Patent Publication Number: US-2022217628-A1

Title: Wireless device-autonomous procedures for missed-wake up signals

Description:
TECHNICAL FIELD 
     The present disclosure relates to wireless communications, and in particular, to wireless device (WD) autonomous procedures for missed wake up signals (WUS). 
     BACKGROUND 
     One of the power consuming activities of wireless devices (WD) in a Radio Resource Control Connected mode (RRC_CONNECTED) mode according to 3GPP standard specifications, is to monitor the physical downlink control channel (PDCCH). In this activity, the WD should perform blind detection in its configured control resource sets (CORESETs) to identify whether there is a PDCCH sent to it, and act accordingly. On the other hand, the WD is not scheduled in most PDCCH monitoring occasions (MOs) and thus, the WD wastes its energy monitoring the channel. 
     Given this, techniques that can reduce unnecessary PDCCH MOs, i.e., allowing the WD to go to sleep or wake-up only when required can be beneficial. Here, a wake-up signal (WUS) can be considered an efficient solution to improve WD power consumption. In this technique, the WD monitors the PDCCH in the discontinuous reception (DRX) ON-duration, only when a WUS is detected prior to the ON-duration. If there is no WUS transmission by the network node, the WD can remain asleep, i.e., in a low-power mode, during the next ON-duration. Therefore, by conducting the PDCCH monitoring only when there will be physical downlink shared channel (PDSCH) scheduling, the WD power consumption can be reduced. In addition, WUS monitoring can also be conducted in a more power efficient manner compared to that of normal PDCCH monitoring and thus improves the WD energy efficiency even further. 
     If transmitted by the network node, the WUS is then detected or decoded by the WD and if the WUS is intended for waking up that WD (either specifically or as part of a group), the WD wakes up and monitors the PDCCH search space (SS) in the next ON-duration or follows other types of network-configured actions upon detection of WUS (e.g., perform an aperiodic channel state information (CSI) report, receive PDSCH through WUS commands, etc.) 
     One of the problems of using WUS arises because the WD may not always successfully detect/decode the WUS in the WUS MOs even when the network (NW) actually sends the WUS to wake-up the WD for the next ON-duration. In this case, as the WD remains in a sleep state, the WD will miss the scheduling PDCCH from the NW during the ON-duration. The data transmission through PDSCH, therefore, cannot be received by the WD in this scenario. 
     Such circumstances cause an increase in latency and a reduction of throughput. Even more, when the WD misses the PDSCH transmission from the network node for several occasions, and does not provide expected ACK/NACK feedback, the network node can consider the WD to be in Out of Sync (OOS) or in Radio Link Failure (RLF), hence that it has lost its connection to the network. In this condition, the WD needs to restart the connection set-up which requires a significant amount of power. The intended power saving, therefore, is diluted. On the other hand, while in most cases using the WUS is good for power saving, always relying on the WUS is also not the optimum solution. 
     Therefore, there is a need in defining autonomous procedures/methods/steps that can be taken by the WD to minimize the effect of the missed or un-decoded WUS. 
     SUMMARY 
     Some embodiments advantageously provide methods and wireless devices for autonomous wake up of the WD when wake up signals (WUS) are missed or not decoded. 
     Some embodiments include mechanisms that can be taken by the WD when the WD does not detect WUS in the WUS MOs and can be summarized as follows: 
     Aspect 1: The WD examines some information that can be used as criteria that the WUS may have been transmitted but not detected. The information can be in the form of history and expected traffics, channel quality, presence of certain signal structures or signal energy, etc. 
     Aspect 2: The WD may follow some procedures (i.e., autonomous procedures also referred to as one or more actions) by considering the information obtained in the Aspect 1, such as to wake-up on the next ON-duration, send a UL transmission, etc. 
     Some embodiments lead to a more robust WD operation with respect to WUS transmission. More specifically, the WD could avoid a performance degradation on latency and throughput due to the missed-WUS detection/decoding. In addition, some embodiments also reduce the probability of unnecessary data retransmission and reconnection from the WD to the network node. 
     According to one aspect of the disclosure, a wireless device configured to communicate with a network node is provided. The wireless device includes processing circuitry configured to: determine that a transmitted wake up signal has been missed before a discontinuous reception (DRX) ON-duration, and perform at least one action during the DRX ON-duration based at least in part on the determination that the wake signal has been missed. 
     According to one or more embodiments of this aspect, the processing circuitry is further configured to determine at least one configuration parameter included in the wake up signal that has been missed by the wireless device, and the at least one action is based at least in part on the at least one configuration parameter. According to one or more embodiments of this aspect, the processing circuitry is further configured to, if the at least one configuration parameter only includes a command to wake up, implement a previously received configuration parameter for monitoring the DRX ON-duration. According to one or more embodiments of this aspect, the at least one configuration parameter corresponds to at least one command related to the missed wake up signal. 
     According to one or more embodiments of this aspect, the at least one configuration parameter includes a plurality of configuration parameters for monitoring the DRX ON-duration, and the processing circuitry is further configured to select a subset of the plurality of configuration parameters for monitoring the DRX ON-duration, the subset of the plurality of configuration parameters corresponding to one of a default configuration, a configuration based at least in part on previously received configurations and a plurality of configurations. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed is based at least in part on historic traffic data. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed includes analyzing the historic traffic data to determine that traffic data is expected during at least one predefined duration. 
