Conditional termination of RSTD measurements
11496992 · 2022-11-08
Assignee
Inventors
- Sara Modarres Razavi (Linköping, SE)
- Johan Bergman (Stockholm, SE)
- Åke Busin (Sollentuna, SE)
- Fredrik GUNNARSSON (Linköping, SE)
- Olof Liberg (Stockholm, SE)
- Xingqin Lin (Santa Clara, CA)
- Henrik Rydèn (Solna, SE)
- Yutao Sui (Solna, SE)
- Martin Van Der Zee (Malmö, SE)
Cpc classification
H04M1/72403
ELECTRICITY
H04W64/00
ELECTRICITY
H04M1/724
ELECTRICITY
H04W24/10
ELECTRICITY
G01S5/10
PHYSICS
H04W64/006
ELECTRICITY
International classification
H04W64/00
ELECTRICITY
G01S5/10
PHYSICS
Abstract
Methods and device for use in a wireless device of reporting positioning measurements comprises receiving network assistance information from a network node. The network assistance information is for assisting the wireless device in performing Observed Time Difference Of Arrival (OTDOA), and comprises: a list of reference cells; a list of neighbor cells; and a rule for terminating Reference Signal Time Difference (RSTD) measurements. The method further comprises performing RSTD measurement between a cell in the reference cell list and a cell in the neighbor cell list. Upon determining the RSTD measurement satisfies the rule for terminating RSTD measurements, the method includes reporting the RSTD measurements to the network node. Upon determining the RSTD measurement does not satisfy the rule for terminating RSTD measurements, performing another RSTD measurement between the cell in the reference cell list and a cell in the neighbor cell list.
Claims
1. A method for use in a network node of providing network assistance for positioning measurements, the method comprising: transmitting network assistance information to a wireless device, the network assistance information forassisting the wireless device in performing Observed Time Difference Of Arrival (OTDOA), the network assistance information comprising: a list of reference cells; a list of neighbor cells; a rule for terminating Reference Signal Time Difference (RSTD) measurements; and receiving a report that provides the RSTD measurements from the wireless device; wherein the rule for terminating the RSTD measurements indicates terminating the RSTD measurements after taking at least a pre-determined number (N) of RSTD measurements having a least a pre-determined quality (X).
2. The method of claim 1, wherein the pre-determined number (N) is less than fifteen.
3. The method of claim 1, wherein the report includes a quality of the RSTD measurements.
4. The method of claim 1, wherein the report includes an indication that the rule for terminating RSTD measurements was satisfied.
5. The method of claim 1, wherein the rule for terminating RSTD measurements indicates terminating RSTD measurements after taking at least a first pre-determined number (N1) of RSTD measurements having a least a first pre-determined quality (X1) or at least a second pre-determined number (N2) of RSTD measurements having a least a second pre-determined quality (X2).
6. A network node capable of providing network assistance for positioning measurements, the network node comprising processing circuitry operable to: transmit network assistance information to a wireless device, the network assistance information for assisting the wireless device in performing Observed Time Difference Of Arrival (OTDOA), the network assistance information comprising: a list of reference cells; a list of neighbor cells; a rule for terminating Reference Signal Time Difference (RSTD) measurements; and receive a report that provides the RSTD measurements from the wireless device; wherein the rule for terminating the RSTD measurements indicates terminating the RSTD measurements after taking at least a pre-determined number (N) of RSTD measurements having a least a pre-determined quality (X).
7. The network node of claim 6, wherein the pre-determined number (N) is less than fifteen.
8. The network node of claim 6, wherein the report includes a quality of the RSTD measurements.
9. The network node of claim 6, wherein the report includes an indication of whether the rule for terminating RSTD measurements was satisfied.
10. The network node of claim 6, wherein the rule for terminating RSTD measurements indicates terminating RSTD measurements after taking at least a first pre-determined number (N1) of RSTD measurements having a least a first pre-determined quality (X1) or at least a second pre-determined number (N2) of RSTD measurements having a least a second pre-determined quality (X2).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) For a more complete understanding of the embodiments and their features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
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DETAILED DESCRIPTION
(12) Particular embodiments disclosed herein assist Internet of Things (IoT) devices (e.g., narrowband IoT (NB-IoT) devices) to terminate a reference signal time difference (RSTD) measurement procedure early if adequate measurement is available. Assisting the IoT devices may avoid performance of unnecessary measurements by the device.
