Technical Field

The disclosure relates to a client device for operation of an inactivity timer associated with a bandwidth part. Furthermore, the disclosure relates to corresponding methods and a computer program.

Background

The cell bandwidth in 5G new radio (NR) is expected to be large compared to the cell bandwidth in long term evolution (LTE). A receive and transmit bandwidth of a user equipment (UE) is not necessarily required to be same as the cell bandwidth. As per 3GPP specification 38.300, the receive and transmit bandwidth of the UE can be adjusted to a subset, or a part of the total cell bandwidth which is referred to as a bandwidth part (BWP). The BWP can be adapted to different use cases such that e.g. the BWP can be decreased during a period of low activity to save power, etc. The bandwidth adaption can be achieved by pre-configuring the UE with a set of BWPs, and by using a second mechanism the network can instruct the UE which of the pre-configured BWPs is currently the active BWP to be used by the UE. There are three allocation types of BWP available in NR, namely:

. Initial BWP,

• Active BWP (UE specific), and

. Default BWP (UE specific).

The initial BWP is used to perform Initial Access Process. A UE configured for operation in BWPs of a serving cell, is configured by higher layers for the serving cell a set of at most four BWPs for receptions by the UE (i.e. the downlink BWP set) in a downlink (DL) bandwidth by the parameter BWP-Downlink and a set of at most four BWPs for transmissions by the UE (i.e. the uplink BWP set) in an uplink (UL) bandwidth by the parameter BWP-Uplink. If a UE is not provided initialDownlinkBWP, an initial active DL BWP is defined by a location and number of contiguous physical resource blocks (PRBs), starting from a PRB with the lowest index and ending at a PRB with the highest index among PRBs of a control resource set (CORESET) for TypeO-PDCCH common search space (CSS) set, and a subcarrier spacing (SCS) and a cyclic prefix for PDCCH reception in the CORESET for TypeO-PDCCH CSS set; otherwise, the initial active DL BWP is provided by initialDownlinkBWP. For operation on a primary cell or on a secondary cell, a UE is provided an initial active UL BWP by initialuplinkBWP. If the UE is configured with a supplementary UL carrier, the UE can be provided an initial active UL BWP on the supplementary UL carrier by initialUplinkBWP in supplementaryUplink. If a UE has dedicated BWP configuration, the UE can be provided by firstActiveDownlinkBWP-ld a first active DL BWP for reception and by firstActiveUplinkBWP-ld a first active UL BWP for transmissions on a carrier of the primary cell.

The active BWP is UE specific and can be used to perform initial access process, such as a random access procedure. It is the first BWP where UE starts data transfer after a radio resource control (RRC) configuration and reconfiguration. The very first active BWP should be different from the default BWP.

The default BWP is also UE specific and is configured by RRC signaling from the network. If the UE is not configured with a default BWP it can be assumed that the initial BWP is the default BWP. A UE shall switch back to the default BWP when a BWP inactivity timer expires.

The traffic patterns within one active data session can change frequently as the data rate may increase or decrease based on the type of service and the user behavior, e.g. accessing the internet or answering a phone call. It becomes very important to quickly switch between different BWPs to manage different power consumptions for different data rates.

According to TS 38.321 , BWP selection and switching can be done through different methods as listed:

• RRC based adaptation which is more suitable for semi-static cases since the RRC signaling requires extra time, letting the latency reach ~10 msec. Due to longer switching latency and signaling overhead, a RRC-based method can be used for configuring a BWP set for slow adaptation type services (e.g., voice) where the resource allocation is not changing rapidly within the same data session;

• Medium access control (MAC) control element (CE) which is used upon initiation of a random access procedure;

• Downlink control information (DCI) based adaptation which is based on physical downlink control channel (PDCCH) where a specific BWP can be activated by BWP indicator in DCI Format 0_1 (UL Grant) and Format 1-1 (DL scheduling). This method better fits on- the fly BWP switching the latency is very low with this method. However, this method requires additional considerations for error handling as a UE may fail to decode the DCI with BWP activation/deactivation command; and

• Timer based implicit fallback to default BWP which is a method designed to mitigate possible DCI errors. If the UE is not explicitly scheduled with a BWP after the timer expires the UE will automatically switch to the default BWP. Summary

An objective of embodiments of the invention is to provide a solution which mitigates or solves the drawbacks and problems of conventional solutions.

