodiment of any one of the apparatus above, determining a currently determined location includes averaging the received location information and the previously determined location. Averaging may include taking a weighted average. In a further exemplary embodiment of any one of the apparatus above, the location information is associated with a RSRP and where averaging includes averaging location information associated with a plurality N strongest RSRPs. N may be at least five.

In an additional exemplary embodiment of any one of the apparatus above, the location information includes at least three OTD and where determining the currently determined location for a second network node is performed based on OTDOA positioning.

In a further exemplary embodiment of any one of the apparatus above, the actions also include: to send a first request for first location information to the first network node, where the first request instructions the first network node to generate the first location information based at least in part on signals from the second network node; to send a second request for second location information to the first network node, where the second request instructions the first network node to generate the second location information not based on signals from the second network node; to receive the first location information and the second location information; to determine a first location for the first network node based on the first location information and the currently determined location; to determine a second location for the first network node based on the second location information; and to determine a difference between the first location and the second location. The actions may also include determining whether to use the second network node when determining a location of another network node based at least in part on the difference between the first location and the second location.

In an additional exemplary embodiment of any one of the apparatus above, the apparatus also includes a receiver.

In a further exemplary embodiment of any one of the apparatus above, where determining the currently determined location for the second network node is performed in response to the second network node being activated.

In an additional exemplary embodiment of any one of the apparatus above, the actions also include to determine a location of another network node based at least in part on the currently determined location. In a further exemplary embodiment in accordance with this invention, a computer readable medium is provided for wireless device assisted self-positioning. The computer readable medium is tangibly encoded with a computer program executable by a processor to perform actions. The actions include receiving location information from a first network node. The received location information describes a location of the first network node. Determining a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node is also included in the actions. The actions also include storing the currently determined location. The first network node is a different network node from the second network node.

In an additional exemplary embodiment of the computer readable medium above, the actions also include sending a request for location information to the first network node. Receiving the location information is performed in response to sending the request.

In a further exemplary embodiment of any one of the computer readable media above, determining a currently determined location includes averaging the received location information and the previously determined location. Averaging may include taking a weighted average.

In an additional exemplary embodiment of any one of the computer readable media above, the location information is associated with a RSRP and where averaging includes averaging location information associated with a plurality N strongest RSRPs. N maybe at least five.

In a further exemplary embodiment of any one of the computer readable media above, the location information includes at least three OTD and where determining the currently determined location for a second network node is performed based on OTDOA positioning.

In an additional exemplary embodiment of any one of the computer readable media above, the actions also include: sending a first request for first location information to the first network node, where the first request instructions the first network node to generate the first location information based at least in part on signals from the second network node; sending a second request for second location information to the first network node, where the second request instructions the first network node to generate the second location information not based on signals from the second network node; receiving the first location information and the second location information; determining a first location for the first network node based on the first location information and the currently determined location; determining a second location for the first network node based on the second location information; and determining a difference between the first location and the second location. The actions may also include determining whether to use the second network node when determining a location of another network node based at least in part on the difference between the first location and the second location.

In a further exemplary embodiment of any one of the computer readable media above, where determining the currently determined location for the second network node is performed in response to the second network node being activated.

In an additional exemplary embodiment of any one of the computer readable media above, the actions also include determining a location of another network node based at least in part on the currently determined location.

In a further exemplary embodiment in accordance with this invention, an apparatus is provided for wireless device assisted self-positioning. The apparatus includes means for receiving location information from a first network node. The received location information describes a location of the first network node. Means for determining a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node is also included in the apparatus. The apparatus also include means for storing the currently determined location. The first network node is a different network node from the second network node.

In an additional exemplary embodiment of the apparatus above, the apparatus also includes means for sending a request for location information to the first network node. Receiving the location information is performed in response to sending the request.

In a further exemplary embodiment of any one of the apparatus above, the means for determining a currently determined location includes means for averaging the received location information and the previously determined location. The means for averaging may include means for taking a weighted average.

In an additional exemplary embodiment of any one of the apparatus above, the location information is associated with a RSRP and where the means for averaging includes means for averaging location information associated with a plurality N strongest RSRPs. N may be at least five.

In a further exemplary embodiment of any one of the apparatus above, the location information includes at least three OTD and where the means for determining the currently determined location for a second network node is configured to determine based on OTDOA positioning.

In an additional exemplary embodiment of any one of the apparatus above, the apparatus also include: means for sending a first request for first location information to the first network node, where the first request instructions the first network node to generate the first location information based at least in part on signals from the second network node; means for sending a second request for second location information to the first network node, where the second request instructions the first network node to generate the second location information not based on signals from the second network node; means for receiving the first location information and the second location information; means for determining a first location for the first network node based on the first location information and the currently determined location; means for determining a second location for the first network node based on the second location information; and means for determining a difference between the first location and the second location. The apparatus may also include means for determining whether to use the second network node when determining a location of another network node based at least in part on the difference between the first location and the second location.

In an additional exemplary embodiment of any one of the apparatus above, the apparatus also includes means for determining a location of another network node based at least in part on the currently determined location.

In general, the various exemplary embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. For example, some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the exemplary embodiments of this invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods described herein may be implemented in, as nonlimiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof. It should thus be appreciated that at least some aspects of the exemplary embodiments of the inventions may be practiced in various components such as integrated circuit chips and modules, and that the exemplary embodiments of this invention may be realized in an apparatus that is embodied as an integrated circuit. The integrated circuit, or circuits, may comprise circuitry (as well as possibly firmware) for embodying at least one or more of a data processor or data processors, a digital signal processor or processors, baseband circuitry and radio frequency circuitry that are configurable so as to operate in accordance with the exemplary embodiments of this invention.

