WO2025030404A1

WO2025030404A1 - Mechanism for improving rational discontinuous reception cycle

Info

Publication number: WO2025030404A1
Application number: PCT/CN2023/111852
Authority: WO
Inventors: Jian Song; Stefano PARIS; Chunli Wu; Andrea MARCANO; Jorma Johannes Kaikkonen
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Priority date: 2023-08-08
Filing date: 2023-08-08
Publication date: 2025-02-13
Anticipated expiration: 2026-02-08

Abstract

The present disclosure relates to a solution on improving rational discontinuous reception (DRX) cycle is proposed. In particular, a network device transmits, to a terminal device, a configuration of a discontinuous reception indicating at least one of a DRX cycle of the discontinuous reception or a start time offset of the DRX cycle. The terminal device determines, based on a predefined formula, a target start time offset for an on duration of the DRX cycle without rounding errors. The target start time offset is ensured to match the start time offset of the DRX cycle when the DRX cycle is represented as a rational number. The terminal device performs the discontinuous reception based on the determined target start time offset. In this way, there are not rounding errors when the DRX cycle is represented as rational number, thereby reducing delays for transmissions.

Description

MECHANISM FOR IMPROVING RATIONAL DISCONTINUOUS RECEPTION CYCLE

FIELDS

Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices, apparatuses and computer readable storage medium for improving rational discontinuous reception cycle.

BACKGROUND

With developments of communication technologies, a technology named “discontinuous reception (DRX) ” has been proposed in order to save power. DRX is a technique that allows a User Equipment (UE) to turn off its transceiver for a duration of a DRX cycle when there are no packets to be received. In other words, within such duration, the UE does not need to receive the packet and does not performing monitoring on channels. Further, it also proposes to support non-integer periodicities of DRX. Therefore, further studies on non-integer periodicities of DRX are needed.

SUMMARY

In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to: receive, from a second apparatus, a configuration of a discontinuous reception indicating at least one of a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle; determine, based on a predefined formula, a target start time offset for an on duration of the discontinuous reception cycle without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number; and perform the discontinuous reception based on the determined target start time offset.

In a second aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: transmit, to a first apparatus, a configuration of a discontinuous reception indicating at least one of a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle, wherein a target start time offset for an on duration of the discontinuous reception cycle is determined based on a predefined formula, without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number.

In a third aspect of the present disclosure, there is provided a method. The method comprises: receiving, at a first apparatus and from a second apparatus, a configuration of a discontinuous reception indicating at least one of a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle; determining, based on a predefined formula, a target start time offset for an on duration of the discontinuous reception cycle without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number; and performing the discontinuous reception based on the determined target start time offset.

In a fourth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, at a second apparatus and to a first apparatus, a configuration of a discontinuous reception indicating at least one of a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle, wherein a target start time offset for an on duration of the discontinuous reception cycle is determined based on a predefined formula, without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number.

In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus, a configuration of a discontinuous reception indicating at least one of a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle; means for determining, based on a predefined formula, a target start time offset for an on duration of the discontinuous reception cycle without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number; and means for performing the discontinuous reception based on the determined target start time offset.

In a sixth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for transmitting, to a first apparatus, a configuration of a discontinuous reception indicating at least one of a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle, wherein a target start time offset for an on duration of the discontinuous reception cycle is determined based on a predefined formula, without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number.

In a seventh aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the third aspect.

In an eighth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the fourth aspect.

It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.

BRIEF DESCRIPTION OF THE DRAWINGS

Some example embodiments will now be described with reference to the accompanying drawings, where:

FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

FIG. 2 illustrates a schematic diagram of simulations according to example embodiments of the present disclosure;

FIG. 3 illustrates a signaling chart for determining a start time offset according to example embodiments of the present disclosure;

FIG. 4 illustrates a schematic diagram of a DRX configuration according to example embodiments of the present disclosure;

FIG. 5 illustrates a flowchart of a method implemented at a first device according to some example embodiments of the present disclosure;

FIG. 6 illustrates a flowchart of a method implemented at a second device according to some example embodiments of the present disclosure;

FIG. 7 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

FIG. 8 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

References in the present disclosure to “one embodiment, ” “an embodiment, ” “an example embodiment, ” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

It shall be understood that although the terms “first, ” “second, ” …, etc. in front of noun (s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun (s) . For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and/or” includes any and all combinations of one or more of the listed terms.