(13) One potential advantage of using Observed Time Difference of Arrival (OTDOA) as the positioning method for IoT devices is preserving the legacy signaling procedure for these devices as it was for legacy long term evolution (LTE) user equipment (UEs). LTE uses LTE positioning protocol (LPP) signaling between an evolved-serving mobile location center (E-SMLC) to the UE, which provides OTDOA network assistance information. The signaling can be useful for IoT devices considering the limited capability and power consumption of IoT devices. Therefore, advantages may be realized reusing LTE signaling for IoT devices, and improvements may be realized by tailoring the content of the signaling to the capabilities of the IoT devices.
(14) As an example, in certain embodiments, the network node (i.e., E-SMLC) provides the NB-IoT UE with a list of potential reference cell and neighbor cells to be used for RSTD measurements. For each of these lists, the E-SMLC provides a set of information including the physical cell ID, the global cell ID, the positioning reference signal (PRS) info, etc. The network node may also provide the expected RSTD measurement and the expected RSTD uncertainty measurement, which can be useful to the UE.
(15) References in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described may include a particular feature, structure, or characteristic, but every embodiment may not necessarily include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to implement such feature, structure, or characteristic in connection with other embodiments, whether or not explicitly described.
(16) Generally, all terms used herein are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to “a/an/the element, apparatus, component, means, step, etc.” are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.
(17) Particular embodiments are described with reference to
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(19) In general, wireless devices 110 that are within coverage of radio network node 120 (e.g., within cell 115 served by network node 120) communicate with radio network node 120 by transmitting and receiving wireless signals 130. For example, wireless devices 110 and radio network node 120 may communicate wireless signals 130 containing voice traffic, data traffic, and/or control signals. A network node 120 communicating voice traffic, data traffic, and/or control signals to wireless device 110 may be referred to as a serving network node 120 for the wireless device 110.
(20) In some embodiments, wireless device 110 may be referred to by the non-limiting term “UE.” A UE may include any type of wireless device capable of communicating with a network node or another UE over radio signals. The UE may comprise radio communication device, target device, device to device (D2D) UE, machine type UE or UE capable of machine to machine communication (M2M), a sensor equipped with UE, iPAD, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), etc.
(21) In some embodiments, network node 120 may include any type of network node such as a base station, radio base station, base transceiver station, base station controller, network controller, evolved Node B (eNB), Node B, multi-RAT base station, Multi-cell/multicast Coordination Entity (MCE), relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., MME, SON node, a coordinating node, etc.), or even an external node (e.g., 3rd party node, a node external to the current network), etc.
(22) Wireless signals 130 may include both downlink transmissions (from radio network node 120 to wireless devices 110) and uplink transmissions (from wireless devices 110 to radio network node 120).
(23) Each network node 120 may have a single transmitter or multiple transmitters for transmitting wireless signals 130 to wireless devices 110. In some embodiments, network node 120 may comprise a multi-input multi-output (MIMO) system. Similarly, each wireless device 110 may have a single receiver or multiple receivers for receiving signals 130 from network nodes 120.
(24) Network 100 may include carrier aggregation. For example, wireless device 110 may be served by both network node 120a and 120b and communicate wireless signals 130 with both network node 120a and 120b.
(25) In certain embodiments, network nodes 125 may interface with a radio network controller (RNC). The radio network controller may control network nodes 120 and may provide certain radio resource management functions, mobility management functions, and/or other suitable functions. In certain embodiments, the functions of the radio network controller may be included in network node 120. The radio network controller may interface with a core network node (CN), such as core network node 320.
(26) In certain embodiments, the radio network controller may interface with core network node 320 via an interconnecting wired or wireless network. The interconnecting network may refer to any interconnecting system capable of transmitting audio, video, signals, data, messages, or any combination of the preceding. The interconnecting network may include all or a portion of a public switched telephone network (PSTN), a public or private data network, a local area network (LAN), a metropolitan area network (MAN), a wide area network (WAN), a local, regional, or global communication or computer network such as the Internet, a wireline or wireless network, an enterprise intranet, or any other suitable communication link, including combinations thereof.
(27) In some embodiments, core network node 320 may manage the establishment of communication sessions and various other functionalities for wireless devices 110. Examples of core network node 320 may include mobile switching center (MSC), mobility management entity (MME), serving gateway (SGW), packet data network gateway (PGW), operation and maintenance (O&M), operations support system (OSS), SON, positioning node (e.g., Enhanced Serving Mobile Location Center, (E-SMLC)), MDT node, etc. Wireless devices 110 may exchange certain signals with core network node 320 using the non-access stratum layer. In non-access stratum signaling, signals between wireless devices 110 and core network node 320 may be transparently passed through the radio access network. In certain embodiments, network nodes 120 may interface with one or more network nodes 120 over an internode interface, such as, for example, an X2 interface.
