HK1195189A - Methods and apparatuses for altering measurement time and bandwidth during a measurement - Google Patents

Description

Method and apparatus for changing measurement time and bandwidth during measurement

Technical Field

Example embodiments described herein are directed towards a user equipment for handling cell changes and corresponding methods therein. Example embodiments described herein are also directed towards a network node for handling a cell change of a user equipment and corresponding method therein.

Background

Overview of a Wireless communication network

In a typical cellular system, also referred to as a wireless communication network, wireless terminals, also referred to as mobile stations or user equipment, communicate via a Radio Access Network (RAN) with one or more core networks. The wireless terminals can be mobile stations or user equipment units such as mobile telephones, also known as "cellular" telephones, and laptop computers with wireless capability, e.g., mobile termination, and thus can be, for example, portable, pocket, hand-held, computer-included, or car-mounted mobile devices that communicate voice and/or data with a radio access network.

The geographical area covered by the radio access network is divided into cell areas, wherein each cell area is served by a base station, e.g. a Radio Base Station (RBS) (which in some networks is also referred to as "eNodeB" or "NodeB" and in this document also referred to as base station). A cell is a geographical area in which radio coverage is provided by radio base station equipment installed at a base station site. Each cell is identified by an identification code broadcast in the cell within the local radio area. The base station communicates over an air interface operating on radio frequencies with user equipment units within range of the base station.

In some versions of the radio access network, several base stations are typically connected to a Radio Network Controller (RNC), e.g. by landlines or microwave. A radio network controller (also sometimes referred to as a Base Station Controller (BSC)) monitors and coordinates various activities of the multiple base stations connected thereto. The radio network controller is typically connected to one or more core networks. In some networks there is also an interface between radio nodes, e.g. the X2 interface between enodebs in LTE.

The Universal Mobile Telecommunications System (UMTS) is a third generation mobile communication system that has evolved from the global system for mobile communications (GSM) and is designed to provide improved mobile communication services based on Wideband Code Division Multiple Access (WCDMA) access technology. UMTS Terrestrial Radio Access Network (UTRAN) is essentially a radio access network that uses wideband code division multiple access for user equipment units. The third generation partnership project (3GPP) has set out to further evolve UTRAN and GSM based radio access network technologies. Long Term Evolution (LTE) is common with the Evolved Packet Core (EPC) as the latest addition to the 3GPP family.

Radio measurements play a key role in wireless communications. At a general level, radio measurements can be classified into signal strength/quality measurements, timing measurements, and other measurements. The measurements may be performed by a user equipment and/or a radio network node equipped with a radio interface. The different categories or radio measurements and other network aspects related to radio measurements are described in more detail below in accordance with the provided subheadings.

Signal strength and quality measurement

Examples of LTE measurements that characterize the signal strength or quality of a given cell are Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), received interference power, and thermal noise power. RSRP and RSRQ are currently defined as user equipment measurements, e.g., at DL, and are associated with cell-specific reference signals (CRS). However, received signal strength and received signal quality measurements are known to be more general, for example, for any type of signal and for DL and UL. Similar measurements exist in UMTS, GSM, and CDMA2000, among others.

Timing measurement

In LTE, the following user equipment timing measurements have been standardized since release 9: user equipment Rx-Tx time difference, Reference Signal Time Difference (RSTD) and user equipment GNSS timing of a cell frame for user equipment positioning. The following E-UTRAN measurements have been standardized since release 9: eNodeB Rx-Rx time Difference, Timing Advance (TA), TA type 1= (eNB Rx-Tx time Difference) + (user Equipment Rx-Tx time Difference), TA type 2= (eNB Rx-Tx time Difference), and E-UTRAN GNSS timing for a cell frame used for user equipment positioning.

In addition, there may also be measurements that are not explicitly standardized, but which may still be implemented by the user equipment or the E-UTRAN or standardized later. Some examples of these measurements may be time of arrival measured by a radio node, e.g. an eNodeB or a radio measurement node such as an LMU, RSTD measured by a radio node, estimated one-way propagation delay measured by an eNodeB to be signalled to the user equipment for timing advance (similar user equipment measurements will be defined as well) and timing measurements over various links. Similar measurements may also exist in other RATs, e.g., Rx-Tx measurements may be similar to Round Trip Time (RTT) measurements in UMTS, and RSTD may be similar to System Frame Number (SFN) to SFN time differences in UMTS.

Timing measurements may be used for positioning (e.g., using enhanced cell identification (E-CID), adaptive enhanced cell id (aecid), pattern matching, observed time difference of arrival (OTDOA), uplink time difference of arrival (U-TDOA), hybrid positioning methods), drive test Miniaturization (MDT), network planning, self-optimization/organization network (SON), enhanced inter-cell resource and interference coordination (eICIC), and heterogeneous network (HetNet) (e.g., for optimizing cell ranges for different cell types), handover parameter configuration, time coordinated scheduling, etc. The general purpose measurements are typically configured by the serving/primary cell. The specific purpose measurements may be configured by other nodes, e.g. by a positioning node, e.g. an evolved serving mobile location center (E-SMLC) or a secure user plane location platform (SLP) in LTE, a SON node, an MDT node, etc.

The timing advance may also be used to control timing adjustment of user equipment UL transmissions. The adjustments are transmitted to the UE in a timing advance command. In LTE, for user equipment that does not support LPP, the user equipment timing adjustment may be based on TA type 2.

User equipment measurements configured by the network are typically reported to a network node, e.g., eNodeB, positioning node, etc. The radio node measurements may also be reported to a network node, e.g. another radio node such as an eNodeB or a LUM, or other network nodes such as a positioning node. Some measurements may not be reported but used internally by the measurement node including the user equipment. Furthermore, some measurements may involve two directions (DL and UL), e.g. Rx-Tx measurements. It should also be understood that the user equipment may also be involved in radio node (e.g. eNodeB) measurements, e.g. Rx-Tx measurements, and that the eNodeB may also be involved in user equipment measurements, e.g. Rx-Tx measurements.

Other measurements

An example of a measurement that does not belong to the first two sets of measurements is an angle of arrival (AoA) measurement. In the current LTE standard, AoA is defined as E-UTRAN measurement. However, AoA measurements performed by the user equipment are also known.

Inter-frequency, inter-band and inter-RAT measurements

The user equipment typically supports all intra-RAT measurements (i.e. inter-frequency and in-band measurements) and meets the association requirements. However, inter-band and inter-RAT measurements are user equipment capabilities that are reported to the network during call setup. User equipment supporting certain inter-RAT measurements should meet corresponding requirements. For example, a user equipment supporting LTE and WCDMA should support intra-LTE measurements, intra-WCDMA measurements, and inter-RAT measurements (i.e., measure WCDMA when the serving cell is LTE and measure LTE when the serving cell is WCDMA). Thus, the network is able to use these capabilities according to its policy. These capabilities are driven largely by factors such as market demand, cost, typical network deployment scenarios, frequency allocations, and the like.

Inter-frequency measurements

Inter-frequency measurements relate to measurements for at least one cell belonging to a different frequency/carrier than the serving/primary cell frequency/carrier (e.g., RSTD measurements relate to two cells). Examples of inter-frequency measurements are inter-frequency RSRP, inter-frequency RSRQ, inter-frequency RSTD, etc.

The user equipment performs inter-frequency and inter-RAT measurements in the measurement gaps. Measurements can be made for various purposes: mobility, positioning, self-organizing networks (SON), drive test miniaturization, etc. Furthermore, the same gap pattern is used for all types of inter-frequency and inter-RAT measurements. Therefore, the E-UTRAN must provide a single measurement gap pattern with a constant gap duration for concurrent monitoring (i.e., cell detection and measurement) of all frequency layers and RATs.

inter-RAT measurement

In general, in LTE, inter-RAT measurements are typically defined similarly to inter-frequency measurements, e.g. they may also require configuring measurement gaps as for inter-frequency measurements, but with more measurement restrictions and generally more relaxed requirements for inter-RAT measurements. As a particular example, there may also be multiple networks using overlapping sets of RATs. Examples of current inter-RAT measurements specified for LTE are UTRA FDD CPICH RSCP, UTRA FDD carrier RSSI, UTRA FDD CPICH Ec/No, GSM carrier RSSI, and CDMA 20001 x RTT pilot strength. LTE FDD and TDD may also be considered as different RATs.

Inter-band measurement

Inter-band measurements refer to measurements made by the user equipment for a target cell on a carrier frequency belonging to a different frequency band than the serving/primary cell. Both inter-frequency and inter-RAT measurements can be in-band or inter-band.

The motivation for inter-band measurements is that most of the user equipments today support multiple frequency bands even for the same technology. This is facilitated by interests from the service provider; a single service provider may own carriers in different frequency bands and may efficiently utilize the carriers by performing load balancing on the different carriers. A well-known example is the example of a multi-band GSM terminal with the 800/900/1800/1900 frequency band.

In addition, the user equipment may also support multiple technologies, such as GSM, UTRA FDD, and E-UTRAN FDD. Since all UTRA and E-UTRA bands are common, a multi-RAT user equipment may support the same band for all supported RATs.

Carrier Aggregation (CA) network

Multi-carrier systems, or interchangeably referred to as Carrier Aggregation (CA), allow user equipment to receive and/or transmit data simultaneously over more than one carrier frequency. Each carrier frequency is often referred to as a Component Carrier (CC) or simply a serving cell in a serving sector, and more particularly a primary or secondary serving cell. The multi-carrier concept is used in both HSPA and LTE. Carrier aggregation is supported for both adjacent and non-adjacent component carriers, and component carriers originating from the same eNodeB need not provide the same coverage. Further, the carriers may also belong to different RATs. The following definitions are provided for various cells in a CA network.

A serving cell: for a user equipment in RRC _ CONNECTED that is not configured with CA, there may be only one serving cell including a primary cell. For a user equipment in RRC CONNECTED configured with CA, the term 'serving cell' is used to denote a set of one or more cells consisting of a primary cell and all secondary cells.

