Patent Publication Number: US-2021195458-A1

Title: Early measurement report

Description:
TECHNICAL FIELD 
     Various examples of the invention generally relate to measurement reports. Various examples specifically relate to providing measurement reports as part of a random access procedure. 
     BACKGROUND 
     In wireless communication systems, a wireless communication device (sometimes referred to as terminal or user equipment, UE) typically measures channel quality of a respective wireless link between the UE and an access node (AN). This is referred to as performing a channel measurement. Performing the channel measurement facilitates determining parameters of wireless communication. 
     Typically, the UE can report on the channel measurement to the AN. This is referred to as a measurement report. The AN can set one or more parameters of the wireless communication. The AN can be implemented by a base station (BS) of a communication network. 
     Example parameters that can be set depending on the channel measurement include a modulation and coding scheme (MCS); and a serving BS in case of a cellular communication network including multiple BSs: hence, a handover may or may not be triggered depending on the channel measurement. 
     Example implementations of the measurement report include a Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), and/or a Channel Quality Indication (CQI). For example, based on the measurement report, the BS may select a suitable MCS for the subsequent data transmission or—in case of a cellular communication network—the BS may decide whether the UE needs to perform a handover to another neighboring BS. 
     Sometimes, a UE may operate in idle mode. Here, a data connection between the UE and the AN is not maintained, but rather released. This is typically done to reduce power consumption. To transition the UE into operation in connected mode—where the data connection is established—typically various steps need to be performed. Typically, measurement reports are only transmitted by the UE once operating in connected mode. 
     Various techniques are based on the finding that in reference implementation—where the UE provides the measurement report in connected mode—the latency introduced by the steps required to transition operation of the UE into the connected mode can be significant. 
     SUMMARY 
     Therefore, a need exists for advanced techniques of performing and reporting on channel measurements. 
     This need is met by the features of the independent claims. The features of the dependent claims define embodiments. 
     A method of operating a wireless communication device includes performing a channel measurement of a wireless link. The wireless link is between the wireless communication device and a network node of a communication network. The method also includes transmitting, as part of a random access procedure for accessing the communication network, an uplink message to the network node. The uplink message carries a measurement report of the channel measurement. The method further includes providing, to the network node, an indication related to whether the uplink message carries the measurement report. 
     A computer program includes program code. The program code can be executed by a control circuitry. Executing the program code causes the control circuitry to perform a method of operating a wireless communication device which method includes performing a channel measurement of a wireless link. The wireless link is between the wireless communication device and a network node of a communication network. The method also includes transmitting, as part of a random access procedure for accessing the communication network, an uplink message to the network node. The uplink message carries a measurement report of the channel measurement. The method further includes providing, to the network node, an indication related to whether the uplink message carries the measurement report. 
     Also, a computer program product and a computer-readable storage medium are provided which include such program code. 
     A wireless communication device is configured to perform a channel measurement of a wireless link between the wireless communication device and a network node of a communication network; and to transmit, as part of a random access procedure for accessing the communication network, an uplink message to the network node, the uplink message carrying a measurement report of the channel measurement; and to provide, to the network node, an indication related to whether the uplink message carries the measurement report. 
     A method of operating a network node of a communication network includes receiving, as part of a random access procedure of a wireless communication device accessing the communication network, an uplink message from the wireless communication device. The uplink message carries a measurement report of a channel measurement of the wireless link performed by the wireless communication device. The method also includes obtaining, from the wireless communication device, an indication related to whether the uplink message carries the measurement report. The method also includes processing the uplink message in accordance with the indication. 
     A computer program includes program code. The program code can be executed by a control circuitry. Executing the program code causes the control circuitry to perform a method of operating a network node of a communication network, which method includes receiving, as part of a random access procedure of a wireless communication device accessing the communication network, an uplink message from the wireless communication device. The uplink message carries a measurement report of a channel measurement of the wireless link performed by the wireless communication device. The method also includes obtaining, from the wireless communication device, an indication related to whether the uplink message carries the measurement report. The method also includes processing the uplink message in accordance with the indication. 
     Also, a computer program product and a computer-readable storage medium are provided which include such program code. 
     A network node of a communication network is configured to receive, as part of a random access procedure of a wireless communication device accessing the communication network, an uplink message from the wireless communication device, the uplink message carrying a measurement report of a channel measurement of the wireless link performed by the wireless communication device; and to obtain, from the wireless communication device, an indication related to whether the uplink message carries the measurement report; and to process the uplink message in accordance with the indication. 
     A system includes a wireless communication device and a network node of a communication network. The wireless communication device is configured to perform a channel measurement of a wireless link between the wireless communication device and the network node. The wireless communication device is further configured to transmit, as part of a random access procedure for accessing the communication network, an uplink message to the network node, the uplink message carrying a measurement report of the channel measurement. The wireless communication device is further configured to provide, to the network node, an indication related to whether the uplink message carries the measurement report. The network node is configured to receive the uplink message and to obtain the indication and to process the uplink message in accordance with the indication. 
     It is to be understood that the features mentioned above and those yet to be explained below may be used not only in the respective combinations indicated, but also in other combinations or in isolation without departing from the scope of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  schematically illustrates a communication system according to various examples. 
         FIG. 2  schematically illustrates the communication system of  FIG. 1  in greater detail. 
         FIG. 3  schematically illustrates a communication network that can implement the communication system according to various examples. 
         FIG. 4  schematically illustrates operation of a UE according to various examples. 
         FIG. 5A  is a flowchart of a method according to various examples. 
         FIG. 5B  is a flowchart of a method according to various examples. 
         FIG. 6A  is a flowchart of a method according to various examples. 
         FIG. 6B  is a flowchart of a method according to various examples. 
         FIG. 7  is a signaling diagram of communication between a UE and a BS according to various examples, the communication pertaining to a random access procedure. 
         FIG. 8  schematically illustrates a message according to various examples. 
         FIG. 9  schematically illustrates a method according to various examples. 
         FIG. 10  schematically illustrates a method according to various examples. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
     In the following, embodiments of the invention will be described in detail with reference to the accompanying drawings. It is to be understood that the following description of embodiments is not to be taken in a limiting sense. The scope of the invention is not intended to be limited by the embodiments described hereinafter or by the drawings, which are taken to be illustrative only. 
     The drawings are to be regarded as being schematic representations and elements illustrated in the drawings are not necessarily shown to scale. Rather, the various elements are represented such that their function and general purpose become apparent to a person skilled in the art. Any connection or coupling between functional blocks, devices, components, or other physical or functional units shown in the drawings or described herein may also be implemented by an indirect connection or coupling. A coupling between components may also be established over a wireless connection. Functional blocks may be implemented in hardware, firmware, software, or a combination thereof. 
