WO2023200390A1

WO2023200390A1 - Mechanisms for efficient wake-up radio operation

Info

Publication number: WO2023200390A1
Application number: PCT/SE2023/050343
Authority: WO
Inventors: Mohammad MOZAFFARI; Yi-Pin Eric Wang; Andreas HÖGLUND
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2022-04-14
Filing date: 2023-04-13
Publication date: 2023-10-19

Abstract

A method, network node and wireless device (WD) for efficient wakeup radio operation are disclosed. According to one aspect, a method in a WD includes configuring a wakeup receiver (WUR) to operate in one of at least two operational modes based at least in part on at least one of coverage conditions, a battery power 5 level, and a target latency of communications with the network node, the at least two operational modes of the WUR including at least two of a first operational mode in which the WUR continuously monitors a wakeup signal (WUS) a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled. The method also includes operating 10 the WUR in the configured operational mode.

Description

MECHANISMS FOR EFFICIENT WAKE-UP RADIO OPERATION

TECHNICAL FIELD

The present disclosure relates to wireless communications, and in particular, to methods for efficient wakeup radio operation.

BACKGROUND

The Third Generation Partnership Project (3GPP) has developed and is developing standards for Fourth Generation (4G) (also referred to as Long Term Evolution (LTE)) and Fifth Generation (5G) (also referred to as New Radio (NR)) wireless communication systems. Such systems provide, among other features, broadband communication between network nodes, such as base stations, and mobile wireless devices (WD), as well as communication between network nodes and between WDs. Sixth Generation (6G) wireless communication systems are also under development.

In addition to these standards, the Institute of Electrical and Electronic Engineers (IEEE) has developed and continues to develop standards for other types of wireless communication networks, including Wireless Local Area Networks (WLANs), including Wireless Fidelity (Wi-Fi) networks and Bluetooth networks. WLANS include wireless communication between access points (APs) and WDs (non-AP STAs). Such IEEE standards include IEEE 802.11a/b/g/n/ac/ax and IEEE 802.15.

A wake-up receiver (WUR), sometimes also referred to as a ‘wake-up radio’, includes a low power receiver in WDs. When a WUR detects a wake-up signal (WUS), the WUR wakes up the main receiver of the WD to detect an incoming message on a physical downlink control channel (PDCCH) in paging occasions (PO), scheduling the paging message on a physical downlink shared channel (PDSCH). A benefit of employing a WUR is lower energy consumption and longer device battery life, or at a fixed energy consumption the downlink latency may be reduced (shorter discontinuous reception (DRX)/duty-cycles and more frequent checks for incoming transmissions).

In general, there are two approaches for detecting WUS:

Using the main receiver: o No need for additional dedicated hardware/ receiver for monitoring WUS; o Coverage of the main receiver is not typically impacted; and o Limited power saving gain as the main receiver monitors WUS;

• Having a dedicated receiver (WUR): o Extremely low power, simple and low-cost receiver architecture, relaxed requirements, noisier (i.e., less accurate) clock or oscillator; o Significant power saving gain may be achieved by maximizing the time in which the main receiver may be in the sleep mode; o Enablers for zero energy /battery-less devices, and energy harvesting operations; and o There are coverage considerations given the tradeoff between WUR power consumption and sensitivity.

WUS for NB-IoT and LTE-M

Release 15

In 3GPP Technical Release 15 (3GPP Rel-15, V15.12.0), a WUS was specified for narrowband Internet of Things (NB-IoT) and LTE-Machine (M) communications to achieve lower WD energy consumption since. With enhanced coverage, the PDCCH might be repeated many times, whereas the WUS is shorter and requires less reception time.

FIG. 1 illustrates an example location of a WUS and the paging occasion (PO) to which it is associated. A WD checks for a WUS a certain time before its PO, and only if a WUS is detected would the WD continue to check for the PDCCH in the PO. If the WUS is not received, which is most of the time, the WD may go back to a sleep state to conserve energy. Due to coverage enhancements, the WUS may be of variable length depending on the WD’s coverage.

FIG. 2 illustrates an example WUS for NB-IOT and LTE-M. A WUS is a short signal that indicates to the WD that the WD should continue to decode the downlink (DL) control channel, e.g., full narrowband PDCCH (NPDCCH) for NB- loT. If the WUS is absent (or if the WD does not detect it), then the WD may go back to sleep without decoding the DL control channel. The decoding time for a WUS is considerably shorter than that of the full NPDCCH since the WUS essentially only needs to contain one bit of information. In contrast, the NPDCCH may contain up to 35 bits of information. Processing these many bits increases WD power consumption and leads to shorter WD battery life. The WUS would be transmitted only when the WD is being paged. When there is no paging for the WD, the WUS is not transmitted (i.e. , implying a discontinuous transmission, DTX). The WD goes back to deep sleep e.g., upon detecting DTX instead of the WUS. This is illustrated in FIG. 1 where white blocks indicate possible WUS and PO positions whereas the black boxes indicate actual WUS and PO positions.

In 3GPP Rel-15, the WUS is spread out over several parts of the LTE 36- series standard, e.g., 3GPP Technical Standards (TS) 36.211 vl5.14.0, 36.213 V15.14.0, 36.304 vl5.14.0 and 36.331 V15.14.0.

WUS WD grouping objective in 3 GPP Rel-16

In the 3GPP Rel-16 work item description (WID), specifying that the WUS should include WD grouping was considered, so that the number of WDs that are triggered by a WUS is further narrowed down to a smaller subset of the WDs that are associated with a specific paging occasion (PO).

A purpose is to reduce the false paging rate, i.e., avoid waking up a WD unnecessarily when a WUS transmission intended for another WD. A WUS that includes WD grouping is referred to as a 3GPP Rel-16 group WUS, or GWUS.

Rel-17 NR PEI

In 3GPP Rel-17, a WUS for NR was introduced and called a ‘Paging Early Indication’ (PEI). However, since at the time no coverage enhancement was specified for NR, the only gain of the 3GPP Rel-17 PEI was in scenarios where a small fraction of WDs are in bad coverage and have large synchronization errors due to the use of longer DRX cycles. The gains for such WDs arose from the fact that to acquire and decode the PEI would require one synchronization signal block (SSB), instead of up to 3 SSBs when the PEI is not used. So, for most WDs, 3GPP Rel-17 PEI will result in gains or increased performance.

The 3GPP Rel-17 PEI will also support WD grouping for false paging reduction, similar to the 3GPP Rel-16 GWUS mentioned above, resulting in some gains at higher paging load.

In 3GPP RAN#93e, it was considered that the PEI will be PDCCH-based, making it much less useful for the WUR (i.e., when the main baseband receiver is required for decoding the PEI). Rel-18 NR WUR

In 3GPP Rel-18, there has been interest in introducing a WUR for NR to achieve greater energy efficiency compared to previously specified solutions. As explained above, the only specification support to be able to use a WUR in the WD, is the specification of a WUS and a long enough time gap between the WUS and the PDCCH in the PO (to allow the WD to start up the main receiver). Therefore, a difference between the WUS of 3GPP Rel-18 and the WUS of prior releases, is that that the WUS is not PDCCH-based, which allows for a simple, low power WUR with simple demodulation and detection techniques (e.g., using on-off keying, (OOK) demodulation and non-coherent detection).

In 3GPP Rel-18, a study item on “low-power wake-up signal and receiver for NR” was approved. The relevant justification and objective sections are copied below:

• “Justification

5G systems are designed and developed targeting for both mobile telephony and vertical use cases. Besides latency, reliability, and availability, WD energy efficiency is also critical to 5G. Currently, 5G devices may have to be recharged per week or day, depending on individual’s usage time. In general, 5G devices consume tens of milliwatts in RRC idle/inactive state and hundreds of milliwatts in RRC connected state. Designs to prolong battery life is a necessity for improving energy efficiency as well as for better user experience.

Energy efficiency is even more critical for WDs without a continuous energy source, e.g., WDs using small rechargeable and single coin cell batteries. Among vertical use cases, sensors and actuators are deployed extensively for monitoring, measuring, charging, etc. Generally, their batteries are not rechargeable and expected to last at least few years as described in TR 38.875. Wearables include smart watches, rings, eHealth related devices, and medical monitoring devices. With typical battery capacity, it is challenging to sustain up to 1-2 weeks of capacity as required.

The power consumption depends on the configured length of wake-up periods, e.g., paging cycle. To meet the battery life requirements above, eDRX cycle with large value is expected to be used, resulting in high latency, which is not suitable for such services with requirements of both long battery life and low latency. For example, in fire detection and extinguishment uses, fire shutters should be closed and fire sprinklers should be turned on by the actuators within 1 to 2 seconds from the time the fire is detected by sensors, long extended discontinuous reception (eDRX) cycle cannot meet the delay requirements. eDRX is apparently not suitable for latency-critical use cases. Thus, the intention is to study ultra-low power mechanism that may support low latency in Rel-18, e.g., lower than eDRX latency.