Primary cell (PCell): a cell operating in a primary frequency, wherein the user equipment performs an initial connection establishment procedure or initiates a connection re-establishment procedure, or a cell indicated as a primary cell in a handover procedure.

Secondary cell (SCell): a cell operating on a secondary frequency, which may be configured once an RRC connection is established, and which may be used to provide additional radio resources.

In the downlink, the carrier corresponding to the PCell is a downlink primary component carrier (DL PCC), and in the uplink, it is an uplink primary component carrier (UL PCC). Depending on the user equipment capabilities, a secondary cell (SCell) can be configured to form a set of serving cells together with the PCell. In the downlink, the carrier corresponding to the SCell is a downlink secondary component carrier (DL SCC), and in the uplink, it is an uplink secondary component carrier (UL SCC).

In CA, a base station (e.g., eNode B) in LTE is able to deactivate one or more secondary cells on a corresponding secondary carrier. Deactivation is done by the eNode B using lower layer signaling (e.g., through PDCCH in LTE), using a short command such as ON/OFF (e.g., using 1 bit for each SCell). The activation/deactivation command is transmitted to the user equipment via the PCell. Typically, deactivation occurs when there is no data to be transmitted on one or more scells. Activation/deactivation can be done independently of the uplink and downlink scells. The purpose of the deactivation is therefore to achieve user equipment battery saving. Deactivating one or more scells can also be activated through the same lower layer signaling.

Cell change in LTE

Herein, cell change refers to changing a cell with which a user equipment is associated. Cell change may also refer to, for example:

serving cell change (e.g., handover in non-CA systems or when the user equipment is not configured with any SCell),

serving cell set change (e.g., adding/removing/modifying scells in CA system),

PCell change (e.g. changing a current PCell, which is a cell with a first cell identity, to another cell with a second cell identity in a CA system).

The cell change may occur, for example, during the following:

handover (intra-frequency, inter-frequency or inter-RAT), or

PCell change on the same PCC (in a CA system), or

Carrier switching (change the current PCC to another frequency carrier, which also means PCell change).

Cell change may be due to, for example, mobility, load balancing, energy saving, carrier activation/deactivation or cell activation/deactivation, secondary carrier activation/deactivation or secondary cell (or secondary serving cell) activation/deactivation, etc.

Measurement requirements for cell change

Most of the measurements characterize the signal of a particular cell, e.g., a serving or neighboring cell. Part of the measurements relates to signals of two specific cells, e.g. relative measurements such as RSTD between neighbouring cells and a reference cell. Several measurements characterize the radio environment at a particular location (e.g., interference and noise related measurements such as thermal noise power, received interference power, RSSI, or noise rise).

Measurements may be specified for a certain cell (e.g., identified by a cell identity) or a certain cell category (e.g., serving cell, reference cell, neighboring cell). When e.g. a serving cell change occurs for the user equipment, the cell identity of the same cell is not changed. However, when the user equipment moves from one cell to another, the class of the cell may or may not change, e.g. the serving cell changes during handover or carrier switching, but the OTDOA reference cell may not change. Thus, measurements associated with a certain cell (e.g. as in OTDOA) may generally continue after e.g. a handover, while measurements associated with a certain cell class may need to be stopped or restarted at the time of a handover, depending on the measurements and the cell class.

Example 1: requirement of user equipment Rx-Tx measurement for positioning when handover occurs

The current standard specifies that if the user equipment is performing user equipment Rx-Tx time difference measurements when the serving cell changes due to handover, the user equipment will restart Rx-Tx measurements on the new cell. In this case the user equipment will also meet the user equipment Rx-Tx time difference measurement and accuracy requirements. However, the physical layer measurement period of the user equipment Rx-Tx measurements will not exceed that defined by：

Wherein K is the measurement period of the serving cellThe number of times of the above change is made,time to change serving cell due to handover; it can be up to 45 ms.

Example 2: user equipment Rx-Tx measurement requirements for positioning when PCell exchange occurs with carrier aggregation.

User supporting E-UTRA carrier aggregation if configured with secondary component carriersThe device is performing user equipment Rx-Tx time difference measurement when the PCell is changed regardless of whether the primary component carrier is changed, the user equipment will restart Rx-Tx measurement for a new PCell. In this case the user equipment will also meet the user equipment Rx-Tx time difference measurement and accuracy requirements. However, the physical layer measurement period of the user equipment Rx-Tx measurements will not exceed that defined by：Wherein: n is PCell in measurement periodThe number of times of the above change is made,is the time to change the PCell; it can be up to 25 ms.

For OTDOA, the user equipment performs RSTD measurements for the reference cell, so in general the user equipment should be able to continue with RSTD measurements after the serving/primary cell is changed when assistance data is provided for the reference cell (which is not restricted to the serving cell).

Effect of RF receiver reconfiguration on measurements

In single carrier LTE, a cell may operate with a channel bandwidth varying in the range from 1.4 MHz to 20 MHz. However, single carrier legacy user equipment will be able to receive and transmit over 20 MHz, the maximum single carrier LTE bandwidth. The user equipment may also shorten the bandwidth of its RF front end if the serving cell bandwidth is less than 20 MHz. For example, if the serving cell Bandwidth (BW) is 5 MHz, the user equipment may also configure its RF BW to 5 MHz. This approach has several advantages. For example, it enables the user equipment to:

-protecting the user equipment from noise outside the current reception bandwidth,

saving its battery life by reducing power consumption.

The reconfiguration of the user equipment reception and/or transmission bandwidth involves a certain delay, e.g. 0.5-2 ms or longer, depending on the user equipment implementation and also depending on whether the UL BW and DL BW are reconfigured at the same time. This small delay is commonly referred to as an 'error'. During the error, the user equipment cannot receive from or transmit to the serving cell. This may therefore cause an interruption of data reception/transmission from/to the serving cell. The user equipment is also unable to perform any type of measurement during the error. Errors occur when a user equipment expands its bandwidth (e.g., from 5 MHz to 10 MHz) or when it shortens its bandwidth (e.g., from 10 MHz to 5 MHz).

Furthermore, when the user equipment is operating at a bandwidth below its maximum reception capability and the user equipment wishes to make measurements at a bandwidth larger than the current bandwidth, e.g. for measuring cells on the same frequency, it must turn on its receiver for performing the measurements. Thus, in this case (i.e. when the current BW < maximum BW), errors occur before and after the user equipment gets the measurement samples if the user equipment reconfigures back to its current operation after the measurement samples over the larger bandwidth. On the other hand, keeping the receiver on, e.g. up to the maximum bandwidth, without errors when the system bandwidth of the first measuring cell is less than the maximum BW, in order to achieve measurement of larger bandwidth neighbor cells on the same frequency, may cause a degradation of the performance of the first cell measurements.

Errors also occur when a CA-capable user equipment reconfigures its bandwidth from single carrier to multi-carrier mode or vice versa, or when CA cells or component carriers are activated/deactivated. For example, consider a CA capable user equipment supporting 2 DL component carriers (PCC and 1 SCC) of 20 MHz each. If the secondary component carrier is deactivated by the serving/primary cell, the user equipment will shorten its BW, e.g. from 40 MHz to 20 MHz. This may result in 1-2 ms or even longer interruptions on the PCC.

Positioning architecture in LTE

Three key network elements in the LTE positioning architecture are the LCS client, the LCS target and the LCS server. An LCS server is a physical or logical entity that manages the positioning of an LCS target device (typically a user equipment or a radio node) by collecting measurements and other location information, assisting the terminal in making the measurements when necessary, and estimating an LCS target location. An LCS client is a software and/or hardware entity interacting with an LCS server in order to obtain location information for one or more LCS targets, i.e. located entities. The LCS client may reside in a network node, a radio network node, a user equipment, and it may also reside in the LCS target itself. The LCS client sends a request to the LCS server for location information, and the LCS server processes and services the received request and sends the positioning result and optionally a velocity estimate to the LCS client. The location request can originate from a terminal, a radio network or a network.

The location calculation can be performed, for example, by a location server (e.g., E-SMLC or SLP in LTE) or the UE. The former corresponds to a user equipment assisted positioning mode and the latter corresponds to a user equipment based positioning mode.

Two positioning protocols operating via the radio network exist in LTE, LPP and LPPa. LPP is a point-to-point protocol used between an LCS server and an LCS target device to locate the target device. LPP can be used in both the user and control planes and allows multiple LPP processes in series and/or parallel, thereby reducing latency. LPPa is a protocol between eNodeB and LCS server specified only for control plane positioning procedures, but it is still able to assist user plane positioning by querying eNodeB information and eNodeB measurements. The SUPL protocol is used for transmission of LPP in the user plane. LPP also has the possibility to transfer LPP extension messages inside the LPP message, e.g. specifying the current OMA LPP extension (LPPe) in order to allow e.g. operator specific assistance data or assistance data which cannot be provided with LPP, or to support other location reporting formats or new positioning methods.

As currently standardized in LTE, a higher layer architecture is shown in fig. 1, where the LCS target is a terminal and the LCS server is an E-SMLC or SLP. In the figure, the control plane location protocol with E-SMLC as termination point is shown in blue and the user plane location protocol is shown in red. The SLP may comprise two components, an SPC and an SLC, which may also reside in different nodes. In an example implementation, the SPC has a proprietary interface with the E-SMLC and a LIp interface with the SLC, and the SLC portion of the SLP communicates with the P-GW (PDN gateway) and external LCS clients.

Additional positioning infrastructure elements may also be deployed to further enhance the performance of a particular positioning method. For example, deploying radio beacons is a cost effective solution that can significantly improve positioning performance indoors and also outdoors by, for example, employing proximity location technology to allow more accurate positioning.

Disclosure of Invention

During operation, the user equipment may often change from one cell to another, referred to as a cell change operation. Positioning measurements performed by the user equipment during mobility procedures causing cell changes may be interrupted or adversely affected. Accordingly, at least one object of a portion of the example embodiments described herein is to provide a way of handling such cell changes in order to minimize or reduce interruption of measurements caused by the cell changes.