     According to one or more embodiments of this aspect, the determination that the wake up signal has been missed is based at least in part on a signal quality of a previously received wake up signal. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed is further based at least in part on a detection of a channel state information reference signal, CSI-RS. According to one or more embodiments of this aspect, the at least one action includes: 
     determining a channel quality between the network node and the wireless device, comparing the determined channel quality to a predefined threshold, and
 
trigger the DRX ON-duration monitoring based at least in part on the comparison. The DRX ON-duration monitoring corresponds to at least one DRX ON-duration associated with the wake up signal that has been missed.
 
     According to one or more embodiments of this aspect, the at least one action includes exiting a sleep state and monitoring a physical downlink control channel, PDCCH, search space in a next DRX ON-duration. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed corresponds to determining the wake up signal has been at least one of not detected and not decoded. According to one or more embodiments of this aspect, the processing circuitry is further configured to determine a demodulation reference signal, DMRS, has been detected, the determination that the wake up signal has been missed being based at least in part on the detected DMRS. 
     According to one or more embodiments of this aspect, the processing circuitry is further configured to examine power levels of a plurality of resource elements that are configured to carry the wake up signal that has been missed, the determination that the wake up signal has been missed being based at least in part on the examined power levels of the plurality of resource elements. According to one or more embodiments of this aspect, the processing circuitry is further configured to cause transmission of an indication indicating that a wake up signal was missed and that the wireless device performed DRX ON-duration monitoring associated with the wake up signal that has been missed. According to one or more embodiments of this aspect, the indication is a negative acknowledgment, NACK. According to one or more embodiments, the processing circuitry is configured to determine that a channel quality of a first antenna beam is deteriorated based at least in part on detection of another WUS over a second antenna beam during synchronization signal block, SSB, measurements, and the determination that the transmitted wake up signal has been missed is based at least in part on the determination of the channel quality of the first antenna beam. 
     According to another aspect of the disclosure, a method implemented by a wireless device that is configured to communicate with a network node is provided. A determination is made that a transmitted wake up signal has been missed before a discontinuous reception (DRX) ON-duration. At least one action is performed during the DRX ON-duration based at least in part on the determination that the wake signal has been missed. 
     According to one or more embodiments of this aspect, at least one configuration parameter included in the wake up signal that has been missed by the wireless device is determined where the at least one action is based at least in part on the at least one configuration parameter. According to one or more embodiments of this aspect, if the at least one configuration parameter only includes a command to wake up, a previously received configuration parameter for monitoring the DRX ON-duration is implemented. According to one or more embodiments of this aspect, the at least one configuration parameter corresponds to at least one command related to the missed wake up signal. 
     According to one or more embodiments of this aspect, the at least one configuration parameter includes a plurality of configuration parameters for monitoring the DRX ON-duration. A subset of the plurality of configuration parameters for monitoring the DRX ON-duration are selected where the subset of the plurality of configuration parameters correspond to one of a default configuration, a configuration based at least in part on previously received configurations and a plurality of configurations. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed is based at least in part on historic traffic data. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed includes analyzing the historic traffic data to determine that traffic data is expected during at least one predefined duration. 
     According to one or more embodiments of this aspect, the determination that the wake up signal has been missed is based at least in part on a signal quality of a previously received wake up signal. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed is further based at least in part on a detection of a channel state information reference signal, CSI-RS. According to one or more embodiments of this aspect, the at least one action includes: 
     determining a channel quality between the network node and the wireless device, comparing the determined channel quality to a predefined threshold, and triggering the DRX ON-duration monitoring based at least in part on the comparison, the DRX ON-duration monitoring corresponding to at least one DRX ON-duration associated with the wake up signal that has been missed. 
     According to one or more embodiments of this aspect, the at least one action includes exiting a sleep state and monitoring a physical downlink control channel, PDCCH, search space in a next DRX ON-duration. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed corresponds to determining the wake up signal has been at least one of not detected and not decoded. According to one or more embodiments of this aspect, a determination is made that a demodulation reference signal, DMRS, has been detected where the determination that the wake up signal has been missed is based at least in part on the detected DMRS. 
     According to one or more embodiments of this aspect, power levels of a plurality of resource elements that are configured to carry the wake up signal that has been missed are examined where the determination that the wake up signal has been missed is based at least in part on the examined power levels of the plurality of resource elements. According to one or more embodiments of this aspect, transmission is caused of an indication indicating that a wake up signal was missed and that the wireless device performed DRX ON-duration monitoring associated with the wake up signal that has been missed. According to one or more embodiments of this aspect, the indication is a negative acknowledgment, NACK. According to one or more embodiments, a determination that a channel quality of a first antenna beam is deteriorated is made based at least in part on detection of another WUS over a second antenna beam during synchronization signal block, SSB, measurements, and the determination that the transmitted wake up signal has been missed is based at least in part on the determination of the channel quality of the first antenna beam. 
     According to another aspect of the disclosure, a computer readable medium is provided. The computer readable medium includes instructions which, when executed by a processor, cause the processor to: determine that a transmitted wake up signal has been missed before a discontinuous reception, DRX, ON-duration, and perform at least one action during the DRX ON-duration based at least in part on the determination that the wake signal has been missed. According to one or more embodiments, the computer readable medium further includes instructions which, when executed by the processor, cause the processor to perform one or more of the additional steps described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A more complete understanding of the present embodiments, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein: 
         FIG. 1  is a schematic diagram of an exemplary network architecture illustrating a communication system according to the principles in the present disclosure; 
         FIG. 2  is a block diagram of a network node and a wireless device communicating over an at least partially wireless connection according to some embodiments of the present disclosure; 
         FIG. 3  is a flowchart of an exemplary process in a wireless device according to some embodiments of the present disclosure; and 
         FIG. 4  is a flowchart of an exemplary process in a wireless device according to some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to wireless device (WD) autonomous procedures for handling missed wake up signals (WUS). As used herein, a missed wake up signal at the wireless device may correspond to a wake up signal that has been transmitted to the wireless device where the wireless device does not detect the wake up signal, or where the wireless device receives a wake up signal (including sample collection) but fails to properly decode the wake up signal. 
     Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein. Like numbers refer to like elements throughout the description. 
     As used herein, relational terms, such as “first” and “second,” and the like, may be used solely to distinguish one entity or element from another entity or element without necessarily requiring or implying any physical or logical relationship or order between such entities or elements. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the concepts described herein. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including” when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. 
     In embodiments described herein, the joining term, “in communication with” and the like, may be used to indicate electrical or data communication, which may be accomplished by physical contact, induction, electromagnetic radiation, radio signaling, infrared signaling or optical signaling, for example. One having ordinary skill in the art will appreciate that multiple components may interoperate and modifications and variations are possible of achieving the electrical and data communication. 
     In some embodiments described herein, the term “connected,” and the like, may be used herein to indicate a connection, although not necessarily directly, and may include wired and/or wireless connections. 
     The term “network node” or “radio network node” used herein can be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi-standard radio (MSR) radio node such as MSR BS, multi-cell/multicast coordination entity (MCE), integrated access and backhaul (IAB) node, relay node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The network node may also comprise test equipment. 
     In some embodiments, the non-limiting terms wireless device (WD) or a user equipment (UE) are used interchangeably. The WD herein can be any type of wireless device capable of communicating with a network node or another WD over radio signals, such as wireless device (WD). The WD may also be a radio communication device, target device, device to device (D2D) WD, machine type WD or WD capable of machine to machine communication (M2M), low-cost and/or low-complexity WD, a sensor equipped with WD, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (IoT) device, or a Narrowband IoT (NB-IOT) device etc. 
     Note that although terminology from one particular wireless system, such as, for example, 3GPP LTE and/or New Radio (NR), may be used in this disclosure, this should not be seen as limiting the scope of the disclosure to only the aforementioned system. Other wireless systems, including without limitation Wide Band Code Division Multiple Access (WCDMA), Worldwide Interoperability for Microwave Access (WiMax), IEEE 802-11, Wireless Local Area Network (WLAN), Ultra Mobile Broadband (UMB) and Global System for Mobile Communications (GSM), may also benefit from exploiting the ideas covered within this disclosure. 
     Note further, that functions described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and/or network nodes. In other words, it is contemplated that the functions of the network node and wireless device described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices. 
     Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. 
     Referring now to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in  FIG. 1  a schematic diagram of a communication system  10 , according to an embodiment, such as a 3GPP-type cellular network that may support standards such as LTE and/or NR (5G), which comprises an access network  12 , such as a radio access network, and a core network  14 . The access network  12  comprises a plurality of network nodes  16   a ,  16   b ,  16   c  (referred to collectively as network nodes  16 ), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area  18   a ,  18   b ,  18   c  (referred to collectively as coverage areas  18 ). Each network node  16   a ,  16   b ,  16   c  is connectable to the core network  14  over a wired or wireless connection  20 . A first wireless device (WD)  22   a  located in coverage area  18   a  is configured to wirelessly connect to, or be paged by, the corresponding network node  16   a . A second WD  22   b  in coverage area  22   b  is wirelessly connectable to the corresponding network node  16   b . While a plurality of WDs  22   a ,  22   b  (collectively referred to as wireless devices  22 ) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole WD is in the coverage area or where a sole WD is connecting to the corresponding network node  16 . Note that although only two WDs  22  and three network nodes  16  are shown for convenience, the communication system may include many more WDs  22  and network nodes  16 . 
     Also, it is contemplated that a WD  22  can be in simultaneous communication and/or configured to separately communicate with more than one network node  16  and more than one type of network node  16 . For example, a WD  22  can have dual connectivity with a network node  16  that supports LTE and the same or a different network node  16  that supports NR. As an example, WD  22  can be in communication with an eNB for LTE/E-UTRAN and a gNB for NR/NG-RAN. 
     The intermediate network  28  may be one of, or a combination of more than one of, a public, private or hosted network. The intermediate network  28 , if any, may be a backbone network or the Internet. In some embodiments, the intermediate network  28  may comprise two or more sub-networks (not shown). 
     A wireless device  22  is configured to include a signal evaluator unit  30  which is configured to evaluate at least one signal to determine an indication of a time for the WD  22  to wake up in the absence of receiving or decoding a wake up signal from the network node. In particular, it may be assumed, for example, that a WD is configured with one or more WUS monitoring occasions (MOs) X slots before the ON-duration. Alternatively, a WUS can also occur X slots before any data which needs to be transmitted from the network node to the WD (e.g., a scheduling PDCCH). If there is no WUS detected or decoded by the WD during the WUS MOs, the default option for the WD may be to skip monitoring the PDCCH SS in the next DRX ON-duration; however, other options such as more robust options that can be taken by the WD such as via the signal evaluator unit  30  when there is no WUS detected/decoded are further described below. In one or more embodiments, as used herein, DRX-ON-duration may refer to a period of time (i.e., awake state/period) during which the wireless device  22  monitors a downlink control channel (e.g., PDCCH) where the wireless device  22  may enter a sleep state (e.g., non-monitoring state) when not in the ON-duration. 