(28) In particular embodiments, core network node 320 may perform positioning for a wireless device, such as wireless device 110. Core network node 320 may transmit positioning reference signals (PRS) and positioning assistance information to wireless device 110. Core network node 320 may receive positioning measurements from wireless device 110.
(29) In some embodiments, wireless device 110 may report positioning measurements. Wireless device 110 may receive network assistance information from a network node, such as core network node 320. The network assistance information is for assisting wireless device 110 in performing OTDOA. The network assistance information comprises: a list of reference cells; a list of neighbor cells; and a rule for terminating RSTD measurements.
(30) In some embodiments, wireless device 110 may use the network assistance information to perform RSTD measurement between a cell in the reference cell list and a cell in the neighbor cell list. When wireless device 110 determines the RSTD measurement satisfies the rule for terminating RSTD measurements, wireless device 110 may report the RSTD measurements to the network node. When wireless device 110 determines the RSTD measurement does not satisfy the rule for terminating RSTD measurements, wireless device 110 may perform another RSTD measurement between the cell in the reference cell list and a cell in the neighbor cell list.
(31) In particular embodiments, the rule for terminating RSTD measurements indicates terminating RSTD measurements after taking at least a pre-determined number (N) of RSTD measurements having a least a pre-determined quality (X). The pre-determined number (N) may be less than fifteen.
(32) In particular embodiments, the report to the network node includes a quality of the RSTD measurements and/or an indication whether the rule for terminating RSTD measurements was satisfied.
(33) In particular embodiments, the rule for terminating RSTD measurements indicates terminating RSTD measurements after taking at least a first pre-determined number (N1) of RSTD measurements having a least a first pre-determined quality (X1) or at least a second pre-determined number (N2) of RSTD measurements having a least a second pre-determined quality (X2). Additional details are described below with respect to
(34) In wireless network 100, each radio network node 120 may use any suitable radio access technology, such as long term evolution (LTE), LTE-Advanced, NR, UMTS, HSPA, GSM, cdma2000, WiMax, WiFi, and/or other suitable radio access technology. Wireless network 100 may include any suitable combination of one or more radio access technologies. For purposes of example, various embodiments may be described within the context of certain radio access technologies. However, the scope of the disclosure is not limited to the examples and other embodiments could use different radio access technologies.
(35) As described above, embodiments of a wireless network may include one or more wireless devices and one or more different types of radio network nodes capable of communicating with the wireless devices. The network may also include any additional elements suitable to support communication between wireless devices or between a wireless device and another communication device (such as a landline telephone). A wireless device may include any suitable combination of hardware and/or software. For example, in particular embodiments, a wireless device, such as wireless device 110, may include the components described below with respect to
(36) Particular embodiments include response time termination. IoT devices may aggregate a downlink reference signal (e.g., positioning reference signal (PRS)) for several/many occasions (repetitions) to achieve an acceptable positioning estimation. Aggregating the downlink reference signal impacts the response time. Thus, in particular embodiments the network node provides network assistance information to the UE. The network assistance information enables the UE to optimize performance regarding the response time. The assistance may also minimize the complexity and power consumption of the UE. In one embodiment, the legacy response time can be sub-divided into more numbers to assist the UE in prioritizing the RSTD measurement performance, meaning that the response time can be modified to also include time to measure N cells.
(37) Some embodiments include a predefined rule for measurement termination. In conventional positioning procedures, the UE reports fifteen RSTDs assuming that the signal to interference-plus-noise ratio (SINR) is above a threshold. To further assist an NB-IoT UE, and to avoid unnecessary measurement at the UE, in particular embodiments the location server provides the UE with the option that if N RSTDs with quality X have been measured, then the UE is allowed to report the RSTD measurement, and the UE does not continue with further measurements. N and X may be configured via a measurement instruction. In some embodiments, it may be sufficient to do the positioning estimation with a fewer number of RSTDs if the RSTDs have adequate RSTD quality.
(38) In some embodiments, a location server provides a UE with the option that if N RSTDs with quality X have been measured, then the UE is allowed to report the RSTD measurement, and the UE does not continue with further measurements. The quality of RSTD measurement (rstd-Quality) may be defined based on error-Resolution, error-Value and error-NumSamples, as described in Table 1.