Accordingly, example embodiments described herein are directed to improved positioning measurements during user equipment cell change. Some of the example embodiments described herein may be summarized generally as follows:

-enabling a network node (e.g. eNode B, MDT, SON, positioning node, etc.) to obtain user equipment cell change information (e.g. serving/primary cell list, additional user equipment trajectory information, etc.) over a certain time period.

-configuring the node with specific measurements while taking into account cell changes of the user equipment.

-the user equipment performing the configured measurements while taking into account the cell change.

-the resulting user equipment cell change information is used by the network node for one or more tasks associated with monitoring, managing and/or planning, positioning, tracking, etc. of the network.

-predefined rules for user equipment behaviour to ensure that the user equipment fulfils positioning measurement requirements during cell change (i.e. at serving cell/PCell change) over a positioning measurement period while taking into account at least the bandwidth of all serving cell (s)/PCell(s).

Accordingly, some of the example embodiments described herein may be directed to a method in a user equipment for handling a cell change, wherein the user equipment is comprised in a wireless communication network. The method includes performing at least one measurement and receiving, from a network node, a notification of a cell change from a first cell to a second cell and information associated with the cell change. The method also includes performing a cell change during the at least one measurement and varying a duration of a measurement time over which the at least one measurement is performed. The method also includes changing a measurement bandwidth of at least one measurement, where the changing is based on the associated bandwidths of the first and second cells. The method also includes completing at least one measurement based on the changed duration of the measurement time and the changed measurement bandwidth.

Some example embodiments may be directed to a user equipment for handling a cell change, wherein the user equipment is comprised in a wireless communication network, the user equipment comprising: a measurement unit configured to perform at least one measurement; and a receiving port configured to receive, from the network node, a notification of a cell change from the first cell to the second cell and information associated with the cell change. The measurement unit is further configured to perform a cell change during the at least one measurement. The user equipment further comprises a changing unit configured to change a duration of the measurement time on which the at least one measurement is performed. The changing unit is further configured to change a measurement bandwidth of at least one measurement, wherein the change of the measurement time and the measurement bandwidth is based on the associated bandwidths of the first and second cells. The measurement unit is further configured to complete at least one measurement based on the changed duration of the measurement time and the changed measurement bandwidth.

Some example embodiments are directed to a method in a network node for handling a cell change of a user equipment, wherein the network node is comprised in a wireless communication network. The method comprises sending a request to perform at least one measurement to a user equipment and determining information associated with a cell change from a first cell to a second cell, wherein the information associated with the cell change comprises a change instruction for changing the user equipment measurement time and measurement bandwidth in the presence of the cell change. The method also includes sending a notification of the cell change and information associated with the cell change to the user equipment. The method also includes receiving measurement data from the user equipment, the measurement data including at least one other measurement performed on a duration of change in measurement time and a bandwidth of the change measurement, wherein the duration of change in measurement time and the bandwidth of the change measurement are based on bandwidths associated with the first and second cells.

Some example embodiments may be directed to a network node for handling a cell change of a user equipment, wherein the network node is comprised in a wireless communication network. The network node comprises: a transmit port configured to transmit a request to perform at least one measurement to a user equipment; and a changing unit configured to determine an instruction for changing the user equipment measurement time and the measurement bandwidth in a case where a cell change from the first cell to the second cell exists. The transmit port is further configured to send a notification of the cell change and information associated with the cell change to the user equipment, the information including an instruction for the change. The network node further comprises a receiving port configured to receive measurement data from the user equipment, the measurement data comprising at least one other measurement performed on a changing duration of the measurement time and a changing measurement bandwidth, wherein the changing duration of the measurement time and the changing measurement bandwidth are based on the transmitted instructions for changing the bandwidth associated with the first and second cells.

Example embodiments described herein provide increased accuracy of location measurements in a radio network and enable maintaining positioning performance when cell changes occur during measurements. Further, greater efficiency in the use of network resources may be provided using the example embodiments described herein.

Drawings

The foregoing will be apparent from the following more particular description of example embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating example embodiments.

Fig. 1 is a schematic diagram of a positioning architecture in LTE;

FIG. 2 is an illustrative example of a user equipment performing positioning measurements;

FIG. 3 is an illustrative example of a user device record in accordance with a portion of an example embodiment;

FIG. 4 is a schematic diagram of a user device, according to a portion of an example embodiment;

fig. 5 is a schematic diagram of a network node according to a portion of an example embodiment;

FIG. 6 is a flowchart illustrating example operations that may be performed by the user device of FIG. 4; and

fig. 7 is a flow diagram illustrating example operations that may be performed by the network node of fig. 5.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular components, elements, techniques, etc. in order to provide a thorough understanding of the example embodiments. However, example embodiments may be practiced in other ways than these specific details. In other instances, detailed descriptions of well-known methods and elements are omitted so as not to obscure the description of the example embodiments.

Overview of positioning measurements

For ease of illustration, an overview of the positioning method will be provided. Hereafter, limitations of this approach will be identified and discussed. Fig. 1 shows a positioning architecture in an LTE system. The positioning architecture may include a user equipment 101, which may be configured to perform positioning measurements. User equipment 101 may communicate with base station 103. The base station 103 may communicate with a core network that includes a Serving Gateway (SGW)109, a packet data network gateway (PGW)111, and a Mobility Management Entity (MME) 107. The core network may also include one or more nodes with location functionality, such as a Gateway Mobile Location Center (GMLC)105, an enhanced serving mobile location center (E-SMLC)115, and/or a secure user plane location platform (SLP) 113.

The GMLC 105 may be used to request routing information from an HLR (home location register) or HSS (home subscriber server). The GMLC 105 may also be used to send a location request to a VMSC (visited mobile switching center), SGSN (serving GPRS support node), MSC (mobile switching center) server or MME and receive a final location estimate from the corresponding entity. E-SMLC 115 may communicate with user equipment 101 using the LPP protocol for location services and assistance data transfer. E-SMLC 115 may also use the LPPa protocol with base station 103 for assistance data purposes. SLP 113 may be responsible for coordinating and managing functions to provide location services. SLP 113 may also be responsible for location functions. SLP 113 is a positioning node in the user plane.

Fig. 2 shows an overview of positioning measurements performed by the user equipment 101. During the measurement, the user equipment may communicate with the serving base station 103S. The user equipment 101 may be configured to receive measurements from a plurality of base stations 103A-103C. The user equipment may also communicate with location node E-SMLC 115 and/or SLP 113. During positioning measurements, it may generally be desirable to consider the bandwidth of the serving cell associated with the serving base station 103S, the bandwidth of various measurement cells associated with the base stations 103A-103C, and the bandwidth of various Positioning Reference Signals (PRSs).

Limitations of current solutions

The following is a discussion of limitations of current solutions that the inventors have identified. The discussion of limitations also includes a discussion of possible solutions to such limitations that the inventors have recognized. During the mobility procedure, the positioning measurements performed by the user equipment 101 may be interrupted or adversely affected. The interruption and/or adverse effect may be caused by a cell change resulting from the mobility procedure.

There are a number of problems associated with current positioning solutions during cell change. At least the following problems have been identified:

for positioning measurements, the serving cell may not be in OTDOA assistance data and thus the user equipment will not report its measurements, so the positioning node does not know to the current standard whether the serving cell has changed during the measurement period, but the serving cell configuration and the number of changes do affect the measurement accuracy and reporting time.

For measurements on reference cells (e.g. RSTD measurements or relative RSRP/RSRQ measurements), the user equipment behavior and measurement time are still unclear at serving/primary cell change.

Theoretically, the user equipments should be able to continue to make measurements when they are also defined for non-serving cells; but there may be different effects on complexity depending e.g. on whether this is a CA system or whether the frequency/carrier has changed (since the intra-and inter-frequency requirements are different).

This aspect may also need to be considered if there are multiple cell changes during the measurement.

The network node (e.g. positioning node) is not aware of the serving/primary cell change that may occur during ongoing measurements.

When a measurement is received by the network, the received measurement may be less accurate and/or reported after a longer time, but the network may collect statistics on the measurement and use it for other purposes (e.g. SON), and may erroneously classify the measurement without knowing the cause of degraded performance.

When performing measurements, the network does not know the reason for the long measurement time, which can interrupt the session before the measurement is received, even if the measurement time is on demand that can take into account the number of cell exchanges;

when the test takes into account the measurement requirements of the serving/primary cell change, the test equipment must know e.g. information associated with the cell change.

When multiple cell changes occur during measurements, the network (e.g. positioning node or SON) will benefit from a history of cell changes, which currently cannot be reported as a single measurement, and which may be particularly beneficial in network deployments with small cells, in particular for positioning, MDT, user equipment tracking, etc.

Thus, according to a part of the example embodiments, the user equipment may be configured to adapt its behavior during positioning measurements as a result of the mobility procedure. Such adaptation may take into account cell changes as a result of the mobility procedure. Further, some example embodiments may be directed to a network node that adapts positioning measurement instructions (which may be provided to a user equipment) based on cell changes.

Brief summary of the exemplary embodiments

To remedy the above-noted problems with the prior art, exemplary embodiments are shown herein that may provide improved measurement management during cell change. Part of the example embodiments may include the recording and use of information associated with the current cell by the user equipment. Such information may be used by the user equipment, the positioning node, the base station or any other network node for measurement management or general resource management. Other example embodiments may include changing the current measurement scheme based on implementation rules and/or data derived by the user equipment. Various aspects of the example embodiments are described in more detail below under appropriate sub-headings.

Recording of user equipment trajectories

According to a part of the example embodiment, the user equipment 101 may be configured to record data associated with a cell with which the user equipment is currently associated. Example embodiments also include user equipment that retains such information upon leaving such a cell. Thus, the user equipment may retain information associated with the user equipment trajectory and various cell changes.

According to example embodiments, there are various signaling procedures and configuration methods for obtaining information associated with a cell change of a user equipment. The information may be obtained from the user equipment and/or from an appropriate network node that may serve the user equipment.

The following nodes may be involved in communicating information associated with a cell change. It should be understood that the examples provided are non-limiting and are not method steps.