     Example implementations, in accordance with an embodiment, of the WD  22  and network node  16  discussed in the preceding paragraphs will now be described with reference to  FIG. 2 . 
     The communication system  10  includes a network node  16  provided in a communication system  10  and including hardware  32  enabling it to communicate with the WD  22 . The hardware  32  may include a communication interface  34  for setting up and maintaining a wired or wireless connection with an interface of a different communication device of the communication system  10 , as well as a radio interface  36  for setting up and maintaining at least a wireless connection  37  with a WD  22  located in a coverage area  18  served by the network node  16 . The radio interface  36  may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers. The communication interface  34  may be configured to facilitate a connection to one or more other entities in communication system  10  such as another network node  16  and/or the core network  14 . The connection may be direct or it may pass through a core network  14  of the communication system  10  and/or through one or more intermediate networks  28  outside the communication system  10 . 
     In the embodiment shown, the hardware  32  of the network node  16  further includes processing circuitry  38 . The processing circuitry  38  may include a processor  40  and a memory  42 . In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry  38  may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor  40  may be configured to access (e.g., write to and/or read from) the memory  42 , which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory). 
     Thus, the network node  16  further has software  44  stored internally in, for example, memory  42 , or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node  16  via an external connection. The software  44  may be executable by the processing circuitry  38 . The processing circuitry  38  may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by network node  16 . Processor  40  corresponds to one or more processors  40  for performing network node  16  functions described herein. The memory  42  is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software  44  may include instructions that, when executed by the processor  40  and/or processing circuitry  38 , causes the processor  40  and/or processing circuitry  38  to perform the processes described herein with respect to network node  16 . 
     The communication system  10  further includes the WD  22  already referred to. The WD  22  may have hardware  46  that may include a radio interface  48  configured to set up and maintain a wireless connection  38  with a network node  16  serving a coverage area  18  in which the WD  22  is currently located. The radio interface  48  may be formed as or may include, for example, one or more RF transmitters, one or more RF receivers, and/or one or more RF transceivers. 
     The hardware  46  of the WD  22  further includes processing circuitry  50 . The processing circuitry  50  may include a processor  52  and memory  54 . In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry  50  may comprise integrated circuitry for processing and/or control, e.g., one or more processors and/or processor cores and/or FPGAs (Field Programmable Gate Array) and/or ASICs (Application Specific Integrated Circuitry) adapted to execute instructions. The processor  52  may be configured to access (e.g., write to and/or read from) memory  54  (i.e., computer readable medium), which may comprise any kind of volatile and/or nonvolatile memory, e.g., cache and/or buffer memory and/or RAM (Random Access Memory) and/or ROM (Read-Only Memory) and/or optical memory and/or EPROM (Erasable Programmable Read-Only Memory). 
     Thus, the WD  22  may further comprise software  56 , which is stored in, for example, memory  54  at the WD  22 , or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the WD  22 . The software  56  may be executable by the processing circuitry  50 . The software  56  may include a client application  58 . The client application  58  may be operable to provide a service to a human or non-human user via the WD  22 , in providing the service to the user, the client application  58  may receive request data and provide user data in response to the request data. The client application  58  may interact with the user to generate the user data that it provides. 
     The processing circuitry  50  may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by WD  22 . The processor  52  corresponds to one or more processors  52  for performing WD  22  functions described herein. The WD  22  includes memory  54  that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software  56  and/or the client application  58  may include instructions that, when executed by the processor  52  and/or processing circuitry  50 , causes the processor  52  and/or processing circuitry  50  to perform the processes described herein with respect to WD  22 . For example, the processing circuitry  50  of the wireless device  22  may include a signal evaluator unit  30  configured to perform one or more wireless device  22  functions as described herein. In one or more embodiments, signal evaluator unit  30  is configured to evaluate at least one signal to determine an indication of a time for the WD to wake up in the absence of receiving or decoding a wake up signal from the network node. 
     In some embodiments, the inner workings of the network node  16  and WD  22 , may be as shown in  FIG. 2  and independently, the surrounding network topology may be that of  FIG. 1 . 
     The wireless connection  37  between the WD  22  and the network node  16  is in accordance with the teachings of the embodiments described throughout this disclosure. In one or more embodiments, the teachings of some of these embodiments may improve the data rate, latency, and/or power consumption and thereby provide benefits such as reduced user waiting time, relaxed restriction on file size, better responsiveness, extended battery lifetime, etc. 
     In some embodiments, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. 
     In some embodiments, the cellular network also includes the network node  16  with a radio interface  36 . In some embodiments, the network node  16  is configured to, and/or the network node&#39;s  16  processing circuitry  38  is configured to perform the functions and/or methods described herein for preparing/initiating/maintaining/supporting/ending a transmission to the WD  22 , and/or preparing/terminating/maintaining/supporting/ending in receipt of a transmission from the WD  22 . 
     In some embodiments, the WD  22  is configured to, and/or comprises a radio interface  36  and/or processing circuitry  38  configured to perform the functions and/or methods described herein for preparing/initiating/maintaining/supporting/ending a transmission to the network node  16 , and/or preparing/terminating/maintaining/supporting/ending in receipt of a transmission from the network node  16 . 
     Although  FIGS. 1 and 2  show various “units” such as signal evaluator unit  30  as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry. 