Currently, WDs need to periodically wake up once per DRX cycle, which dominates the power consumption in periods with no signalling or data traffic. If WDs are able to wake up only when they are triggered, e.g., paging, power consumption may be dramatically reduced. This may be achieved by using a wake-up signal to trigger the main radio and a separate receiver which has the ability to monitor wake-up signal with ultra-low power consumption. Main radio works for data transmission and reception, which may be turned off or set to deep sleep unless it is turned on.

The power consumption for monitoring wake-up signal depends on the wake-up signal design and the hardware module of the wake-up receiver used for signal detecting and processing.

The study should primarily target low-power WUS/WUR for powersensitive, small form-factor devices including loT use cases (such as industrial sensors, controllers) and wearables. Other use cases are not precluded, e.g., XR/smart glasses, smart phones.

• An Objective of SI

As opposed to the work on WD power savings in previous releases, this study will not require existing signals to be used as WUS. All WUS solutions identified shall be able to operate in a cell supporting legacy WDs. Solutions target substantial gains compared to the existing Rel-15/16/17 WD power saving mechanisms. Other aspects such as detection performance, coverage, WD complexity, should be covered by the evaluation.

The study item addresses the following:

• Identify evaluation methodology (including the use cases) & KPIs [RANI] o Primarily target low-power WUS/WUR for powersensitive, small form-factor devices including loT use cases (such as industrial sensors, controllers) and wearables

■ Other use cases are not precluded

• Study and evaluate low-power wake-up receiver architectures [RANI, RAN4]

• Study and evaluate wake-up signal designs to support wake-up receivers [RAN 1 , RAN4]

• Study and evaluate LI procedures and higher layer protocol changes needed to support the wake-up signals [RAN2, RANI]

• Study potential WD power saving gains compared to the existing Rel-15/16/17 WD power saving mechanisms and their coverage availability, as well as latency impact. System impact, such as network power consumption, coexistence with non-low-power- WUR WDs, network coverage/capacity/resource overhead should be included in the study [RANI], o Note: The need for RAN2 evaluation will be triggered by RANI when necessary.”

A benefit of a WUR is to reduce receiver energy consumption so that unless there is any paging and data for the WD it may remain in a power saving state. This will extend the battery life of the WD, or alternatively enable shorter downlink latency (shorter DRX) at a fixed battery life. For short-range communication, the WUR power may be low enough (~3 uW) that this may even, in combination with energy harvesting, enable the WUR to be continuously on (i.e., DRX or duty-cycling is not used) without the need for a battery. This may be considered an enabler of battery-less devices in 6G WDs.

IEEE WUR

In standards activities of the Institute for Electrical and Electronics Engineers (IEEE), support for WUR has been specified to a greater extent than by the 3GPP, focusing on a low power WUR and design of the WUR to receive not only the WUS, but also other control signals and signaling, such as synchronization and mobility information. This allows the stations (corresponding to WDs in 3GPP) to only use the WUR when there is no user-plane data transmission ongoing.

Similar to the 3GPP solution, the use of WUR by the IEEE is only enabled in stations and not in access points (APs). In other words, the solution is for downlink communication only. The AP advertises that it has WUR operational capability, along with WUR configuration parameters (which include an indication of which band/channel of a WUR is operational, which may be different from the band/channel used for data transmission using the main receiver. For example, the. WUR may operate in the 2.4 GHz band, whereas data communication may be performed in the 5 GHz band. Also note that the WUR operating channel is advertised in a beacon, and that the WUR discovery operating channel may be different from the WUR operating channel. Stations may then request to be configured with a WUR mode of operation. This request is to be granted by the AP, and if granted, the station is further configured/setup for a WUR mode of operation for this particular AP. The configuration is be tom down/de-configured when the WUR is no longer used. Both continuous WURs (receiver open all the time) and duty-cycled WURs (receiver only open during preconfigured time slots) modes of operation are supported. For the latter, the length of the duty-cycles and on-time during wake up is part of the WUR configuration.

Unlike the 3GPP solution, the IEEE WUR operational mode is a “sub-state” of the regular operation and depends on the detection of a WUS transmission from the AP. Then, the station will resume the power saving mechanism it was configured with before entering the WUR operational mode. That is, IEEE has specified a number of different power saving mechanisms. For example, if duty-cycled monitoring of the downlink has been configured for the station, the station will switch to that mode of operation upon detection of the WUS (i.e., unlike the specified 3GPP mechanism which only covers paging and wherein the WD will continue to monitor PDCCH if a WUS is detected. In this way, the IEEE WUR functionality is more general, and still allows for the station to, upon detection of WUS, monitor paging by checking in the beacon from the AP for which stations there is data, or for the station to directly respond with an uplink transmission.

The physical wake-up signal (WUS) in IEEE contains complete frames which must be processed by the station. The drawback with this design is that it requires more handling and processing in the station, i.e., compared to a simple WUR design which triggers one pre-defined activity when the WUS is detected. A benefit of the IEEE WUS is that it contains more information and the solution is more general. The IEEE WUS contains information to indicate if the WUS is a WUR synchronization beacon, a WUR discovery beacon, or a regular WUS (intended to wake the station up). The WUS may also contain proprietary frames, which may, e.g., be used to directly turn actuators on/off. The transmission uses on/off keying (OOK) modulation, using Manchester coding, and may use multi-carrier OOK, which may be generated by an orthogonal frequency division multiplexing (OFDM) transmitter. In other words, the WUR may be enabled as a software upgrade in APs. The WUS is 4 MHz wide, but a whole 20 MHz channel is reserved. The WUS starts with a 20 MHz legacy preamble (to allows other stations to perform carrier sensing) followed by 4 MHz Manchester coded OOK. Two data rates are supported: 62.5 kbps and 250 kbps. Link adaptation is up to the AP. Each packet is self-contained and includes the data rate. In the WUR, there are two possible synchronization words used to signal the data rate). Power vs. sensitivity tradeoff

The design challenge in receivers for loT applications is to minimize the power consumption with an adequate sensitivity level. In WUR design, receiver sensitivity is a parameter that indicates a lowest power level at which the receiver may detect a WUS. Generally, high sensitivity requires more power consuming electronics (e.g., a low noise amplifier (LN A)) at the receiver, which increases power demand. In contrast, low sensitivity for the same communication range will require high radiated power by the transmitter. Because of this, sensitivity requirements often lead to over- design to ensure reliable communication in adverse conditions. When the WUR is used to trigger a less energy-efficient and more power consuming main receiver, ideally the WUR and the main receiver should have the same range.

As an example, the tradeoff between sensitivity/cov erage and energy consumption of WUR is shown in FIG. 3, based on the existing low-power radio designs. As may be seen from FIG. 3, for every 20 dB improvement in sensitivity, there is at least a factor of 10 increase in power consumption.

Another tradeoff in WUR design and operation is energy consumption versus latency. For example, to achieve a minimum latency, the WUR may need to be always on to continuously monitor for downlink transmissions (e.g., a WUS). The average power consumption may be reduced by relaxing latency and allowing the WUR to go to sleep.

An objective in the design of a WUR is to ensure that the WUR sensitivity results in a coverage which matches that of the main radio. If not, a WD would effectively have a coverage reduction when WUR operation is configured for the WD, and the WD would become unreachable at the cell-edge since there, the WUS cannot be received. In particular, low power WURs should be efficiently employed in various deployment scenarios while satisfying the coverage requirements. However, since the main radio has more advanced capabilities compared to a low complexity WUR, the main radio has a higher sensitivity. For instance, to support 5GNR WDs in macro deployment scenarios, the receiver sensitivity should be around -100 dBm (especially for WDs located at the cell-edge). Given the fundamental tradeoff between sensitivity/coverage and power consumption, achieving high sensitivity with low power consumption for WUR is challenging. This may result in a limited deployment of WUR (e.g., indoor-only), or a relatively high power consumption for WUR, which is not desired.

SUMMARY

Some embodiments advantageously provide methods, network nodes and wireless devices for efficient wakeup radio operation.

Some embodiments may provide for handling the coverage mismatch between WUR and the main radio while minimizing WUR power consumption. Some embodiments may provide solutions for determining efficient WUR operational modes and switching mechanisms based on various criteria (jointly or individually) such as the WD coverage conditions, latency requirements, the WUR sensitivity, the WUR power consumption, and WD battery power level. In some embodiments, the WUR may operate in different operational modes according to the coverage conditions, WUR battery power level, and latency targets in order to ensure that the WD is reachable in various coverage conditions and scenarios. The WUR may switch between different operational modes including: always-on WUR operation, multiple duty-cycled WUR operation, each operational modes having specific parameters, and a disabled WUR operational mode to maximize the power saving while maintaining the WD connectivity and latency requirements.

Some embodiments may address the following: 1) joint metrics (coverage/latency /battery power level of both the WUR and the main radio) for WUR operation, 2) general operational modes (e.g., multi duty-cycled WUR operations each with different parameters), and 3) efficient switching mechanisms between different operational modes.