The user equipment may receive (e.g., via LPP or RRC) a request or indication to collect and report information associated with the cell change. Information associated with a cell change may be collected, stored, and signaled by a user equipment to another node (e.g., a positioning node, eNodeB, LUM, MDT node, SON node, etc.).

The radio node may also be involved in the transfer of information associated with a cell change. The radio node may receive (e.g., via LPPa) a request or indication to collect and report information associated with a cell change. Information associated with a cell change may be collected, stored, and signaled by a radio node to another node (e.g., another radio node, a positioning node, a SON node, an MDT node, etc.). Information associated with the cell change may be received from a user equipment. Information associated with the cell change may be received in a handover command or other signaling, for example, from another radio node (e.g., eNodeB or LMU) via X2.

Various other network nodes may also be involved in the communication of information associated with the cell change. The network node may send a request or indication to the user equipment to collect and report information associated with the cell change. The network node may send a request or indication to the radio node to collect and report information associated with the cell change. The network node may send a request to another network node and receive information associated with a cell change for a particular user equipment or statistics of information associated with cell changes collected over time and/or for a group of user equipments.

Information associated with the cell change may be received from a user equipment. Information associated with the cell change may be received from another network node (e.g., a positioning node, SON node, MDT node, etc.). Information associated with the cell change may also be received from the radio node.

The information associated with the cell change may include user equipment trajectory information. The user equipment trajectory information may comprise at least a list of cell IDs or an ordered sequence of cell IDs of cells to which the user equipment is connected or camped (camp) during a certain time period. The list order may be in the order of cell change over time.

According to a part of the exemplary embodiments, all cells over a predetermined time period may be included in the user equipment record. According to a part of the exemplary embodiments, only cells occupied by or connected to the user equipment for at least some minimum time are provided. According to a part of the exemplary embodiment, the list of cells may be obtained over a time period associated with some type of measurement, such as the time for which the user equipment performs and logs the MDT measurement (e.g., typically 2 hours for MDT). According to a part of the exemplary embodiments, the time period over which the cell change information is to be obtained may be linked to a positioning measurement session or period (e.g., a time interval of one RSTD measurement session), etc.

The user equipment may also report an ordered sequence (cell _ ID1, cell _ ID2, …, cell _ IDN), wherein the cell with cell _ ID1, cell _ ID2, …, cell _ IDN is the serving/primary cell during the time interval or one positioning measurement session (e.g. for OTDOA or E-CID). The user equipment may report a physical cell id (pci) or a cell global id (cgi). The user equipment may be configured by the network node to report a certain type of cell identifier.

The cells in the list/sequence may also be time stamped, for example, along with the cell identifier. The time stamped information may be provided in different ways. In one example, when a user equipment is initially connected to/occupying a cell, the user equipment may provide time for that cell. According to a portion of an example embodiment, a user equipment may provide time for a cell when the user equipment leaves a serving cell. According to a portion of an example embodiment, the timestamp of a cell may correspond to a time during which the user equipment is connected to or camped on that cell. The user equipment may report the relative timestamp of each cell in the list. The relative time may be a time reference of the time provided by the network node or a timestamp corresponding to the last serving/primary cell or to the reference cell. The user equipment may also be configured by the network node to report the time stamp of each serving cell in accordance with any of the examples listed above.

The user equipment may also be configured with a set of cell IDs (e.g., a first set and a second set) that indicate the start and end of tracking of the trajectory. For example, the user equipment then starts recording of the trajectory information when the serving/primary cell belongs to the first set of cell IDs, and it stops recording when the serving/primary cell belongs to the second set of cell IDs. The network is also capable of configuring time periods. For example, after this time expires, the user equipment may stop recording the trajectory information even if it does not find a serving/primary cell whose cell ID does not match the second set of cell IDs. Another non-limiting example of the first cell ID may be associated with a first type of cell (e.g., a large or macro cell) and another non-limiting example of the second set of cell IDs may be associated with a second type of cell (e.g., a small cell such as a femto or pico cell).

The user equipment may also be configured by the network node to report at least N (e.g. N =5) neighbouring cells of each serving/PCell or of a particular serving cell/PCell as part of the trajectory information. Thus, the user equipment acquires and stores all neighbouring cells of a given serving cell/PCell and reports the results to the network node. As a special case, the user equipment may also be configured by the network node to report at least the strongest neighbor cell and/or the strongest neighbor cell of each serving/PCell or of a particular serving cell/PCell as part of the trajectory information.

The user equipment may also be configured to record cell identification information (which may be used independently of whether the trajectory information is used in the network) for at least one cell in the list/sequence. Examples of such cell identities may be the last serving/primary cell during a predetermined time interval, the carrier frequency of each cell during a predetermined time interval, the first serving/primary cell during a predetermined time interval, the cell that is the serving/primary cell during the longest time within a predetermined time interval, one or more cells selected according to a predefined rule, one or more cells on a certain frequency and/or one or more cells of a certain type (e.g. CSG cell, macrocell, picocell).

The user equipment may also be configured to record cell identification information for signal measurements. In particular, the user equipment may be configured to record signal measurement (e.g. RSRP, RSRQ) results for the serving/primary cell. Examples of such measurements may be minimum and maximum values of certain measurements made on the serving/primary cell when the user equipment is connected to/camped on this serving/primary cell and/or values of certain measurements made on the serving/primary cell when the user equipment is initially connected to/camped on the serving/primary cell and/or when the user equipment is away from this serving/primary cell.

Other examples of cell information (related to measurements) may include an indication of a cell type of at least one cell in the list/sequence and/or bandwidth information of at least one cell in the list/sequence, as part of an example embodiment. Examples of such bandwidth information may include system bandwidth (also referred to as channel bandwidth, cell transmission bandwidth, etc.) and/or measurement bandwidth (bandwidth used to make one or more particular types of measurement (s)). Some non-limiting examples of such bandwidths are a cell measurement bandwidth, a specific signal (e.g., PRS) measurement bandwidth, an SRS measurement bandwidth, a minimum measurement bandwidth of a serving/primary cell (e.g., among all serving/primary cells) during the interval, a maximum measurement bandwidth of a serving/primary cell (e.g., among all serving/primary cells) during the interval, a minimum system/transmission/channel bandwidth of a serving/primary cell (e.g., among all serving/primary cells) during the interval, and/or a maximum system/transmission/channel bandwidth of all serving/primary cells (e.g., among all serving/primary cells) during the interval.

According to some example embodiments, the user equipment may be further configured to record bandwidth information associated with the entire reported measurement during which the at least one cell change occurred. An example of such information may be a measurement bandwidth based on which a measurement reporting time is to be defined (this information may be particularly important for testing measurement requirements, for example). The user equipment may also be configured to record the cell type. Examples of such cell types may be macro, micro, pico, femto, etc.

The user equipment may also be configured to record cell access information. For example, the user equipment may be configured to indicate whether the cell is fully or partially accessible to all user equipment. Examples of such information may be CSG cells, non-CSG, hybrid CSG, any restricted or forbidden cell, forbidden cell for a particular operation/service, etc., proximity; whether a cell is close to a CSG, etc., a frequency associated with at least one cell, and/or timing information associated with at least one cell, such as an SFN.

According to a part of the example embodiment, the information associated with the cell change may be provided upon request or upon configuration (e.g., the configuration message may indicate which elements of the information are to be provided). According to some example embodiments, the logging of information may also be mandatory for certain measurements (e.g., for MDT measurements, for E-CID, OTDOA, UTDOA, or other positioning measurements, for measurements during which at least one cell change has occurred, etc.).

It should be appreciated that the user equipment trajectory information can be provided by user equipment in any RRC state (e.g., CELL _ PCH, URA _ PCH, CELL _ FACH state, etc.), such as idle state, connected state, low activity state, etc.

It should also be understood that the user equipment also gets all examples of recorded cell information for the neighboring cells associated with each serving/PCell, while getting cell change/trajectory information.

Fig. 3 shows an example of a recorded user equipment trajectory. In some example embodiments, the user equipment 101 may be configured to store user equipment trajectory information internally, for example in the form of a cell table 130. As shown, cell table 130 may include any entries, where each entry may include any number of fields. In the example provided in FIG. 3, each entry may be time stamped, as described above. Further, the table may include any number of different entry types. In the example provided in fig. 3, cell table 130 includes a last serving cell ID, a first primary cell, and a longest serving primary cell ID entry.

It should be understood that the use of a cell table is for illustration only and that any other form of record or list may be utilized. Furthermore, the above-described recording techniques are also provided as examples. Any form of cell-related information may be recorded and used for management of radio resources.

User equipment behavior during serving/primary cell change

In accordance with a portion of the exemplary embodiments,

+ a the user equipment may take appropriate action when receiving the measurement configuration or scheme while taking into account cell changes during the measurement interval or during the configured interval. Cell change may occur for various reasons, such as handover, cell reselection, RRC re-establishment, RRC connection release to redirect to a target cell, PCell exchange (also called PCell change or primary serving cell change), and so on.

Several non-limiting examples are provided herein to illustrate user equipment behavior during a serving/primary cell change over a certain time period (e.g., a measurement period of OTDOA RSTD measurements) as part of an example embodiment.

An OTDOA session can have several seconds, and thus a HO can occur during the session. Without these requirements, OTDOA sessions can be aborted by a HO. This would require the positioning node to initiate a new session, resulting in waste of previous measurements and a much longer overall delay. The problem becomes even more severe in areas with many small cells, where the HW probability is high.

User equipment behavior at HO when measuring intra-frequency RSTD:

consider a first example in which a user equipment is connected to its serving cell and it is configured by a positioning node to perform OTDOA intra-frequency and/or inter-frequency measurements. The user equipment may receive OTDOA assistance data for performing RSTD measurements on cells in the assistance data. When the user equipment performs RSTD measurements, the serving cell of the user equipment may change (e.g., due to HO). As an example, the serving cell may change K times during the time period. All K serving cells during this time period may not have the same system bandwidth. For example, some cells have a smaller BW (e.g., 15 RB), while other cells may have a BW equal to 50 RB. The Positioning Reference Signal (PRS) BW of a cell in OTDOA can be greater than, less than, or equal to the BW of the serving cell. For example, assume PRS BW of all cells is 50 RB. When the user equipment serving cell BW is greater than or equal to the PRS BW, then the UE can measure RSTD for the entire PRS BW of the cell. Otherwise, when the serving cell BW is smaller than the PRS BW, the UE is able to measure at most the PRS BW equal to the serving cell BW.