       FIG. 3  is a flowchart of an exemplary process in a wireless device  22  according to some embodiments of the present disclosure. One or more blocks described herein may be performed by one or more elements of wireless device  22  such as by one or more of processing circuitry  50  (including the signal evaluator unit  30 ), processor  52 , and/or radio interface  48 . Wireless device  22  such as via processing circuitry  50  and/or processor  52  and/or radio interface  48  is configured to evaluate (Block S 100 ) at least one signal to determine an indication of a time for the WD  22  to wake up in the absence of receiving or decoding a wake up signal from the network node, as described herein. The process also includes waking (Block S 102 ) up the WD  22  if the signal evaluation indicates a time for the WD to wake up, as described herein. 
       FIG. 4  is a flowchart of another exemplary process in the wireless device  22  according to some embodiments of the disclosure. One or more blocks described herein may be performed by one or more elements of wireless device  22  such as by one or more of processing circuitry  50  (including the signal evaluator unit  30 ), processor  52 , and/or radio interface  48 . In one or more embodiments, wireless device  22  such as via one or more of processing circuitry  50 , processor  52 , signal evaluator unit  30 , and radio interface  48  is configured to determine (Block S 104 ) that a transmitted wake up signal has been missed before a discontinuous reception (DRX) ON-duration, as described herein. In one or more embodiments, wireless device  22  such as via one or more of processing circuitry  50 , processor  52 , signal evaluator unit  30 , and radio interface  48  is configured to perform (Block S 106 ) at least one action (i.e., at least one autonomous procedure) during the DRX ON-duration based at least in part on the determination that the wake signal has been missed, as described herein. 
     According to one or more embodiments of this aspect, the processing circuitry  50  is further configured to determine at least one configuration parameter included in the wake up signal that has been missed by the wireless device, and the at least one action is based at least in part on the at least one configuration parameter. According to one or more embodiments of this aspect, the processing circuitry  50  is further configured to, if the at least one configuration parameter only includes a command to wake up, implement a previously received configuration parameter for monitoring a DRX ON-duration. According to one or more embodiments of this aspect, the at least one configuration parameter corresponds to at least one command related to the missed wake up signal. 
     According to one or more embodiments of this aspect, the at least one configuration parameter includes a plurality of configuration parameters for monitoring a discontinuous reception, DRX, ON-duration, and the processing circuitry is further configured to select a subset of the plurality of configuration parameters for monitoring the DRX ON-duration, the subset of the plurality of configuration parameters corresponding to one of a default configuration, a configuration based at least in part on previously received configurations and a plurality of configurations. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed is based at least in part on historic traffic data. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed includes analyzing the historic traffic data to determine that traffic data is expected during at least one predefined duration. 
     According to one or more embodiments of this aspect, the determination that the wake up signal has been missed is based at least in part on a signal quality of a previously received wake up signal. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed is further based at least in part on a detection of a channel state information reference signal, CSI-RS. According to one or more embodiments of this aspect, the at least one action includes: 
     determining a channel quality between the network node  16  and the wireless device  22 , comparing the determined channel quality to a predefined threshold, and
 
trigger a discontinuous reception, DRX, ON-duration monitoring based at least in part on the comparison. The DRX ON-duration monitoring corresponds to at least one DRX ON-duration associated with the wake up signal that has been missed.
 
     According to one or more embodiments of this aspect, the at least one action includes exiting a sleep state and monitoring a physical downlink control channel, PDCCH, search space in a next discontinuous reception, DRX, ON-duration. According to one or more embodiments of this aspect, the determination that the wake up signal has been missed corresponds to determining the wake up signal has been at least one of not detected and not decoded. According to one or more embodiments of this aspect, the processing circuitry  50  is further configured to determine a demodulation reference signal, DMRS, has been detected, the determination that the wake up signal has been missed being based at least in part on the detected DMRS. 
     According to one or more embodiments of this aspect, the processing circuitry  50  is further configured to examine power levels of a plurality of resource elements that are configured to carry the wake up signal that has been missed, the determination that the wake up signal has been missed being based at least in part on the examined power levels of the plurality of resource elements. According to one or more embodiments of this aspect, the processing circuitry  50  is further configured to cause transmission of an indication indicating that a wake up signal was missed and that the wireless device  22  performed discontinuous reception, DRX, ON-duration monitoring associated with the wake up signal that has been missed. According to one or more embodiments of this aspect, the indication is a negative acknowledgment, NACK. According to one or more embodiments, the processing circuitry  50  is configured to determine that a channel quality of a first antenna beam is deteriorated based at least in part on detection of another WUS over a second antenna beam during synchronization signal block, SSB, measurements, and the determination that the transmitted wake up signal has been missed is based at least in part on the determination of the channel quality of the first antenna beam. 
     Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for wireless device (WD)  22  autonomous procedures for missed wake up signals (WUS) where, in one or more embodiments, the WUS may be missed before a DRX ON-duration and.an action performed during the DRX ON-duration based at least on the missed WUS. 
     Aspect 1: Criterion for Possible Missing WUS Detection/Decoding 
     Some information that can be used by the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. as criterion/criteria for possible missed WUS detection and decoding are addressed below: 
     Expected Traffic/History of Past Traffic 
     In mobile communication, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may have an awareness of the currently running applications (i.e., software application(s) operating at WD  22 ), and thus, the WD  22  has knowledge of the history of the past traffic and can statistically anticipate the upcoming traffic. If, based on this knowledge, the WD  22 , such as via processing circuitry  50  and/or signal evaluator unit  30 , determines that it has to be awoken, or usually is awoken, on the next ON-duration although there is no WUS detected/decoded such as before a DRX ON-duration, the WD  22  can assume that the WUS has been transmitted but missed. In some embodiments, the number of missed, or simply not detected/received (i.e., deliberately skipped or not received), WUS occasions can also be considered such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. For example, based on the expected traffic, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may expect that it should not miss some predetermined number of (X) WUS MOs. In one or more embodiments, a missed WUS or WUS that was missed by the WD  22  may correspond to WUS reception that was deliberately skipped by the WD  22  such that the WD  22  skips a decoding attempt and may also skip sample collection associated with the WUS MO. 