Some embodiments may support efficient WUR operational modes in various deployment scenarios, each operational mode having different WUR sensitivity/power consumption/latency tradeoffs when there is potential coverage mismatch between the WUR and the main radio. Efficient use of a WUR to maximize power savings while maintaining WD coverage in various deployment scenarios are provided in some embodiments. Some embodiments may provide one or more of the following:

1) Network flexibility for properly employing WUR based on various requirements such coverage, energy efficiency, and latency;

2) Capturing the sensitivity-power consumption tradeoff and addressing the problem of coverage mismatch between WUR and the main radio in WUR deployment scenarios; and/or

3) The solutions may be considered as an enabler of battery-less (zeroenergy) devices and energy harvesting operations towards 5G Advanced and 6G.

According to one aspect, a network node configured to communicate with a wireless device (WD) is provided. The network node includes processing circuitry configured to configure a wakeup signal, WUS, according to one of at least two operational modes of a wakeup receiver, WUR, of the WD, the at least two operational modes of the WUR including at least two of a first operational mode in which the WUR continuously monitors the WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled, The network node also includes a radio interface in communication with the processing circuitry and configured to transmit the WUS to the WD.

According to this aspect, in some embodiments, transmitting the WUS includes transmitting the WUS at a power level that is based at least in part on a current operational mode of the WUR. In some embodiments, configuring the WUS includes configuring the WUS to have a duty cycle in the second operational mode that is based at least in part on a discontinuous reception, DRX, cycle. In some embodiments, the duty cycle is further based at least in part on a target latency of communications with the WD. In some embodiments, configuring the WUS is based at least in part on an indication of coverage conditions at the WD. In some embodiments, the processing circuitry is further configured to configure the WD to operate in a succession of operational modes of the at least two operational modes based at least in part on a set of joint metrics that include at least two of coverage conditions, battery power level and target latency. In some embodiments, the radio interface is further configured to indicate at least one threshold for determining an operational mode in one of a system information block and a DownlinkConfigCommon information element.

According to another aspect, a method implemented in a network node configured to communicate with a wireless device is provided. The method includes configuring a wakeup signal, WUS, according to one of at least two operational modes of a wakeup receiver, WUR, of the WD, the at least two operational modes of the WUR including at least two of a first operational mode in which the WUR continuously monitors the WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled. The method also includes transmitting the WUS to the WD.

According to this aspect, in some embodiments, transmitting the WUS includes transmitting the WUS at a power level that is based at least in part on a current operational mode of the WUR. In some embodiments, configuring the WUS includes configuring the WUS to have a duty cycle in the second operational mode that is based at least in part on a discontinuous reception, DRX cycle. In some embodiments, the duty cycle is further based at least in part on a target latency of communications with the WD, In some embodiments, configuring the WUS is based at least in part on an indication of coverage conditions at the WD. In some embodiments, the method includes configuring the WD to operate in a succession of operational modes of the at least two operational modes based at least in part on a set of joint metrics that include at least two of coverage conditions, battery power level and target latency. In some embodiments, the method includes indicating at least one threshold for determining an operational mode in one of a system information block and a DownlinkConfigCommon information element.

According to yet another aspect, a wireless device (WD) configured to communicate with a network node is provided. The WD includes processing circuitry configured to configure a wakeup receiver, WUR, of the WD to operate in one of at least two operational modes based at least in part on at least one of coverage conditions, a battery power level, and a target latency of communications with the network node, the at least two operational modes of the WUR including at least two of a first operational mode in which the WUR continuously monitors a wakeup signal, WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled. The WUR is in communication with the processing circuitry and configured to operate in the configured operational mode.

In some embodiments, the processing circuitry is further configured to switch the WUR between operational modes of the at least two operational modes when a function of at least one of the coverage conditions, the battery power level and the target latency crosses a threshold. In some embodiments, the processing circuitry is further configured to switch the WUR between operational modes of the at least two operational modes when each of a plurality of functions cross a respective threshold, each one of the plurality of functions being a function of at least one of the coverage conditions, the battery power level and the target latency. In some embodiments, a respective threshold is received from the network node in one of a system information block and a DownlinkConfigCommon information element. In some embodiments, In some embodiments, the processing circuitry is further configured to switch from a first operational mode of the at least two operational modes to a default operational mode of the at least two operational modes followed by switching to one of the first operational mode and a second operational mode of the at least two operational modes. In some embodiments, the processing circuitry is further configured to switch the WUR between operational modes of the at least two operational modes based at least in part on a target average power consumption. In some embodiments, configuring the operational mode of the WUR includes setting at least one of a duration of the operational mode, a sequence of operational modes, and a default operational mode of the at least two operational modes. In some embodiments, the operational mode of the at least two operational modes is determined based at least in part on information received from the network node. In some embodiments, the operational mode of the at least two operational modes is determined based at least in part on measurements of at least one of a reference signal received power, RSRP, a reference signal received quality, RSRQ, a signal to noise ratio, SNR, and a signal to interference plus noise ratio, SINR. In some embodiments, the processing circuitry is further configured to configure the WD to operate in a succession of operational modes of the at least two operational modes based at least in part on a set of joint metrics that include at least two of coverage conditions, battery power level and target latency.

According to yet another aspect, a method implemented in a wireless device, WD, configured to communicate with a network node is provided. The method includes configuring a wakeup receiver, WUR, to operate in one of at least two operational modes based at least in part on at least one of coverage conditions, a battery power level, and a target latency of communications with the network node, the at least two operational modes of the WUR including at least two of a first operational mode in which the WUR continuously monitors a wakeup signal, WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled. The method includes operating the WUR in the configured operational mode.

According to this aspect, in some embodiments, the method includes switching the WUR between operational modes of the at least two operational modes when a function of at least one of the coverage conditions, the battery power level and the target latency crosses a threshold. In some embodiments, the method includes switching the WUR between operational modes of the at least two operational modes when each of a plurality of functions cross a respective threshold, each one of the plurality of functions being a function of at least one of the coverage conditions, the battery power level and the target latency. In some embodiments, a respective threshold is received from the network node in one of a system information block and a DownlinkConfigCommon information element. In some embodiments, the method includes switching from a first operational mode of the at least two operational modes to a default operational mode of the at least two operational modes followed by switching to one of the first operational mode and a second operational mode of the at least two operational modes. In some embodiments, the method includes switching the WUR between operational modes of the at least two operational modes based at least in part on a target average power consumption. In some embodiments, configuring the operational mode of the WUR includes setting at least one of a duration of the operational mode, a sequence of operational modes, and a default operational mode of the at least two operational modes. In some embodiments, the operational mode of the at least two operational modes is determined based at least in part on information received from the network node. In some embodiments, the operational mode of the at least two operational modes is determined based at least in part on measurements of at least one of a reference signal received power, RSRP, a reference signal received quality, RSRQ, a signal to noise ratio, SNR, and a signal to interference plus noise ratio, SINR. In some embodiments, the method includes configuring the WD to operate in a succession of operational modes of the at least two operational modes based at least in part on a set of joint metrics that include at least two of coverage conditions, battery power level and target latency.

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 illustrates a sequence of WUSs and Pos;

FIG. 2 illustrates a WUS, a gap, and a PO;

FIG. 3 illustrates a relationship between sensitivity and power;

FIG. 4 is a schematic diagram of an example network architecture illustrating a communication system connected via an intermediate network to a host computer according to the principles in the present disclosure;

FIG. 5 is a block diagram of a host computer communicating via a network node with a wireless device over an at least partially wireless connection according to some embodiments of the present disclosure;

FIG. 6 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for executing a client application at a wireless device according to some embodiments of the present disclosure;

FIG. 7 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data at a wireless device according to some embodiments of the present disclosure;

FIG. 8 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data from the wireless device at a host computer according to some embodiments of the present disclosure;

FIG. 9 is a flowchart illustrating example methods implemented in a communication system including a host computer, a network node and a wireless device for receiving user data at a host computer according to some embodiments of the present disclosure;

FIG. 10 is a flowchart of an example process in a network node for methods for efficient wakeup radio operation;

FIG. 11 is a flowchart of an example process in a wireless device for methods for efficient wakeup radio operation;

FIG. 12 is flowchart of another example process in a network node for methods for efficient wakeup radio operation;

FIG. 13 is a flowchart of an example process in a wireless device for methods for efficient wakeup radio operation;

FIG. 14 illustrates a main receiver and a WUR;

FIG. 15 illustrates different operational modes of a WUR that may be used in different coverage conditions; and

FIG. 16 illustrates switching between WUR operational modes.

DETAILED DESCRIPTION

Before describing in detail example embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to methods for efficient wakeup radio operation. 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,” “top” and “bottom,” 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 “coupled,” “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” used herein may 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. The term “radio node” used herein may be used to also denote a wireless device (WD) such as a wireless device (WD) or a radio network node.