(39) TABLE-US-00001 TABLE 1 List of higher-layer result parameters. Description Symbol Unit Reference Reference signal time difference measured at the UE Δt.sub.i T.sub.s 5.1.12 antenna connector to be obtained in RRC_CONNECTED RSTD report map state (intra- and inter-frequency) and requires [1], 9.1.10.3 compensation of potential bandwidth- or band dependent group delays (LPP reporting: rstd) Δt.sub.i = t.sub.i − T.sub.REF Measurement range: −16384, . . . , 16383 Reportable range: −15391, . . . , 15391 (LPP: rstd-Quality) 6.5.1.2 error-Resolution, bit string (2) error = X * R to Values: 5, 10, 20, 30 meters (X + 1) * R − 1 meters, error-Value, bit string (5) where X is given by Values: 0, . . . , 31 error-Value and R by error-NumSamples, bit string (3) error-Resolution. Value: 0 (i.e., not the baseline metrics) Note: Not the baseline metrics shall he reported by which the UE can derive previous two fields based on e.g., SINR. Moreover we avoid disclosing information about how we derive the RSTD estimates.
(40) In some embodiments, the choice of X by the location server is based on, but not limited to, the following: (a) error-Value; (b) error-Value times error-Resolution; (c) SINR; (d) cross-correlation characteristics of the estimated channels used for forming the RSTDs; and (e) an ordering rule in the neighbor list. As an example, A UE may measure SINR and the choice of N and X may be as follows: (N, X)={(12, −14 dB), (10, −13 dB), (8, −12 dB), (6, −11 dB), (5, −10 dB)}
(41) In particular embodiments, the IoT device performs RSTD measurements based on the assistance information sent by the location server. The UE may report both the RSTD and RSTD quality to the E-SMILC. The RSTD quality is according to the estimated RSTD measurement sent by the location server. If the IoT device has terminated the RSTD measurement procedure according to one of the conditional termination criteria sent by the network as the assistance data, the IoT device can optionally report the condition used together with the RSTD measurements.
(42) Some embodiments may include signaling support via LPP. An example is given below.
(43) TABLE-US-00002 -- ASN1START CommonIEsRequestLocationInformation ::= SEQUENCE { locationInformationType LocationInformationType, triggeredReporting TriggeredReportingCriteria OPTIONAL, -- Cond ECID periodicalReporting PeriodicalReportingCriteria OPTIONAL, -- Need ON additionalInformation AdditionalInformation OPTIONAL, -- Need ON qos QoS OPTIONAL, -- Need ON environment Environment OPTIONAL, -- Need ON locationCoordinateTypes LocationCoordinateTypes OPTIONAL, -- Need ON velocityTypes VelocityTypes OPTIONAL, -- Need ON ... } LocationInformationType ::= ENUMERATED { locationEstimateRequired, locationMeasurementsRequired, locationEstimatePreferred, locationMeasurementsPreferred, ... } PeriodicalReportingCriteria ::= SEQUENCE { reportingAmount ENUMERATED { ra1, ra2, ra4, ra8, ra16, ra32, ra64, ra-Infinity } DEFAULT ra-Infinity, reportingInterval ENUMERATED { noPeriodicalReporting, ri0-25, ri0-5, ri1, ri2, ri4, ri8, ri16, ri32, ri64 } } TriggeredReportingCriteria ::= SEQUENCE { cellchange BOOLEAN, reportingDuration ReportingDuration, ... } ReportingDuration ::= INTEGER (0..255) AdditionalInformation ::= ENUMERATED { onlyReturnInformationRequested, mayReturnAditionalInformation, ... } QoS ::= SEQUENCE { horizontalAccuracy HorizontalAccuracy OPTIONAL, -- Need ON verticalCoordinateRequest BOOLEAN, verticalAccuracy VerticalAccuracy OPTIONAL, -- Need ON responseTime ResponseTime OPTIONAL, -- Need ON velocityRequest BOOLEAN, [[ adequatePos-r14 AdequatePos-r14 OPTIONAL, -- Need ON ]] ... } HorizontalAccuracy ::= SEQUENCE { accuracy INTEGER(0..127), confidence INTEGER(0..100), ... } VerticalAccuracy ::= SEQUENCE { accuracy INTEGER(0..127), confidence INTEGER(0..100), ... } ResponseTime ::= SEQUENCE { time INTEGER (1..128), ..., [[ responseTimeEarlyFix-r12 INTEGER (1..128) OPTIONAL -- Need ON ]] } AdequatePos-r14 ::= SEQUENCE { minNoOfCells INTEGER (1..16), minMeasQuality OTDOA-MeasQuality OPTIONAL -- Need ON, ... } Environment ::= ENUMERATED { badArea, notBadArea, mixedArea, ... } -- ASN1STOP
(44) Particular embodiments include methods in a wireless device and a network node. Examples are illustrated in
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(46) The method begins at step 412, where the user equipment receives network assistance information from a network node. For example, wireless device 110 may receive network assistance information from core network node 320. The network assistance information is for assisting the wireless device in performing OTDOA.