Various modifications and adaptations to the foregoing exemplary embodiments of this invention may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings. However, any and all modifications will still fall within the scope of the non-limiting and exemplary embodiments of this invention. For example, while the exemplary embodiments have been described above in the context of the E-UTRAN (UTRAN-LTE) system, it should be appreciated that the exemplary embodiments of this invention are not limited for use with only this one particular type of wireless communication system, and that they may be used to advantage in other wireless communication systems such as for example (WLAN, UTRAN, GSM as appropriate). It should be noted that the terms "connected," "coupled," or any variant thereof, mean any connection or coupling, either direct or indirect, between two or more elements, and may encompass the presence of one or more intermediate elements between two elements that are "connected" or "coupled" together. The coupling or connection between the elements can be physical, logical, or a combination thereof. As employed herein two elements may be considered to be "connected" or "coupled" together by the use of one or more wires, cables and/or printed electrical connections, as well as by the use of electromagnetic energy, such as electromagnetic energy having wavelengths in the radio frequency region, the microwave region and the optical (both visible and invisible) region, as several non-limiting and non-exhaustive examples.

Further, the various names assigned to different channels (e.g., P-SCH, S-SCH etc.) are not intended to be limiting in any respect, as these various channels may be identified by any suitable names.

Furthermore, some of the features of the various non-limiting and exemplary embodiments of this invention may be used to advantage without the corresponding use of other features. As such, the foregoing description should be considered as merely illustrative of the principles, teachings and exemplary embodiments of this invention, and not in limitation thereof.

Claims

CLAIMS What is claimed is:

1. A method comprising:

receiving location information from a first network node, where the received location information describes a location of the first network node; and

determining, by a processor, a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node; and

storing the currently determined location,

where the first network node is a different network node from the second network node.

2. The method of claim 1 , further comprising sending a request for location information to the first network node,

where receiving the location information is in response to sending the request.

3. The method of claim 1, where determining a currently determined location comprises averaging the received location information and the previously determined location.

4. The method of claim 3, where averaging comprises taking a weighted average.

5. The method of claim 3, where the location information is associated with a reference signal received power and where averaging comprises averaging location information associated with a plurality N strongest reference signal received powers.

6. The method of claim 5, where N is at least five.

7. The method of claim 1, where the location information comprises at least three observed time differences and where determining the currently determined location for a second network node is performed based on observed time difference of arrival positioning.

8. The method of claim 1, further comprising:

sending a first request for first location information to the first network node, where the first request instructions the first network node to generate the first location information based at least in part on signals from the second network node;

sending a second request for second location information to the first network node, where the second request instructions the first network node to generate the second location information not based on signals from the second network node;

receiving the first location information and the second location information;

determining a first location for the first network node based on the first location information and the currently determined location;

determining a second location for the first network node based on the second location information; and

determining a difference between the first location and the second location.

9. An apparatus, comprising at least one processor; and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to perform at least the following:

to receive location information from a first network node, where the received location information describes a location of the first network node; and

to determine a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node; and

to store the currently determined location,

10. The apparatus of claim 9, where the computer program code is further configured to cause the apparatus to send a request for location information to the first network node, where receiving the location information is in response to sending the request.

11. The apparatus of claim 9, where the computer program code is further configured to cause the apparatus, when determining a currently determined location, to average the received location information and the previously determined location.

12. The apparatus of claim 11, where the location information is associated with a reference signal received power and where the computer program code is further configured to cause the apparatus, when averaging, to average location information associated with a plurality N strongest reference signal received powers.

13. The apparatus of claim 9, where the computer program code is further configured to cause the apparatus:

to send a first request for first location information to the first network node, where the first request instructions the first network node to generate the first location information based at least in part on signals from the second network node;

to send a second request for second location information to the first network node, where the second request instructions the first network node to generate the second location information not based on signals from the second network node;

to receive the first location information and the second location information;

to determine a first location for the first network node based on the first location information and the currently determined location;

to determine a second location for the first network node based on the second location information; and

to determine a difference between the first location and the second location.

14. A computer readable medium tangibly encoded with a computer program executable by a processor to perform actions comprising:

receiving location information from a first network node, where the received location information describes a location of the first network node; and determining a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node; and

storing the currently determined location,

15. The computer readable medium of claim 14, where the actions further comprise sending a request for location information to the first network node,

where receiving the location information is in response to sending the request.

16. The computer readable medium of claim 14, where determining a currently determined location comprises averaging the received location information and the previously determined location.

17. The computer readable medium of claim 16, where the location information is associated with a reference signal received power and where .averaging comprises averaging location information associated with a plurality N strongest reference signal received powers.

18. The computer readable medium of claim 14, where the actions further comprise: sending a first request for first location information to the first network node, where the first request instructions the first network node to generate the first location information based at least in part on signals from the second network node;

receiving the first location information and the second location information;

determining a difference between the first location and the second location.

19. An apparatus, comprising:

means for receiving location information from a first network node, where the received location information describes a location of the first network node; and

means for determining a currently determined location for a second network node, based at least in part on the received location information and a previously determined location for the second network node; and

means for storing the currently determined location,

20. The apparatus of claim 14, where apparatus further comprises means for sending a request for location information to the first network node,

where the means for the receiving location information is configured to receive the location information in response to sending the request.