The above and further objectives are solved by the subject matter of the independent claims. Further advantageous embodiments of the invention can be found in the dependent claims.

According to a first aspect of the invention, the above mentioned and other objectives are achieved with a client device for a communication system, the client device being configured to operate in a connected mode discontinuous reception, C-DRX; and further being configured to obtain one or more C-DRX configuration parameters;determine whether the client device is configured to operate with a short DRX cycle or a long DRX cycle based on the obtained one or more C-DRX configuration parameters; and adapt operation of an inactivity timer associated with a bandwidth part, BWP, in C-DRX depending on whether the client device is determined to be configured to operate with the short DRX cycle or the long DRX cycle.

To adapt operation of an inactivity timer may mean that the inactivity timer is somehow manipulated, e.g. by suspending, stopping, and resuming said inactivity timer. This can also imply that the value of the inactivity timer will change due to the mentioned manipulation.

An advantage of the client device according to the first aspect is that it can provide improved performance in respect of lower data latency and reduced power consumption when the client device is in C-DRX.

In an implementation form of a client device according to the first aspect, the client device is determined to be configured to operate with the long DRX cycle, and further configured to stop the inactivity timer or set a value of the inactivity timer to zero when a DRX off duration starts.

In this implementation form the inactivity timer may be considered as expired.

In an implementation form of a client device according to the first aspect, the client device is further configured to operate in an initial BWP or in a default BWP in C-DRX when a DRX on duration starts.

An advantage with this implementation form is improved power saving in the client device by using an initial or a default BWP that could be a narrow BWP during a long DRX cycle in which data rarely may be transmitted. In an implementation form of a client device according to the first aspect, the client device is determined to be configured to operate with the short DRX cycle, and further configured to suspend the inactivity timer when a DRX off duration starts; and resume the inactivity timer when a DRX on duration starts.

In an implementation form of a client device according to the first aspect, the client device is further configured to operate in a previous active BWP in C-DRX when the DRX on duration starts.

An advantage with this implementation form is reduced data latency by operating in the previous active BWP that could be a wide BWP during a short DRX cycle in which a large amount of data may be transmitted.

In an implementation form of a client device according to the first aspect, the client device is further configured to stop the inactivity timer or set a value of the inactivity timer to zero upon switching from the short DRX cycle to a long DRX cycle.

In this implementation form the inactivity timer may be considered as expired.

In an implementation form of a client device according to the first aspect, the client device is further configured to operate in a default BWP in C-DRX when a DRX on duration starts.

An advantage with this implementation form is improved power saving in the client device by switching to a default BWP that could be a narrow BWP during a long DRX cycle in which data rarely may be transmitted.

In an implementation form of a client device according to the first aspect, the inactivity timer is bwp-lnactivityTimer.

In an implementation form of a client device according to the first aspect, obtain the one or more C-DRX configuration parameters comprises receive the C-DRX configuration parameters from a network access node (300) of the communication system.

In an implementation form of a client device according to the first aspect, the one or more C- DRX configuration parameters comprises any of: DRX Cycle, onDurationTimer, drx-lnactivity timer, drx-Retransmission timer, shortDRX-Cycle, or drxShortCycleTimer. According to a second aspect of the invention, the above mentioned and other objectives are achieved with a method for a client device configured to operate in a C-DRX; the method comprises obtaining one or more C-DRX configuration parameters; determining whether the client device is configured to operate with a short DRX cycle or a long DRX cycle based on the obtained one or more C-DRX configuration parameters; and adapting operation of an inactivity timer associated with a BWP in C-DRX depending on whether the client device is determined to be configured to operate with the short DRX cycle or the long DRX cycle.

