Patent Publication Number: US-2023147613-A1

Title: Spatial domain measurements for beam based positioning

Description:
TECHNICAL FIELD 
     The present application generally relates to information technology. In particular, some example embodiments of the present application relate to positioning of user equipment using spatial domain measurements. 
     BACKGROUND 
     In 3GPP NR (new radio) an extended version of the LTE Positioning Protocol (LPP) or a corresponding NR protocol between a user equipment (UE) and a location management function (LMF) may be utilized to support positioning of the UE by the radio network. In some situations, a direct communication link between the UE and LPP or a corresponding new radio (NR) protocol may not be available. For example, in the case of a radio link failure between the UE and its serving base station the signaling exchange through the LPP between LMF and UE is interrupted, and real-time positioning based on new positioning measurements may not be possible anymore. For example, in case the UE is a vehicle, such a situation may occur when the vehicle enters a tunnel or any other area with bad coverage. Also, achievable accuracy may be very bad if the signals are reflected at buildings in a dense urban environment. On the other hand, for applications like autonomous driving, industrial internet of things, or vulnerable road user protection, ubiquitous real-time positioning without any service interruption may be desired. 
     SUMMARY 
     This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. 
     Example embodiments enable high accuracy positioning of UE. The example embodiments may enable positioning the UEs in presence of non-line-of-sight radio propagation environments. This may be achieved by the features of the independent claims. Further implementation forms are provided in the dependent claims, the description, and the drawings. 
     According to a first aspect, an apparatus comprises at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: receive, at a target network node, a positioning measurement configuration from a network node; connect to a plurality of anchor network nodes with a pair of uplink and/or downlink transmission and/or reception beams; compute at least one positioning assistance measurement of the target network node comprising an angular difference between the pair of uplink and/or downlink transmission and/or reception beam directions based on the positioning measurement configuration; and determine a positioning report comprising the at least one positioning assistance measurement of the target network node. 
     According to a second aspect, a method comprises receiving, at a target network node, a positioning measurement configuration from a network node; connecting to a plurality of anchor network nodes with a pair of uplink and/or downlink transmission and/or reception beams; computing at least one positioning assistance measurement of the target network node comprising an angular difference between the pair of uplink and/or downlink transmission and/or reception beam directions based on the positioning measurement configuration; and determining a positioning report comprising the at least one positioning assistance measurement of the target network node. 
     According to a third aspect, a computer program is configured, when executed by a processor, to cause an apparatus at least to: receive, at a target network node, a positioning measurement configuration from a network node; connect to a plurality of anchor network nodes with a pair of uplink and/or downlink transmission and/or reception beams; compute at least one positioning assistance measurement of the target network node comprising an angular difference between the pair of uplink and/or downlink transmission and/or reception beam directions based on the positioning measurement configuration; and determine a positioning report comprising the at least one positioning assistance measurement of the target network node. 
     According to a fourth aspect, an apparatus comprises means for receiving, at a target network node, a positioning measurement configuration from a network node; means for connecting to a plurality of anchor network nodes with a pair of uplink and/or downlink transmission and/or reception beams; means for computing at least one positioning assistance measurement of the target network node comprising an angular difference between the pair of uplink and/or downlink transmission and/or reception beam directions based on the positioning measurement configuration; and means for determining a positioning report comprising the at least one positioning assistance measurement of the target network node. 
     According to a fifth aspect, an apparatus comprises at least one processor; and at least one memory including computer program code; the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: connect to a network node and a target node with a pair of uplink and/or downlink transmission and/or reception beams; receive, at an anchor node, a positioning measurement configuration from the network node; compute at least one positioning assistance measurement of the anchor node comprising an angular difference between the pair of uplink and/or downlink transmission and/or reception beam directions based on the positioning measurement configuration; receive a positioning report from the target node comprising a positioning assistance measurement associated with the target node and a plurality of anchor nodes connected with the target node; and determine a second positioning report comprising the positioning assistance measurements of the anchor node and the target node. 
     According to a sixth aspect, a method comprises connecting to a network node and a target node with a pair of uplink and/or downlink transmission and/or reception beams; receiving, at an anchor node, a positioning measurement configuration from the network node; computing at least one positioning assistance measurement of the anchor node comprising an angular difference between the pair of uplink and/or downlink transmission and/or reception beam directions based on the positioning measurement configuration; receiving a positioning report from the target node comprising a positioning assistance measurement associated with the target node and a plurality of anchor nodes connected with the target node; and determining a second positioning report comprising the positioning assistance measurements of the anchor node and the target node. 
     According to a seventh aspect, a computer program is configured, when executed by a processor, to cause an apparatus at least to: connect to a network node and a target node with a pair of uplink and/or downlink transmission and/or reception beams; receive, at an anchor node, a positioning measurement configuration from the network node; compute at least one positioning assistance measurement of the anchor node comprising an angular difference between the pair of uplink and/or downlink transmission and/or reception beam directions based on the positioning measurement configuration; receive a positioning report from the target node comprising a positioning assistance measurement associated with the target node and a plurality of anchor nodes connected with the target node; and determine a second positioning report comprising the positioning assistance measurements of the anchor node and the target node. 
     According to an eighth aspect, an apparatus comprises means for connecting to a network node and a target node with a pair of uplink and/or downlink transmission and/or reception beams; means for receiving, at an anchor node, a positioning measurement configuration from the network node; means for computing at least one positioning assistance measurement of the anchor node comprising an angular difference between the pair of uplink and/or downlink transmission and/or reception beam directions based on the positioning measurement configuration; means for receiving a positioning report from the target node comprising a positioning assistance measurement associated with the target node and a plurality of anchor nodes connected with the target node; and means for determining a second positioning report comprising the positioning assistance measurements of the anchor node and the target node. 
     According to a ninth aspect, there is provided an apparatus comprising at least one processor; and at least one memory including computer program code; the at least one memory and the computer code configured to, with the at least one processor, cause the apparatus at least to: establish a plurality of connections to a target node via a plurality of anchor nodes; determine, by a network node, a positioning measurement configuration of positioning assistance measurements for the target node and the plurality of anchor nodes; and dispatch the positioning measurement configuration to at least one of the target node and/or to the plurality of anchor nodes. 