(47) In particular embodiments, the network assistance information comprises: a list of reference cells; a list of neighbor cells; and a rule for terminating Reference Signal Time Difference (RSTD) measurements. In some embodiments, the network assistance information includes any of the assistance information according to any of the embodiments and examples above.
(48) At step 414, the user equipment performs RSTD measurement between a cell in the reference cell list and a cell in the neighbor cell list. For example, wireless device 110 may calculate a time of arrival (TOA) for a reference signal from a reference cell, such a cell 115a, and may calculate a time of arrival (TOA) for a reference signal from a neighbor cell, such as cell 115b. Wireless device may determine a reference signal time difference between the two measurements.
(49) In some embodiments, the method continues to step 416, where the user equipment determines an RSTD quality of the measured RSTD. For example, wireless device 110 may measure an SINR of the reference signal as −10 dB. In some embodiments, the measurements include any of the measurements described with respect to any of the embodiments and examples above.
(50) At step 418, the user equipment determines whether the RSTD measurement satisfies the rule for terminating RSTD measurements. For example, the rule may require three positioning measurements with an SINR above −12 dB. The UE determines whether the most recent measurement from steps 414 and 416 satisfy the rule. If so, the method continues to step 420, otherwise the method returns to step 414.
(51) In particular embodiments, the rule for terminating RSTD measurements indicates terminating RSTD measurements after taking at least a pre-determined number (N) of RSTD measurements having a least a pre-determined quality (X). Some embodiments may include multiple criteria. For example, in some embodiments the rule for terminating RSTD measurements indicates terminating RSTD measurements after taking at least a first pre-determined number (N1) of RSTD measurements having a least a first pre-determined quality (X1) or at least a second pre-determined number (N2) of RSTD measurements having a least a second pre-determined quality (X2) (e.g., three measurements of a lower quality, or two measurements of a higher quality). In some embodiments, the determination is made according to any of the embodiments and examples above.
(52) At step 420, the user equipment the RSTD measurements to the network node. For example, wireless device 110 may report RSTD measurements (e.g., the measurements from any previous iterations of step 414) to network node 320. Network node 320 may use the measurements for multilateration calculations in determining a position of wireless device 110. The report may include a quality of the RSTD measurements.
(53) In some embodiments, the method includes step 422, where the user equipment also reports that the rule for terminating RSTD measurements was satisfied. For example, wireless device 110 may indicate that the measurement report is being sent early based on satisfaction of the rule, and may specify the rule used. The information may be included in Lug same report as in the previous step. In some embodiments, the report includes any suitable information according to any of the embodiments and examples above.
(54) Modifications, additions, or omissions may be made to method 400 illustrated in
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(56) The method begins at step 512, where the network node transmits network assistance information to a wireless device. The network assistance information is for assisting the wireless device in performing OTDOA. For example, network node 320 transmits network assistance information to wireless device 110.
(57) In particular embodiments, the network assistance information comprises a list of reference cells, a list of neighbor cells, and a rule for terminating RSTD measurements. The assistance information may include any of the assistance information described above with respect to
(58) At step 514, the network node receives a report that provides the RSTD measurements from the wireless device. For example, network node 320 may receive a report from wireless device 110. The report may include any of the information described above with respect to
(59) Modifications, additions, or omissions may be made to method 500 illustrated in
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(61) Particular examples of a wireless device include a mobile phone, a smart phone, a PDA (Personal Digital Assistant), a portable computer (e.g., laptop, tablet), a sensor, a modem, a machine type (MTC) device/machine to machine (M2M) device, laptop embedded equipment (LEE), laptop mounted equipment (LME), USB dongles, a device-to-device capable device, a vehicle-to-vehicle device, or any other device that can provide wireless communication. The wireless device includes transceiver 1110, processing circuitry 1120, memory 1130, and power source 1140. In some embodiments, transceiver 1110 facilitates transmitting wireless signals to and receiving wireless signals from wireless network node 120 (e.g., via an antenna), processing circuitry 1120 executes instructions to provide some or all of the functionality described herein as provided by the wireless device, and memory 1130 stores the instructions executed by processing circuitry 1120. Power source 1140 supplies electrical power to one or more of the components of wireless device 110, such as transceiver 1110, processing circuitry 1120, and/or memory 1130.