In some embodiments, the non-limiting terms wireless device (WD) or a user equipment (UE) are used interchangeably. The WD herein may 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 (loT) device, or a Narrowband loT (NB-IOT) device, etc. Also, in some embodiments the generic term “radio network node” is used. It may be any kind of a radio network node which may comprise any of base station, radio base station, base transceiver station, base station controller, network controller, RNC, evolved Node B (eNB), Node B, gNB, Multi-cell/multicast Coordination Entity (MCE), IAB node, relay node, access point, radio access point, Remote Radio Unit (RRU) Remote Radio Head (RRH).

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), 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, may 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.

Some embodiments provide methods for efficient wakeup radio operation as compared with other solutions. Referring again to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in FIG. 4 a schematic diagram of a communication system 10, according to an embodiment, such as a 3 GPP-type cellular network that may support standards such as LTE and/or NR (5G) or a WLAN that may support IEEE standards. The communication system 10 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 16a, 16b, 16c (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 18a, 18b, 18c (referred to collectively as coverage areas 18). Each network node 16a, 16b, 16c is connectable to the core network 14 over a wired or wireless connection 20. A first wireless device (WD) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second WD 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of WDs 22a, 22b (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. The WD 22 may be compatible with 3 GPP standards and/or IEEE standards.

Also, it is contemplated that a WD 22 may 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 may 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 may be in communication with an eNB for LTE/E-UTRAN and a gNB for NR/NG-RAN.

The communication system 10 may itself be connected to a host computer 24, which may be embodied in the hardware and/or software of a standalone server, a cloud-implemented server, a distributed server or as processing resources in a server farm. The host computer 24 may be under the ownership or control of a service provider, or may be operated by the service provider or on behalf of the service provider. The connections 26, 28 between the communication system 10 and the host computer 24 may extend directly from the core network 14 to the host computer 24 or may extend via an optional intermediate network 30. The intermediate network 30 may be one of, or a combination of more than one of, a public, private or hosted network. The intermediate network 30, if any, may be a backbone network or the Internet. In some embodiments, the intermediate network 30 may comprise two or more sub-networks (not shown).

The communication system of FIG. 4 as a whole enables connectivity between one of the connected WDs 22a, 22b and the host computer 24. The connectivity may be described as an over-the-top (OTT) connection. The host computer 24 and the connected WDs 22a, 22b are configured to communicate data and/or signaling via the OTT connection, using the access network 12, the core network 14, any intermediate network 30 and possible further infrastructure (not shown) as intermediaries. The OTT connection may be transparent in the sense that at least some of the participating communication devices through which the OTT connection passes are unaware of routing of uplink and downlink communications. For example, a network node 16 may not or need not be informed about the past routing of an incoming downlink communication with data originating from a host computer 24 to be forwarded (e.g., handed over) to a connected WD 22a. Similarly, the network node 16 need not be aware of the future routing of an outgoing uplink communication originating from the WD 22a towards the host computer 24.

A network node 16 is configured to include a WUS configuration unit 32 which is configured to configure a wakeup signal, WUS, according to an operational mode of a wakeup receiver WUR of the WD, an operational mode of the WUR including at least one of a first operational mode in which the WUR continuously monitors the WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled. A wireless device 22 is configured to include a WUR configuration unit 34 which is configured to configure an operational mode of a wakeup receiver, WUR, based at least in part on at least one of coverage conditions, a battery power level, and a target latency of communications with the network node, an operational mode of the WUR including at least one of a first operational mode in which the WUR continuously monitors the WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled.

Example implementations, in accordance with an embodiment, of the WD 22, network node 16 and host computer 24 discussed in the preceding paragraphs will now be described with reference to FIG. 5. In a communication system 10, a host computer 24 comprises hardware (HW) 38 including a communication interface 40 configured to set up and maintain a wired or wireless connection with an interface of a different communication device of the communication system 10. The host computer 24 further comprises processing circuitry 42, which may have storage and/or processing capabilities. The processing circuitry 42 may include a processor 44 and memory 46. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 42 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 44 may be configured to access (e.g., write to and/or read from) memory 46, 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).

Processing circuitry 42 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 host computer 24. Processor 44 corresponds to one or more processors 44 for performing host computer 24 functions described herein. The host computer 24 includes memory 46 that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 48 and/or the host application 50 may include instructions that, when executed by the processor 44 and/or processing circuitry 42, causes the processor 44 and/or processing circuitry 42 to perform the processes described herein with respect to host computer 24. The instructions may be software associated with the host computer 24.

The software 48 may be executable by the processing circuitry 42. The software 48 includes a host application 50. The host application 50 may be operable to provide a service to a remote user, such as a WD 22 connecting via an OTT connection 52 terminating at the WD 22 and the host computer 24. In providing the service to the remote user, the host application 50 may provide user data which is transmitted using the OTT connection 52. The “user data” may be data and information described herein as implementing the described functionality. In one embodiment, the host computer 24 may be configured for providing control and functionality to a service provider and may be operated by the service provider or on behalf of the service provider. The processing circuitry 42 of the host computer 24 may enable the host computer 24 to observe, monitor, control, transmit to and/or receive from the network node 16 and or the wireless device 22.

The communication system 10 further includes a network node 16 provided in a communication system 10 and including hardware 58 enabling it to communicate with the host computer 24 and with the WD 22. The hardware 58 may include a communication interface 60 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 62 for setting up and maintaining at least a wireless connection 64 with a WD 22 located in a coverage area 18 served by the network node 16. The radio interface 62 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 60 may be configured to facilitate a connection 66 to the host computer 24. The connection 66 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 30 outside the communication system 10.

In the embodiment shown, the hardware 58 of the network node 16 further includes processing circuitry 68. The processing circuitry 68 may include a processor 70 and a memory 72. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 68 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 70 may be configured to access (e.g., write to and/or read from) the memory 72, 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 74 stored internally in, for example, memory 72, 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 74 may be executable by the processing circuitry 68. The processing circuitry 68 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 70 corresponds to one or more processors 70 for performing network node 16 functions described herein. The memory 72 is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 74 may include instructions that, when executed by the processor 70 and/or processing circuitry 68, causes the processor 70 and/or processing circuitry 68 to perform the processes described herein with respect to network node 16. For example, processing circuitry 68 of the network node 16 may include a WUS configuration unit 32 which is configured to configure a wakeup signal, WUS, according to an operational mode of a wakeup receiver WUR of the WD.

The communication system 10 further includes the WD 22 already referred to. The WD 22 may have hardware 80 that may include a radio interface 82 configured to set up and maintain a wireless connection 64 with a network node 16 serving a coverage area 18 in which the WD 22 is currently located. The radio interface 82 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. In some embodiments, the radio interface 82 includes a main receiver 94 and a WUR 96, each having functionality as described below for various embodiments.

The hardware 80 of the WD 22 further includes processing circuitry 84. The processing circuitry 84 may include a processor 86 and memory 88. In particular, in addition to or instead of a processor, such as a central processing unit, and memory, the processing circuitry 84 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 86 may be configured to access (e.g., write to and/or read from) memory 88, 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 90, which is stored in, for example, memory 88 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 90 may be executable by the processing circuitry 84. The software 90 may include a client application 92. The client application 92 may be operable to provide a service to a human or non-human user via the WD 22, with the support of the host computer 24. In the host computer 24, an executing host application 50 may communicate with the executing client application 92 via the OTT connection 52 terminating at the WD 22 and the host computer 24. In providing the service to the user, the client application 92 may receive request data from the host application 50 and provide user data in response to the request data. The OTT connection 52 may transfer both the request data and the user data. The client application 92 may interact with the user to generate the user data that it provides.

The processing circuitry 84 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 86 corresponds to one or more processors 86 for performing WD 22 functions described herein. The WD 22 includes memory 88 that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software 90 and/or the client application 92 may include instructions that, when executed by the processor 86 and/or processing circuitry 84, causes the processor 86 and/or processing circuitry 84 to perform the processes described herein with respect to WD 22. For example, the processing circuitry 84 of the wireless device 22 may include a WUR configuration unit 34 which is configured to configure an operational mode of a wakeup receiver, WUR, based at least in part on at least one of coverage conditions, a battery power level, and a target latency of communications with the network node.

In some embodiments, the inner workings of the network node 16, WD 22, and host computer 24 may be as shown in FIG. 5 and independently, the surrounding network topology may be that of FIG. 4.

In FIG. 5, the OTT connection 52 has been drawn abstractly to illustrate the communication between the host computer 24 and the wireless device 22 via the network node 16, without explicit reference to any intermediary devices and the precise routing of messages via these devices. Network infrastructure may determine the routing, which it may be configured to hide from the WD 22 or from the service provider operating the host computer 24, or both. While the OTT connection 52 is active, the network infrastructure may further take decisions by which it dynamically changes the routing (e.g., on the basis of load balancing consideration or reconfiguration of the network).