     According to a tenth aspect, there is provided a method comprising establishing a plurality of connections to a target node via a plurality of anchor nodes; determining, by a network node, a positioning measurement configuration of positioning assistance measurements for the target node and the plurality of anchor nodes; and dispatching the positioning measurement configuration to at least one of the target node and/or to the plurality of anchor nodes. 
     According to an eleventh aspect, a computer program is configured, when executed by a processor, to cause an apparatus at least to: establish a plurality of connections to a target node via a plurality of anchor nodes; determine, by a network node, a positioning measurement configuration of positioning assistance measurements for the target node and the plurality of anchor nodes; and dispatch the positioning measurement configuration to at least one of the target node and/or to the plurality of anchor nodes. 
     According to a twelfth aspect, an apparatus comprises means for establishing a plurality of connections to a target node via a plurality of anchor nodes; determining, by a network node, a positioning measurement configuration of positioning assistance measurements for the target node and the plurality of anchor nodes; and dispatching the positioning measurement configuration to at least one of the target node and/or to the plurality of anchor nodes. 
     Many of the attendant features will be more readily appreciated as they become better understood by reference to the following detailed description considered in connection with the accompanying drawings. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are included to provide a further understanding of the example embodiments and constitute a part of this specification, illustrate example embodiments and together with the description help to explain the example embodiments. In the drawings: 
         FIG.  1    illustrates an example of an apparatus configured to practice one or more example embodiments; 
         FIG.  2    illustrates an example of beam-domain based processing of positioning information for localizing a user equipment when the user equipment is not directly reachable by a network node according to an example embodiment; 
         FIG.  3    illustrates an example of beam-domain based processing of positioning information for localizing a user equipment when the user equipment is directly reachable by a network node according to an example embodiment; 
         FIG.  4    illustrates an example of obtaining a weighted difference between transmission and reception beam angles according to an example embodiment; 
         FIG.  5    illustrates an example of a joint use of positioning assistance measurements and time difference measurements for estimating position of a user equipment according to an example embodiment; 
         FIG.  6    illustrates an example of a message sequence chart for estimating a position of a user equipment when the position is estimated by a network node according to an example embodiment; 
         FIG.  7    illustrates an example of a message sequence chart for estimating a position of a user equipment when the position is estimated by an anchor node according to an example embodiment; 
         FIG.  8    illustrates an example of a message sequence chart for estimating a position of a user equipment when the position is estimated by a target node according to an example embodiment; 
         FIG.  9    illustrates an example of localizing a user equipment based on angular difference measurements of network nodes connected with the user equipment according to an example embodiment; 
         FIG.  10    illustrates an example of a beam-domain procedure to localize a user equipment when the user equipment is out of coverage of a network node according to an example embodiment. 
         FIG.  11    illustrates an example of a beam-domain procedure to localize a user equipment when the user equipment is out of coverage of a network node according to another example embodiment. 
         FIG.  12    illustrates a method for estimating a position of a user equipment when the position is estimated by a network node according to an example embodiment; 
         FIG.  13    illustrates a method for estimating a position of a user equipment when the position is estimated by an anchor node according to an example embodiment; 
         FIG.  14    illustrates a method for estimating a position of a user equipment when the position is estimated by a target node according to an example embodiment; 
     
    
    
     Like references are used to designate like parts in the accompanying drawings. 
     DETAILED DESCRIPTION 
     Reference will now be made in detail to example embodiments, examples of which are illustrated in the accompanying drawings. The detailed description provided below in connection with the appended drawings is intended as a description of the present examples and is not intended to represent the only forms in which the present examples may be constructed or utilized. The description sets forth the functions of the example and a possible sequence of steps for constructing and operating the example. However, the same or equivalent functions and sequences may be accomplished by different examples. 
     Positioning of a UE may be provided by utilizing an anchor node assisted beam-based procedure using, for example, an anchor angle difference (AAD) and time-of-arrival (TOA) measurements for localizing out-of-coverage target nodes. The anchor node may be, for example, a UE, a sidelink UE, an integrated access and backhaul (IAB) node, a network node, or the like. Also, the target network node may be, for example, a UE, a sidelink UE, an integrated access and backhaul (IAB) node, or the like. The anchor and target nodes may be assumed to communicate through non-line-of-sight (NLoS) radio channel propagation. Additionally, there may exist scatterers that are associated with each TX-RX (transmission-reception) beam-pair per link between the anchor and target nodes. The measurement results may be reported to a Next Generation NodeB (gNB) that in its turn provides respective positioning reports to a location server via higher layer signaling. Based on the positioning reports, the location server may utilize the ToA and AAD measurements to estimate the position of the target node. 
     However, a wide uncertainty region related to the accuracy of positioning may result from using the combination of AAD and TOA, which may lead to a failure when estimating the target node position. The combination of ToA and AAD may not properly take into account NLoS components in the radio channel between the anchor and target nodes and thus positioning performance in terms of accuracy may be poor in such propagation conditions. Therefore, positioning based on only time measurements and AAD may be unfeasible in deployment scenarios wherein the radio channel is characterized by NLoS propagation. 
     Example embodiments provide new positioning measurement techniques and reporting mechanisms for both anchor and target nodes that may enable high-accuracy positioning also in NLoS radio propagation environments. The example embodiments may further provide enhanced positioning for utilization by applications requiring high positioning accuracy, for example, industrial IoT (internet of things), factory of the future, collaboration robots, V2X (vehicle-to-anything), etc. 
     According to an example embodiment, a target node based angular difference (TAD) measurement and a related positioning reporting enhancements for beam-based positioning are provided to enhance positioning accuracy of target and/or anchor nodes. By leveraging the combination of the TAD, AAD, and time measurement reports for a network-based or UE-based positioning, the positioning accuracy of the target and/or anchor UE in the presence of NLoS radio channels may be enhanced. To enable more flexible positioning measurements for UEs/network nodes with different capabilities in various deployment scenarios, further enhancements for TAD and AAD measurements are disclosed such as a possibility for obtaining the measurements in a local and a global coordinate system. Further, angle difference measurements between different combinations of transmission (TX) and reception (RX) beams associated with downlink (DL) and uplink (UL) resources are provided. 