The method according to the second aspect can be extended into implementation forms corresponding to the implementation forms of the client device according to the first aspect. Hence, an implementation form of the method comprises the feature(s) of the corresponding implementation form of the client device.

The advantages of the methods according to the second aspect are the same as those for the corresponding implementation forms of the client device according to the first aspect.

The invention also relates to a computer program, characterized in program code, which when run by at least one processor causes said at least one processor to execute any method according to embodiments of the invention. Further, the invention also relates to a computer program product comprising a computer readable medium and said mentioned computer program, wherein said computer program is included in the computer readable medium, and comprises of one or more from the group: ROM (Read-Only Memory), PROM (Programmable ROM), EPROM (Erasable PROM), Flash memory, EEPROM (Electrically EPROM) and hard disk drive.

Further applications and advantages of the embodiments of the invention will be apparent from the following detailed description.

Brief Description of the Drawings

The appended drawings are intended to clarify and explain different embodiments of the invention, in which:

- Fig. 1 shows a client device according to an embodiment of the invention;

- Fig. 2 shows a method for a client device according to an embodiment of the invention;

- Fig. 3 illustrates a communication system according to an embodiment of the invention;

- Fig. 4 shows a timing diagram of an embodiment of the invention;

- Fig. 5 shows a timing diagram of an embodiment of the invention; and Fig. 6 shows a timing diagram of an embodiment of the invention.

Detailed Description

Furthermore, in order to save energy in a UE a discontinuous reception (DRX) mechanism was introduced in LTE and NR. In DRX mode the UE may go into sleep mode for a certain period of time and wake up for another period of time. In normal operation, i.e. not in the DRX mode, the UE has to be awake all the time to monitor a control channel for every subframe meaning that the UE has to be awake all the time since the UE will not know exactly when the network will transmit data. However, if the UE is always awake even when there is no data being transmitted to the UE the power consumption in the UE will be an issue.

It has been realized by the inventors that there is a tradeoff between UE power saving and data latency and/or throughput when the UE operates in connected mode DRX (C-DRX) together with BWP operation. A UE in C-DRX mode operating with a wide BWP consumes more power during C-DRX mode compared to a UE operating in C-DRX mode with a narrow BWP. However, operating in wide BWP can have better performance in respect of data latency and/or throughput due to its wide operating bandwidth.

Furthermore, in C-DRX switching to a default BWP based on a related timer should not be affected by DRX off duration for which the UE may not monitor the PDCCH. This requirement can make the related cell specific timer, i.e. the bwp-lnactivityTimer in NR, be set to the appropriate values for all the UEs in RRC_CONNECTED regardless of their mode. That is, whether or not they are in C-DRX. Another insight of the inventors is that the operation of C- DRX with short DRX cycle and long DRX cycle should also be considered to reduce unnecessary BWP switching between different operating BWPs based on the related timer expiration.

Therefore, it is herein disclosed an optimized operation of an inactivity timer related to various DRX parameters to achieve reduction of unnecessary BWP switching. Thereby improved latency and throughput while not increasing UE power consumption compared to legacy C- DRX procedure when a UE in C-DRX mode adapts its operating bandwidth based on BWP operation is possible.

Fig. 1 shows a client device 100 according to an embodiment of the invention. In the embodiment shown in Fig. 1 , the client device 100 comprises a processor 102, a transceiver 104 and a memory 106. The processor 102 may be coupled to the transceiver 104 and the memory 106 by communication means 108 known in the art. The client device 100 may further comprise an antenna or antenna array 110 coupled to the transceiver 104, which means that the client device 100 may be configured for wireless communications in a wireless communication system. That the client device 100 may be configured to perform certain actions can in this invention be understood to mean that the client device 100 comprises suitable means, such as e.g. the processor 102 and the transceiver 104, configured to perform said actions.