     Techniques are described which generally relate to communicating on a wireless link. The wireless link can be between two nodes of a wireless communication system. The wireless link may generally relate to a communication link between two nodes of a communication system using electromagnetic waves or light as a transmission medium. 
     As a general rule, the wireless communication system can be implemented in various manners. For example, a Wireless Local Area Network (WLAN) communication system or a Bluetooth communication system or a peer-to-peer wireless communication system may be implemented. It would also be possible to implement the wireless communication system by a cellular communication network to which UE:s can connect. 
     For sake of simplicity, hereinafter, techniques will be described in which a communication system is implemented by a cellular communication network to which UE:s are connectable. A UE may be connectable to the cellular communication network through a respective data connection. The UE may connect to the cellular communication network through multiple BSs of a radio access network (RAN) of the cellular communication network. Example implementations include a Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) cellular communication network. However, similar techniques may be readily applied to different kinds and type of cellular communication networks, e.g., the upcoming 3GPP New Radio (NR) cellular communication network or Internet of Things (IOT) communication networks, e.g., based on Narrowband(NB)-IOT or Machine Type Communication (MTC). 
     Hereinafter, generally techniques with respect to performing and/or configuring channel measurements of the wireless link are described. Specifically, techniques will be described that relate to performing and/or configuring channel measurements at the UE. 
     Channel measurements may generally provide an indication of a quality of communication on the wireless link. For example, channel measurements may allow to derive an error rate, a reliability, a fading profile, and/or a path loss, etc. of data or signals communicated via the wireless link. 
     As a general rule, the channel measurements can be implemented in various manners. For example, downlink reference signals (sometimes also referred to as pilot signals) may be transmitted by a BS and may be received by the UE. Then, a receive property—e.g., amplitude and/or phase—of the downlink reference signal can be measured to perform the channel measurement. 
     Further, hereinafter, techniques with respect to reporting on channel measurements are described. A respective measurement report may be implemented by one or more indicators that are indicative of a result of the channel measurement. Different kinds and types of measurement reports may be used, e.g., an RSRP, an RSRQ or a CQI. For example, Layer  1  measurement reports defined on a Physical layer of a transmission protocol stack could be used. It would also be possible to use Layer  2  or Layer  3  measurement reports. 
     According to various examples, a UE can provide the measurement report to the communication network before a data connection has been fully established between the UE and the communication network. The measurement report may be transmitted during a random access (RA) procedure for connecting the UE to the communication network. This is referred to as early measurement report (EMR), hereinafter. 
     An uplink (UL) message of the RA procedure may carry the EMR. For example, a 4-step RA procedure may be used. Here, the channel measurement report may be carried by the third of four messages (Msg. 3 ) of the 4-step RA procedure (including Msg. 1 —i.e., the RA preamble—, Msg. 2 —including an UL grant for Msg. 3 , Msg.  3 , and Msg. 4 ). 
     In other words, it would be possible to implement the EMR at a point in time at which the UE is not (yet) operating in a connected mode. For example, it would be possible to implement the EMR while implementing a transition of operation of the UE in idle mode to operation of the UE in connected mode. This transition is associated with setting up the data connection. This transition can include Layer  3  Radio Resource Control (RRC) control signaling. The data connection and/or the connected mode operation is typically defined on Layer  3  of the transmission protocol stack associated with communication on the wireless link. The data connection may define one or more logical channels for payload and/or higher-layer control data. 
     Generally, in the various examples described herein EMR may help to improve DL transmission efficiency and reduce UE power consumption. 
     According to some examples, the EMR may be transmitted together with an early data transmission (EDT) in Msg. 3  of the RA procedure. EDT facilitates transmission of payload data and/or Layer  3  RRC control data prior to completing set-up of the data connection. Details with respect to EDT are described in 3GPP TSG-RAN WG1 Meeting #93, R1-1807971, Busan, Korea, 21-25 May, 2018, sections 1.5 and 2.5. 
     According to various examples, it is possible to selectively activate the EMR. For example, the EMR may be activated for a first set of UE:s and may be deactivated for a second set of UE:s. Thereby, backwards compatibility can be provided for. For example, older UE:s may not activate the EMR. From a BS perspective, the BS may receive EMRs from the first set of UE:s, but may not receive EMRs from the second set of UE:s. 
     Selective activation of the EMR may not only be available across different UE:s. In some scenarios, it would be possible to selectively activate the EMR for a given UE. In other words, the UL message transmitted by the given UE may or may not carry the EMR, depending on a trigger criterion. Thereby, it is possible to avoid unnecessary control signaling overhead on the wireless link, by transmitting the EMR on demand. For example, typically, the given UE performs multiple RA procedures over the course of time. Then, it would be possible to sometimes activate the EMR and sometimes deactivate the EMR, depending on the particular instance of the RA procedure and taking into account the trigger criterion. As a general rule, various trigger criteria for activating or deactivating the EMR at the given UE are conceivable. Example trigger criteria include a request for the EMR received from the communication network (EMR request); and a result of the channel measurement fulfilling or not fulfilling one or more predefined criteria. An example criteria may include the RSRP falling below a certain predefined threshold, or the like. 
     Above, examples have been provided which pertained to selectively activating or deactivating the EMR. Various scenarios described herein are based on the finding that such selective activation or deactivation of the EMR may require awareness at the BS: if the BS receives an UL message from a given UE as part of a RA procedure of the given UE for connecting to the communication network, this awareness may help the BS to correctly interpret the information carried by the UL message. According to various examples, this awareness can be facilitated by an EMR indication. 
     According to various examples, the EMR indication is provided by the UE and obtained by the BS, the EMR indication pertaining to whether the EMR is activated or deactivated. In other words, the EMR indication relates to whether an UL message of one or more associated RA procedures carries or does not carry the EMR. 
     For example, an exemplary Boolean-type implementation of the EMR indication would be conceivable where “TRUE” indicates that the UL message carries the EMR and “FALSE” indicates that the UL message does not carry the EMR. As a general rule, less explicit options are available for implementing the EMR indication. 
     By means of the EMR indication the BS can determine whether a certain UL message—e.g. received from one (a-priori unknown) of a plurality of UEs or received from a UE that can selectively transmit the EMR—carries the EMR or does not carry the EMR. Thus, the BS may determine, based on the EMR indication, whether a given one of a plurality of UL messages carries or does not carry the EMR. The EMR indication is suited for enabling such a determination by the BS. 