The wireless connection 64 between the WD 22 and the network node 16 is in accordance with the teachings of the embodiments described throughout this disclosure. One or more of the various embodiments improve the performance of OTT services provided to the WD 22 using the OTT connection 52, in which the wireless connection 64 may form the last segment. More precisely, 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. There may further be an optional network functionality for reconfiguring the OTT connection 52 between the host computer 24 and WD 22, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection 52 may be implemented in the software 48 of the host computer 24 or in the software 90 of the WD 22, or both. In embodiments, sensors (not shown) may be deployed in or in association with communication devices through which the OTT connection 52 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software 48, 90 may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 52 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not affect the network node 16, and it may be unknown or imperceptible to the network node 16. Some such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary WD signaling facilitating the host computer’s 24 measurements of throughput, propagation times, latency and the like. In some embodiments, the measurements may be implemented in that the software 48, 90 causes messages to be transmitted, in particular empty or ‘dummy’ messages, using the OTT connection 52 while it monitors propagation times, errors, etc.

Thus, in some embodiments, the host computer 24 includes processing circuitry 42 configured to provide user data and a communication interface 40 that is configured to forward the user data to a cellular network for transmission to the WD 22. In some embodiments, the cellular network also includes the network node 16 with a radio interface 62. In some embodiments, the network node 16 is configured to, and/or the network node’s 16 processing circuitry 68 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 host computer 24 includes processing circuitry 42 and a communication interface 40 that is configured to a communication interface 40 configured to receive user data originating from a transmission from a WD 22 to a network node 16. In some embodiments, the WD 22 is configured to, and/or comprises a radio interface 82 and/or processing circuitry 84 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. 4 and 5 show various “units” such as WUS configuration unit 32, and WUR configuration unit 34 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. 6 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIGS. 4 and 5, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIG. 5. In a first step of the method, the host computer 24 provides user data (Block SI 00). In an optional substep of the first step, the host computer 24 provides the user data by executing a host application, such as, for example, the host application 50 (Block SI 02). In a second step, the host computer 24 initiates a transmission carrying the user data to the WD 22 (Block SI 04). In an optional third step, the network node 16 transmits to the WD 22 the user data which was carried in the transmission that the host computer 24 initiated, in accordance with the teachings of the embodiments described throughout this disclosure (Block SI 06). In an optional fourth step, the WD 22 executes a client application, such as, for example, the client application 92, associated with the host application 50 executed by the host computer 24 (Block SI 08).

FIG. 7 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG. 4, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS. 4 and 5. In a first step of the method, the host computer 24 provides user data (Block SI 10). In an optional substep (not shown) the host computer 24 provides the user data by executing a host application, such as, for example, the host application 50. In a second step, the host computer 24 initiates a transmission carrying the user data to the WD 22 (Block SI 12). The transmission may pass via the network node 16, in accordance with the teachings of the embodiments described throughout this disclosure. In an optional third step, the WD 22 receives the user data carried in the transmission (Block SI 14).

FIG. 8 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG. 4, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS. 4 and 5. In an optional first step of the method, the WD 22 receives input data provided by the host computer 24 (Block SI 16). In an optional substep of the first step, the WD 22 executes the client application 92, which provides the user data in reaction to the received input data provided by the host computer 24 (Block SI 18). Additionally or alternatively, in an optional second step, the WD 22 provides user data (Block SI 20). In an optional substep of the second step, the WD provides the user data by executing a client application, such as, for example, client application 92 (Block S122). In providing the user data, the executed client application 92 may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the WD 22 may initiate, in an optional third substep, transmission of the user data to the host computer 24 (Block SI 24). In a fourth step of the method, the host computer 24 receives the user data transmitted from the WD 22, in accordance with the teachings of the embodiments described throughout this disclosure (Block S126).

FIG. 9 is a flowchart illustrating an example method implemented in a communication system, such as, for example, the communication system of FIG. 4, in accordance with one embodiment. The communication system may include a host computer 24, a network node 16 and a WD 22, which may be those described with reference to FIGS. 4 and 5. In an optional first step of the method, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 16 receives user data from the WD 22 (Block SI 28). In an optional second step, the network node 16 initiates transmission of the received user data to the host computer 24 (Block S130). In a third step, the host computer 24 receives the user data carried in the transmission initiated by the network node 16 (Block S132).

FIG. 10 is a flowchart of an example process in a network node 16 for methods for efficient wakeup radio operation. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 68 (including a WUS configuration unit 32), processor 70, radio interface 62 and/or communication interface 60. Network node 16 such as via processing circuitry 68 and/or processor 70 and/or radio interface 62 and/or communication interface 60 is configured to configure a wakeup signal, WUS, according to an operational mode of a wakeup receiver WUR 96 of the WD, an operational mode of the WUR including at least one of a first operational mode in which the WUR continuously monitors the WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled (Block SI 34). The process also includes transmitting the WUS to the WD (Block SI 36).

In some embodiments, transmitting the WUS includes transmitting the WUS at a power level that is based at least in part on a current operational mode of the WUR 96. In some embodiments, configuring the WUS includes configuring the WUS to have a duty cycle in the second operational mode that is based at least in part on a discontinuous (DRX) cycle. . In some embodiments, the duty cycle is further based on a target latency of communications with the WD, In some embodiments, a configuration of the WUS is based at least in part on an indication of coverage conditions at the WD. In some embodiments, the process also includes configuring the WD to operate in at least one of a particular operational mode and a succession of particular operational modes based at least in part on a set of joint metrics that include at least two of coverage, energy and latency.

FIG. 11 is a flowchart of an example 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 84 (including the WUR configuration unit 34), processor 86, radio interface 82 and/or communication interface 60. Wireless device 22 such as via processing circuitry 84 and/or processor 86 and/or radio interface 82 is configured to configure an operational mode of a wakeup receiver, WUR, based at least in part on at least one of coverage conditions, a battery power level, and a target latency of communications with the network node, an operational mode of the WUR including at least one of a first operational mode in which the WUR continuously monitors the WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled (Block S138).

In some embodiments, the method also includes switching the WUR 96 between operational modes when a function of at least one of the coverage conditions, the power level and the target latency crosses a threshold. In some embodiments, the method also includes switching the WUR 96 between operational modes when each of a plurality of functions cross a respective threshold, each one of the plurality of functions being a function of at least one of the coverage conditions, the power level and the target latency. In some embodiments, the method also includes configuring a default operational mode to separate two operational modes. In some embodiments, the method also includes switching the WUR 96 between operational modes based at least in part on a target average power consumption. In some embodiments, configuring an operational mode of the WUR 96 includes setting at least one of a duration of the operational mode, a sequence of operational modes, and a default operational mode. In some embodiments, the operational mode is determined based at least in part on information received from the network node. In some embodiments, the operational mode is determined based at least in part on measurements of at least one of a reference signal received power, RSRP, a reference signal received quality, RSRQ, a signal to noise ratio, SNR, and a signal to interference plus noise ratio, SINR. In some embodiments, the method also includes configuring the WD to operate in at least one of a particular operational mode and a succession of particular operational modes based at least in part on a set of joint metrics that include at least two of coverage, energy and latency.

FIG. 12 is a flowchart of an example process in a network node 16 for methods for efficient wakeup radio operation. One or more blocks described herein may be performed by one or more elements of network node 16 such as by one or more of processing circuitry 68 (including a WUS configuration unit 32), processor 70, radio interface 62 and/or communication interface 60. Network node 16 such as via processing circuitry 68 and/or processor 70 and/or radio interface 62 and/or communication interface 60 is configured to configure a wakeup signal, WUS, according to one of at least two operational modes of a wakeup receiver, WUR, of the WD, the at least two operational modes of the WUR including at least two of a first operational mode in which the WUR continuously monitors the WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled (Block SI 40). The method also includes transmitting the WUS to the WD (Block S142).

In some embodiments, transmitting the WUS includes transmitting the WUS at a power level that is based at least in part on a current operational mode of the WUR. In some embodiments, configuring the WUS includes configuring the WUS to have a duty cycle in the second operational mode that is based at least in part on a discontinuous reception, DRX cycle. In some embodiments, the duty cycle is further based at least in part on a target latency of communications with the WD, In some embodiments, configuring the WUS is based at least in part on an indication of coverage conditions at the WD. In some embodiments, the method includes configuring the WD to operate in a succession of operational modes of the at least two operational modes based at least in part on a set of joint metrics that include at least two of coverage conditions, battery power level and target latency. In some embodiments, the method includes indicating at least one threshold for determining an operational mode in one of a system information block and a DownlinkConfigCommon information element.

FIG. 13 is a flowchart of an example 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 84 (including the WUR configuration unit 34), processor 86, radio interface 82 and/or communication interface 60. Wireless device 22 such as via processing circuitry 84 and/or processor 86 and/or radio interface 82 is configured to configure a wakeup receiver, WUR, to operate in one of at least two operational modes based at least in part on at least one of coverage conditions, a battery power level, and a target latency of communications with the network node, the at least two operational modes of the WUR including at least two of a first operational mode in which the WUR continuously monitors a wakeup signal, WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled (Block S144). The method includes operating the WUR in the configured operational mode (Block SI 46).