The client device 100 in this invention includes but is not limited to: a UE such as a smart phone, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device having a wireless communication function, a computing device or another processing device connected to a wireless modem, an in-vehicle device, a wearable device, an integrated access and backhaul node (IAB) such as mobile car or equipment installed in a car, a drone, a device-to- device (D2D) device, a wireless camera, a mobile station, an access terminal, an user unit, a wireless communication device, a station of wireless local access network (WLAN), a wireless enabled tablet computer, a laptop-embedded equipment, an universal serial bus (USB) dongle, a wireless customer-premises equipment (CPE), and/ora chipset. In an Internet of things (IOT) scenario, the client device 100 may represent a machine or another device or chipset which performs communication with another wireless device and/or a network equipment.

The UE may further be referred to as a mobile telephone, a cellular telephone, a computer tablet or laptop with wireless capability. The UE in this context may e.g. be portable, pocket- storable, hand-held, computer-comprised, or vehicle-mounted mobile device, enabled to communicate voice and/or data, via the radio access network, with another entity, such as another receiver or a server. The UE can be a station (STA), which is any device that contains an IEEE 802.11 -conformant media access control (MAC) and physical layer (PHY) interface to the wireless medium (WM). The UE may also be configured for communication in 3GPP related LTE and LTE-Advanced, in WiMAX and its evolution, and in fifth generation wireless technologies, such as NR.

The processor 102 of the client device 100 may be referred to as one or more general-purpose central processing units (CPUs), one or more digital signal processors (DSPs), one or more application-specific integrated circuits (ASICs), one or more field programmable gate arrays (FPGAs), one or more programmable logic devices, one or more discrete gates, one or more transistor logic devices, one or more discrete hardware components, and one or more chipsets. The memory 106 of the client device 100 may be a read-only memory, a random access memory, or a non-volatile random access memory (NVRAM).

The transceiver 104 of the client device 100 may be a transceiver circuit, a power controller, an antenna, or an interface which communicates with other modules or devices.

In embodiments, the transceiver 104 of the client device 100 may be a separate chipset or being integrated with the processor 102 in one chipset. While in some embodiments, the processor 102, the transceiver 104, and the memory 106 of the client device 100 are integrated in one chipset.

According to embodiments of the invention the client device 100 is configured to operate in a C-DRX. The client device 100 is further configured to obtain one or more C-DRX configuration parameters. The client device 100 is further configured to determine whether the client device 100 is configured to operate with a short DRX cycle or a long DRX cycle based on the obtained one or more C-DRX configuration parameters. The client device 100 is further configured to adapt operation of an inactivity timer associated with a BWP in C-DRX depending on whether the client device 100 is determined to be configured to operate with the short DRX cycle or the long DRX cycle.

Fig. 2 shows a flow chart of a corresponding method 200 which may be executed in a client device 100, such as the one shown in Fig. 1. The method 200 comprises obtaining 202 one or more C-DRX configuration parameters. The method 200 further comprises determining 204 whether the client device 100 is configured to operate with a short DRX cycle or a long DRX cycle based on the obtained one or more C-DRX configuration parameters. The method 200 further comprises adapting 206 operation of an inactivity timer associated with a BWP in C- DRX depending on whether the client device 100 is determined to be configured to operate with the short DRX cycle or the long DRX cycle.

The client device 100 may determine whether the client device 100 is configured to operate with a short DRX cycle or a long DRX cycle in a number of different ways. For example, if the client device 100 is configured with a short DRX cycle and if drx-lnactivityTimer expires or a DRX command MAC CE is received, the client device 100 determines that the client device 100 is configured to operate with the short DRX cycle. If the client device 100 is not configured with a short DRX cycle and if drx-lnactivityTimer expires or a DRX command MAC CE is received, the client device 100 determines that the client device 100 is configured to operate with the long DRX cycle. In addition, if drx-ShortCycleTimer expires or a long DRX command MAC CE is received, the client device 100 determines that the client device 100 is configured to operate with the long DRX cycle. Also, other solutions are possible.