     Hence, by means of the EMR indication, it is possible to flexibly support selective activation of the EMR, e.g., across multiple UE:s or across multiple RA procedures of a given UE. By means of the EMR indication, the BS can correctly interpret the information content of the UL message. For example, the BS can distinguish between different information included in the UL message. For example, the BS can distinguish between a RRC connection request and the EMR, both being carried by the UL message; it would also be possible to distinguish between the EMR and an EDT, both being carried by the UL message. It is possible to receive messages from UEs supporting EMR and UEs not supporting EMR. 
     As a general rule, the EMR indication can be implemented in various manners. For example, the EMR indication can be provided explicitly or implicitly. An example of an explicit indication would be that the UE provides some dedicated information that can be directly used by the BS to derive whether the UL message carries or does not carry the EMR, e.g., the above-identified Boolean-type implementation. In an implicit implementation, the BS may require some processing, possibly based on additional information, to derive whether the UL message carries or does not carry the EMR. 
     As a further general rule, the EMR indication can be prospectively provided, i.e., ahead of the EMR; or can be provided along with the EMR. This is explained in further detail below. 
     (i) The EMR indication can be prospectively provided. For example, a RRC control message may be communicated while the UE operates in connected mode, i.e., prior to commencing the RA procedure. The RRC control message may prospectively (and explicitly) indicate whether the EMR will or will not be activated for the next one or more RA procedure performed by the UE. 
     As will be appreciated, in such a scenario of prospective EMR indication, the EMR indication is not provided in a strict timing relationship with the EMR. For example, if the EMR indication is provided while the UE is being operated in connected mode and before operation of the UE is transitioned into idle mode, the time duration between the EMR indication and the actual EMR may not be well-defined. 
     In other examples, the prospective EMR indication may be provided in a well-defined temporal relationship ahead of the associated EMR. For example, it would be possible that the EMR indication is provided during the RA procedure that also includes the EMR. For example, it would be possible that the EMR indication is provided by selection of a RA preamble of the RA procedure from a subset of all available RA preambles, the subset being associated with selective activation of the EMR. Alternatively or additionally, the EMR indication could be provided by selection of time-frequency resources for transmission of RA preambles. Such techniques are generally referred to as physical RA channel (PRACH) partitioning. 
     (ii) In other examples, it would be possible that the EMR indication is provided as part of the UL message that also carries or does not carries the EMR. For example, it would be possible that the UL message includes a respective indicator in a header thereof. In another example, an implicit EMR indication may be provided by appropriately structuring a transport block (TB) associated with the UL message. In other words, the structure of a TB that is associated with the UL message may be implemented depending on whether the UL message includes or does not include the EMR. Then, the structure of the TB functions as the EMR indication. For example, different sizes of TBs may be selected depending on whether the UL message carries or does not carry the EMR. Alternatively or additionally, a partitioning of the transport block may be selected depending on whether the UL message carries or does not carry the EMR. For example, the partitioning of the TB can relate to a sequence of information elements of the UL message. Then, the BS—e.g., by performing blind decoding—on the logical channel on which the UL message is received, may be able to test various assumptions for the TB structure and test whether a meaningful result is obtained in the decoding, e.g., based on checksum, etc.. 
     Further, the EMR indication can be generally combined with an EMR request. By means of the EMR request, the network may be able to selectively activate transmission of the EMR. For example, the EMR indication could be prospectively provided by the UE, e.g., by PRACH partitioning or by the above-described RRC control message. Then, the BS may transmit an EMR request, based on the reception of the EMR indication. If the UE receives the EMR request, it will transmit the UL message carrying the EMR. On the other hand, if the UE provides the EMR indication, but the BS decides to not transmit the EMR request, the UE may not transmit the EMR. The EMR indication in combination with the EMR request can thus trigger the EMR to be carried by the UL message; in this sense, the EMR indication is implicit, because the EMR indication in combination with the EMR request decides whether the UL message carries or does not carry the EMR. The EMR indication may hence be indicative of the capability of the UE to activate the EMR. Nonetheless, still, the BS—transmitting the EMR request and obtaining the EMR indication—has full awareness of whether the UL message carries or does not carry the EMR. 
     As will be appreciated from the above, various options are generally available for implementing the EMR indication. Such options can be combined with each other to form further options. 
       FIG. 1  schematically illustrates a wireless communication system  100  that may benefit from the techniques disclosed herein. 
     The wireless communication system  100  includes an AN  101  and a UE  102 . A wireless link  111  is established between the AN  101  and the UE  102 . The wireless link  111  includes a DL link from the AN  101  to the UE  102 ; and further includes an UL link from the UE  102  to the AN  101 . 
     The UE  102  may be one of the following: a smartphone; a cellular phone; a table; a notebook; a computer; a smart TV; an MTC device; an eMTC device; an loT device; an NB-IoT device; a sensor; an actuator; etc. 
     The AN  101  can be part of a communication network, e.g., a Local Area Network (LAN) or a cellular communication network; in latter case, the AN  101  is referred to BS. 
     Hereinafter, the techniques are described for illustrative purposes with respect to an implementation of the AN  101  by a BS. 
       FIG. 2  schematically illustrates the BS  101  and the UE  102  in greater detail. The BS  101  includes a processor  5011  and an interface  5012 , sometimes also referred to as frontend. The interface  5012  is coupled via antenna ports (not shown in  FIG. 2 ) with an antenna array  5013  including a plurality of antennas  5014 . Generally, the antenna array is optional. Each antenna  5014  may include one or more LC-oscillators implemented by the electrical traces. The BS  101  further includes a memory  5015 , e.g., a non-volatile memory. The memory may store program code that can be executed by the processor  5011 . Executing the program code may cause the processor  5011  to perform techniques with respect to: participating in a RA procedure with the UE  102 ; obtaining an EMR indication; participating in an EDT; receiving a message potentially carrying an EMR; decoding and specifically blind decoding of an UL message of the RA procedure potentially carrying the EMR; etc.. 
     The UE  102  includes a processor  5021  and an interface  5022 , sometimes also referred to as frontend. The interface  5022  is coupled via antenna ports (not shown in  FIG. 2 ) with an antenna array  5023  including a plurality of antennas  5024 . The antenna array is optional. The UE  102  may include a single antenna  5024 . Each antenna  5024  may include one or more electrical traces to carry a radio frequency current. Each antenna  5024  may include one or more LC-oscillators implemented by the electrical traces. The UE  102  further includes a memory  5025 , e.g., a non-volatile memory. The memory  5025  may store program code that can be executed by the processor  5021 . Executing the program code may cause the processor  5021  to perform techniques with respect to participating in a RA procedure with the BS  101 ; providing an EMR indication; participating in an EDT; transmitting a message carrying an EMR; etc.. 