     According to example embodiments, positioning reports comprising both TAD and AAD measurements may be combined and used in conjunction with time difference measurements and/or round-trip-time measurements and/or carrier phase measurements and/or angle of arrival measurements and/or angle of departure measurements, and/or reference signal received power measurements at the network, for example at a localization server, or at the UE side. This may enable accurate network or UE based positioning for a target UE and/or anchor UE in NLoS scenarios. The joint use of AAD and TAD as well time difference measurements and/or round-trip-time measurements and/or carrier phase measurements and/or angle of arrival measurements and/or angle of departure measurements, and/or reference signal received power measurements may allow the network or the UE to emulate transmitted signal propagation over different channel obstacles, such as clusters, reflections or scatterers, in the spatial domain associated with measured TX-RX beam pair per link. The TAD measurements may enable to emulate the spatial spread of the transmission signal in the vicinity of the target UE resulting in enhanced positioning accuracy in NLoS scenarios. 
     To enable the utilization of TAD measurements for UE or network-based positioning, new positioning information reporting may be defined using the TAD and AAD measurements from the target and anchor nodes involved. The AAD and TAD measurements may be provided in one or more positioning reports for UE or network node to perform the positioning of a certain node. 
       FIG.  1    illustrates an example of an apparatus  100  configured to practice one or more example embodiments. The apparatus may be configured to at least assist in localizing a user equipment (UE). The apparatus  100  may be, for example, a network node, a target node or an anchor node. The target node and the anchor node may be, for example, a UE. 
     Apparatus  100  may comprise at least one processor  101 . The at least one processor  101  may comprise, for example, one or more of various processing devices, such as for example a co-processor, a microprocessor, a controller, a digital signal processor (DSP), a processing circuitry with or without an accompanying DSP, or various other processing devices including integrated circuits such as, for example, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a microcontroller unit (MCU), a hardware accelerator, a special-purpose computer chip, or the like. 
     The apparatus  100  may further comprise at least one memory  102 . The memory  102  may be configured to store, for example, computer program code  103  or the like, for example operating system software and application software. The memory  102  may comprise one or more volatile memory devices, one or more non-volatile memory devices, and/or a combination thereof. For example, the memory  102  may be embodied as magnetic storage devices (such as hard disk drives, magnetic tapes, etc.), optical magnetic storage devices, or semiconductor memories (such as mask ROM, PROM (programmable ROM), EPROM (erasable PROM), flash ROM, RAM (random access memory), etc.). 
     The apparatus  100  may further comprise communication interface  104  configured to enable apparatus  100  to transmit and/or receive information, to/from other apparatuses. The communication interface may be configured to provide at least one wireless radio connection, such as for example a 3GPP mobile broadband connection (e.g. 3G, 4G, 5G). However, the communication interface  104  may be configured to provide one or more other type of connections, for example a wireless local area network (WLAN) connection such as for example standardized by IEEE 802.11 series or Wi-Fi alliance; a short range wireless network connection such as for example a Bluetooth, NFC (near-field communication), or RFID connection; a wired connection such as for example a local area network (LAN) connection, a universal serial bus (USB) connection or an optical network connection, or the like; or a wired Internet connection. The communication interface  104  may comprise, or be configured to be coupled to, at least one antenna to transmit and/or receive radio frequency signals. One or more of the various types of connections may be also implemented as separate communication interfaces, which may be coupled or configured to be coupled to a plurality of antennas. 
     The apparatus  100  may further comprise a user interface  105  comprising an input device and/or an output device. The input device may take various forms such a keyboard, a touch screen, or one or more embedded control buttons. The output device may for example comprise a display, a speaker, a vibration motor, or the like. 
     When the apparatus  100  is configured to implement some functionality, some component and/or components of the apparatus  100 , such as for example the at least one processor and/or the memory, may be configured to implement this functionality. Furthermore, when the at least one processor  101  is configured to implement some functionality, this functionality may be implemented using program code  103  comprised, for example, in the memory  102 . 
     The functionality described herein may be performed, at least in part, by one or more computer program product components such as software components. According to an embodiment, the apparatus  100  comprises a processor or processor circuitry, such as for example a microcontroller, configured by the program code when executed to execute the embodiments of the operations and functionality described. Alternatively, or in addition, the functionality described herein can be performed, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), application-specific Integrated Circuits (ASICs), application-specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), Graphics Processing Units (CPUs). 
     The apparatus  100  comprises means for performing at least one method described herein. In one example, the means comprises the at least one processor  101 , the at least one memory  102  including program code  103  configured to, when executed by the at least one processor  101 , cause the apparatus  100  to perform the method. 
     Apparatus  100  may comprise for example a computing device such as for example a server device, a client device, a mobile phone, a tablet computer, a laptop, or the like. In one example, the apparatus  100  may comprise a vehicle. Although the apparatus  100  is illustrated as a single device it is appreciated that, wherever applicable, functions of apparatus  100  may be distributed to a plurality of devices. 
       FIG.  2    illustrates an example of beam-domain based processing of positioning information for localizing a UE  200  in a network when the UE  200  is not directly reachable by a network node  201  according to an example embodiment. The network may comprise the network node  201 , a target node  200 , and a plurality of anchor nodes  202 ,  203 . The target node  200  and the plurality of anchor nodes  202 ,  203  may be also referred to as a user node, a client node, a user equipment (UE),a network node, an LAB node, a sidelink node, a transmission-Reception Point (TRP), which may be a set of geographically co-located antennas (e.g. antenna array (with one or more antenna elements)) supporting TP and/or RP functionality, a V2X (vehicle-to-everything) node or a V2V (vehicle-to-vehicle) node. The target and anchor nodes  200 ,  202 ,  203  may communicate with one or more base stations  201  over wireless radio channel(s). Base stations may be also called network nodes  201 . In general, a network node may comprise any suitable radio access point. For example, UE  200 ,  202 ,  203  may be configured to communicate with the network node  201 , such as a 5G node, gNB, and/or a 4G node, eNB. The target node  200  may have a non-line-of-sight path with an unknown position of a scatterer  204  to the first anchor node  203 . The second anchor node may have a line-of-sight path to the target node  200 . 
     If only a time difference measurement, such as a time-of-flight measurement of a signal between the target node and at least one of the anchor nodes is used, there is an uncertainty of the position of the UE  200 . The time difference measurements related to propagation of signals may be used to estimate distance between the target UE and the anchor node, as illustrated with an arch  208  of a circle around the corresponding anchor node. The time difference measurements may only enable estimating the location of the UE  200  within the circle where the estimated distance corresponds to the radius of the circle. 