In some embodiments, the method includes switching the WUR between operational modes of the at least two operational modes when a function of at least one of the coverage conditions, the battery power level and the target latency crosses a threshold. In some embodiments, the method includes switching the WUR between operational modes of the at least two operational modes when each of a plurality of functions cross a respective threshold, each one of the plurality of functions being a function of at least one of the coverage conditions, the battery power level and the target latency. In some embodiments, a respective threshold is received from the network node in one of a system information block and a DownlinkConfigCommon information element. In some embodiments, the method includes switching from a first operational mode of the at least two operational modes to a default operational mode of the at least two operational modes followed by switching to one of the first operational mode and a second operational mode of the at least two operational modes. In some embodiments, the method includes switching the WUR between operational modes of the at least two operational modes based at least in part on a target average power consumption. In some embodiments, configuring the operational mode of the WUR includes setting at least one of a duration of the operational mode, a sequence of operational modes, and a default operational mode of the at least two operational modes. In some embodiments, the operational mode of the at least two operational modes is determined based at least in part on information received from the network node. In some embodiments, the operational mode of the at least two operational modes is determined based at least in part on measurements of at least one of a reference signal received power, RSRP, a reference signal received quality, RSRQ, a signal to noise ratio, SNR, and a signal to interference plus noise ratio, SINR. In some embodiments, the method includes configuring the WD to operate in a succession of operational modes of the at least two operational modes based at least in part on a set of joint metrics that include at least two of coverage conditions, battery power level and target latency.

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 efficient wakeup radio operation.

In some scenarios, a dedicated wake up radio (WUR 96) is used for monitoring a wake-up signal (WUS). Once the WUR 96 detects the intended WUS, the WUR 96 wakes up the main receiver (which has power-consuming baseband processing and RF processing, resulting in lower power efficiency) to detect further incoming messages. Such a configuration is shown in FIG. 14. Therefore, the main receiver may go to sleep mode and save power until it is triggered by the WUR 96.

Given the sensitivity and power consumption tradeoff in designing the WUS and/or the WUR 96, the coverage of the WUR 96 may not be the same as that of the main radio/receiver. In particular, high sensitivity receivers may typically be needed to reach users located at the cell edge of macro cells or in poor coverage conditions.

In some embodiments, the WUR operational mode is determined based on one or more of WD coverage conditions, a latency target, the WUR sensitivity, and the WUR power consumption. For example, the WD 22 may determine its coverage conditions based on various measurements and explicit/implicit information. The WUR 96 may operate in different operational modes according to the coverage conditions in order to ensure that the WD 22 reachable in various coverage conditions. Specifically, three general operational modes may be considered for a WUR 96, as illustrated in FIG. 15:

1) Always-on WUR: in this case the WUR 96 is continuously on for monitoring a WUS. With such operation, the WUR power consumption must be extremely low which results in a reduced sensitivity;

2) Multi duty-cycled WUR operations each with specific parameters (e.g., A, B): in this case the WUR 96 periodically monitors the WUS and may go to sleep mode during inactive times to save energy. Therefore, given a fixed average power, the active power may be higher compared to the always-on operation. With this operation, the WUR 96 may have a better sensitivity at the cost of additional latency. Moreover, sensitivity may be improved by allowing the WUR 96 to enable and use more advanced features, processing capabilities, and coverage enhancement techniques. Alternatively, for a given sensitivity, the average power consumption of the WUR 96 may be reduced by duty-cycled WUR operation. Note that, there may be multiple duty-cycled WUR operational modes each with specific parameters (e.g., DRX cycle); and/or

3) Disabled WUR corresponding to fallback operation: in this case, the WUR 96 is disabled, and the main radio monitors all downlink transmissions according to legacy operation.

Considering the potential coverage mismatch between the WUR 96 and the main radio, different latency requirements, and battery power levels of the WUR 96 and the main radio, some embodiments adopt the WUR operational mode and switching mechanism likely to ensure that the WD coverage and latency requirements are met while having the benefit of power savings by employing a WUR 96.

In general, the number of different WUR operational modes does not need to be limited to three (as discussed above), and various operational modes may be defined. For example:

• Two operational modes: always-on WUR and disabled WUR; and/or

• N operational modes: always on WUR, (N-2) different WUR configurations (e.g., WUR with different duty cycles), and disable WUR. Accordingly, a desired WUR operational mode among the existing modes is determined based on conditions such as coverage, power consumption, and latency. See FIG. 16, which shows an example of switching between different WUR operational modes.

Coverage-based operation

The WUR operational mode is determined based on various signal measurements such as RSRP, RSRQ, RSSI, SNR, and SINR. Depending on the considered metric, WUR operation changes based on the certain thresholds.

In one embodiment, the rule for WUR operational modes is based on multiple metrics (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), reference signal strength indicator (RSSI), signal to noise ratio (SNR), and signal to interference plus noise ratio (SINR)), multiple thresholds, or a single threshold capturing the impact of multiple metrics. For example, a multivariate function (e.g., Function) may be used as a decision metric:

• Function (RSRP, RSRQ, SNR, SINR) > T1 : use always-on WUR;

• T2 < Function (RSRP, RSRQ, SNR, SINR) < T1 : use duty-cycled WUR with parameters A;

• T3 < Function (RSRP, RSRQ, SNR, SINR) < T2: use duty-cycled WUR with parameters B; and/or

• Function (RSRP, RSRQ, SNR, SINR) < T3 : use disabled WUR; where the above Function may be linear or non-linear. Also, Tl, T2, and T3 are specific thresholds which may be functions of WUR sensitivity and the main radio sensitivity.

In some embodiments, the WUR operational mode is based on the deployment scenario (e.g., indoor, urban, etc.), location of the WD 22, or distance from the base station. In some embodiments, the WUR operational mode is determined based on the mobility pattern and speed of the WD 22. For example, as the WD 22 moves towards the cell edge, the operational mode may be switched from always-on to disabled. This may be done at pre-determined time instances.

Energy-based operation

Another factor that may be considered is WUR power consumption and battery power level. In some embodiments, the WUR operational mode changes based on the WUR battery power level. For example, the WUR 96 may be disabled once the battery power level falls below a certain threshold.

In some embodiments, the parameters of duty-cycled operation are determined based on the WUR battery power level. For example, K different duty cycle parameters may be considered for WUR operation and the switching between different operational modes may be based on the battery power level. The switching may or may not be dependent on the other metrics such as coverage conditions. For example, in good coverage conditions, the WUR 96 may be always on while meeting the required sensitivity. However, for the purpose of saving power, the WUR 96 may switch to different duty-cycled operations (without increasing sensitivity). For example, a case with two different WUR DRX operations is:

• WUR battery power level > LI: use always-on WUR;

• L2 < WUR battery power level <L1 : use duty-cycled WUR with parameters A (e.g., short DRX cycle);

• L3 < WUR battery power level <L2: use duty-cycled WUR with parameters B (e.g., long DRX cycle); and/or

• Battery-level < L3: use disabled WUR;

In some embodiments, the WUR operational mode changes considering both coverage conditions and WUR battery level jointly. For example:

• {RSRP > LI & WUR battery level>Ql } : use enabled WUR (e.g., always-on WUR); and/or

• Otherwise: use disabled WUR; where LI and QI are the thresholds. Note that the WUR operation may also depend on the battery power level of the main radio. For instance, the WUR 96 does not need to be frequently used when the main radio has a sufficient battery. In this way, the WUR 96 may save energy and use it when the main radio needs power saving.

In some embodiments, the WUR operational mode is determined based on both the WUR battery power level and the main radio battery power level. For example:

• Main radio battery level > R1 : use disabled WUR;

• {Main radio battery level < R1 & WUR battery level > QI } : use enabled WUR (always on); and/or

• {Main radio battery level < R1 & Q2 < WUR battery level < QI } : use enabled WUR (duty cycled);

Latency-based operation

The WUR operational mode may also be based on latency requirements. For low latency targets, the WUR operation may be always-on or duty-cycled with short duty cycle. For relaxed latency targets, the WUR 96 may operate with a longer duty cycle to minimize the WUR average power consumption.

Latency requirements may depend on various factors such as the use case, deployment scenario, frequency of operation, and OFDM subcarrier spacing. For example, a higher subcarrier spacing and operation in higher frequencies may imply lower latency targets.

In some embodiments, the WUR operational mode may be adjusted based on the explicit latency targets and/or information about subcarrier spacing, frequency range, deployment scenario, and cell size.