Thus, according to a part of the example embodiments, the following rules may be implemented, for example, when the user equipment performs RSTD measurements and HO occurs. Examples may apply to both FDD and TDD.

Rule of RSTD measurement period within frequency:

if an intra-frequency handover occurs while an intra-frequency RSTD measurement is performed, the user equipment may complete an ongoing OTDOA measurement session. However, in this case (i.e. when a handover occurs), the RSTD measurement period (the RSTD on which the user equipment performs the cell in assistance data) may be longer than usual. This typically indicates when there is no handover. The reason is that the user equipment may not be able to measure the RSTD when the user equipment performs handover. Another reason is that the PRS signal (by which the user equipment measures RSTD) may collide with or overlap (i.e., in whole or in part) with the time instant at which the handover occurs. Another implication is the bandwidth of the serving cell. It should also be noted that more than one handover may occur over the RSTD measurement period.

Thus, as an example, the RSTD measurement periodCan be expressed in terms of the following general expression as a function of the following parameters:one particular non-limiting example may be:

and K is switched in frequencyThe number of times that the period occurred,T_PRSis a cell specific positioning subframe configuration period such as 1024 ms,is the time for intra-frequency RSTD measurement when no HO is occurring, and T_HOIs the time during which intra-frequency RSTD measurement may not be possible due to intra-frequency switching, which can be up to 45 ms.

Rules for RSTD accuracy within frequency.

Another aspect of the user equipment behavior described above relates to the serving cell BW when the user equipment performs RSTD measurements on the cell. If the user equipment crosses more than one serving cell (i.e. served by 2 or more cells) over the RSTD measurement period, the serving cell BW may affect the accuracy of the RSTD measurement. RSTD measurement accuracy is typically expressed in terms of a basic time unit (Ts) (e.g., about +/-100 ns). The accuracy depends on factors such as PRS BW, number of PRS subframes, etc. The serving cell BW may affect the bandwidth over which the user equipment can measure the RSTD of the measured cell (which can be done on PRS).

Thus, as a general rule, it may be predefined that if a user equipment is performing RSTD measurement at the time of handover occurrence, the user equipment can satisfy the RSTD measurement accuracy by considering at least the bandwidths (i.e., channel/system transmission BWs) of all its serving cells over the RSTD measurement period. According to another general rule, it can be predefined that if the user equipment is making RSTD measurements at the time of the handover occurrence, the user equipment can satisfy the RSTD measurement accuracy by considering at least the bandwidths (i.e., channel/system BWs) of all its serving cells and the PRS BWs of the measuring cells over the RSTD measurement period.

More specifically, it may be predefined that the user equipment satisfies the PRS bandwidth (which is not greater than the RSTD measurement)Minimum channel/system/transmission bandwidth of all serving cells in the period) corresponding to the RSTD measurement accuracy.

Rules for inter-frequency RSTD measurement period and user equipment behavior at HO when measuring inter-frequency RSTD:

the user equipment behavior when an inter-frequency or intra-frequency HO occurs when the user equipment makes an inter-frequency RSTD measurement is very similar to the user equipment behavior in the case of an intra-frequency HO when the user equipment makes an intra-frequency HO (as described above). For example, the inter-frequency RSTD delay can be longer than a usual inter-frequency RSTD delay. More specifically, the RSTD measurement periodThe following expression can be followed:wherein: k isNumber of times of inter-and/or intra-frequency switching of the period, T_HOIs the time during which inter-frequency RSTD measurements may not be possible due to inter-frequency handover; it can be up to 45 ms.

Inter-frequency measurements may be performed in gaps, which may be reconfigured by a new serving cell, for example, when a HO occurs. Thus, additional delay due to gap reconfiguration may be required, for example

Wherein

Is the time to configure or reconfigure the inter-frequency measurement gap; it can be up to 50 ms.

Rules for inter-frequency RSTD accuracy.

Similarly, RSTD measurement accuracy may be affected by serving cell BW. For example, if the inter-frequency over which the user equipment makes RSTD measurements changes to be within frequency, the serving cell BW may affect the RSTD accuracy. Similarly, if the user equipment does not need a gap for measuring inter-frequency (on which the user equipment makes RSTD measurements), the serving cell BW may affect the RSTD accuracy. Similarly, if the reference cell is on the serving carrier, the serving cell BW may affect RSTD accuracy.

Thus, as a general rule, it may also be predefined that if the user equipment is making inter-frequency RSTD measurements when an inter-frequency or intra-frequency handover occurs, the user equipment can satisfy RSTD measurement accuracy by considering at least the bandwidths (i.e., channel/system/transmission BWs) of all its serving cells over the RSTD measurement period.

According to another general rule, it can be predefined that if the user equipment is making inter-frequency RSTD measurements when an inter-frequency or intra-frequency handover occurs, the user equipment satisfies the RSTD measurement accuracy by considering at least the bandwidth (i.e. channel/system BW) of all its serving cells and the PRS BW of the measuring cells over the RSTD measurement period. More specifically, it may be predefined that the user equipment satisfies the RSTD measurement accuracy corresponding to the PRS bandwidth (which is not greater than the minimum channel/system/transmission bandwidth of all serving cells during inter-frequency RSTD measurement).

User equipment behavior under primary cell change when measuring RSTD:

user equipment behavior may also be defined if the user equipment is configured in carrier aggregation (e.g., with at least one secondary cell) and the primary cell is changed while the user equipment is making RSTD measurements. The behavior in terms of RSTD measurement period and accuracy is very similar to that in the HO case described below by way of example.

Rule of RSTD measurement period under PCell change in CA:

if PCell is measuring on a cell belonging to a Primary Component Carrier (PCC) or a Secondary Component Carrier (SCC) at RSTD orWhen the primary and secondary component carriers are changed, independently of whether the primary component carrier is changed, the user equipment completes the ongoing OTDOA measurement session. The user equipment may also meet OTDOA measurements and accuracy requirements for the primary or secondary component carriers, or all carriers, depending on whether the cell is measured on the PCC, the SCC, or both the PCC and SCC. Total RSTD measurement periodThe following expression can be followed:wherein K is PCellThe number of times the period is changed,is the time during which RSTD measurements may not be possible due to PCell changes; it can be up to ms; andcorresponding to the RSTD measurement period within the E-UTRAN frequency.

Rule for RSTD measurement accuracy under PCell change in CA:

the RSTD measurement accuracy may also depend on the BW of all Pcell(s) during the RSTD measurement period. For example, as a general rule, it may be predefined that if a PCell is changed (regardless of whether a primary carrier is changed) while a user equipment is making RSTD measurements while configured with at least one secondary cell (SCell), the user equipment may satisfy RSTD measurement accuracy by considering at least the bandwidths (i.e., channel/system/transmission BWs) of all its PCell(s) over the RSTD measurement period. According to another general rule, it may be predefined that if the user equipment is making RSTD measurements at the time of a PCell change, the user equipment satisfies the RSTD measurement accuracy by considering at least the bandwidth (i.e. channel/system BW) of all its PCell(s) over the RSTD measurement period and the PRS BW of the measuring cell.

More specifically, it may be predefined that the user equipment satisfies the RSTD measurement accuracy corresponding to the PRS bandwidth (which is not larger than the minimum channel/system/transmission bandwidth of all pcells during the RSTD measurement when at least one SCell is configured).

It will be appreciated that the modification or user equipment behaviour and/or the current measurement scheme may be based on the rules established above and/or cell information recorded and stored by the user equipment, as described under the previous heading entitled 'recording of user equipment trajectories'.

Using information associated with cell change

Information associated with a cell change may be collected, stored and used by different nodes for different purposes, e.g. measurement or general resource management. Non-limiting examples of nodes from which cell change information for a user equipment or for a wireless terminal or for a mobile relay may be obtained are:

radio network nodes, e.g. eNode Bs, radio network controllers, base stations, relay nodes, donor node serving relays, mobile relay nodes, etc

Positioning nodes, e.g. E-SMLC in LTE

General network nodes, such as MDT nodes, SON nodes, core network nodes (e.g. MME in LTE), OSS nodes, O & M nodes, network management and planning nodes, etc

-testing the device node/system simulator, e.g. to get information during testing to verify that the user equipment or wireless terminal or mobile repeater complies with predefined rules, signalling and requirements associated with cell change of the user equipment.

The above-mentioned nodes may collect information associated with cell changes of different user equipments and create statistics, e.g. over time and/or for a specific group of user equipments. Generally, the acquired cell change information can be used by the acquisition node for 'monitoring, planning and management' of the network. More specifically, the above-described nodes may use results/statistics of one or more of the following tasks or functions (which are provided as non-limiting examples):

positioning (e.g. enhanced RFPM, pattern matching or AECID),

UE tracking, e.g. to learn typical UE paths or subscriber travel routes,

-SON; automatic tuning of network parameters, addition of new cells/removal of existing cells, upgrading of existing cells (e.g. extended cell BW or PRS BW etc.),

-an MDT; general network planning, such as installation of new BS sites, updating of cell types (e.g., increase or decrease in BS maximum output power), etc.,

-HO optimization; improving parameters related to handover, e.g. HO margin, time-to-trigger

CA configuration optimization.

Applicability to test conditions and test equipment

The user equipment configuration (or any wireless device, such as a mobile repeater) may also be configured in a Test Equipment (TE) node, also called a System Simulator (SS). The TE or SS may implement all configuration methods related to cell change so that the user equipment for the test can be configured. The test aims at verifying that the user equipment complies with predefined rules, protocols, signalling and/or requirements associated with cell change characteristics, such as tracking and recording of user equipment trajectories during cell change.