Fig. 3 shows a communication system 500 according to an embodiment of the invention. The communication system 500 illustrates a client device 100 and a network access node 300 configured to operate in the communication system 500. The network access node 300 can be a base station such as a gNB. For simplicity, the communication system 500 shown in Fig. 5 only comprises one client device 100 and one network access node 300. However, the communication system 500 may comprise any number of client devices 100 and any number of network access nodes 300 without deviating from the scope of the invention.

As illustrated in Fig. 3, the client device 100 may be configured to communicate with the network access node 300 in the downlink (DL) and in the uplink (UL) using control and data channels, such as physical downlink control channel (PDCCH), physical downlink shared channel (PDSCH), physical uplink control channel (PUCCH) and physical uplink shared channel (PUSCH). The network of the communication system 500 may via the network access node 300 configure the client device 100 for different C-DRX operations e.g. as defined in 3GPP specifications. Hence, in embodiments to obtain the C-DRX configuration parameters comprises receive the C-DRX configuration parameters 510 from a network access node 300 of the communication system 500, e.g. through downlink control signaling as illustrated in Fig. 3.

In embodiments, the C-DRX configuration parameters comprises any of: DRX Cycle, onDurationTimer, drx-lnactivityTimer, drx-Retransmission timer, shortDRX-Cycle, or drxShortCycleTimer. Hence, the client device 100 will adapt its operation of the inactivity timer associated with the BWPs based on mentioned C-DRX configuration parameters.

In NR the network decides when to let a UE sleep and when to wake up the UE and inform the timing to the UE using RRC messages. The network informs the UE of the DRX timing using RRC ConnectionReconfiguration or RRC Connection Setup. Table 1 below shows the meaning of each DRX parameter. Table 1

Some typical use cases when the UE is in DRX mode include:

1. Only long DRX cycle is configured and no PDCCH is received during the cycle.

2. Only long DRX cycle is configured and a PDCCH is received during a cycle.

3. Only long DRX cycle is configured and a PDCCH and DRX command MAC CE are received during a cycle.

4. Both long DRX cycle and short DRX cycle are configured and no PDCCH is received during the cycle. This may be the most complicated case related to DRX cycle. The overall logic goes like this: i. when C DRX is configured and the last DCI arrived, ii. drx-lnactivityTimer starts/restart and 'Wake-up status' continues until the drx- InactivityTimer expires, iii. after drx-lnactivityTimer expired and the shortDRX-Cycle condition meet, the shortDRX-Cycle starts and drxShortCycleTimer starts, iv. if there is no downlink control information (DCI), e.g. no PDCCH, until drxShortCycleTimer expires and then long Drx cycle starts, and v. if a DCI arrives during the wake-up period of any DRX cycle, go to step ii). Moreover, for providing even deeper understanding of embodiments of the invention Figs. 4 to 6 illustrate different embodiments set in a 3GPP NR context hence the terminology and expressions used in these sections. For example, the inactivity timer is a bwp-lnactivityTimer, and the client device 100 is a UE in these examples. However, embodiments of the invention are not limited thereto.

Further, the upper timeline in Figs. 4 to 6 illustrates the C-DRX configuration of the client device/UE 100. The dashed blocks in the upper timeline in Figs. 4 to 6 illustrate transmission to or transmission from the UE. The transmission to the UE may be DL transmission from a gNB and the transmission from the UE may be UL transmission to a gNB. The DL and UL transmission may also be part of sidelink (SL) transmissions. The lower timeline in Figs. 4 to 6 illustrates the BWP set up and operation of the bwp-lnactivityTimer, i.e. the inactivity timer, in relation to the C-DRX configuration parameters.

Fig. 4 shows an embodiment when a UE is configured with a long DRX cycle. In this embodiment the UE is therefore determined to be configured to operate with the long DRX cycle, and further configured to stop the inactivity timer or set a value of the inactivity timer to zero when a DRX off duration starts. This can be understood to mean that the bwp- lnactivityTimer is considered as expired when a DRX off duration starts. The UE is in this embodiment further configured to use a default BWP or initial BWP when a DRX on duration starts. In this disclosure the expression “consider bwp-lnactivityTimer as expired” may mean that the UE stops the bwp-lnactivityTimer and takes the related action for the timer expiry, e.g. switching to the default or initial BWP.