Joint coverage/energy /latency-based operation

In a general case, an optimal WUR operation may be determined based on coverage, latency, and battery power level. In this case, a single multivariate function or multiple functions may be defined to capture different metrics. Any combinations of two or three different aforementioned metrics may be considered for a multivariate function or multiple functions,, such as: {coverage and energy}, {coverage and latency}, {latency and energy}, {coverage, energy, and latency}. As a non-limiting example:

• Function (coverage, latency, battery level) > QI: use always-on WUR; • Q2 < Function (coverage, latency, battery level) < QI : use duty-cycled WUR with parameter^;

• Q3 < Function (coverage, latency, battery level) < Q2: use duty-cycled WUR with parameter!?; and/or

• Function (coverage, latency, battery level) < Q3: use disabled WUR; where the above Function may be linear or non-linear, and Q1-Q3 are specified thresholds. Note that other metrics such as data rates, traffic load, and number of WDs in the cell may also be employed to determine a WUS and/or a mode of WUR operation.

Switching mechanism for WUR operation

In some embodiments, operational mode switching is done based on the criteria and various conditions described above. For examplejoint coverage/latency /battery power level metrics for the WUR 96 and main radio may be considered. Moreover, switching gaps may be considered to accommodate WUR operational mode switching. For example, a time gap T may be considered between two operational modes and during this time a default operation may be adopted (e.g., disabled WUR).

In some embodiments, the WUR 96 periodically switches between different operational modes to adjust the average power consumption and maintain a minimum energy level. In this case, a configuration may include: 1) duration in each operational mode, 2) sequence of operational modes (e.g., for each mode, an identity of subsequent modes to which the WUR 96 may switch), and 3) a default operational mode which may be based on scenario and requirements (e.g., the WUR 96 may automatically move to default operational mode under certain conditions).

In some embodiments, the switching occurs is event-triggered. This may be based on sudden changes in the channel conditions, any failure in the WUR/main radio operation such as battery power depletion, or any emergency requirements (e.g., latency) in a specific scenario.

In some embodiments, one or more of the above-mentioned thresholds may be indicated through cell-specific or WD-specific signaling. Based on the cell-specific or WD-specific signaling, the WD 22 may configure its WUR operational mode according to its WUR sensitivity level as well as according to measurements of RSRP, RSRQ, SNR, SINR, and/or batery power level. The cell-specific signaling may carry an information element in a system information block or in DownlinkConfigCommon .

In some embodiments, the network configures the WUS operational mode for the WD 22 based on radio resource management (RRM) measurements and/or information about battery power status and/or WUR sensitivity level provided by the WD 22. The configuration of the WD WUS operational mode may be provided through WD-specific radio resource control (RRC) signaling.

Some embodiments may include one or more of the following:

Embodiment Al. A network node configured to communicate with a wireless device (WD), the network node configured to, and/or comprising a radio interface and/or comprising processing circuitry configured to: configure a wakeup signal, WUS, according to an operational mode of a wakeup receiver WUR of the WD, an operational mode of the WUR including at least one of a first operational mode in which the WUR continuously monitors the WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled; and transmit the WUS to the WD.

Embodiment A2. The network node of Embodiment Al , wherein transmiting the WUS includes transmiting the WUS at a power level that is based at least in part on a current operational mode of the WUR.

Embodiment A3. The network node of any of Embodiments Al and A2, wherein configuring the WUS includes configuring the WUS to have a duty cycle in the second operational mode that is based at least in part on a discontinuous reception, DRX, cycle.

Embodiment A4. The network node of Embodiment A3, wherein the duty cycle is further based at least in part on a target latency of communications with the WD.

Embodiment A5. The network node of any of Embodiments A1-A4, wherein a configuration of the WUS is based at least in part on an indication of coverage conditions at the WD.

Embodiment A6. The network node of any of Embodiments A1-A5, wherein the network node, radio interface and/or processing circuitry are further configured to configure the WD to operate in at least one of a particular operational mode and a succession of particular operational modes, based at least in part on a set of joint metrics that include at least two of coverage, energy and latency. .

Embodiment Bl. A method implemented in a network node, the method comprising: configuring a wakeup signal, WUS, according to an operational mode of a wakeup receiver WUR of the WD, an operational mode of the WUR including at least one of a first operational mode in which the WUR continuously monitors the WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled; and transmitting the WUS to the WD.

Embodiment B2. The method of Embodiment B 1 , wherein transmitting the WUS includes transmitting the WUS at a power level that is based at least in part on a current operational mode of the WUR.

Embodiment B3. The method of any of Embodiments Bl and B2, wherein configuring the WUS includes configuring the WUS to have a duty cycle in the second operational mode that is based at least in part on a discontinuous reception, DRX cycle.

Embodiment B4. The method of Embodiment B3, wherein the duty cycle is further based at least in part on a target latency of communications with the WD,

Embodiment B5. The method of any of Embodiments B1-B4, wherein a configuration of the WUS is based at least in part on an indication of coverage conditions at the WD.

Embodiment B6. The method of any of Embodiments B1-B5, further comprising configuring the WD to operate in at least one of a particular operational mode and a succession of particular operational modes based at least in part on a set of joint metrics that include at least two of coverage, energy and latency.

Embodiment Cl. A wireless device (WD) configured to communicate with a network node, the WD configured to, and/or comprising a radio interface and/or processing circuitry configured to: configure an operational mode of a wakeup receiver, WUR, based at least in part on at least one of coverage conditions, a battery power level, and a target latency of communications with the network node, an operational mode of the WUR including at least one of a first operational mode in which the WUR continuously monitors the WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled.

Embodiment C2. The WD of Embodiment Cl, wherein the WD, radio interface and/or processing circuitry are further configured to switch the WUR between operational modes when a function of at least one of the coverage conditions, the power level and the target latency crosses a threshold.

Embodiment C3. The WD of Embodiment C2, wherein the WD, radio interface and/or processing circuitry are further configured to switch the WUR between operational modes when each of a plurality of functions cross a respective threshold, each one of the plurality of functions being a function of at least one of the coverage conditions, the power level and the target latency.

Embodiment C4. The WD of any of Embodiments C1-C3, wherein the WD, radio interface and/or processing circuitry are further configured to configure a default operational mode to separate two operational modes.

Embodiment C5. The WD of any of Embodiments C1-C4, wherein the WD, radio interface and/or processing circuitry are further configured to switch the WUR between operational modes based at least in part on a target average power consumption.

Embodiment C6. The WD of any of Embodiments C1-C5, wherein configuring an operational mode of the WUR includes setting at least one of a duration of the operational mode, a sequence of operational modes, and a default operational mode.

Embodiment C7. The WD of any of Embodiments C1-C6, wherein the operational mode is determined based at least in part on information received from the network node.

Embodiment C8. The WD of any of Embodiments C1-C7, wherein the operational mode is determined based at least in part on measurements of at least one of a reference signal received power, RSRP, a reference signal received quality, RSRQ, a signal to noise ratio, SNR, and a signal to interference plus noise ratio, SINR.

Embodiment C9. The WD of any of Embodiments C1-C8, wherein the WD, radio interface and/or processing circuitry are further configured to configure the WD to operate in at least one of a particular operational mode and a succession of particular operational modes based at least in part on a set of joint metrics that include at least two of coverage, energy and latency.

Embodiment DI . A method implemented in a wireless device, WD, configured to communicate with a network node, the method comprising: configuring an operational mode of a wakeup receiver, WUR, based at least in part on at least one of coverage conditions, a battery power level, and a target latency of communications with the network node, an operational mode of the WUR including at least one of a first operational mode in which the WUR continuously monitors the WUS, a second operational mode in which the WUR periodically wakes up to monitor the WUS and a third operational mode in which the WUR is disabled.

Embodiment D2. The method of Embodiment DI, further comprising switching the WUR between operational modes when a function of at least one of the coverage conditions, the power level and the target latency crosses a threshold.

Embodiment D3. The method of any of Embodiments DI and D2, further comprising switching the WUR between operational modes when each of a plurality of functions cross a respective threshold, each one of the plurality of functions being a function of at least one of the coverage conditions, the power level and the target latency.

Embodiment D4. The method of any of Embodiments D1-D3, further comprising configuring a default operational mode to separate two operational modes.

Embodiment D5. The method of any of Embodiments D1-D4, further comprising switching the WUR between operational modes based at least in part on a target average power consumption.

Embodiment D6. The method of any of Embodiments D1-D5, wherein configuring an operational mode of the WUR includes setting at least one of a duration of the operational mode, a sequence of operational modes, and a default operational mode.

Embodiment D7. The method of any of Embodiments D1-D6, wherein the operational mode is determined based at least in part on information received from the network node.

Embodiment D8. The method of any of Embodiments D1-D7, wherein the operational mode is determined based at least in part on measurements of at least one of a reference signal received power, RSRP, a reference signal received quality, RSRQ, a signal to noise ratio, SNR, and a signal to interference plus noise ratio, SINR.