As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” and similar wording, where the list of two or more elements are joined by “and” or “or” , mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. 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” , “has” , “having” , “includes” and/or “including” , when used herein, specify the presence of stated features, elements, and/or components etc., but do not preclude the presence or addition of one or more other features, elements, components and/or combinations thereof.

As used in this application, the term “circuitry” may refer to one or more or all of the following:

(a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry) and

(b) combinations of hardware circuits and software, such as (as applicable) :

(i) a combination of analog and/or digital hardware circuit (s) with software/firmware and

(ii) any portions of hardware processor (s) with software (including digital signal processor (s) ) , software, and memory (ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and

(c) hardware circuit (s) and or processor (s) , such as a microprocessor (s) or a portion of a microprocessor (s) , that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and/or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR) , Long Term Evolution (LTE) , LTE-Advanced (LTE-A) , Wideband Code Division Multiple Access (WCDMA) , High-Speed Packet Access (HSPA) , Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G) , the second generation (2G) , 2.5G, 2.75G, the third generation (3G) , the fourth generation (4G) , 4.5G, the fifth generation (5G) , the sixth generation (6G) communication protocols, and/or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP) , for example, a node B (NodeB or NB) , an evolved NodeB (eNodeB or eNB) , an NR NB (also referred to as a gNB) , a Remote Radio Unit (RRU) , a radio header (RH) , a remote radio head (RRH) , a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) device, a watch or other wearable, a head-mounted display (HMD) , a vehicle, a drone, a medical device and applications (e.g., remote surgery) , an industrial device and applications (e.g., a robot and/or other wireless devices operating in an industrial and/or an automated processing chain contexts) , a consumer electronics device, a device operating on commercial and/or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node) . In the following description, the terms “terminal device” , “communication device” , “terminal” , “user equipment” and “UE” may be used interchangeably.

As used herein, the term “resource, ” “transmission resource, ” “resource block, ” “physical resource block” (PRB) , “uplink resource, ” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and/or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

As used herein, the term “RRC connected state” or “RRC connected mode” used herein may refer to a state in which service radio bearer and data radio bearer are allocated for the terminal device. The term “RRC idle state” or “RRC idle mode” used herein may refer to a state where the terminal device is switched on but does not have any established RRC connection. The term “RRC inactive state” or “RRC inactive mode” used herein may refer to a state when there is an RRC connection that has been suspended.

As used herein, the term “discontinuous reception (DRX) ” used herein may refer to a technique that allows a device to receive data or sleep within a period. There may be two types of DRX, i.e., long DRX and short DRX. The term “discontinuous transmission (DTX) ” used herein refers to a technique that allows the device to transmit data or sleep within a period. The term “on duration” or “active period” used for DRX refers to a time period during which the device is able to monitor a channel, for example, a physical control channel or a physical shared channel, and receive data or control information on the channel. The term “DRX period” or “opportunity for DRX” or “off time” or “off duration” or “non-active/inactive period” used for DRX refers to a time period during which the device does not monitor the channel and does not receive data or control information on the channel. The term “DRX cycle” used herein comprises an on-duration during which the device may monitor the channel and a DRX period during which the device can skip reception of channel. The term “on duration” or “active period” used for DTX refers to a time period during which the device is able to transmit data or control information on a channel, for example, a physical control channel or a physical shared channel. The term “DTX period” or “opportunity for DTX” or “off time” or “off duration” or “non-active/inactive period” for DTX used herein refers to a time period during which the device does not transmit data or control information on the channel. The term “DTX cycle” used herein comprises an on-duration during which the device may transmit data or control information on the channel and a DTX period during which the device can skip transmission of channel. The term “short DRX cycle” used herein may refer to a relatively shorter DRX cycle, which is used when the device has data to transmit or receive and needs to stay active for a shorter duration. The term “long DRX cycle” used herein may refer to a relatively longer DRX cycle. For example, the short DRX cycle may span from 2 ms to 640 ms and the long DRX cycle my span from 10 ms to 1024ms. The long DRX cycle may offer better UE power saving gain, at the expense of longer radio latency, i.e., the device is not reachable during the DRX OFF periods.