     In one such embodiment, for example, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may observe that video streaming buffer-filling bursts arrive at certain regular intervals, which is likely in low-loaded networks having a regular streaming bit rate. The WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may then monitor ON-durations during the next anticipated buffer-filling burst location even if a WUS is not detected. In one or more embodiments, WD  22  may perform ON-duration monitoring using multiple configurations corresponding to multiple configuration parameters that may be determined/selected based at least in part on the awareness of the currently running applications, for example, as described above, such that decoding of the PDCCH is performed using the multiple configurations. In one such embodiment, for example, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc., may observe that file downloading may be performed at certain intervals. In one such embodiment, for example, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may observe that voice-over-NR voice calls may be performed at certain intervals. Other network node  16  events and/or wireless device  22  actions may be considered such that the wireless device  22  may observe/determine that the event(s)/action(s) occur at regular intervals or in pattern over a period of time. 
     The decision of whether to perform such unconditional ON-duration monitoring may be based on previous and recent WUS reception quality. If the channel conditions and WUS signal format result in reliable detection, and possibly a high decoding margin as assessed via e.g., a soft decoder metric or explicit margin evaluation using tentative decoding, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may not perform unconditional monitoring but may rely on WUS reception as a criterion for ON-duration monitoring. 
     Channel Quality 
     One of the reasons that the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may fail to detect/decode the WUS may be that channel quality between the network node and the WD  22  is not sufficient for the WD  22  to decode the WUS. Therefore, once the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. fails to decode the WUS, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can check its channel quality, i.e., whether the channel quality at the WUS MO is lower than a certain threshold or not. To do so, the WD  22 , such as via processing circuitry  84  and/or signal evaluator unit  30 , can use for example, the SSB measurements during the Connected mode-DRX OFF duration or during the On-durations to obtain an up to date channel knowledge. The WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can also utilize the value of signal to interference plus noise ratio (SINR), reference signal received quality (RSRQ), reference signal received power (RSRP), etc. If the channel quality is detected to be lower than what is required for reliable reception of recently transmitted WUS formats and modulation and coding schemes (MCS)/aggregation level (AL), the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may perform unconditional ON-duration monitoring (i.e., an example of at least one configuration that may correspond to one or more configuration parameters of an autonomous procedure) even if a WUS has not been received. 
     DMRS Detection 
     In 3GPP New Radio (NR), a PDCCH transmission is also equipped with the demodulation reference signal (DMRS). The WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can use this reference signal as to determine whether a WUS detection is implied (i.e., WUS was received or likely received before a DRX ON-duration even though the WUS signal, itself, was missed) to determine whether to wake-up on the next ON-duration. The presence of demodulation reference signals (DMRS) can be determined e.g., by performing matched filtering of the DMRS resource elements (REs) with reference DMRS patterns that the WD  22  would expect to be present for WUS-PDCCH detection and decoding. Depending on the channel variations (dispersion and Doppler) and coherence time/bandwidth (BW), the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may perform matched filtering with full or partial (locally coherent) DMRS patterns. For example, a correlation matrix output from the match filter representing the DMRS signal can be used as a tentative indication that there is actually a WUS being transmitted by the network node  16  (i.e., implied WUS) although the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. determines the WUS was missed, i.e., does not successfully detect/decode the WUS in the WUS MOs. Depending on the WUS configuration, the presence of DMRS may also be detected such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. if a WUS is transmitted to other WDs  22 , or other (non-WUS) PDCCH transmissions are present. The WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may determine whether to trigger ON-duration monitoring based on DMRS indications depending on the individual trade-off between the increased energy cost of additional ON-duration monitoring and latency/throughput losses due to missing relevant ON-durations. The trade-offs may depend on current traffic types or services, battery state, etc. 
     Power Level in the Resource Elements 
     In the WUS transmission, it is possible that the disruption occurs only in a certain number of the information bits. For cases where the WUS has reserved frequency for transmission per cell, the WD  22 , such as via processing circuitry  50  and/or signal evaluator unit  30 , can examine the power across all the resource elements used for the presumed WUS transmission (i.e., implied WUS detection even though the WUS was determined to have been missed before a DRX ON-duration). A significant number of REs inside the WUS resource region having power that exceeds a certain threshold can be used by the WD  22  as an indication that there is actually a WUS transmission by the network node  16  even when there was no WUS successfully detected or decoded. The threshold may be an absolute power threshold, or the threshold may be formulated as a ratio of RE powers in relation to average occupied RE power, average total carrier power, or to power of REs surrounding the WUS resource region. 
     The decision of whether or not the WD  22  should do the autonomous procedure (i.e., at least one action such as during the DRX ON-duration) can be determined in different ways. For example, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can decide to take further action if one of the parameter&#39;s value is larger/smaller than the threshold value. In another option, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can decide to take further action if a certain number of parameter&#39;s values are larger than the threshold values. In a more advanced option, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can multiply each gap between the observed values and the threshold values with a certain weighting function. In addition, a threshold value can be set as a fixed value or it is also possible to set the threshold value to depend on the transmission configuration (e.g., the number of receive antennas, bandwidth, mobility, etc.), or even historical data. Furthermore, the threshold value can be in terms of a real value or the Boolean type of value. If the total weighted gap exceeds a certain threshold, the WD  22  then can perform the autonomous procedures such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. 