     When anchor node based angular difference (AAD) measurements  206 ,  207  are used together with a transmission/reception beam angle ϕ of the network node  201 , the estimated position of the UE  200  may be within a segment  209 . Hence, there is still uncertainty about the true location of the UE  200 . 
     When both the time difference measurements and the AAD measurements are used, the estimated position of the UE  200  may be, for example, within a circle  210 . The estimated location may not be accurate, because it may not be possible to take into account the effect of the scatterer  204  using only the AAD and time difference measurements. 
     However, when also target node based angular difference (TAD) measurements are obtained from the target node  200 , the target node  200  may be localized accurately also in the non-line-of-sight scenarios. In an embodiment, a geometry of the network comprising the network node, the target node and the plurality of anchor nodes may be reconstructed based on the AAD and TAD measurements and the time difference measurements to localize the target node  200 . With the additional TAD measurements, the anchor nodes  202 ,  203  and the network node  201  may know the direction of projections caused by any obstacles, such as the scatterer  204 , between the target node  200  and the network/anchor nodes. Hence, positioning accuracy of the target node  200  may be increased. In addition, or alternatively, the reconstructed geometry of the network may be used to estimate positions of other nodes, such as the anchor nodes  202 ,  203 . 
       FIG.  3    illustrates an example of beam-domain based processing of positioning information for localizing the UE  200  when the UE  200  is directly reachable by the network node  201  according to an example embodiment. The network is like the network in  FIG.  2   , but there is line-of-sight between the network node  201 , the UE  200 , and the anchor nodes  202 ,  203 . Even when there are no scatterers, the TAD measurements  305  may be used together with the AAD measurements  306 ,  307  to improve the positioning accuracy as described above, for example, in case of noisy measurements. 
       FIG.  4    illustrates an example of obtaining a weighted difference between transmission  407 ,  408  and reception  403 ,  404  beam angles according to an example embodiment. The angular differences in spatial domain may be computed by the anchor node  402  based on combining a weighted angle of departure and/or reception of multiple transmission or reception beams  407 ,  408  to and/or from a network node  401  and a weighted angle of arrival of multiple reception beams  403 ,  404  from the target node  400 . The weighted angles of arrival and/or departure may be weighted with the corresponding quality of reference signals, e.g. layer one reference signal reception power (L1-RSRP) and/or spatial weighting pattern (e.g. weights associated with different reported beam pairs) configured by the network. In an embodiment, the target node  400  may be configured to compute the angular differences of the target node  400  based on the weighted angular differences of multiple transmission and/or reception beam directions weighted with the corresponding reference signals. The weighted angular differences may enable accounting inherent uncertainty in the transmission and/or reception beam directions. 
       FIG.  5    illustrates an example of a joint use of positioning assistance measurements  505 ,  506 ,  507  and time difference measurements in a network for estimating position of a target node  500  according to an example embodiment. 
     The network may comprise a network node  501 , a target node  500 , such as a UE, and a plurality of anchor nodes  502 ,  503 . Each of the target and anchor nodes may comprise one or more antenna panels configured to receive and transmit radio frequency signals associated with at least one of uplink and downlink transmission resources. 
     The UE  500  may not be directly reachable by the network node  501 . For example, a non-line-of-sight radio channel may be caused by one or more scatters  504 ,  508  reflecting the transmission and/or reception beams. The UE  500  may be connected to the network node  501  with two anchor nodes  502 ,  503  via sidelink or device-to-device connections. The network node  501  and each of the anchor nodes  502 ,  503  may be connected using a pair of uplink and/or downlink beams. Likewise, the anchor nodes and the target node may be connected using a pair of uplink and/or downlink beams. The network node  501  may have configured positioning assistance measurements, such as AAD measurements for anchor nodes  502 ,  503  and TAD measurements for target node  500 . Furthermore, at least one of the target node  500  or the anchor nodes may be configured to perform time difference measurements related to propagation of signals. The time difference measurements may comprise, for example, time difference of arrival measurements, time of arrival measurements, received signal time difference, or round-trip time measurements between the target node and one or more anchor nodes, or between the anchor node and the network node. Depending on the configured TAD measurement, the target node  500  may measure the angular difference either between at least one of an uplink and/or downlink resources associated with reception and/or transmission beams. After the target node  500  and the one or more anchor nodes  502 ,  503  have performed the TAD and AAD measurements as well as time difference measurements, one or more of the anchor nodes  502 ,  503  may provide a positioning report including the AAD measurement results for the network node  501  or the target node  500 , for example, via NRLPP (new radio/LTE positioning protocol) or other higher layer signaling or MAC or physical layer signaling. Similarly, the target node  500  may provide a positioning report comprising at least one of the TAD and/or time difference measurement results for the one or more anchor nodes  502 ,  503  or to the network node  501  via the one or more anchor nodes  502 ,  503 , for example, via NRLPP or other higher layer signaling or MAC or physical layer signaling. Based on the positioning reports, the network node, one or more anchor nodes, or the target node may emulate, by combining the AAD, TAD and time difference measurements, transmitted signal propagation over different channel clusters, reflections or scatterers in the spatial domain associated with the measured beam pair per links. For example, the network node, the anchor node or the target node may reconstruct a geometry of the network based on the positioning reports. As a result of the joint use of the AAD, TAD and time difference measurements, the network node  500  or one or more anchor nodes  502 ,  503  may estimate accurately the position of the target node  500 . The position of the target node  500  may be estimated accurately in the presence of non-line-of-sight radio propagation environment. 
       FIG.  6    illustrates an example of a message sequence chart for estimating a position of a user equipment  600  when the position is estimated by a network node  601  according to an example embodiment. 
     At  604 , the network node  601  may be configured to determine a positioning measurement configuration. The network node  601  may determine in the positioning measurement configuration, for example, positioning assistance measurements for the target node  600  and the plurality of anchor nodes  602 ,  603 . In an embodiment, the positioning measurement configuration may comprise at least one of a local or global coordinate system for obtaining the positioning assistance measurements. When global reference coordinates are configured by the network node  601 , the network node  601  may configure a global reference direction comprising at least one relative global reference point. The global reference direction may be, for example, a compass north, a set of cartesian points or a set of polar coordinate points with respect to which the target and anchor nodes compute the positioning assistance measurements. The positioning measurement configuration may configure the target node  600  to perform the positioning assistance measurements comprising the TAD measurements in at least one of an azimuth or elevation domain. Similarly, the positioning measurement configuration may configure the anchor nodes  602 ,  603  to perform the positioning assistance measurements comprising the AAD measurements in at least one of an azimuth or elevation domain. 