     The BS  101  and the UE  102  can communicate on the wireless link  111  across a certain channel bandwidth  166 . For example, an Orthogonal Frequency Division Multiplex (OFDM) modulation may be employed where a carrier includes multiple subcarriers that span the channel bandwidth  166 . 
     In  FIG. 2 , there is also illustrated a narrowband  165  that only occupies a sub-fraction of the entire channel bandwidth  166 . Sometimes, the narrowband  165  can be implemented by one or more sub-carriers of an OFDM carrier. In other examples, the narrowband can also be implemented by a separate carrier, e.g., not operating according to OFDM. 
     In the scenario  FIG. 2 , a downlink (DL) reference signal  150  is transmitted by the BS  101  and received by the UE  102 . The DL reference signal  150  may have a well-defined signal shape. Based on the DL reference signal  150 , the UE  102  can perform a channel measurement. The channel measurement may yield a quality of communicating on the wireless link  111 , e.g., in DL direction and/or in UL direction. Reciprocity of the channel of the wireless link  111  may be assumed. Based on the channel measurement, an EMR  160  is transmitted by the UE  102  and received by the BS  101 . 
     As a general rule, various options are available for performing the channel measurement. For example, based on a comparison of the receive amplitude and a transmit amplitude of the DL reference signal  150 , a path loss of the channel of the wireless link  111  can be estimated. The RSRP may be determined based on the receive amplitude of the DL reference signal  150 . Furthermore, the RSRQ may be determined. Also, a channel state indication (CSI) such as a CQI can be determined. The EMR  160  may be indicative of or include the RSRP, RSRQ or the CQI. This may correspond to Layer  1  channel measurements. Further, while measuring receive amplitude and/or receive phase of the DL reference signal  150  can correspond to a low-level channel measurement (e.g., Layer  1  channel measurements), in other examples, other kinds and types of channel measurements may be implemented. For example, a decoding quality of one or more repetitions of a DL message may be taken into consideration. Again, various implementations for the decoding quality are conceivable. Some common decoding algorithms provide a reliability measure of the decoding. For example, this reliability measure may be used to determine the decoding quality. In another example, early decoding attempts may be implemented. Such a scenario is particular applicable to a Coverage Enhancement (CE) policy. Here, multiple repetitions of a message are transmitted and combined at the receiver, before decoding. The count of the multiple repetitions is defined by a CE repetition count. For example, the time-domain baseband waveforms of a number of repetitions of a DL message may be combined, to thereby yield a higher signal to noise ratio. Then, the combined waveforms may be decoded. In this regard, early decoding attempts may refer to premature decoding, before the reception of the number of repetitions has been completed. Sometimes, due to a good channel quality, it is possible to successfully decode data included in a message using an early decoding attempt. Generally, the result of the early decoding attempt can be used to perform the channel measurement. In a CE scenario, the EMR  160  can then correspond to a CE repetition level indicator, i.e., can be indicative of whether the CE repetition count should be decreased or increased or whether the CE repetition count should be set to an appropriate value. 
     As a general rule, the channel measurements may be performed across the entire channel bandwidth  166  or may be restricted to the narrowband  165 . For example, the reference signals  150  may be transmitted on the narrowband  165 . Then the channel measurements can be performed for the narrowband  165  based on a receive property of the reference signals  150 . It would also be possible that a DL message of the RA procedure—e.g., Msg. 2 —is transmitted on the narrowband  165 . Then, for example if the channel measurements are based on received reference signal located on the narrowband  165 , it is possible that the channel measurements are performed for the narrowband  165 . As a general rule, the narrowband  165  that is used for performing the channel measurements may be defined by the BS  101  or, generally, the communication network. 
       FIG. 3  illustrates aspects with respect to the architecture of a cellular communication network  90  according to some examples implementations. In particular, the cellular communication network  90  according to the example of  FIG. 3  implements the 3GPP LTE architecture, sometimes referred to as evolved packet system (EPS). The BS  101  and the UE  102  implement the evolved UMTS terrestrial radio access technology (E-UTRAN); therefore, the BS  101  is labeled evolved node B (eNB) in  FIG. 3 . 
     The UE  102  is registered to the cellular communication network  90 . In the example of  FIG. 3 , the UE  102  is connected to the cellular communication network  90  via the wireless link  111  to a BS  101  of the cellular communication network  90 . A data connection  699  is established. Thus, the UE  102  operates in connected mode. In other examples, the UE  102  may be registered to the cellular communication network  90 , but no active data connection  699  may be maintained. Then, the UE  102  operates in idle mode. To set-up the data connection  699 , a RA procedure may be performed by the UE  102  and the BS  101 . The RA procedure thus transitions the UE  102  from operation in idle mode to operation in connected mode. The data connection  699  may be implemented by one or more bearers which are used to communicate service-specific data. The data connection  699  may be, at least partly, defined on a Layer  2  or Layer  3  of a transmission protocol stack implemented by the BS  101  and the UE  102  for communicating on the wireless link  111 . For example, in connection with the 3GPP LTE E-UTRAN, the data connection  699  may be implemented on the RRC layer. 
     The BS  101  is connected with a gateway node implemented by a serving Gateway (SGW)  117 . The SGW  117  may route and forward payload data and may act as a mobility anchor during handovers of the UE  102 . The SGW  117  is connected with a gateway node implemented by a packet data network Gateway (PGW)  118 . The PGW  118  serves as a point of exit and point of entry of the cellular network  90  for data towards a packet data network (PDN; not shown in  FIG. 3 ): for this purpose, the PGW  118  is connected with an access point node  121  of the packet data network. The access point node  121  is uniquely identified by an access point name (APN). The APN is used by the UE  102  to seek access to the packet data network. The PGW  118  can be an endpoint of the data connection  699  for packetized payload data of the UE  102 . 
     A control layer of the core network includes a mobility management entity (MME)  116 . The MME  116  handles mobility and security tasks such as paging and access credentials. The MME  116  also keeps track of the operational mode of the UE  102 , e.g., whether the UE  102  operates in connected or disconnected mode. The MME  116  is the termination point of the non-access stratum (NAS) connection, i.e., a control connection implemented on the layer above the RRC layer. A home subscriber server (HSS)  115  includes a repository that contains user- and subscriber-related information such as authentication and subscription information. In A Policy and Charging Rules Function (PCRF) implements policy control to thereby facilitate a certain QoS. 