The TE or SS will also be able to:

-receiving UE measurements associated with cell change

-analyzing the received result, e.g. comparing it with a reference result. The reference can be based on predefined requirements or UE behavior.

Example user equipment configuration

Fig. 4 illustrates an example of a user equipment node 101 according to a portion of an example embodiment. User device 101 may include any number of communication ports, such as receive port 307 and transmit port 308. The communication ports may be configured to receive and transmit any form of communication data 303 and 305, respectively. It should be understood that the user equipment 101 may alternatively comprise a single transceiver port. It should also be appreciated that the communication or transceiver port may take the form of any input/output communication port known in the art.

User device 101 may also include at least one memory unit 309, where memory unit 309 may be in communication with communication ports 307 and/or 308. Memory unit 309 may be configured to store any kind of received, transmitted and/or measured data and/or executable program instructions. The memory unit 309 is any suitable type of computer-readable memory and may be of the volatile and/or nonvolatile type.

The user equipment 101 may further comprise a measurement unit 313, the measurement unit 313 may be configured to perform measurements. The user equipment 101 may further comprise a changing unit 315, the changing unit 315 being configurable to change aspects of the measurements performed by the user equipment (e.g. duration of the measurement time and/or measurement bandwidth). User equipment 101 may also include a general purpose processing unit 311.

It should be appreciated that the measurement unit 313, the change unit 315 and/or the processing unit 311 may be any suitable type of computational unit, such as a microprocessor, a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC), or any form of processing circuitry. It should also be understood that the measurement unit 313, the change unit 315 and/or the processing unit 311 need not be included as separate units. The measurement unit 313, the change unit 315 and/or the processing unit 311 may be comprised as a single calculation unit or any number of units. It should also be understood that the user equipment 100 may be a mobile phone, a Personal Digital Assistant (PDA) or any other LTE network element capable of communicating with a base station over a radio channel. Example network node configuration

Fig. 5 provides an illustrative example of a network node configuration in accordance with a portion of an example embodiment. In some example embodiments, the network node may be a radio base station 103, an E-SMLC node 115, or an SLP node 113.

The network node may include any number of communication ports, such as a receive port 207 and a transmit port 208. The communication ports may be configured to receive and transmit any form of communication data 203 and 205, respectively. It should be understood that the network node may alternatively comprise a single transceiver port. It should also be appreciated that the communication or transceiver port may take the form of any input/output communication port known in the art.

The network node may further comprise at least one memory unit 209, which memory unit 209 may communicate with the communication ports 207 and/or 208. Memory unit 209 may be configured to store any kind of received, transmitted and/or measured data and/or executable program instructions. Memory unit 209 is any suitable type of computer-readable memory and may be of the volatile and/or nonvolatile type.

The network node may further comprise a changing unit 213, the changing unit 213 may be configured to determine an instruction for changing an aspect of the user equipment measurement (e.g. changing the duration of the measurement time and/or the measurement bandwidth). The changing unit 213 may also be configured to provide the user equipment with information related to the cell change. The network node may also comprise a general processing unit 311.

It is to be understood that the changing unit 213 and/or the processing unit 211 may be any suitable type of computing unit, such as a microprocessor, a Digital Signal Processor (DSP), a Field Programmable Gate Array (FPGA) or an Application Specific Integrated Circuit (ASIC). It should also be understood that the change unit 213 and/or the processing unit 211 need not be included as separate units. The changing unit 213 and/or the processing unit 211 may be comprised as a single computing unit or any number of units.

Example user device operations

Fig. 6 illustrates example operations performed by the user equipment 101 of fig. 3 in accordance with a portion of the example embodiments. Example operations are directed to handling of a cell change. A cell change refers to the user equipment 101 changing the cell in which the user equipment is currently located, e.g. a cell change from a first or current cell to a second cell. It should be understood that the network node may be a base station 103, an E-SMLC node 115, or an SLP node 113.

Operation 41

The user equipment 101 is configured to perform 41 at least one measurement. The measurement unit 313 is configured to perform at least one measurement. According to a part of the example embodiments, the at least one measurement may be an RSTD measurement, an RSRP, an RSRQ of an OTDOA positioning and/or a user equipment Rx-Tx time difference measurement.

Operation 43

The user equipment 101 is further configured to receive 43 a notification of a cell change from the first cell to the second cell and information associated with the cell change from the network node. The receiving port 307 is configured to receive a notification of a cell change and information associated with the cell change.

According to some example embodiments, the cell change may be a serving cell change, a serving cell set change, an active cell set change, a PCell change on the same frequency carrier, or a cell change due to a carrier exchange. According to a part of the example embodiments, the cell change may be a result of any of a handover procedure, a cell reselection, a radio resource control, RRC, connection re-establishment, an RRC connection release to redirect to a target cell, a primary cell, PCell, change on the same frequency as a primary component carrier, PCC, in a multi-carrier system, a PCell change due to a change of PCC in a multi-carrier system, a serving cell set change in a multi-carrier system, or an active cell set change in a multi-carrier system. According to a portion of an example embodiment, the first cell may be a serving cell during a first period and the second cell may be a serving cell during a second period, wherein the second period occurs after the first period in time.

According to some example embodiments, the received information associated with the cell change may include a type of measurement to be performed, a type of cell identity used for reporting, and/or bandwidth information. According to a part of the example embodiments, the received information and/or the received notification associated with the cell change is received at the time of the request and/or periodically based on a configuration which may be programmable.

Operation 45

The user equipment is further configured to perform 45 cell change during the at least one measurement. The measurement unit 313 is configured to perform a cell change during at least one measurement.

Operation 47

The user equipment is further configured to change 47 the duration of the measurement time at which the at least one measurement is performed. The changing unit 315 is configured to change a duration of a measurement time on which at least one measurement is performed.

It should be appreciated that the change 47 may be performed based on a rule associated with the user device. For example, the rule associated with the user device may be a predefined rule, which may be provided in the user device. It should also be understood that such rules may be adjustable or user programmable. Furthermore, it should be understood that such rules may also be provided by the network node along with the received notification and/or information associated with the cell change.

Operation 49

The user equipment is further configured to change 49 the at least one measured measurement bandwidth, wherein the change is based on the associated bandwidths of the first and second cells. The changing unit 315 is configured to change the measurement bandwidth of the at least one measurement, wherein the change is based on the associated bandwidths of the first and second cells.

It should be appreciated that the change 49 may be performed based on a rule associated with the user device. For example, the rules associated with the user device may be predefined rules, which may be provided in the user device. It should also be understood that such rules may be adjustable or user programmable. Furthermore, it should be understood that such rules may also be provided by the network node along with the received notification and/or information associated with the cell change.

Example operation 55

According to a portion of the example embodiment, changing 49 may further include changing 55 the measurement bandwidth to at least one of a minimum number of bandwidths of the first and second cells and/or a bandwidth not greater than the bandwidths of the first and second cells. The changing unit 315 may be configured to change the measurement bandwidth to at least one of a minimum number of bandwidths of the first and second cells and/or a bandwidth not greater than the bandwidths of the first and second cells.

According to a part of the exemplary embodiments, the bandwidth of the first or second cell may be a channel bandwidth or a transmission bandwidth. According to a part of an example embodiment, the measurement bandwidth may be a bandwidth of a reference signal to be measured. According to a portion of an example embodiment, the reference signal may be a Positioning Reference Signal (PRS) and the measurement bandwidth may be a PRS bandwidth.

Operation 57

The user equipment is further configured to complete 57 at least one measurement based on the changed duration of the measurement time and the changed measurement bandwidth. The measurement unit 313 may be configured to perform at least one measurement based on the varying duration of the measurement time and the varying measurement bandwidth.

Example operation 61

According to a part of the example embodiment, the user equipment may be configured to time stamp 61 the result of the at least one measurement. The measurement unit 313 may be configured to time stamp the result of the at least one measurement.

Example operation 63

According to a part of the example embodiment, the user equipment may be configured to store 63 coding information associated with a cell change of the first cell to the second cell, wherein the coding information is provided by the user equipment. The memory unit 309 may be configured to store coding information associated with a cell change of a first cell to a second cell, wherein the coding information is provided by the user equipment.

According to a portion of an example embodiment, the compiled information associated with the change of the first cell to the second cell may include user equipment trajectory information. The user equipment trajectory data may comprise an ordered or non-ordered list of cell identities of cells (to which the user equipment is connected and/or camped during the time period) and/or cell information. The cell information may include a carrier frequency, a system band, a measurement bandwidth, and/or a cell type of each serving cell.

Example operation 65

According to a part of the example embodiment, the user equipment may be configured to send 65 the compiled information to the network node or to another user equipment. The transmission port 308 may be configured to send the compiled information to a network node or another user equipment.

Example operation 67

According to a part of the example embodiment, the user equipment may be configured to adjust 67 the measurement accuracy of at least one measurement with respect to a changing duration of the measurement time and a changing measurement bandwidth. The varying unit 315 may be configured to adjust the measurement accuracy of the at least one measurement with respect to a varying duration of the measurement time and a varying measurement bandwidth.

Example network node operation

Fig. 7 illustrates example operations performed by the network node of fig. 4 in accordance with a portion of the example embodiments. Example operations are directed to handling a cell change of a user equipment. A cell change refers to the user equipment 101 changing the cell in which the user equipment is currently located, e.g. a cell change from a first or current cell to a second cell. It should be understood that the network node may be a base station 103, an E-SMLC node 115, or an SLP node 113.

Operation 71

The network node is configured to send 71 a request to the user equipment to perform at least one measurement. The transmit port 208 is configured to send a request to perform at least one measurement to the user equipment.

According to a part of the example embodiments, the at least one measurement may be an RSTD measurement, an RSRP, an RSRQ of an OTDOA positioning and/or a user equipment Rx-Tx time difference measurement.

Operation 73

The network node is further configured to determine 73 information associated with a cell change from the first cell to the second cell. The information associated with the cell change includes a change instruction for changing the user equipment measurement time and measurement bandwidth in the presence of the cell change. The changing unit 213 is configured to determine information associated with a cell change from the first cell to the second cell.