     At operations  605 ,  606 ,  607  the network node  601  sends the positioning measurement configuration to the target node  600  and a plurality of the anchor nodes  602 ,  603 . The information sent at  605 ,  606 ,  607  may be different for the target node  600  and the anchor nodes  602 ,  603 . For example, for target node  600  the positioning measurement configuration may comprise an indication of a TAD measurement. For anchor nodes  602 ,  603  the positioning measurement configuration may comprise an indication of an AAD measurement. 
     Alternatively, the same information including indications of both AAD and TAD measurements may be sent to target node  600  and anchor nodes  602 ,  603 . The measurement to be performed may be determined based on a type of the node. For example, since target node  600  has sidelink connections to anchor nodes  602 ,  603 , the target node may determine to perform a TAD measurement. The positioning measurements may be preconfigured, as illustrated in  FIG.  6   . Alternatively, or in addition, the positioning measurements may be configured after a failure in connection between the target node  600  and the network node  601 . The failure in connection may be caused, for example, when the target node  600  enters an area without a network coverage. When the (NR)LPP connection has failed, the target node  600  may still be able to obtain the positioning assistance measurements according to the previously received positioning measurement configuration, but may not be able to report the positioning assistance measurements to the network node. 
     At  608 ,  609 , and  610 , the network node  601  may establish or trigger sidelink (SL) connections between the target node  600  and at least two anchor nodes  602 ,  603 , for example in response to the connection failure, for example in LPP connection or a corresponding positioning protocol, such as NRLPP. In an embodiment, the at least two anchor network nodes  602 ,  603  may establish the SL connections between the target node  600  and the anchor nodes  602 ,  603 . The plurality of SL connections to a target node via the plurality of anchor nodes may enable seamless positioning service of the target node  600  when the target node  600  is not directly reachable by the network node  601 . Hence, the (NR)LPP connection may be re-established via the SL connections. The SL connection may be established with a pair of uplink and/or downlink beams between the anchor nodes  602 ,  603  and the target node  600 . The network node  601  and each of the anchor nodes  602 ,  603  may be connected using a pair of uplink and/or downlink beams. 
     At operation  611 , the target node may compute at least one positioning assistance measurement comprising a target node based angular difference (TAD) between the pair of uplink and/or downlink beam directions based on the positioning measurement configuration. The target node may further compute at least one time difference measurement related to propagation of signals between the target node and/or at least one anchor node. The one or more time difference measurements may comprise, for example, time of arrival, time difference of arrival, round trip time or reference signal difference measurements between the target node  600  and at least one anchor node  602 ,  603 . 
     The one or more positioning assistance measurements may be computed in at least one of a local or a global coordinate system based on the positioning measurement configuration. In an embodiment, the positioning assistance measurements may be determined in a global coordinate system with respect to at least one relative global coordinate reference point comprising at least one of a compass north, a cartesian coordinate point or a polar coordinate point. In an embodiment, the at least one global coordinate reference point comprises combinations of the compass north, one or more cartesian coordinate points or one or more polar coordinate points associated with a single or multiple reference transmission reception point(s). In an embodiment, the positioning assistance measurements may be computed in at least one of an azimuth domain or an elevation domain based on the positioning measurement configuration. 
     In the local coordinate system, the positioning assistance measurements may comprise an angular difference between a reception or a transmission beam angle of a downlink or an uplink transmission resource from/to one anchor node  602 ,  603  and a reception or a transmission beam angle of an uplink or a downlink transmission resource from/to another anchor node  602 ,  603 . The target node  600  may compute a difference of the transmission and/or reception beam angles and take an absolute value of the result. In an embodiment, the target node  600  may compute a reception beam angle associated with a downlink transmission resource from the anchor node  602  and a reception beam angle associated with an uplink transmission resource from the anchor node  603 . In an embodiment, the target node  600  may compute the angular difference between a reception beam angle associated with a downlink transmission resource from the anchor node  602  and a transmission beam angle associated with an uplink transmission resource to the anchor node  603 . In an embodiment, the target node  600  may compute the angular difference between a transmission beam angle associated with an uplink transmission resource to the anchor node  602  and a transmission beam angle associated with an uplink transmission resource to the anchor node  603 . In an embodiment, the target node  600  may compute the angular difference between a transmission beam angle associated with an uplink transmission resource to the anchor node  602  and a reception beam angle associated with an uplink transmission resource from the anchor node  603 . In an embodiment, the target node  600  may compute the angular difference between a reception beam angle associated with a downlink transmission resource from the anchor node  602  and a reception beam angle associated with a downlink transmission resource from the network node  603 . In an embodiment, the angular differences of the beam angles comprise an antenna panel orientation of the target node  600 . The above positioning assistance measurements i.e. angle difference between DL and/or UL resources associated with reception or/and transmission beams are also valid for computation between any network nodes, e.g. anchor nodes, sidelink nodes, gNBs, Transmission-Reception Points (TRP)s, which may be a set of geographically co-located antennas (e.g. antenna array (with one or more antenna elements)) supporting TP and/or RP functionality, or a combination thereof. 
     In the global coordinate system, the positioning assistance measurements may comprise a target node based angular difference (TAD) between one of a reception or a transmission beam angle associated with a downlink or uplink transmission resource from/to one anchor node with respect to at least one configured global coordinate reference point and a reception or a transmission beam angle associated with an uplink or a downlink transmission resource from/to another anchor node with respect to the at least one configured global coordinate reference point. In an embodiment, the target node  600  may compute a relative TAD measurement between a reception beam angle associated with a downlink transmission resource from the anchor node  602  with respect to the configured global reference point(s). In addition, the target node  600  may compute the relative TAD measurement between a reception beam angle associated with an uplink transmission resource from the anchor node  603  with respect to the configured global reference point(s). In an embodiment, the target node  600  may compute the relative TAD measurement between a transmission beam angle associated with a uplink transmission resource to the anchor network node  602  with respect to the configured global reference point(s). In addition, the target node  600  may compute the relative TAD measurement between a reception beam angle associated with an downlink transmission resource from the anchor node  603  with respect to the configured global reference point(s). In an embodiment, the angular differences of the beam angles may comprise an antenna panel orientation of the target node  600 . The above positioning assistance measurements i.e. angle difference between DL and/or UL resources associated with reception or/and transmission beams are with respect to global coordination point(s) also valid for computation between any network nodes, e.g. anchor nodes, sidelink nodes, gNBs, TRPs, or a combination thereof. 