       FIG. 4  illustrates aspects with respect to the operation of the UE  102 . For example, the method of  FIG. 4  may be performed by the processor  5021 . 
     Initially, at  1051 , the UE  102  operates in idle mode. Then, at block  1001 , a RA procedure is performed. For example, a 4-step RA procedure may be performed. As part of the RA procedure, the data connection  699  can be established. For this, the UE  102  can transmit a RRC connection request. 
     Then, at  1052 , the UE has transitioned into the connected mode. The data connection  699  is established. 
     At block  1002 , RRC control signaling can be implemented using the data connection  699 . This corresponds to Layer  3  control signaling. For example, UL Layer  3  control data and/or DL Layer  3  control data may be communicated. RRC control data can be communicated. 
     At block  1003 , payload data—e.g., application layer data—can be communicated along the data connection  699 . For example, UL payload data and/or DL payload data may be communicated 
     At block  1004 , the data connection  699  is released. For example, an inactivity timer may expire since no payload data is queued for transmission. 
     Thus, at  1053 , the UE  102  is again operated in idle mode. For example, during idle mode, the UE  102  may implement a discontinuous reception cycle. 
     At block  1005 , the UE  102  is paged. For example, a paging indicator can be transmitted by the BS  101 . The paging triggers the RA procedure at block  1001 ; a new iteration of the process flow according to  FIG. 4  commences. As a general rule, there are other criteria conceivable for triggering the RA procedure, e.g., UL data queued for transmission at the UE  102 . 
       FIG. 5A  illustrates aspects with respect to the operation of a wireless communication device, e.g., the UE  102 . For example, the method of  FIG. 5A  may be performed by the processor  5021 .  FIG. 5A  illustrates a method according to various examples. 
     At optional block  1020 , an EMR request is received, e.g., from a BS of a cellular communication network or, generally, from an AN. The EMR request triggers the following blocks  1021 - 1023 . 
     As a general rule, the EMR request may be received prior to commencing a RA procedure. For example, the EMR request may be received as RRC control signaling at block  1002  (cf.  FIG. 4 ), i.e., before transitioning to idle mode. Alternatively, it would also be possible that the EMR request is received in a DL message of the RA procedure, i.e., as part of block  1001  (cf.  FIG. 4 ). For example, the EMR request may be carried by the RA Msg. 2 . It would also be possible that the EMR request is included in a paging indicator or paging message of the paging (cf.  FIG. 4 : block  1005 ). For example, the paging message may be communicated on the Physical Downlink Shared Channel (PDSCH) on resources indicated by the paging indicator. 
     At block  1021 , a channel measurement is performed. For example, a receive property of a DL reference signal may be determined. For example, a power level measurement may be determined. 
     For example, the channel measurement may be performed in response to receiving the EMR request at block  1020 . For example, it would be possible that the channel measurement at block  1021  is performed while the UE  102  is in idle mode, e.g., at  1053  (cf.  FIG. 4 ). Alternatively, it would also be possible that the channel measurement is performed during the RA procedure, i.e., in between  1051  and  1052  (cf.  FIG. 4 ). 
     At block  1022 , an UL message is transmitted during a RA procedure, the UL message carrying the EMR that is indicative of a result of the channel measurement performed at block  1021 . In other words, the UL message can be transmitted as part of block  1001  (cf.  FIG. 4 ). 
     At block  1023 , an EMR indication is provided. The EMR indication is related to the EMR. In the example of  FIG. 5A , the EMR indication signals that the UL message carries the EMR. As already explained above, the EMR indication can take various forms, e.g., an implicit implementation and an explicit implementation are conceivable. For example, the EMR indication could be indicative of whether the wireless communication device is generally capable of transmitting the UL message carrying the EMR; such a scenario may be combined with the EMR request of block  1020 . 
     Generally, block  1023  may be performed in parallel to block  1022 , i.e., the UL message itself may be indicative of it carrying the EMR. It would also be possible that block  1022  is performed prior to block  1023 , e.g., using RRC control signaling at block  1002  (cf.  FIG. 4 ). Also, the EMR request of block  1020  may be received after providing the EMR indicator at block  1023 —such a scenario is illustrated in  FIG. 5B . 
       FIG. 5B  illustrates aspects with respect to the operation of a wireless communication device, e.g., the UE  102 . For example, the method of  FIG. 5B  may be performed by the processor  5021 .  FIG. 5B  illustrates a method according to various examples. 
     The example of  FIG. 5B  generally corresponds to the example of  FIG. 5A . In the example of  FIG. 5B , at block  1071 , the EMR indication is provided. The EMR indication provided at block  1071  is related to the EMR. In the example of  FIG. 5B , the EMR indication is indicative of a capability of the wireless communication device to transmit the UL message carrying the EMR (wireless communication devices that do not have this capability do not provide the EMR indication). For example, PRACH partitioning may be used to provide the EMR indication at block  1071 . This helps to avoid ambiguities between different wireless communication devices attempting to connect to the network. 
     At block  1072 , the wireless communication device receives the EMR request. This is optional. Sometimes, the wireless communication device may not receive the EMR request, e.g., because the network decides that the EMR is not required. 
     If, at block  1072 , the EMR request is received, the wireless communication device performs the channel measurement at block  1073  and transmits the RA UL message carrying the EMR at block  1074  If the EMR request is not received then the RA UL message can be transmitted without the EMR. It may be dispensable to perform the channel measurement at block  1073 . As such, receipt of the EMR request is a trigger criterion for performing the channel measurement at block  1073  and transmitting the RA UL message carrying the EMR at block  1074 . 
       FIG. 6A  illustrates aspects with respect to the operation of an AN, e.g., a node of a communication network. For example, the method of  FIG. 6A  may be implemented by the BS  101 .  FIG. 6A  illustrates a method according to various examples. For example, the method of  FIG. 6A  could be implemented by the processor  5011  (cf.  FIG. 2 ). 
     At block  1030 , an EMR request is transmitted. Block  1030  is optional. Block  1030  is inter-related to block  1020  (cf.  FIG. 5A ). 
     At block  1032 , and UL message is received as part of a RA procedure of a UE attempting to connect to the communication network. The UL message carries an EMR. As such, block  1032  is inter-related to block  1022  (cf.  FIG. 5A ). 
     At block  1033 , an EMR indicator is obtained. As such, block  1033  is inter-related to block  1023  (cf.  FIG. 5A ). For example, the EMR indication could be indicative of whether the wireless communication device is generally capable of transmitting the UL message carrying the EMR; such a scenario may be combined with the EMR request of block  1030 . 