According to some example embodiments, the cell change may be a serving cell change, a serving cell set change, an active cell set change, a PCell change on the same frequency carrier, or a cell change due to a carrier exchange. According to a part of the example embodiments, the cell change may be a result of any of a handover procedure, a cell reselection, a radio resource control, RRC, connection re-establishment, an RRC connection release to redirect to a target cell, a primary cell, PCell, change on the same frequency as a primary component carrier, PCC, in a multi-carrier system, a PCell change due to a change of PCC in a multi-carrier system, a serving cell set change in a multi-carrier system, or an active cell set change in a multi-carrier system. According to a portion of an example embodiment, the first cell may be a serving cell during a first period and the second cell may be a serving cell during a second period, wherein the second period occurs after the first period in time.

Operation 75

The network node is further configured to send 75 a notification of the cell change and information associated with the cell change to the user equipment. The information associated with the cell change includes an instruction for the change. The transmit port 208 is configured to send a notification of a cell change and information associated with the cell change to the user equipment.

According to a portion of an example embodiment, the instructions for changing may include instructions for determining to change the measurement time and/or change the measurement bandwidth, and the instructions for changing may be based on a predetermined rule. According to a portion of the example embodiments, the instructions for changing may include instructions for changing the measurement bandwidth to at least one of a minimum number of bandwidths of the first and second cells and/or a bandwidth not greater than the bandwidths of the first and second cells. In some example embodiments, the bandwidth of the first or second cell is a channel bandwidth or a transmission bandwidth. In some example embodiments, the measurement bandwidth is a bandwidth of a reference signal to be measured. In some example embodiments, the reference signal is a Positioning Reference Signal (PRS), and the measurement bandwidth is a PRS bandwidth.

Operation 81

The network node is further configured to receive 81 measurement data from the user equipment, wherein the measurement data comprises at least one other measurement performed on a varying duration of the measurement time and a varying measurement bandwidth. The varying duration of the measurement time and the varying measurement bandwidth are based on bandwidths associated with the first and second cells. The receiving port 207 is configured to receive measurement data from the user equipment.

Example operation 83

According to a part of the example embodiment, the network node may be configured to send 83 a change measurement instruction based on the received measurement data. The transmit port 208 may be configured to send a change measurement instruction based on the received measurement data.

According to a portion of an example embodiment, the change measurement instruction may include an instruction to adjust a measurement accuracy of the at least one measurement with respect to a change duration of the measurement time and a change measurement bandwidth.

Conclusion

The embodiments described herein are not limited to a particular measurement unless otherwise specified. The signaling described in the exemplary embodiments is via a direct link (protocol or physical channel) or a logical link (e.g., via a higher layer protocol and/or via one or more network nodes). For example, in LTE, in the case of signaling between the E-SMLC and LCS clients, the positioning results may be communicated via multiple nodes (at least via the MME and/or GMLC).

Although the description is given primarily for user equipment, those skilled in the art will appreciate that "user equipment" is a non-limiting term that denotes any wireless device or node (e.g., PDA, laptop, mobile, sensor, fixed relay, mobile relay, or even a radio base station such as a femto base station) that is generally capable of receiving in the DL and transmitting in the UL. Example embodiments may be adapted for use with non-CA UEs or for use with user equipment capable and incapable of performing inter-frequency measurements without gaps, e.g. also including user equipment capable of carrier aggregation.

The positioning nodes described in the different embodiments are nodes with positioning functionality. For example, for LTE, one can understand a positioning platform in the user plane (e.g., SLP in LTE) or a positioning node in the control plane (e.g., E-SMLC in LTE). The SLP may also consist of SLC and SPC, where the SPC may also have a proprietary interface with the E-SMLC. In a test environment, at least the positioning nodes may be simulated or emulated by the test equipment.

A cell is associated with a radio node, wherein a radio node or radio network node or eNodeB, which are used interchangeably in the description of example embodiments, includes in a general sense any node that transmits radio signals for measurements, such as an eNodeB, macro/micro/pico base station, home eNodeB, relay, beacon device or repeater. A radio node herein may comprise a radio node operating at one or more frequencies or frequency bands. It may be a CA capable radio node. It may also be a single RAT or multi-RAT node. The multi-RAT node may include a node or a hybrid radio node having co-existing RATs or supporting multi-standard radio (MSR).

Coordinating other network or radio network nodes and/or coordinating nodes receiving/transmitting information or coordination messages associated with cell change may be present in the network. Example nodes that may function, at least in part, as coordinating nodes are SON nodes, MDT nodes, positioning nodes, O & M nodes, and the like.

The example embodiments are not limited to LTE but may be applied with any RAN, single RAT, or multi-RAT. Some other RAT examples are LTE-advanced, UMTS, HSPA, GSM, cdma2000, HRPD, WiMAX, and WiFi.

The foregoing description of the example embodiments has been presented for purposes of illustration and description. The foregoing description is not intended to be exhaustive or to limit example embodiments to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of various alternatives to the provided embodiments. The examples described herein were chosen and described in order to explain the principles and the nature of various example embodiments and its practical application to enable one skilled in the art to utilize the example embodiments in various ways and with various modifications as are suited to the particular use contemplated. The features of the embodiments described herein may be combined in all possible combinations of methods, apparatus, modules, systems, and computer program products. It should be understood that any of the example embodiments provided herein may be used in combination with each other or in any combination with each other.

It should be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed and the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. It should also be noted that any reference signs do not limit the scope of the claims, that the exemplary embodiments may be implemented at least in part by both hardware and software, and that several "means", "units" or "devices" may be represented by the same item of hardware.

Some example embodiments may include portable or non-portable phones, media players, Personal Communication Systems (PCS) terminals, Personal Digital Assistants (PDAs), laptop computers, palm receivers, cameras, televisions and/or any appliances that include transducers designed to transmit and/or receive radio, television, microwave, telephone and/or radar signals.

Various example embodiments described herein are described in the general context of method steps or processes that may be implemented in one aspect by a computer program product, embodied in a computer-readable medium, that includes computer-executable instructions (e.g., program code) and executed by computers in networked environments. Computer-readable media can include removable and non-removable storage devices including, but not limited to, read-only memory (ROM), random-access memory (RAM), Compact Discs (CDs), Digital Versatile Discs (DVDs), and the like. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program modules represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

In the drawings and specification, there have been disclosed exemplary embodiments. However, many variations and modifications can be made to these embodiments. Further, it should be understood that the example embodiments provided herein may be used in any combination with one another. Accordingly, although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the embodiments being defined by the following claims.

Claims (58)

1. A method in a user equipment (101) for handling a cell change, the user equipment being comprised in a wireless communication network (100), the method comprising:

performing (41) at least one measurement;

receiving (43), from a network node (103,113,115), a notification of a cell change from a first cell to a second cell and information associated with the cell change;

performing (45) the cell change during the at least one measurement;

varying (47) a duration of a measurement time over which the at least one measurement is performed;

changing (49) the at least one measured measurement bandwidth, wherein the changing is based on the associated bandwidths of the first and second cells; and

completing (57) the at least one measurement based on the changed duration of the measurement time and the changed measurement bandwidth.

2. The method of claim 1, wherein the cell change of the first cell to the second cell is a result of any of a handover procedure, a cell reselection, a Radio Resource Control (RRC) connection re-establishment, an RRC connection release to redirect to a target cell, a primary cell (PCell) change on the same frequency as a Primary Component Carrier (PCC) in a multi-carrier system, a PCell change due to a change of the PCC in a multi-carrier system, a serving cell set change in a multi-carrier system, or an active cell set change in a multi-carrier system.

3. The method of any of claims 1-2, wherein the first cell is a serving cell during a first period and the second cell is a serving cell during a second period, wherein the second period occurs after the first period in time.

4. The method according to any of claims 1-3, wherein the received information associated with the cell change comprises any one or a combination of: the type of measurements to be performed, the type of cell identity used for reporting, and bandwidth information.

5. The method according to any of claims 1-4, further comprising storing (63) compilation information associated with the cell change of the first cell to the second cell, the compilation information being provided by the user equipment.

6. The method of claim 5, wherein the compiled information associated with the change of the first cell to the second cell comprises user equipment trajectory information, the user equipment trajectory data comprising an ordered or non-ordered list of cell identities of cells to which the user equipment is connected and/or camped during a time period and/or cell information, the cell information comprising a carrier frequency, a system bandwidth, a measurement bandwidth and/or a cell type of each serving cell.

7. The method according to any of claims 5-6, further comprising sending (65) the compiled information to a network node or another user equipment.

8. The method according to any of claims 1-7, wherein the received information and/or the received notification associated with the cell change is received at the time of the request and/or periodically based on a configuration.

9. The method of any one of claims 1-8, wherein the completing (57) further comprises utilizing (59) the received information associated with the cell change in the at least one measurement while the at least one measurement is ongoing.

10. The method of any one of claims 1-9, wherein performing (45) and/or completing (57) the at least one measurement further comprises time stamping (61) a result of the at least one measurement.

11. The method according to any of claims 1-10, wherein the duration of the change in measurement time and the bandwidth of the change are based on predefined rules associated with the user equipment.

12. The method according to any of claims 1-11, wherein the duration of the change of measurement time and the bandwidth of the change are based on information associated with the change of the first cell to the second cell and/or at least one rule provided in the received notification.

13. The method according to any of claims 1-12, wherein the step of changing (49) the measurement bandwidth further comprises changing (55) the measurement bandwidth to at least one of a minimum number of bandwidths of the first and second cells and/or a bandwidth not larger than the bandwidths of the first and second cells.

14. The method of claim 13, wherein the bandwidth of the first or second cell is a channel bandwidth or a transmission bandwidth.

15. The method of claim 14, wherein the measurement bandwidth is a bandwidth of a reference signal to be measured.

16. The method of claim 15, wherein the reference signal is a Positioning Reference Signal (PRS), and the measurement bandwidth is a PRS bandwidth.