     In an embodiment, the different relative angle difference measurements between the pair of reception and/or transmission beam of the uplink and/or downlink resources may be ordered for each configured global reference point associated with a network node separately under node measurement configuration by the network. For example, the network may configure a specific measurement order in time, e.g. firstly an angle difference between a downlink resource from a network node associated with a reception beam angle and a downlink resource from another network node associated with the reception beam angle, secondly an angle difference between a downlink resource from a network node associated with a reception beam angle and an uplink resource to another network node associated with the transmission beam angle. For each configured reference point, relative angle information in global coordinate system may be computed based on a difference between the transmission and/or reception beam of the uplink and/or downlink resources. In addition, an absolute value may be taken from the computed difference value. 
     In an embodiment, the network node  601  may configure the positioning assistance measurements to be periodic or semi-persistent or aperiodic at the target node  600 . Alternatively, the positioning report comprising the one or more positioning assistance measurements may be dynamically requested by the network node  601  based on a required positioning accuracy. For example, the target node  600  may not need to report the positioning assistance measurements, or the positioning assistance measurements may not need to be conveyed to network node  601 , e.g. if a positioning service does not require accurate position or the potential positioning error may be tolerated. 
     At operations  612  and  613 , at least one positioning assistance measurement comprising an anchor node based angular difference (AAD) between the pair of uplink and/or downlink beam directions may be computed based on the positioning measurement configuration by each respective anchor node  602 ,  603 . The AAD measurements may be computed by the anchor nodes  602 ,  603  based on a local and/or global coordinate system configured by the network node  601 . In an embodiment, the positioning assistance measurements of the anchor nodes  602 ,  603  may be determined in a global coordinate system with respect to at least one relative global coordinate reference point comprising at least one of a compass north, a cartesian coordinate point or a polar coordinate point. In an embodiment, the positioning assistance measurements of the anchor nodes  602 ,  603  may be computed in at least one of an azimuth domain or an elevation domain based on the positioning measurement configuration. 
     In the local coordinate system, the positioning assistance measurements of the anchor nodes  602 ,  603  may comprise an angular difference between a reception or a transmission beam angle of a downlink or an uplink transmission resource from/to the network node  601  and a reception or a transmission beam angle of an uplink or a downlink transmission resource from/to the target node  600 . The anchor node  602 ,  603  may compute a difference of the transmission and/or reception beam angles and take an absolute value of the result. In an embodiment, the anchor node  602 ,  603  may compute a reception beam angle associated with a downlink transmission resource from the network node  601  and a reception beam angle associated with an uplink transmission resource from the target node  600 . In an embodiment, the anchor node  602 ,  603  may compute the angular difference between a reception beam angle associated with a downlink transmission resource from the network node  601  and a transmission beam angle associated with an uplink transmission resource to the target node  600 . In an embodiment, the anchor node  602 ,  603  may compute the angular difference between a transmission beam angle associated with an uplink transmission resource to the network node  601  and a transmission beam angle associated with an uplink transmission resource to the target node  600 . In an embodiment, the anchor node  602 ,  603  may compute the angular difference between a transmission beam angle associated with an uplink transmission resource to the network node  601  and a reception beam angle associated with an uplink transmission resource from the target node  600 . In an embodiment, the angular differences of the beam angles comprise an antenna panel orientation of the respective anchor node  602 ,  603 . 
     In global coordinate system, the positioning assistance measurements may comprise an anchor node based angular difference (AAD) between a reception or a transmission beam angle associated with a downlink or uplink transmission resource from/to the network node  601  with respect to at least one configured global coordinate reference point and a reception or a transmission beam angle associated with an uplink or a downlink transmission resource from/to the target node  600  with respect to the at least one configured global coordinate reference point. In an embodiment, the anchor node  602 ,  603  may compute a relative AAD measurement between a reception beam angle associated with a downlink transmission resource from the network node  601  with respect to the configured global reference point(s). In addition, the anchor node  602 ,  603  may compute the relative AAD measurement between a reception beam angle associated with an uplink transmission resource from the network node  601  with respect to the configured global reference point(s). In an embodiment, the anchor node  602 ,  603  may compute the relative AAD measurement between a transmission beam angle associated with a uplink transmission resource to the network node  601  with respect to the configured global reference point(s). In addition, the anchor node  602 ,  603  may compute the relative AAD measurement between a reception beam angle associated with a downlink transmission resource from the network node  601  with respect to the configured global reference point(s). In an embodiment, the angular differences of the beam angles may comprise an antenna panel orientation of the respective anchor node  602 ,  603 . 
     In an embodiment, the different relative angle difference measurements between the pair of reception and/or transmission beam of the uplink and/or downlink resources may be ordered for each configured global reference point associated with a network node separately under node measurement configuration by the network. For example, the network may configure a specific measurement order in time, e.g. firstly an angle difference between a downlink resource from a network node associated with a reception beam angle and a downlink resource from another network node associated with the reception beam angle, secondly an angle difference between a downlink resource from a network node associated with a reception beam angle and an uplink resource to another network node associated with the transmission beam angle. For each configured reference point, relative angle information in global coordinate system may be computed based on a difference between the transmission and/or reception beam of the uplink and/or downlink resources. In addition, an absolute value may be taken from the computed difference value. 
     In an embodiment, the downlink resources defined in the above AAD or TAD positioning assistance measurements may be associated with at least one of reference signals, data or control. The positioning assistance measurements may be associated, for example, with a non-zero-power channel state information reference signal (NZP-CSI-RS) for beam management (BM), time-frequency tracking, a channel state information (CSI) acquisition, a positioning reference signal (PRS), a phase tracking reference signal (PTRS), a demodulation reference signal (DMRS) of physical downlink shared channel (PDSCH), a DMRS of physical downlink control channel (PDCCH) or a synchronization signal block (SSB). 
     In an embodiment, the uplink resources defined in the above AAD or TAD positioning assistance measurements may be associated with at least one of reference signals, data or control. For example, the positioning assistance measurements may be associated with a sounding reference signal (SRS), uplink positioning reference signal (PRS), a phase tracking reference signal (PTRS), a DMRS of physical uplink shared channel (PUSCH) or a DMRS of physical uplink control channel (PUCCH). 