     At block  1034 , the RA UL message received in block  1032  is processed. This may include decoding, forwarding from Layer  1  to Layer  2 , etc.. The processing in block  1034  depends on the EMR indicator of block  1033 . Thereby, the RA UL message may be processed differently than another RA UL message for which no EMR indicator is obtained or for which an EMR indicator is obtained that is indicative of the RA UL message not carrying the EMR. 
       FIG. 6B  illustrates aspects with respect to the operation of an AN, e.g., a node of a communication network. For example, the method of  FIG. 6B  may be implemented by the BS  101 .  FIG. 6B  illustrates a method according to various examples. For example, the method of  FIG. 6B  could be implemented by the processor  5011  (cf.  FIG. 2 ). 
       FIG. 6B  generally corresponds to  FIG. 6A . 
     At block  1081 , the EMR indicator is obtained from a wireless communication device. As such, block  1081  is inter-related to block  1071  (cf.  FIG. 5B ). 
     Based on the EMR indicator, the AN is aware of the capability of the respective wireless communication device to transmit the RA UL message carrying the EMR. For example, if the EMR indicator is received during the RA procedure, e.g., using PRACH partitioning, the respective BS (implementing the AN) may not be aware of the unique identity of the wireless communication device (or, more precisely, of the associated subscriber), but can nonetheless conclude that the particular wireless communication device is able to transmit the EMR. Ambiguities between multiple UE:s having and not having the capability to transmit the EMR can be avoided. 
     The AN can then check if it requires the EMR. For example, the AN may determine whether another measurement report is still up-to-date. Depending on this check, the AN may or may not execute block  1082 , i.e., the AN may or may not transmit the EMR request at block  1082 . As such, block  1082  is inter-related to block  1072  (cf.  FIG. 5B ). 
     If the AN does not obtain the EMR indicator at block  1081 , it is not required to transmit the EMR request at block  1082 . 
     Block  1083  is then inter-related to block  1074  (cf.  FIG. 5B ) an corresponds to block  1032  (cf.  FIG. 6A ). 
     Block  1083  corresponds to block  1034  (cf.  FIG. 6A ). 
       FIG. 7  schematically illustrates aspects with respect to a RA procedure  6000  (cf.  FIG. 4 , block  1001 ).  FIG. 7  is a signaling diagram of communication between the UE  102  and the BS  101 .  FIG. 7  specifically illustrates aspects with respect to a contention-based RA procedure  6000 . Also,  FIG. 7  illustrates details with respect to providing the EMR  160  as part of the RA procedure  6000 . 
     The RA procedure  6000  includes four steps, starting with a RA message  1  (Msg. 1 )  6001  carrying a RA preamble being transmitted from the UE  102  to the BS  101  in  6501 . 
     The RA preamble as used herein may be a pattern or signature. The value of the RA preamble may facilitate distinguishing between different UE:s. The RA preamble may be selected from a set of preambles, e.g., 64 or 128 candidate preambles. Partitioning may be employed to convey an information content along with the RA preamble. The different preambles may use orthogonal codes. Generally, the RA preamble does not uniquely identify a UE  102 . PRACH partitioning may also be employed by assigning other time-frequency resources allocated for transmission of RA preambles with a specific purpose (e.g. EDT, EMR). 
     According to various examples, PRACH partitioning may serve as an EMR indication  190 . The EMR indication  190  may be implemented by selecting and transmitting a RA preamble in the message  6001  (Msg. 1 ). In some examples, from this the BS  101  explicitly knows that a subsequent UL RA message Msg. 3   6003  will carry the EMR  160 . Also, such a scenario can be combined with an EMR request where the EMR indication is indicative of the capability of the UE  102  to transmit the RA message Msg. 3   6003  carrying the EMR; the trigger criterion is then the EMR request. A reserved RA preamble can be used to indicate to the network to expect the EMR  160  in the subsequent RA message Msg. 3   6003 . Various techniques described herein are based on the finding that within a communication network there may be some UE:s that will be transmitting EMRs  160  (e.g., those UE:s that are semi-statically configured to do so) and some UE:s that will not (for example older UE:s, not providing for the EMR functionality, or UE:s semi-statically configured to not transmit the EMRs  160 ). During the RA procedure  6000 , the BS  101  does not know a-priori which RA preambles are associated with UE:s that will transmit EMR  160  and those that will not. This issue is solved by the EMR indication  190 . As a general rule, the EMR indication  190  can be implemented in various manners (not only using RA partitioning as explained above). 
     Next, at  6502 , a DL RA response message  6002  (Msg. 2 ; also referred to as RA Response message, RAR message) is transmitted by the BS  101  and received by the UE  102 . The RAR message  6002  includes an UL grant for resource allocation for one or more physical resource blocks (PRBs) defined in a time-frequency grid of an OFDM carrier (cf.  FIG. 2 ). The RAR message  6002  is addressed to the RA Radio Network Temporary Identity (RA-RNTI) of the UE  102 . 
     In the example of  FIG. 7 , the RAR message  6002  also carries an EMR request  169 . It is generally optional to use the EMR request  169 . Also, if an EMR request  169  is used, the EMR request  169  may be implemented differently than what has been illustrated in  FIG. 7 . For example, the EMR request  169  may be implemented, e.g., using RRC control signaling or an information element of a paging message. 
     In the example of  FIG. 7 , the BS  101  transmits the EMR request  169  in the DL RAR message  6002 . To include the EMR request  169  in the RAR message  6002 , a so-called CSI Request bit in the UL grant of the RAR message  6002  that would otherwise not be used for the contention-based RA procedure  6000 . The EMR request  169  could also be implemented implicitly. For example, a combination of a certain selected modulation and coding scheme (MCS) and/or TB size and/or resource allocation may be used to implement the EMR request  169 . Such an example may be combined with the RA preamble partitioning into a subset for EMR-capable UE:s and a subset for other UE:s. If a UE  102  transmits a RA preamble within the subset for EMR-capable UE:s as EMR indication  190 , the BS  101  knows that this UE  102  will be able to parse the RAR message  6002  that contains above-described EMR request  169 . In another embodiment, the EMR request  169  can be transmitted as an extension to the UL grant carried by the RAR message  6002 . In such a case, a non-EMR-capable UE  102  will read the standard UL grant and will not transmit EMR; an EMR-capable UE  102  will additionally read the extension to the UL grant. 