As mentioned above, it also proposes to support non-integer periodicities of DRX. For example, in order to enhance power saving, DRX support of virtual reality and/or augmented reality (XR) frame rates may be corresponding to non-integer periodicities (through at least semi-static mechanisms, for example, RRC signaling) . By way of example, there may be some type of DRX support for XR periods such as 1/60s and 1/90s . Therefore, solutions on non-integer periodicities of DRX are needed.

FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure can be implemented. In the communication environment 100, a first device 110 and a second device 120 may communicate with each other.

In the following, for the purpose of illustration, some example embodiments are described with the first device 110 operating as a terminal device and the second device 120 operating as a network device. However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at a terminal device or other device.

In some example embodiments, if the first device 110 is a terminal device and the second device 120 is a network device, a link from the second device 120 to the first device 110 is referred to as a downlink (DL) , and a link from the first device 110 to the second device 120 is referred to as an uplink (UL) . In DL, the second device 120 is a transmitting (TX) device (or a transmitter) and the first device 110 is a receiving (RX) device (or a receiver) . In UL, the first device 110 is a TX device (or a transmitter) and the second device 120 is a RX device (or a receiver) .

Communications in the communication environment 100 may be implemented according to any proper communication protocol (s) , comprising, but not limited to, cellular communication protocols of the first generation (1G) , the second generation (2G) , the third generation (3G) , the fourth generation (4G) , the fifth generation (5G) , the sixth generation (6G) , and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA) , Frequency Division Multiple Access (FDMA) , Time Division Multiple Access (TDMA) , Frequency Division Duplex (FDD) , Time Division Duplex (TDD) , Multiple-Input Multiple-Output (MIMO) , Orthogonal Frequency Division Multiple (OFDM) , Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and/or any other technologies currently known or to be developed in the future.

In some solutions, uniform DRX cycles expressed as a rational number may be used. For example, if the frame rate of XR traffic is frame per second (FPS) , a DRX cycle may be 1000/FPS. When DRX cycles are rational numbers (for example, 50/3 for 60 fps) , they are not decimal numbers such as 16.67 for 60 fps. In addition, for rational numbers, there are different ways to implement modulo operations without producing rounding errors. One such example is to apply the below formula (1) :
x mod y=x-y×floor (x/y) (1)

where x and y are parameters. In this formula, the operation x/y may reduce to an Euclidian division of two positive integers, in which the quotient directly yields the final result of the floor operation. That thus ensures no rounding error is introduced during the calculations.

Taken a long DRX cycle as an example. A DRX start offset for the long DRX cycle may be:

where SFN represents a system frame number, drxLongCycle represents the long DRX cycle, and drxStartOffset represents the DRX start offset for the long DRX. For the purpose of illustrations, the following definitions are proposed: A= [ (SFN×10) + subframe number] which is an integer number, B/C=drxLongCycle which is a rational number represented by the ratio of two integers (B and C) , and Z= drxStartOffset which is an integer number. If the above formula (1) is applied to the above formula (2) , it can obtain the following formula (3) .
ffloor (A- [ (B/C) ×floor ( (A×C) /B) ] ) =Z (3)

Moreover, it can be seen that: A×C is an integer since it is the product of two integers, and B is an integer, which results in that (A×C) /B is a rational number as well. Thus, floor ( (A×C) /B) is an integer number. However, the fraction B/C is still a rational number, in particular, multiplying an integer floor ( (A×C) /B) by a fractional number B/C result in different values depending on the numerical precision used to represent the fractional number in a given computation platform.

To be more explicit, the rational number B/C and recurrent decimal (e.g., 50/3 = 16.6666…) represented in machine can cause rounding errors. The numerical representation of the fractional number may cause the product to wrap up the nearest integer toward infinity. This is seen as the machine-dependent problem which cannot be overcome in the practical implementation.