     At operation  614 , the target node may determine a positioning report. The positioning report may comprise at least one positioning assistance measurement. In an embodiment, the positioning report may comprise one or more time difference measurement(s), round-trip-time measurements, carrier phase measurements for positioning, angle of arrival measurements, angle of departure measurements, and/or reference signal received power measurements. 
     At operations  615  and  616 , the target node may dispatch the positioning report to one or more anchor nodes  602 ,  603 . At operations  617  and  618 , in response to receiving the positioning report from the target node  600 , the one or more anchor nodes  602 ,  603  may determine a positioning report comprising one or more positioning assistance measurement(s) of the respective anchor node  602 ,  603  and the measurement results of the positioning report of the target node  600 . In an embodiment, the positioning report may further comprise one or more time difference measurement(s), round-trip-time measurements, carrier phase measurements, angle of arrival measurements, angle of departure measurements, and/or reference signal received power of the respective anchor node  602 ,  603 . If one anchor node does not receive the positioning report of the target node  600 , the measurement results of the target node may be omitted from the positioning report of the respective anchor node. At operations  619  and  620  the one or more anchor nodes  602 ,  603  may dispatch the positioning report of the respective anchor node  602 ,  603  to the network node  601 . 
     At operation  621 , in response to receiving the position report(s) from the one or more anchor nodes  602 ,  603 , the network node  601  may estimate the position of the target node  600 . For example, the network node may reconstruct a geometry of the network comprising the network node, the target node and the plurality of anchor nodes based on the positioning assistance measurements and the time difference measurements and/or round-trip-time measurements and/or carrier phase measurements for positioning and/or angle of arrival measurements and/or angle of departure measurements and/or reference signal received power measurements of at least one of the target node or the anchor nodes to determine position of at least one of the target node or one of the plurality of anchor nodes. 
       FIG.  7    illustrates an example of a message sequence chart for estimating a position of a user equipment when the position is estimated by a target node according to an example embodiment. In  FIG.  7   , operations  604  to  618  correspond to operations of the like references in  FIG.  6   . 
     At operations  701  and  702 , the one or more anchor nodes  602 ,  603  may dispatch their positioning reports to the target node  600 . In response, at operation  703 , the target node  600  may estimate its own position based on the measurement results of the positioning reports. For example, the target node  600  may reconstruct a geometry of the network comprising the network node  601 , the target node  600  and the plurality of anchor nodes  602 ,  603  based on the positioning assistance measurements and the time difference measurements of at least one of the target node or the anchor nodes. In an embodiment, the target node  600  may estimate position of at least one anchor node  602 ,  603  based on the positioning reports. 
       FIG.  8    illustrates an example of a message sequence chart for estimating a position of a user equipment when the position is estimated by an anchor node according to an example embodiment. In  FIG.  8   , operations  604  to  618  correspond to operations of the like references in  FIG.  6    and  FIG.  7   . 
     At operation  801 , one anchor node  603  may dispatch its positioning report to another anchor node  602 . In response to receiving the positioning reports from the target node  600  and the anchor node  603 , at operation  802 , the anchor node  602  may estimate position of at least one of the target node  600  or the anchor node  603  based on the positioning assistance measurements and the time difference measurements and/or carrier phase measurements and/or round-trip-time measurements and/or angle of arrival measurements and/or angle of departure measurements, and/or reference signal received power measurements as described above. In an embodiment, the anchor node  602  may receive the positioning report only from the target node  600  and estimate the position of the target node  600  based on the TAD measurement from the target node  600  and the AAD of the anchor node  602 . 
     Thus, based on the positioning reports comprising the AAD, TAD and/or time difference measurements and/or round-trip-time measurements and/or carrier phase measurements for positioning and/or angle of arrival measurements and/or angle of departure measurements, and/or reference signal received power, both UEs and/or network node may be able to accurately localize at least one of the target node or the anchor node. 
       FIG.  9    illustrates an example of localizing a user equipment based on angular difference measurements of network nodes  901 ,  902 ,  903  connected with the user equipment according to an example embodiment. 
     A target node  900 , such as the UE, may be connected to a plurality of network nodes  901 ,  902 ,  903 , such as gNBs and/or TRPs. The target node  900  may compute angle of arrival differences  905 ,  906  for example, between each network node  901 ,  902 ,  903  from which downlink transmission is received at the target node  900 . The target node  900  may report the angle of arrival differences  904 ,  905 ,  906  between the downlink transmission measurements to one network node  901 . Additionally, the target node  900  may dispatch at least one of one or more time difference measurements, time of arrival measurements, carrier phase measurements, round-trip-time measurements, angle of departure measurements associated with a downlink transmission from one or more network nodes or uplink transmission from the target node, angle of arrival measurements associated to uplink transmission from one or more network nodes and/or carrier phase measurements. The network node  901  may combine each measurements received from the target node  900  for estimating position of the target node  900 . 
     In an embodiment, the target node  900  may be configured to compute angle of differences between different downlink and/or uplink transmission reception and/or transmission beam pairs, for example, associated with one or more network nodes  901 ,  902 ,  903 . The network may configure a specific downlink or uplink TX-RX beam pair as reference with respect to which the angle difference is computed by the target node  900 . Moreover, the network may also dynamically indicate which of the downlink and/or uplink TX-RX beam pairs associated with other network nodes  901 ,  902 ,  903  shall be computed at the target node  900  for position information reporting. The target node  900  may dispatch the configured angle difference measurement results for the network. 
     In an embodiment, the target node  900  may determine autonomously which of angle of differences between different downlink and/or uplink transmission reception and/or transmission beam pairs may be computed, for example, associated with one or more network nodes  901 ,  902 ,  903 . Alternatively, or additionally, the target node  900  may indicate dynamically which of the downlink/uplink TX-RX beam pairs associated with other network nodes  901 ,  902 ,  903  is used as reference downlink/uplink TX-RX beam pair for angle difference computation and reporting between different the network nodes  901 ,  902 ,  903 . The target node  900  may dispatch the autonomously computed angle difference measurement results for the network. 