(62) Processing circuitry 1120 includes any suitable combination of hardware and software implemented in one or more integrated circuits or modules to execute instructions and manipulate data to perform some or all of the described functions of the wireless device. In some embodiments, processing circuitry 1120 may include, for example, one or more computers, one more programmable logic devices, one or more central processing units (CPUs), one or more microprocessors, one or more applications, and/or other logic, and/or any suitable combination of the preceding. Processing circuitry 1120 may include analog and/or digital circuitry configured to perform some or all of the described functions of wireless device 110. For example, processing circuitry 1120 may include resistors, capacitors, inductors, transistors, diodes, and/or any other suitable circuit components.
(63) Memory 1130 is generally operable to store computer executable code and data. Examples of memory 1130 include computer memory (e.g., Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (e.g., a hard disk), removable storage media (e.g., a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or or any other volatile or non-volatile, non-transitory computer-readable and/or computer-executable memory devices that store information.
(64) Power source 1140 is generally operable to supply electrical power to the components of wireless device 110. Power source 1140 may include any suitable type of battery, such as lithium-ion, lithium-air, lithium polymer, nickel cadmium, nickel metal hydride, or any other suitable type of battery for supplying power to a wireless device.
(65) Other embodiments of the wireless device may include additional components (beyond those shown in
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(67) Receiving module 1150 may perform the receiving functions of wireless device 110. For example, receiving module 1150 may receive, from a network node, network assistance information described in any of the embodiments or examples above (e.g., step 412 of
(68) Measuring module 1152 may perform the measuring functions of wireless device 110. For example, measuring module 1152 may measure positioning reference signals according to any of the embodiments or examples above (e.g., steps 414 and 416 of
(69) Reporting module 1154 may perform the reporting functions of wireless device 110. For example, reporting module 1154 may report measurement reports to a network node according to any of the examples described above (e.g., steps 420 and 422 in
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(71) In some embodiments, network interface 1240 is communicatively coupled to processing circuitry 1220 and refers to any suitable device operable to receive input for network node 120, send output from network node 120, perform suitable processing of the input or output or both, communicate to other devices, or any combination of the preceding. Network interface 1240 includes appropriate hardware (e.g., port, modem, network interface card, etc.) and software, including protocol conversion and data processing capabilities, to communicate through a network.
(72) Other embodiments of network node 120 include additional components (beyond those shown in
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(74) Examples of core network nodes can include an Evolved Serving Mobile Location Centre (E-SMLC), a mobile switching center (MSC), a serving GPRS support node (SGSN), a mobility management entity (MME), a radio network controller (RNC), a base station controller (BSC), an access and mobility management function (AMF), and so on. The core network node includes processing circuitry 620, memory 630, and network interface 640. In some embodiments, processing circuitry 620 executes instructions to provide some or all of the functionality described above as being provided by the network node, memory 630 stores the instructions executed by processing circuitry 620, and network interface 640 communicates signals to any suitable node, such as a gateway, switch, router, Internet, Public Switched Telephone Network (PSTN), network nodes 120, radio network controllers or core network nodes 320, etc.
(75) Processing circuitry 620 may include any suitable combination of hardware and software implemented in one or more modules to execute instructions and manipulate data to perform some or all of the described functions of the core network node. In some embodiments, processing circuitry 620 may include, for example, one or more computers, one or more central processing units (CPUs), one or more microprocessors, one or more applications, and/or other logic.
(76) Memory 630 is generally operable to store instructions, such as a computer program, software, an application including one or more of logic, rules, algorithms, code, tables, etc. and/or other instructions capable of being executed by a processor. Examples of memory 630 include computer memory (for example, Random Access Memory (RAM) or Read Only Memory (ROM)), mass storage media (for example, a hard disk), removable storage media (for example, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or or any other volatile or non-volatile, non-transitory computer-readable and/or computer-executable memory devices that store information.
(77) In some embodiments, network interface 640 is communicatively coupled to processing circuitry 620 and may refer to any suitable device operable to receive input for the network node, send output from the network node, perform suitable processing of the input or output or both, communicate to other devices, or any combination of the preceding. Network interface 640 may include appropriate hardware (e.g., port, modem, network interface card, etc.) and software, including protocol conversion and data processing capabilities, to communicate through a network.