In step I at time instance tO in Fig. 4, the UE is configured with a long DRX cycle and further configured to operate in BWP0 which is either an initial or a default BWP.

In step II at time instance t1 in Fig. 4, the UE switches to BWP1 which is a wide BWP and hence wider/larger than BWP0. The UE can switch to BWP1 from BWP0 when the UE detects a DCI format 1_1 indicating an active DL BWP change to BWP1 for a specific cell.

In step III at time instance t2 in Fig. 4, the drx-lnactivityTimer is (re-)started and hence also the bwp-lnactivityTimer if a PDCCH addressed to cell radio network temporary identifier (C-RNTI) or configured scheduling radio network temporary identifier (CS-RNTI) indicating downlink assignment or uplink grant is received on the active BWP, i.e., BWP1. In step IV at time instance t3 in Fig. 4, the drx-lnactivityTimer expires and the bwp- InactivityTimer is therefore considered as expired since at the expiry of the drx-lnactivityTimer the DRX off duration starts. The UE hence stops the bwp-lnactivityTimer or sets a value of the bwp-lnactivityTimer to zero when the DRX off duration starts.

In step V at time instance t4 in Fig. 4, the drx-OnDurationTimer starts which means that the DRX on duration starts. The UE operates in BWPO which as stated previously either is the initial or the default BWP.

A possible non-limiting suggestion of proposed operation of BWP and its related inactivity timer are as below:

1> if drx-lnactivityTimer expires or a DRX Command MAC CE is received:

2> if the Short DRX cycle is configured:

2>else:

3> consider bwo-lnactivitvTimer as expired if running

3> perform BWP switching to a BWP indicated by the defaultDownlinkBWP-ld or the initialDownlinkBWP.

Fig. 5 shows an embodiment when the UE is configured to enter a long DRX cycle. In general wording the UE in this case may be configured to stop the inactivity timer or set a value of the inactivity timer to zero upon switching from a short DRX cycle to a long DRX cycle. The UE can thereafter operate in a default BWP in C-DRX when a DRX on duration starts.

In step I at time instance tO in Fig. 5, the UE is configured with a short DRX cycle and further configured to operate in BWPO which is either an initial or a default BWP.

In step II at time instance t1 in Fig. 5, the UE switches to BWP1 which is a wide BWP. The UE may switch to BWP1 from BWPO due to control signaling as previously mentioned.

In step III at time instance t2 in Fig. 5, the drx-lnactivityTimer is (re-)started and also the bwp- InactivityTimer.

In step IV at time instance t3 in Fig. 5, the drx-lnactivityTimer expires and hence a DRX on duration starts. In step V at time instance t4 in Fig. 5, a short DRX cycle is started and the UE operates in BWP1 during the DRX on durations.

In step VI at time instance t5 in Fig. 5, the UE switches from short DRX cycles to long DRX cycles and therefore also switches to BWPO which in this case is either the initial or the default BWP.

In step VII at time instance t6 in Fig. 5, the UE operates in BWPO for each DRX on duration when being configured with long DRX cycle.

A possible non-limiting suggestion of proposed operation of BWP and its related inactivity timer are as below:

1> if drx-ShortCycleTimer expires:

2>use the Long DRX cycle.

2> consider bwo-lnactivitvTimer as expired if running:

2> perform BWP switching to a BWP indicated by the defaultDownlinkBWP-ld or the initialDownlinkBWP.

1> if a Long DRX Command MAC CE is received:

2>stop drx-ShortCycleTimer,

2>use the Long DRX cycle.

2> consider bwo-lnactivitvTimer as expired if running:

2> perform BWP switching to a BWP indicated by the defaultDownlinkBWP-ld or the initialDownlinkBWP.