     In an embodiment, the reference indication may be dispatched to or determined by anchor nodes. In addition, or alternatively, the anchor nodes may determine autonomously which of angle of differences between different downlink and/or uplink transmission reception and/or transmission beam pairs may be computed, or the downlink and/or uplink transmission reception and/or transmission beam pairs for computation may be configured by a network node. 
       FIGS.  10  and  11    illustrate examples of a beam-domain procedure to localize a user equipment when the user equipment is out of coverage of a network node  1001  according to example embodiments. A target node  1000 , such the UE, may be unreachable by the network node  1001 , for example, due to an out-of-coverage situation caused by a free-space path loss as illustrated in  FIG.  10    with a cell edge  1003 . The out-of-coverage situation may be also caused, for example, due to a blockage  1100  between the target node  1000  and the network node  1001 , as illustrated in  FIG.  11   . In an embodiment, the localization procedure may be triggered by the network node  1001  when the network node  1001  requests one or more in-coverage nodes  1002  to report information about other nodes already connected, for example, through D2D links, or about other out-of-coverage nodes that may have been discovered. The reported information may comprise, for example, the international mobile subscriber identity (IMSI). 
     Upon reception of the request, the in-coverage node  1002  may provide the network node  1001  with the requested information (e.g., the IMSI) about the other nodes already connected through D2D links or about the other out-of-coverage nodes that have been discovered by the node  1002 . Subsequently, the network node  1001  may enable one or more in-coverage nodes  1002  that are connected with the target node  1000  to act as anchor nodes and assist the network in localizing the target node  1000 . The network node  1001  may configure, and/or activate if already configured, time-frequency resources for the target node  1000  to transmit, for example, SRS for positioning (i.e., PRS) in the uplink to the anchor node(s)  1002  and for the anchor node(s)  1002  to receive such SRS. Based on the received configuration, the target node  1000  may schedule sidelink control channel resources for the one or more anchor nodes  1002 , on which it transmits the SRS for positioning. The one or more anchor nodes  1002  may obtain positioning assistance measurements, such as angle and time measurements associated with at least one of the network node  1001  and the target node  1000 , e.g., angle of arrival (AoA), angle of departure (AoD), and time of flight (ToF), from the received sidelink control signaling described above. The one or more anchor nodes  1002  may forward the obtained positioning assistance measurements to the network node  1001 . The network, such as the network node  1001  or a location server may use the positioning assistance measurements provided by the one or more anchor nodes  1002  to estimate the position of the target node  1000 . 
       FIG.  12    illustrates a method for estimating a position of a user equipment when the position is estimated by a network node according to an example embodiment. 
     At  1200 , the method may comprise receiving, at a target network node, a positioning measurement configuration from a network node. 
     At  1201 , the method may comprise connecting to a plurality of anchor network nodes with a pair of uplink and/or downlink transmission and/or reception beams. 
     At  1202 , the method may comprise computing at least one positioning assistance measurement of the target network node comprising an angular difference between the pair of uplink and/or downlink transmission and/or reception beam directions based on the positioning measurement configuration. 
     At  1203 , the method may comprise determining a positioning report comprising the at least one positioning assistance measurement of the target network node. 
       FIG.  13    illustrates a method for estimating a position of a user equipment when the position is estimated by an anchor node according to an example embodiment. 
     At  1300 , the method may comprise connecting to a network node and a target node with a pair of uplink and/or downlink transmission and/or reception beams. 
     At  1301 , the method may comprise receiving, at an anchor node, a positioning measurement configuration from the network node. 
     At  1302 , the method may comprise computing at least one positioning assistance measurement of the anchor node comprising an angular difference between the pair of uplink and/or downlink transmission and/or reception beam directions based on the positioning measurement configuration. 
     At  1303 , the method may comprise receiving a positioning report from the target node comprising a positioning assistance measurement associated with the target node and a plurality of anchor nodes connected with the target node. 
     At  1304 , the method may comprise determining a second positioning report comprising the positioning assistance measurements of the anchor node and the target node. 
       FIG.  14    illustrates a method for estimating a position of a user equipment when the position is estimated by a target node according to an example embodiment. 
     At  1400 , the method may comprise establishing a plurality of connections to a target node via a plurality of anchor nodes. 
     At  1401 , the method may comprise determining, by a network node, a positioning measurement configuration of positioning assistance measurements for the target node and the plurality of anchor nodes. 
     At  1402 , the method may comprise dispatching the positioning measurement configuration to at least one of the target node and/or to the plurality of anchor nodes. 
     Further features of the methods directly result from the functionalities and parameters of the apparatuses, as described in the appended claims and throughout the specification and are therefore not repeated here. It is noted that one or more operations of the method may be performed in different order. 
     An apparatus, for example a network node, a target node or an anchor node, may be configured to perform or cause performance of any aspect of the method(s) described herein. Further, a computer program may comprise instructions for causing, when executed, an apparatus to perform any aspect of the method(s) described herein. Further, an apparatus may comprise means for performing any aspect of the method(s) described herein. According to an example embodiment, the means comprises at least one processor, and memory including program code, the at one memory and the program code configured to, when executed by the at least one processor, cause performance of any aspect of the method(s). 
     Any range or device value given herein may be extended or altered without losing the effect sought. Also, any embodiment may be combined with another embodiment unless explicitly disallowed. 
     Although the subject matter has been described in language specific to structural features and/or acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as examples of implementing the claims and other equivalent features and acts are intended to be within the scope of the claims. 
     It will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. The embodiments are not limited to those that solve any or all of the stated problems or those that have any or all of the stated benefits and advantages. It will further be understood that reference to ‘an’ item may refer to one or more of those items. 
     The operations of the methods described herein may be carried out in any suitable order, or simultaneously where appropriate. Additionally, individual blocks may be deleted from any of the methods without departing from the scope of the subject matter described herein. Aspects of any of the embodiments described above may be combined with aspects of any of the other embodiments described to form further embodiments without losing the effect sought. 
     The term ‘comprising’ is used herein to mean including the method, blocks, or elements identified, but that such blocks or elements do not comprise an exclusive list and a method or apparatus may contain additional blocks or elements. 
     As used in this application, the term ‘circuitry’ may refer to one or more or all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and/or digital hardware circuit(s) with software/firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this application, including in any claims. 
     As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device. 
     It will be understood that the above description is given by way of example only and that various modifications may be made by those skilled in the art. The above specification, examples and data provide a complete description of the structure and use of exemplary embodiments. Although various embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from scope of this specification.