(78) Other embodiments of the network node may include additional components beyond those shown in
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(80) Receiving module 650 may perform the receiving functions of core network node 320. For example, receiving module 650 may receive a measurement report as described in any of the embodiments or examples above (e.g., step 514 of
(81) Transmitting module 652 may perform the transmitting functions of core network node 320. For example, transmitting module 652 may send network assistance information for location measurements to a wireless device according to any of the examples described above (e.g., step 512 of
(82) Some embodiments of the disclosure may provide one or more technical advantages. Some embodiments may benefit from some, none, or all of these advantages. Other technical advantages may be readily ascertained by one of ordinary skill in the art. For example, some embodiments assist a wireless device to terminate a RSTD measurement after the wireless device performs enough measurements. An another example, certain embodiments avoid unnecessary measurements by the wireless device. As another example, certain embodiments minimize the processing effort and power consumption at the device side. As yet another example, certain embodiments reduce the overall overheard of OTDOA positioning method for IoT devices. As a further example, certain embodiments add configurability at the location server to trade-off between positioning accuracy and IoT device power consumption, e.g., because some devices have low positioning accuracy requirements. As a final example, certain embodiments add the configurability to trade-off between time-to-fix and positioning accuracy, a more restrictive termination criterion will lead to a shorter time-to-fix.
(83) Although this disclosure has been described in terms of certain embodiments, alterations and permutations of the embodiments will be apparent to those skilled in the art. Although some embodiments have been described with reference to certain radio access technologies, any suitable radio access technology (RAT) or combination of radio access technologies may be used, such as long term evolution (LTE), LTE-Advanced, NR, UMTS, HSPA, GSM, cdma2000, WiMax, WiFi, etc. Accordingly, the above description of the embodiments does not constrain this disclosure. Other changes, substitutions, and alterations are possible without departing from the spirit and scope of this disclosure.
(84) The following examples are examples of how certain aspects of the embodiments described herein could be implemented within the framework of a specific communication standard. In particular, the following examples provide a non-limiting example of how the embodiments described herein could be implemented within the framework of a 3GPP RAN standard. The changes described by the examples are merely intended to illustrate how certain aspects of the embodiments could be implemented in a particular standard. However, the embodiments could also be implemented in other suitable manners, both in the 3GPP Specification and in other specifications or standards.
(85) An objective of the Rel. 14 NB-IoT enhancements is to improve the positioning support based on OTDOA. In some examples, baseline signal(s) include NB-IoT Rel-13 signals and LTE CRS/PRS in 1 PRB. NB-IoT positioning reference signal resource pattern in one subframe is at least LTE PRS in 1 PRB. NB-IoT PRS do not occur in a subframe containing NPDCCH, NPDSCH, NPBCH or NPSS/NSSS. Some examples include: PSD boosting of NPRS symbols; configuration of time resources for NPRS; indication of exact subframes is by: Part A: A bitmap on subframes which are not NB-IoT DL subframes (i.e. invalid DL subframes). Bitmap is a fixed length of 10 bits, is the same length as valid subframe configuration, i.e. 10 bits or 40 bits, or is a fixed length of x bits (e.g., x=20). Part B: Indicated with one start subframe, one periodicity, and one number of repetitions for the occasions. Indication of exact subframe on an anchor carrier or non-anchor carrier may use Part A and/or Part B. An indication of NPRS muting patterns may be indicated with a periodic NPRS muting sequence.
(86) Particular examples acknowledge the advantage of OTDOA in maintaining the current signaling and architecture as legacy, and some examples refine them for better applicability for NB-IoT.
(87) One advantage in considering the OTDOA method as the positioning method candidate for NB-IoT is that UEs keep the legacy signaling framework procedure for these devices. Providing OTDOA network assistance information can be useful for NB-IoT devices considering the limited capability and power consumption that these devices have. However, the content of this signaling should be different and tailored to the capabilities and requirements of these UEs. Also, minimizing the size of the signaling makes it scalable to NB-IoT limited capabilities. Below are some examples of network assistance information for providing improved positioning performance for these devices.
(88) NB-IoT UEs are expected to have very low capabilities and some minimum requirements such as the sampling rate, bandwidth, supported coverage class, etc. may already be known to the network. Therefore, it is power efficient to omit or limit the UE capability signaling for NB-IoT.