     The UE  102  then, at  6503 , sends the RA message Msg. 3   6003  (Msg. 3 ). The RA message Msg. 3   6003  occupies the one or more PRBs allocated by the UL grant of the RAR message  6002 . Multiple information elements are included in a TB associated with the RA message Msg. 3   6003  that is mapped to the one or more PRBs. 
     The RA message Msg. 3   6003  carries a first information element, namely a RRC connection request  162  or an RRC Connection Resume that includes an ID such as S-TMSI or a Cell Radio Network Temporary Identity (C-RNTI) if available at the UE This is for setting up the data connection  699  on Layer  3  of a respective transmission protocol stack. 
     In the scenario of  FIG. 7 , the RA message Msg. 3   6003  also carries a second information element, namely EDT  161 . This is generally optional. 
     The RA message Msg. 3   6003  also carries a third information element, namely the EMR  160 . As a general rule, the EMR  160  may be selectively activated in some examples. Then, only some instances of the RA message Msg. 3   6003  may carry the EMR  160 . 
     As a general rule, the EMR  160  can take various formats. For example, the EMR  160  can be in form of a RSRP, a RSRQ measurement report and/or CQI measurement report. The EMR  160  implemented by the RSRP can be a value (e.g. an integer value 0, . . . 97) based on the RSRP measurement report mapping as in 3GPP TS 36.133 Table 9.1.4-1. Generally, the resources used to derive the EMR  160 —i.e., the resources on which the channel measurement is performed—can be: (i) the narrowband  165  where the UE  102  monitors for the RAR message  6002 ; or the narrowband  165  where the UE  102  monitors a physical DL control channel (PDCCH). Generally, the narrowband  165  may be configured by the cellular communication network  90 , e.g., the narrowband  165  to be measured may be indicated in the RAR message  6002 . 
     In another example, the UE  102  can operate in a Coverage Enhanced mode where repetitions are used on the physical channels. The UE  102  can report the actual repetition level (or number of repetitions) required to receive a DL message, e.g., on a physical DL shared channel (PDSCH). One example is the number of repetitions required to receive the RAR message  6002  on PDSCH (dashed arrows in  FIG. 7 ). For example, the CE repetition level used for transmitting the RAR message  6002  may be based on the quality of receiving the RA message  6001  (Msg. 1 ), e.g., the number of received repetitions of the RA preamble. If the cellular communication network  90  provides more repetitions of the RAR message  6002  than required to successfully decode, the UE  102  can therefore correct this by reporting the actual repetition level it needed to receive the RAR message  6002 . To test this, the UE may perform early decoding attempts prior to completing reception of all repetitions of the RAR message  6002 . In detail, the UE  102  may receive the RAR message  6002  which is transmitted on PDSCH. During the reception of multiple repetitions of the RAR message  6002 , the UE  102  can perform early decoding attempts. For example, if the RAR message  6002  is transmitted with 64 repetitions, the UE  102  can attempt to decode the PDSCH containing the RAR message  6002  at 16, 32, 48 and 64 repetitions. The UE  102  can then report, in the EMR  160 , the actual number of repetitions that were required to decode the PDSCH. The EMR  160  may hence pertain to a number of CE repetitions. 
     As a general rule, various options are available for implementing the RA message Msg. 3   6003  to carry the EMR  160 . For example, the EMR  160  can be piggybacked to the RRC connection request  162  (cf.  FIG. 8 ). The EMR  160  could also by piggybacked to the EDT  161 , if available (cf.  FIG. 9 ). Here, the EDT  161  bit sequence of the TB may be punctured to include the EMR  160 . By including the EMR  160  as an “RRC measurement report” in EDT  161  carried by the RA message Msg. 3   6003 , the EMR indication  190  can be implemented implicitly. I.e., the presence of the EDT  161  can implement the EMR indication  190  (e.g., instead of using the RA preamble partitioning at message  6001 . By detecting the EDT  161 , the network will recognize that it has received the EMR  160 . In a further example, it would be possible that the EMR  160  is transmitted along with the EDT  161  (cf.  FIG. 10 ), i.e., the EMR  160  is attached to the EDT  161 . In such a scenario, a common TBS table may be used at the UE  102  irrespective of whether the RA message Msg. 3   6003  carries or does not carry the EMR  160 . In such a scenario, the TB size  600  may be selected from the TB table. Then, a first fraction  601  of the TB size  600  may be allocated to the EMR  160  and a second fraction  602  of the TB size  600  may be allocated to the EDT  161 ; a third fraction  603  may be allocated to the RRC connection request  162 . For example, assuming the size of the EMR  160  is fixed (Y bits) and the size of the RRC connection request  162  is fixed (Z bits). The actual TB size available for EDT  161 —i.e., the size of the second fraction  602 —would be X-Y-Z. X bits is the selected TB size  600  as taken from TB size table. It is noted that such structure of the TB can serve as an implicit implementation of the EMR indication  190 : The BS  101  can blind decode the RA message Msg. 3   6003  sent by the UE  102  under the hypotheses that (i) EMR  160  is carried by the RA message Msg. 3   6003  in accordance with the structure; and (ii) EMR  160  is not carried by the RA message Msg. 3   6003 . Hence, the blind decoding can be implemented in accordance with the three TB structures of the RA message Msg. 3   6003 . 
     Also, if the cellular communication network  90  triggers the EMR  160  and the UE  102  does not have any EDT  161  to transmit, a dedicated TB size that is small enough to carry the EMR  160  can be provided by the cellular communication network  90 . The dedicated TB size may be smaller than 328 bits. Hence, instead of inserting padding bits to fill up the TB, which would be inefficient, a smaller TB can be introduced to carry these EMR  160 . 
     At this point, the BS  101  can process the EMR  160 . At the BS  101 , the EMR  160 —e.g., implemented by the RSRP—can be used for example to determine the CE level, i.e., to support various CE levels, to apply to a data transmission that is transmitted after the EMR  160  and to decide whether to stay in the same cell or to perform hand-over. The EMR  160  can also be implemented by means of a CQI, as mentioned above. The CQI may be used by the BS  101  to determine the MCS and/or TBS of the subsequent transmissions, e.g., of the RA DL message  6004  (Msg. 4 ). 
     Generally, There may be two types of CE levels: (i) RACH CE level in which we have 4 different levels, level 0, 1, 2 &amp; 3. This will determine the repetition used on the RA preamble. And (ii) RRC CE. For RRC CE, there are two modes, i.e. CE Mode A and CE Mode B. CE Mode A basically means the normal coverage level equivalent to the coverage of regular LTE (i.e. mobile phone) coverage. CE Mode B is extended coverage e.g. for MTC devices such as utility meters that are buried in basement, which suffers from penetration loss. The RSRP may help the BS to determine which RRC CE level the UE should use. 