     Aspect 2: WD  22  Procedures (i.e., Actions) in Response to the Possible Missed WUS Detection/Decoding 
     After examining the parameters mentioned in Aspect 1, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can then take/perform further actions or perform certain procedures such as during the DRX ON-duration. If the signal to be evaluated or other examined metric is below a certain threshold, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can take/perform the normal action defined by the network node  16 , i.e., to sleep in the next DRX ON-duration. If the examination metric exceeds a certain threshold, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can take/perform one or several possible corrective actions, as discussed below. 
     Monitor ON-Duration Despite not Receiving a WUS 
     In some embodiments, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can wake-up in the upcoming DRX ON-duration even when there is no WUS detected before the upcoming DRX ON-duration. The configuration that can be used by the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. when it wakes up depends on the typical commands that are contained in the WUS such as commands in previously received WUSs or command(s) associated with a default configuration, or based on the default configuration, or the latest configuration that the WD  22  has operated in for the preceding active time. If the WUS that was missed by the WD  22  only has command to wake-up the WD  22 , i.e., the WD configuration follows other commands such as RRC configuration, etc., the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can wake-up in those configurations as the WD  22  may determine that the command in WUS was likely for one or more of those configurations. In other words, in some embodiments, the WD  22  is determining the most likely command(s) (or expected command(s)) included in the WUS that was missed by the WD  22  such that the WD  22  can implement these command(s). As used herein in one or more embodiments, a command may be related the missed wake up signal. 
     In one or more embodiments, when the WUS that was missed before a DRX ON-duration by the WD  22  also contains the configuration (e.g., the number of active ports/antennas, active bandwidth part (BWP), etc.) in which the WD  22  should wake-up, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can wake-up in the most probable configuration(s) (i.e., most likely or expected configuration(s) as determined herein) or the fallback mode (i.e., a default configuration such as a no mode switching command(s)). The most probable configuration(s) can be determined, for example, by keeping the history of the previous configurations between the WD  22  and the respective serving cell. The most probable configuration(s) where the WD  22  wakes up can also be determined in a manner related to this history. For example, if the WD  22  is historically scheduled with PDCCH having configuration A for 80% of the time (i.e., a predefined time period over which historical data is evaluated) and with PDCCH having configuration B for 20% of the time, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc., can wake up in the configuration A, 80% of instances where the WD  22  does not detect WUS and in the configuration B, 20% of the instances where the WD  22  does not detect WUS. In one example, the selection between configuration A and configuration B during one or more instances may be performed randomly or in a predefined manner, but where the total instances where the WD  22  do not detect WUS, configuration A is implemented 80% and configuration B is implemented 20%. 
     In addition, if the WD  22  is capable, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. could also wake in more than one configuration simultaneously (e.g., wakes up in two different BWP configurations or perform tentative PDCCH decoding according to multiple SS and/or WUS format configurations). 
     Indicate Missed WUS to NW 
     In addition to the above, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. could also send a special NACK indication (different from PDSCH ACK/NACK) through PUCCH when the WD  22  does not detect the WUS before a DRX ON-duration but wakes up anyway such as during the DRX ON-duration and successfully detects/decodes PDCCH such as according to one or more determined actions. When receiving this NACK, the network node  16  could then take actions such as sending a more robust WUS in the next WUS MOs. 
     Modify WUS Receiver Configuration 
     In another addition to the primary procedure, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may also change its antenna configuration for reception of PDCCH based WUS or any type of WUS in general. For example, in case the WD  22  in default mode only uses a single antenna, it could increase the number of antennas and employ spatial receiver processing techniques, e.g., maximum ratio combining (MRC), equal gain combining (EGC), or interference rejection combining (IRC) to improve the received quality of the WUS signal in the next WUS MO. 
     Other Aspects 
     In cases where the network node  16  sends a WUS followed by a scheduled aperiodic channel state information reference signal (CSI-RS) (when the WD  22  is expected to send a CSI report back to the network node as an acknowledgement of WUS detection/decoding), the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may stay awake and monitor the coming CSI-RS. The detection of the CSI-RS can also be an indicator of a missing WUS. Then, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may perform channel estimation and report CSI back to the network node  16 . This option can be done especially for the case of the WUS intended for all users or for a specific user. The CSI report may include an indicator, e.g., a bit flag indicating that a WUS was not successfully decoded. 
     In a multi-beam scenario, the WD  22  may expect a WUS over a second specific antenna beam in case SSB measurements lead to the WD  22  understanding that the channel quality of a first specific antenna beam is deteriorated. Then the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can choose to proceed with the autonomous procedures described herein such as by monitoring an on-duration or applying a previously detected command, for example, instead of conducting the default process (i.e., to remain in sleep mode). As such, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. can ignore the WUS operation, wake up for the ON-duration and start the beam recovery procedure. 
     In one embodiment, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may determine that an atypical break in data transmissions has occurred, e.g., according to the typical traffic pattern considerations described above. If the WD  22  observes that no further data is being scheduled to it, e.g., due to radio link failure (RLF) triggered by missed WUS detection and resulting lack of ACK/NACK feedback on multiple PDSCH transmissions, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may perform tentative uplink (UL) transmission, e.g., UL resource request using its radio network temporary identifier (RNTI). If the network node  16  responds with a grant, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may conclude that the network node  16  continues to consider it in connected mode. If the network node  16  does not respond, the WD  22  such as via one or more of processing circuitry  50 , processor  52 , radio interface  48 , signal evaluator unit  30 , etc. may perform an UL access procedure using a regular random-access procedure to re-enter connected mode. 