(89) If the NB-IoT UE has some advanced capability in terms of for example “higher sampling rate” from the standard NB-IoT, the UE can inform the location server in terms of this capability to receive more tailored assistance information from the network according to the specified UE capability.
(90) Another parameter can be the capability of supporting the inter-frequency measurement by the device, this would be also required for the network in providing assistance neighbor cell information, etc.
(91) While there may exist more parameters that can be useful for the network to know about the UE, NB-IoT should require minimum amount of OTDOA signaling for positioning estimation.
(92) Observation 1: NB-IoT should require minimum amount of OTDOA signaling for positioning estimation.
(93) Proposal 1: UE capabilities can be optionally sent to the location server without any explicit request from the network for this information.
(94) Proposal 2: UE capability in supporting inter-frequency measurement should be signaled to the location server in order to activate this feature.
(95) Proposal 3: Inter-frequency measurements can be supported for NB-IoT UEs.
(96) A location server (i.e. E-SMLC) may provide the NB-IoT UE with a list of potential reference cell and neighbor cells to be used for RSTD measurements. For each of these lists, the E-SMLC provides a set of information including the physical cell ID, the global cell ID and the PRS info, etc. Other information is the expected RSTD measurement and the expected RSTD uncertainty measurement, which can be useful at the UE. One parameter to be considered is that NB-IoT UEs should aggregate the downlink reference signal (e.g., PRS) for several/many occasions (repetitions), to achieve an acceptable positioning estimation. While this would also impact the response time, it is important that the network assist the UE for an optimum performance in terms of the response time. This assistance intends to minimize the complexity and power consumption at the UE side.
(97) In the legacy procedure, the UE reports 15 RSTDs assuming that the SINR is above threshold. To further assist the NB-IoT UEs, and to avoid unnecessary measurement at the UE, the location server can provide the UE with the option that if N RSTDs with quality X have been measured, then the UE is allowed to report the RSTD measurement, and do not continue with further measurements. N & X can be configured as measurement instruction. For example, it may be sufficient to have 10 RSTDs with SINR above threshold. On the other hand, if there are 4 cells with high SINR, it is still possible to have a position estimation for the UE.
(98) Observation 2: To avoid unnecessary measurement at the UE, the location server can provide the NB-IoT UE with more conditional time of response, and number of required RSTD measurements.
(99) Proposal 4: The location server can provide the UE with the option that if N RSTDs with quality X have been measured, then the UE is allowed to report the RSTD measurement, and do not continue with further measurements. Example: (N, X)={(12, −14 dB), (10, −13 dB), (8, −12 dB), (6, −11 dB), (5, −10 dB)}
(100) The NB-IoT UE performs RSTD measurements based on the assisted information sent by the E-SMLC. The UE may report both the RSTD and RSTD quality to the E-SMLC. The RSTD quality is according to the estimated RSTD measurement sent by the location server. In case the UE has terminated the RSTD measurement procedure according to one of the conditional termination criteria sent by the network as the assisted data, the NB-IoT can optionally report the condition used together with the RSTD measurements.
(101) Proposal 5: The NB-IoT UE shall optionally report the network in terms of termination condition choice for RSTD measurement together with sending the RSTD measurements.
(102) Abbreviations: 3GPP 3rd Generation Partnership Project ACB Access Class Barring AS Access Stratum CA Carrier Aggregation CC Component Carrier CN Core Network eNB Evolved Node B eNodeB Evolved Node B E-SMLC Evolved Serving Mobile Location Center FeMTC Further enhanced MTC FDD Frequency Division Duplex GNSS Global Navigation Satellite System ID Identifier IoT Internet of Things LPP LTE Positioning Protocol LTE Long-Term Evolution MME Mobility Management Entity MSC Mobile Switching Center MTC Machine Type Communication NAS Non Access Stratum NB-IoT NarrowBand-IoT NR New Radio NW Network OTDOA Observed Time Difference of Arrival PCC Primary Component Carrier PCell Primary Cell PDU Protocol Data Unit PGW Packet Data Network Gateway PRB Physical Resource Block RAT Radio Access Technology RAN Radio Access Network RRC Radio Resource Control RSRP Reference Signal Received Power RSRQ Reference Signal Received Quality RSTD Reference Signal Time Difference SCC Secondary Component Carrier SCell Secondary Cell SGW Serving Gateway SLA Service Level Agreement SRB Signaling Radio Bearer TDD Time Division Duplex TDOA Time Difference Of Arrival TOA Time Of Arrival UE User Equipment UMTS Universal Mobile Telecommunications System UTDOA Uplink Time Difference of Arrival