Fig. 6 shows an embodiment when the UE is configured with short DRX cycle. In general wording the UE in this embodiment is configured to suspend the inactivity timer when a DRX off duration starts, and to resume the inactivity timer when a DRX on duration starts. Further, the UE is configured to operate in a previous active BWP used in the DRX on duration of the previous DRX cycle in C-DRX when the DRX on duration starts.

In step I at time instance tO in Fig. 6, the UE is configured with a short DRX cycle and further configured to operate in BWPO which is either an initial or a default BWP.

In step II at time instance t1 in Fig. 6, the UE switches to BWP1 which is a wide BWP and wider than BWPO. The UE may switch to BWP1 from BWPO due to control signaling from a gNB as previously mentioned. In step III at time instance t2 in Fig. 6, the drx-lnactivityTimer starts.

In step IV at time instance t3 in Fig. 6, the drx-lnactivityTimer expires and hence the bwp- InactivityTimer is suspended. The bwp-lnactivityTimer is thereafter suspended when each DRX on duration ends which is equal to when a DRX off duration starts.

In step V at time instance t4 in Fig. 6, a DRX on duration starts and the bwp-lnactivityTimer is resumed. The bwp-lnactivityTimer is thereafter resumed when each DRX on duration starts which is equal to when a DRX off duration expires.

In step VI at time instance t5 in Fig. 6, the drx-ShortCycleTimer expires and the UE switches from short DRX cycles to long DRX cycles and therefore also switches to BWP0 which in this case is either the initial or the default BWP.

A possible non-limiting suggestion of proposed operation of BWP and its related inactivity timer are as below: when DRX is configured, the MAC entity shall:

1> if drx-lnactivityTimer expires or a DRX Command MAC CE is received:

2> if the Short DRX cycle is configured:

3> start or restart drx-ShortCycleTimer in the first symbol after the expiry of drx- lnactivityTimer or in the first symbol after the end of DRX Command MAC CE reception;

3> use the Short DRX Cycle.

3> If bwp-lnactivityTimer is running:

4> suspend the bwo-lnactivitvTimer associated with the active DL BWP

2>else:

3> use the Long DRX cycle.

1 > if the drx-OnDurationTimer starts:

2> if drx-ShortCycleTimer is running:

3> bwp-lnactivityTimer is being suspended:

4> resume the suspended bwo-lnactivitvTimer associated with the active DL BWP.

Furthermore, any method according to embodiments of the invention may be implemented in a computer program, having code means, which when run by processing means causes the processing means to execute the steps of the method. The computer program is included in a computer readable medium of a computer program product. The computer readable medium may comprise essentially any memory, such as a ROM (Read-Only Memory), a PROM (Programmable Read-Only Memory), an EPROM (Erasable PROM), a Flash memory, an EEPROM (Electrically Erasable PROM), or a hard disk drive.

Moreover, it is realized by the skilled person that embodiments of the client device 100 comprises the necessary communication capabilities in the form of e.g., functions, means, units, elements, etc., for performing the solution. Examples of other such means, units, elements and functions are: processors, memory, buffers, control logic, encoders, decoders, rate matchers, de-rate matchers, mapping units, multipliers, decision units, selecting units, switches, interleavers, de-interleavers, modulators, demodulators, inputs, outputs, antennas, amplifiers, receiver units, transmitter units, DSPs, MSDs, TCM encoder, TCM decoder, power supply units, power feeders, communication interfaces, communication protocols, etc. which are suitably arranged together for performing the solution.

Especially, the processor(s) of the client device 100 may comprise, e.g., one or more instances of a Central Processing Unit (CPU), a processing unit, a processing circuit, a processor, an Application Specific Integrated Circuit (ASIC), a microprocessor, or other processing logic that may interpret and execute instructions. The expression “processor” may thus represent a processing circuitry comprising a plurality of processing circuits, such as, e.g., any, some or all of the ones mentioned above. The processing circuitry may further perform data processing functions for inputting, outputting, and processing of data comprising data buffering and device control functions, such as call processing control, user interface control, or the like.

Finally, it should be understood that the invention is not limited to the embodiments described above, but also relates to and incorporates all embodiments within the scope of the appended independent claims.