     At  6504 , the BS  101  responds with a DL RA contention resolution message  6004  (Msg. 4 ) and any potential contention between other UE:s may be resolved. 
     If the connection attempt of the UE  102  to the cellular communication network  90  is successful, the data connection  699  may be established. Then, wireless communication of payload UL data and/or payload DL data along the data connection  699  can commence. 
     Various scenarios are generally based on the finding that transmission of an EMR  160  when it is not required by the BS  101  is a waste of resources. For example, if the BS  101  is going to make scheduling decisions irrespective of the EMR  160 , there is no need for the UE  102  to transmit the EMR  160 . Hence, according to various examples, the RA message Msg. 3   6003  selectively carries the EMR  160  depending on a trigger criterion. 
     Various options are available for implementing the trigger criterion. A few examples are given for the trigger criterion below. 
     In a first example, the trigger criterion can be a semi-static configuration by the cellular communication network  90 . The trigger criterion can hence include an EMR request received from the BS  101 . The BS  101  may semi-statically configure the UE  102  to provide the EMRs  160 . This semi-static configuration can be performed via RRC signaling (cf.  FIG. 4 , block  1002 ). Here, the EMR request  169  is received prior to commencing the RA procedure  6000  (not illustrated in  FIG. 7 ). 
     A second example trigger criterion is based on a dynamic configuration by the cellular communication network  90 . For example, in the example of  FIG. 6A , the EMR request  169  is included in the RAR message  6002  (cf.  FIG. 7 ). Thereby, the cellular communication network  90  can trigger the EMR  160  on a per-RA procedure basis, i.e., at low latency. 
     A third example trigger criterion is based on UE measurements. The UE may measure channel conditions, e.g. RSRP, before initiating a RA procedure. The RA preamble selection may be based on the CE repetition count. In an example, the UE compares this RSRP to a threshold. If the RSRP measurement is below (worse than) the threshold, the UE is triggered to transmit the EMR. More generally, the trigger criterion may include the result of the channel measurement fulfilling a predefined criterion. This can be beneficial since it is often more important to optimize transmissions for UE:s in poor channel conditions (which use more physical resources) than UE:s in good channel conditions. 
     A fourth example trigger criterion includes an EMR request that is signaled to the UE in a paging message. Here the paging message contains an additional indication (e.g. in a dedicated information element) that tells the UE whether it should perform EMR or not. 
     As a general rule, the EMR  160  may be transmitted some shorter or longer time duration after performing the associated channel measurement. Various options are available for the timing of performing the channel measurement. Depending on the scenario, the UE  102  may perform the channel measurement prior to the RA procedure  6000 —e.g., while operating in idle mode at  1053  (cf.  FIG. 4 )—and/or during the RA procedure  6000 . 
     For example, performing the channel measurement prior to the RA procedure  6000  during idle mode may be suitable if the EMR  160  is triggered by the UE  102 —e.g., depending on a result of the channel measurement. For example, the performing of the channel measurement during idle mode may be autonomous, i.e., up to UE implementation. In order to support EMRs  160 , it would be possible that the performing of the channel measurement during idle mode is mandated by the network, i.e., using the EMR request  169 . 
     In other examples, the UE  102  can commence performing the channel measurement in response to receiving the EMR request  169 , e.g., carried by the RAR message  6002  (cf.  FIG. 7 ). This may be during the time gap  6602  between the RAR message  6002  and the RA message Msg. 3   6003 . In reference implementations, the duration of the time gap  6602  is five subframes. The channel measurement can be performed N sub-frame(s) after the reception of the RAR message  6002 , in which N&lt;5. The respective point in time  6601  is indicated in  FIG. 7 . 
     For cases where performing the channel measurement requires more than 5 sub-frames, e.g. in CE mode where multiple repetitions of the RAR message  6002  are received and early decoding attempts are made, the time gap  6602  can be appropriately set. As a general rule, it would be possible to set the time gap  6602  depending on whether the RA message Msg. 3   6003  carries the EMR  160 , to selectively accommodate for performing the respective channel measurement. If the network has transmitted the EMR request  169 , it can then expect the UE  102  to transmit the RA message Msg. 3   6003  after M sub-frames where M&gt;5 is the configured time gap  6602 . In some examples, the time gap  6602  value M is fixed in the specifications and, hence, hardcoded into the UE  102 . It would also be possible that the time gap  6602  is configured by the cellular communication network  90 . The value M—or, generally, the time gap  6602 —may be indicated in a broadcasted system information block (SIB); for example, the same SIB may carry a value for each CE repetition level to be applied for the RA procedure  6000 . It would also be possible that the cellular communication network  90  configures the time gap  6602  in the RAR message  6002 . 
     Summarizing, above techniques have been described relating to transmission of an EMR from the UE to the BS. Techniques to perform the channel measurement to determine the EMR have been described. Techniques to trigger performing of the channel measurement and/or the EMR have been described. It is has been described that an indication can be provided that the EMR is activated. 
     For example, a PRACH partitioning can be used to implement an EMR indication. Here, multiple scenarios are conceivable. (i) In combination with an EMR indication, the network may configure the UE using an EMR request—e.g., using DL RRC control signaling—to transmit the EMR if a trigger criterion is met, e.g., RSRP below a threshold. The UE uses the PRACH partitioning to identify itself and transmits RA Msg  3  carrying EMR. Alternatively, the EMR request may also be included by the network in a paging message. The UE can again use PRACH partitioning to identify itself as a UE that is capable of activating EMR and transmits RA Msg 3  carrying the EMR. (iii) The UE can use PRACH partitioning to indicate to the network that it is capable of activating EMR. The network then decides to request for EMR in RA Msg. 2 . The UE then transmits Msg 3  carrying EMR. Here, the use of PRACH partitioning indicates the capability of the UE to transmit the Msg 3  carrying EMR, but since EMR activation depends on a further trigger criterion (here, the EMR request from the network) it doesn&#39;t mean the UE will necessarily transmits the UL message carrying EMR since it is up to network to trigger it using the EMR request in RA Msg 2 . If the network does not trigger the EMR, i.e., does not transmit the EMR request in RA Msg. 2 , then UE does not transmit EMR, i.e., transmit RA Msg. 3  not carrying the EMR. 
     Although the invention has been shown and described with respect to certain preferred embodiments, equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications and is limited only by the scope of the appended claims. 
     For illustration, above, various examples have been described with respect to a cellular communication network. Similar techniques may be readily applied to other types of communication networks.