     Some embodiments mitigate the throughput loss and minimize the power saving lost due to the missed WUS in NR WD  22 . Some embodiments reduce/minimize the retransmission procedures as a consequence of the missed WUS in WD  22  and the network node  16 . 
     According to one aspect, a WD  22  is configured to communicate with a network node  16 , and includes processing circuitry  50  configured to evaluate at least one signal to determine an indication of a time for the WD  22  to wake up in the absence of receiving or decoding a wake up signal from the network node  16 . The processing circuitry  50  is further configured to wake up the WD  22  if the signal evaluation indicates a time for the WD  22  to wake up. 
     According to this aspect, in some embodiments, the at least one signal is one of a demodulation reference signal, DMRS, signal to interference plus noise ratio, SINR, a reference signal received quality, RSRQ, and a reference signal received power, RSRP. In some embodiments, the evaluation includes a comparison between a signal of the at least one signal to a threshold. 
     According to another aspect, a method implemented in a wireless device (WD  22 ) is provided. The method includes evaluating at least one signal to determine an indication of a time for the WD  22  to wake up in the absence of receiving or decoding a wake up signal from the network node. The method also includes waking up the WD  22  if the signal evaluation indicates a time for the WD  22  to wake up. 
     According to this aspect, in some embodiments, the at least one signal is one of a demodulation reference signal, DMRS, signal to interference plus noise ratio, SINR, a reference signal received quality, RSRQ, and a reference signal received power, RSRP. In some embodiments, the evaluation includes a comparison between a signal of the at least one signal to a threshold. 
     Some Examples 
     Example A1. A wireless device  22  (WD  22 ) configured to communicate with a network  16  node, the WD  22  configured to, and/or comprising a radio interface  48  and/or processing circuitry  50  configured to: 
     evaluate at least one signal to determine an indication of a time for the WD  22  to wake up in the absence of receiving or decoding a wake up signal from the network node; and 
     wake up the WD  22  if the signal evaluation indicates a time for the WD  22  to wake up. 
     Example A2. The WD  22  of Example A1, wherein the at least one signal is one of a demodulation reference signal, DMRS, signal to interference plus noise ratio, SINR, a reference signal received quality, RSRQ, and a reference signal received power. 
     Example A3. The WD  22  of Example A1, wherein the evaluation includes a comparison between a signal of the at least one signal to a threshold. 
     Example B1. A method implemented in a wireless device  22  (WD  22 ), the method comprising: 
     evaluating at least one signal to determine an indication of a time for the WD  22  to wake up in the absence of receiving or decoding a wake up signal from the network node  16 ; 
     waking up the WD  22  if the signal evaluation indicates a time for the WD  22  to wake up. 
     Example B2. The method of Example B1, wherein the at least one signal is one of a demodulation reference signal, DMRS, signal to interference plus noise ratio, SINR, a reference signal received quality, RSRQ, and a reference signal received power. 
     Example B3. The method of Example B1, wherein the evaluation includes a comparison between a signal of the at least one signal to a threshold. 
     As will be appreciated by one of skill in the art, the concepts described herein may be embodied as a method, data processing system, computer program product and/or computer storage media storing an executable computer program. Accordingly, the concepts described herein may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects all generally referred to herein as a “circuit” or “module.” Any process, step, action and/or functionality described herein may be performed by, and/or associated to, a corresponding module, which may be implemented in software and/or firmware and/or hardware. Furthermore, the disclosure may take the form of a computer program product on a tangible computer usable storage medium having computer program code embodied in the medium that can be executed by a computer. Any suitable tangible computer readable medium may be utilized including hard disks, CD-ROMs, electronic storage devices, optical storage devices, or magnetic storage devices. 
     Some embodiments are described herein with reference to flowchart illustrations and/or block diagrams of methods, systems and computer program products. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer (to thereby create a special purpose computer), special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     These computer program instructions may also be stored in a computer readable memory or storage medium that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instruction means which implement the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     It is to be understood that the functions/acts noted in the blocks may occur out of the order noted in the operational illustrations. For example, two blocks shown in succession may in fact be executed substantially concurrently or the blocks may sometimes be executed in the reverse order, depending upon the functionality/acts involved. Although some of the diagrams include arrows on communication paths to show a primary direction of communication, it is to be understood that communication may occur in the opposite direction to the depicted arrows. 
     Computer program code for carrying out operations of the concepts described herein may be written in an object oriented programming language such as Java® or C++. However, the computer program code for carrying out operations of the disclosure may also be written in conventional procedural programming languages, such as the “C” programming language. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer. In the latter scenario, the remote computer may be connected to the user&#39;s computer through a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). 
     Many different embodiments have been disclosed herein, in connection with the above description and the drawings. It will be understood that it would be unduly repetitious and obfuscating to literally describe and illustrate every combination and subcombination of these embodiments. Accordingly, all embodiments can be combined in any way and/or combination, and the present specification, including the drawings, shall be construed to constitute a complete written description of all combinations and subcombinations of the embodiments described herein, and of the manner and process of making and using them, and shall support claims to any such combination or subcombination. 
     It will be appreciated by persons skilled in the art that the embodiments described herein are not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope of the following claims.