17. The method according to any of claims 1-16, further comprising adjusting (67) a measurement accuracy of the at least one measurement with respect to a duration of change of the measurement time and the bandwidth of the changed measurement.

18. The method according to any of claims 1-17, wherein the at least one measurement is a reference signal time difference, RSTD, measurement, a reference signal received power, RSRP, a reference signal received quality, RSRQ, and/or a user equipment receive-transmit, Rx-Tx, time difference measurement for observed time difference of arrival, OTDOA, positioning.

19. A method in a network node (103,113,115) for handling cell changes of a user equipment, the network node being comprised in a wireless communication network (100), the method comprising:

sending (71) a request to perform at least one measurement to a user equipment;

determining (73) information associated with a cell change from a first cell to a second cell, the information associated with the cell change comprising a change instruction for changing a user equipment measurement time and measurement bandwidth in the presence of the cell change;

sending (75) a notification of the cell change and information associated with the cell change to the user equipment, the information associated with the cell change comprising an instruction for a change; and

receiving (81) measurement data from the user equipment, the measurement data comprising at least one further measurement performed on a duration of change of measurement time and the bandwidth of change measurement, wherein the duration of change of measurement time and the bandwidth of change measurement are based on bandwidths associated with the first cell and the second cell.

20. The method of claim 19, wherein the instructions for changing further comprise instructions for determining a change measurement time and/or the change measurement bandwidth, wherein the instructions for changing are based on predefined rules.

21. The method of any of claims 19-20, wherein the change instruction comprises an instruction to change the measurement bandwidth to at least one of a minimum number of bandwidths of the first and second cells and/or a bandwidth not greater than the bandwidths of the first and second cells.

22. The method of claim 21, wherein the bandwidth of the first or second cell is a channel bandwidth or a transmission bandwidth.

23. The method of claim 21, wherein the measurement bandwidth is a bandwidth of a reference signal to be measured.

24. The method of claim 23, wherein the reference signal is a Positioning Reference Signal (PRS) and the measurement bandwidth is a PRS bandwidth.

25. The method according to any of claims 19-24, wherein the at least one measurement is a reference signal time difference, RSTD, measurement, a reference signal received power, RSRP, a reference signal received quality, RSRQ, and/or a user equipment receive-transmit, Rx-Tx, time difference measurement for observed time difference of arrival, OTDOA, positioning.

26. The method according to any of claims 19-25, wherein the cell change from the first cell to the second cell is caused by one of a handover procedure, cell reselection, radio resource control, RCC, re-establishment, RRC connection release to redirect to a target cell, primary cell/carrier switching/change in a multi-carrier system.

27. The method according to any of claims 19-26, further comprising sending (83) a change measurement instruction based on the received measurement data.

28. The method of claim 27, wherein said change measurement instruction comprises an instruction to adjust a measurement accuracy of said at least one measurement with respect to a change duration of said measurement time and said change measurement bandwidth.

29. A user equipment (101) for handling a cell change, the user equipment being comprised in a wireless communication network (100), the user equipment comprising:

a measurement unit (313) configured to perform at least one measurement;

a receiving port (307) configured to receive a notification of a cell change from a first cell to a second cell and information associated with the cell change from a network node (103,113, 115);

the measurement unit (313) configured to perform the cell change during the at least one measurement;

a changing unit (315) configured to change a duration of a measurement time on which the at least one measurement is performed;

the changing unit (315) further configured to change a measurement bandwidth of the at least one measurement, wherein the change of the measurement time and the measurement bandwidth is based on the associated bandwidths of the first and second cells; and

the measurement unit (313) is further configured to complete the at least one measurement based on a duration of change of a measurement time and the bandwidth of change measurement.

30. The user equipment (101) of claim 29, wherein the cell change of the first cell to the second cell is a result of any of a handover procedure, a cell reselection, a radio resource control, RRC, connection re-establishment, an RRC connection release to redirect to a target cell, a primary cell, PCell, change on the same frequency as a primary component carrier, PCC, in a multi-carrier system, a PCell change due to a change of PCC in a multi-carrier system, a serving cell set change in a multi-carrier system, or an active cell set change in a multi-carrier system.

31. The user equipment (101) according to any of claims 29-30, wherein the first cell is a serving cell during a first periodicity, and the second cell is a serving cell during a second periodicity, wherein the second periodicity occurs after the first periodicity in time.

32. The user equipment (101) according to any of claims 29-31, wherein the received information associated with the cell change comprises any or a combination of a type of measurement to be performed, a type of cell identity used for reporting and bandwidth information.

33. The user equipment (101) according to any of claims 29-32, further comprising a memory (309) configured to store compilation information associated with the cell change of the first cell to the second cell.

34. The user equipment (101) according to claim 33, wherein the compiled information associated with the change of the first cell to the second cell comprises user equipment trajectory information, the user equipment trajectory data comprising an ordered or non-ordered list of cell identities of cells to which the user equipment is connected and/or camped during a time period and/or cell information, the cell information comprising a carrier frequency, a system bandwidth, a measurement bandwidth and/or a cell type of each serving cell.

35. The user equipment (101) according to any of claims 33-34, further comprising a transmission port (308) configured to send the compiled information to a network node or another user equipment.

36. The user equipment (101) according to any of claims 29-35, wherein the received information and/or the received notification associated with the cell change is received at the time of the request and/or periodically based on a configuration.

37. The user equipment (101) according to any of claims 29-36, wherein the measurement unit (313) is configured to utilize received information associated with the cell change in completing the at least one measurement while the at least one measurement is ongoing.

38. The user equipment (101) according to any of claims 29-37, wherein the measurement unit (313) is further configured to time stamp the result of the at least one measurement.

39. The user equipment (101) according to any of claims 29-38, wherein the changing unit (315) is further configured to determine the change in the measurement time and/or the measurement bandwidth based on a predefined rule associated with the user equipment.

40. The user equipment (101) according to any of claims 29-39, wherein the changing unit (315) is further configured to determine the change in the measurement time and/or the measurement bandwidth based on at least one rule provided in the information associated with the change of the first cell to the second cell and/or the received notification.

41. The user equipment (101) according to any of claims 29-40, wherein the changing unit (315) is further configured to change the measurement bandwidth to at least one of a minimum number of bandwidths of the first and second cells and/or a bandwidth not larger than the bandwidths of the first and second cells.

42. The user equipment (101) of claim 41, wherein the bandwidth of the first or second cell is a channel bandwidth or a transmission bandwidth.

43. The user equipment (101) of claim 42, wherein the measurement bandwidth is a bandwidth of a reference signal to be measured.

44. The user equipment (101) of claim 43, wherein the reference signal is a positioning reference signal, PRS, and the measurement bandwidth is a PRS bandwidth.

45. The user equipment (101) according to any of claims 29-44, wherein the varying unit (315) is further configured to adjust the measurement accuracy of the at least one measurement with respect to a varying duration of the measurement time and the varying measurement bandwidth.

46. The user equipment (101) according to any of claims 29-45, wherein the at least one measurement is a reference signal time difference, RSTD, measurement, a reference signal received power, RSRP, a reference signal received quality, RSRQ, and/or a user equipment receive-transmit, Rx-Tx, time difference measurement for observed time difference of arrival, OTDOA, positioning.

47. The user equipment (101) according to any of claims 29-46, wherein the network node is a base station (103), a secure user plane location platform, SLP, (113) or an enhanced serving mobile location center (115).

48. A network node (103,113,115) for handling a cell change of a user equipment, the network node being comprised in a wireless communication network (100), the method comprising:

a transmit port (208) configured to send a request to a user equipment to perform at least one measurement;

a changing unit (213) configured to determine an instruction for changing a user equipment measurement time and measurement bandwidth in case a cell change exists from a first cell to a second cell;

the transmit port (208) further configured to send a notification of the cell change and information associated with the cell change to the user equipment, the information comprising an instruction for a change; and

a receiving port (207) configured to receive measurement data from the user equipment, the measurement data comprising at least one other measurement performed on a duration of change of measurement time and a bandwidth of change measurement, wherein the duration of change of measurement time and the bandwidth of change measurement are based on the transmitted instructions for changing the bandwidth associated with the first cell and the second cell.

49. The network node (103,113,115) according to claim 48, wherein the change further comprises instructions for determining the change measurement time and/or the change measurement bandwidth based on predefined rules.

50. The network node (103,113,115) of any of claims 48-49, wherein the change instructions further comprise instructions to change the measurement bandwidth to at least one of a minimum number of bandwidths of the first and second cells and/or a bandwidth not greater than the bandwidths of the first and second cells.

51. The network node (103,113,115) of claim 50, in which the bandwidth of the first or second cell is a channel bandwidth or a transmission bandwidth.

52. The network node (103,113,115) of claim 50, wherein the measurement bandwidth is a bandwidth of a reference signal to be measured.

53. The network node (103,113,115) of claim 52, in which the reference signal is a positioning reference signal, PRS, and the measurement bandwidth is a PRS bandwidth.

54. The network node (103,113,115) of any of claims 48-53, wherein the at least one measurement is a reference signal time difference, RSTD, measurement, a reference signal received power, RSRP, a reference signal received quality, RSRQ, and/or a user equipment receive-transmit, Rx-Tx, time difference measurement for observed time difference of arrival, OTDOA, positioning.

55. The network node (103,113,115) of any of claims 48-54, wherein the cell change from the first cell to the second cell is caused by one of a handover procedure, a cell reselection, a radio resource control, RCC, re-establishment, an RRC connection release to redirect to a target cell, a primary cell/carrier exchange/change in a multi-carrier system.

56. The network node (103,113,115) according to any of claims 48-55, wherein the transmit port (208) is further configured to send a change measurement instruction based on the received measurement data.

57. The network node (103,113,115) according to claim 56, wherein the change measurement instruction further comprises an instruction for adjusting the measurement accuracy of the at least one measurement with respect to a change duration of the measurement time and the change measurement bandwidth.

58. The network node (103,113,115) of any one of claims 48-57, wherein the network node is a base station (103), a secure user plane location platform, SLP, (113) or an enhanced services mobile location center (115).