Embodiment D9. The method of any of Embodiments D1-D8, further comprising configuring the WD to operate in at least one of a particular operational mode and a succession of particular operational modes based at least in part on a set of joint metrics that include at least two of coverage, energy and latency.

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 may 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, may 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 may 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 Python, 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's computer, partly on the user's computer, as a stand-alone software package, partly on the user'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'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 may 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.

Abbreviations that may be used in the preceding description include:

Abbreviation Explanation

ADC Analog to Digital Convertor

DRX Discontinuous Reception

LNA Low-noise Amplifier

MIB Master Information Block

OOK On-Off Keying

PBCH Physical Broadcast Channel

PSS Primary Synchronization Signal

PLL Phase Locked Loop

RSRP Reference Signal Received Power

RSRQ Reference Signal Received Quality

SSB Synchronization Signal Block

SSS Secondary Synchronization Signal

SINR Signal to noise plus interference

WUR Wake-Up Radio

WUS Wake-Up Signal

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.

Claims

What is claimed is:

1. A network node (16) configured to communicate with a wireless device, WD 22, the network node (16) comprising: processing circuitry (68) configured to configure a wakeup signal, WUS, according to one of at least two operational modes of a wakeup receiver, WUR (96), of the WD (22), the at least two operational modes of the WUR (96) including at least two of a first operational mode in which the WUR (96) continuously monitors the WUS, a second operational mode in which the WUR (96) periodically wakes up to monitor the WUS and a third operational mode in which the WUR (96) is disabled; and a radio interface (62) in communication with the processing circuitry (68) and configured to transmit the WUS to the WD (22).

2. The network node (16) of Claim 1, wherein transmitting the WUS includes transmitting the WUS at a power level that is based at least in part on a current operational mode of the WUR (96).

3. The network node (16) of any of Claims 1 and 2, wherein configuring the WUS includes configuring the WUS to have a duty cycle in the second operational mode that is based at least in part on a discontinuous reception, DRX, cycle.

4. The network node (16) of Claim 3, wherein the duty cycle is further based at least in part on a target latency of communications with the WD (22).

5. The network node (16) of any of Claims 1-4, wherein configuring the WUS is based at least in part on an indication of coverage conditions at the WD (22).

6. The network node (16) of any of Claims 1-5, wherein the processing circuitry (68) is further configured to configure the WD (22) to operate in a succession of operational modes of the at least two operational modes based at least in part on a set of joint metrics that include at least two of coverage conditions, battery power level and target latency.

7. The network node (16) of any of Claims 1-6, wherein the radio interface (62) is further configured to indicate at least one threshold for determining an operational mode in one of a system information block and a DownlinkConfigCommon information element.

8. A method implemented in a network node (16) configured to communicate with a wireless device, WD (22), the method comprising: configuring (S140) a wakeup signal, WUS, according to one of at least two operational modes of a wakeup receiver, WUR (96), of the WD (22), the at least two operational modes of the WUR (96) including at least two of a first operational mode in which the WUR (96) continuously monitors the WUS, a second operational mode in which the WUR (96) periodically wakes up to monitor the WUS and a third operational mode in which the WUR (96) is disabled; and transmitting (S142) the WUS to the WD (22).

9. The method of Claim 8, wherein transmitting the WUS includes transmitting the WUS at a power level that is based at least in part on a current operational mode of the WUR (96).

10. The method of any of Claims 8 and 9, wherein configuring the WUS includes configuring the WUS to have a duty cycle in the second operational mode that is based at least in part on a discontinuous reception, DRX cycle.

11. The method of Claim 10, wherein the duty cycle is further based at least in part on a target latency of communications with the WD (22).

12. The method of any of Claims 8-11, wherein configuring the WUS is based at least in part on an indication of coverage conditions at the WD (22).

13. The method of any of Claims 8-12, further comprising configuring the WD (22) to operate in a succession of operational modes of the at least two operational modes based at least in part on a set of joint metrics that include at least two of coverage conditions, battery power level and target latency.

14. The method of any of Claims 8-13, further comprising indicating at least one threshold for determining an operational mode in one of a system information block and a DownlinkConfigCommon information element.

15. A wireless device, WD (22), configured to communicate with a network node (16), the WD (22) comprising: processing circuitry (84) configured to configure a wakeup receiver, WUR (96) (96), of the WD (22) to operate in one of at least two operational modes based at least in part on at least one of coverage conditions, a battery power level, and a target latency of communications with the network node (16), the at least two operational modes of the WUR (96) including at least two of a first operational mode in which the WUR (96) continuously monitors a wakeup signal, WUS, a second operational mode in which the WUR (96) periodically wakes up to monitor the WUS and a third operational mode in which the WUR (96) is disabled; and the WUR (96) being in communication with the processing circuitry (84) and configured to operate in the configured operational mode.

16. The WD (22) of Claim 15, wherein the processing circuitry (84) is further configured to switch the WUR (96) between operational modes of the at least two operational modes when a function of at least one of the coverage conditions, the battery power level and the target latency crosses a threshold.

17. The WD (22) of Claim 15, wherein the processing circuitry (84) is further configured to switch the WUR (96) between operational modes of the at least two operational modes when each of a plurality of functions cross a respective threshold, each one of the plurality of functions being a function of at least one of the coverage conditions, the battery power level and the target latency.

18. The WD of any of Claims 15-17, wherein a respective threshold is received from the network node in one of a system information block and a DownlinkConfigCommon information element.

19. The WD (22) of any of Claims 15-18, wherein the processing circuitry (84) is further configured to switch from a first operational mode of the at least two operational modes to a default operational mode of the at least two operational modes followed by switching to one of the first operational mode and a second operational mode of the at least two operational modes.

20. The WD (22) of any of Claims 15-19, wherein the processing circuitry (84) is further configured to switch the WUR (96) between operational modes of the at least two operational modes based at least in part on a target average power consumption.

21. The WD (22) of any of Claims 15-20, wherein configuring the operational mode of the WUR (96) includes setting at least one of a duration of the operational mode, a sequence of operational modes, and a default operational mode of the at least two operational modes.

22. The WD (22) of any of Claims 15-21, wherein the operational mode of the at least two operational modes is determined based at least in part on information received from the network node (16).

23. The WD (22) of any of Claims 15-22, wherein the operational mode of the at least two operational modes is determined based at least in part on measurements of at least one of a reference signal received power, RSRP, a reference signal received quality, RSRQ, a signal to noise ratio, SNR, and a signal to interference plus noise ratio, SINR.

24. The WD (22) of any of Claims 15-23, wherein the processing circuitry (84) is further configured to configure the WD (22) to operate in a succession of operational modes of the at least two operational modes based at least in part on a set of joint metrics that include at least two of coverage conditions, battery power level and target latency.

25. A method implemented in a wireless device, WD (22), configured to communicate with a network node (16), the method comprising: configuring (S144) a wakeup receiver, WUR (96), to operate in one of at least two operational modes based at least in part on at least one of coverage conditions, a battery power level, and a target latency of communications with the network node (16), the at least two operational modes of the WUR (96) including at least two of a first operational mode in which the WUR (96) continuously monitors a wakeup signal, WUS, a second operational mode in which the WUR (96) periodically wakes up to monitor the WUS and a third operational mode in which the WUR (96) is disabled; and operating (S146) the WUR (96) in the configured operational mode.

26. The method of Claim 25, further comprising switching the WUR (96) between operational modes of the at least two operational modes when a function of at least one of the coverage conditions, the battery power level and the target latency crosses a threshold.

27. The method of Claim 25, further comprising switching the WUR (96) between operational modes of the at least two operational modes when each of a plurality of functions cross a respective threshold, each one of the plurality of functions being a function of at least one of the coverage conditions, the battery power level and the target latency.

28. The WD of any of Claims 25-27, wherein a respective threshold is received from the network node in one of a system information block and a DownlinkConfigCommon information element.

29. The method of any of Claims 25=28, further comprising switching from a first operational mode of the at least two operational modes to a default operational mode of the at least two operational modes followed by switching to one of the first operational mode and a second operational mode of the at least two operational modes.

30. The method of any of Claims 25-28, further comprising switching the WUR (96) between operational modes of the at least two operational modes based at least in part on a target average power consumption.

31. The method of any of Claims 25-30, wherein configuring the operational mode of the WUR (96) includes setting at least one of a duration of the operational mode, a sequence of operational modes, and a default operational mode of the at least two operational modes.

32. The method of any of Claims 25-31, wherein the operational mode of the at least two operational modes is determined based at least in part on information received from the network node (16).

33. The method of any of Claims 25-32, wherein the operational mode of the at least two operational modes is determined based at least in part on measurements of at least one of a reference signal received power, RSRP, a reference signal received quality, RSRQ, a signal to noise ratio, SNR, and a signal to interference plus noise ratio, SINR.

34. The method of any of Claims 25-33, further comprising configuring the WD to operate in a succession of operational modes of the at least two operational modes based at least in part on a set of joint metrics that include at least two of coverage conditions, battery power level and target latency.