For example, let F be a fractional number and I be an integer number. The product of F×I can result in different values depending on the representation of the fractional F in a computer machine. Let I=50 and F=1/3 (note that this is the typical example 50/3=16.6666…) :

● If the fractional number F is represented as F=1/3=0.3 by a computer machine, it can obtain F×I=50×0.3=15, which result in floor (F×I) = floor (50×0.3) =15.

● If the fractional number F is represented as F=1/3=0.33 by a computer machine, it can obtain F×I=50×0.33=16.5, which result in floor (F× I) =floor (50×0.33) =16.

● If the fractional number F is represented as F=1/3=0.333 by a computer machine, it can obtain F×I=50×0.333=16.6, which result in floor (F× I) =floor (50×0.333) =16.

However, as shown in FIG. 2, according to the formular (3) , there may be some rounding errors. Further, because of the rounding errors, there are occasions in which the result from the formula (3) will not match the start offset, which leads to skipping a DRX cycle and increasing the delays. For example, as shown in FIG. 2, the first rounding error is shown around SFN 250, in this case the formula (3) yields -1 as result for drx-StartOffset when it needs to be 16. Then, the drx-StartOffset pattern of this example is {15, 16, 16} , by having a result of -1 instead of 16 means that the DRX cycle will be skipped since the condition for starting it is not met. Therefore, the rounding error needs to be fixed.

According to embodiments of the present disclosure, a solution on improving rational DRX cycle is proposed. In particular, a network device transmits, to a terminal device, a configuration of a discontinuous reception indicating at least one of a DRX cycle of the discontinuous reception or a start time offset of the DRX cycle. The terminal device determines, based on a predefined formula, a target start time offset for an on duration of the DRX cycle without rounding errors. The target start time offset is ensured to match the start time offset of the DRX cycle when the DRX cycle is represented as a rational number. The terminal device performs the discontinuous reception based on the determined target start time offset. In this way, there are not rounding errors when the DRX cycle is represented as rational number, thereby reducing delays for transmissions.

Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

Reference is made to FIG. 3, which illustrates a signaling flow 300 in accordance with some embodiments of the present disclosure. For the purposes of discussion, the signaling flow 300 will be discussed with reference to FIG. 1, for example, by using the first device 110, the second device 120.

The second device 120 transmits (3010) a configuration of a discontinuous reception (DRX) to the first deice 110. In other words, the first device 110 receives the configuration of the DRX from the second device 120. In some example embodiments, the configuration of the DRX may be transmitted via a RRC signaling.

The configuration of the DRX indicates one or more of a DRX cycle of the DRX or a start time offset of the DRX cycle. For example, as shown in FIG. 4, the configuration of the DRX may indicate the DRX cycle 410. The configuration of DRX may also indicate an on duration 420 of the DRX within which the first device 110 may receive data and/or control information. Further, the configuration of the DRX may indicate the start time offset 430 that indicates a start slot of the DRX.

The first device 110 determines (3030) , based on a predefined formula a target start time offset a target start time offset for an on duration of the DRX cycle without rounding errors. The target start time offset is ensured to match the start time offset of the DRX cycle when the DRX cycle is represented as a rational number. For example, the target start time offset matches the start time offset 430 indicated in the configuration of the DRX. In this way, the rounding errors can be avoided and the delay for the transmission can be reduce.

In some example embodiments, without changing a current DRX formula, the predefined formula to perform floor, division and product operations may be only applied for the UE and/or gNB vendor specific implementation method. For example, Table 1 below shows an example of how to apply the predefined formula, which can be in technical specification (TS) . It is noted that Table 1 is only an example.

Table 1

For example, in some example embodiments, the first device 110 may determine whether the DRX cycle is represented as a rational number or an integer number. In an example embodiment, if the DRX cycle is represented as a rational number and the DRX cycle is a long DRX cycle, the first device 110 may obtain the target start time offset by applying the predefined formula. In this case, the predefined formula may be represented as:

where A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the DRX cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation. The value of SFN may indicate when the first device 110 determines to activate the DRX. In this way, the rounding error caused by floor operation of a rational number B/C multiplied by an integer number floor ( (A×C) /B) will be avoided, because: A×C is an integer number since it is the product of two integers, B is an integer, floor ( (A×C) /B) is an integer. Note that this leads to the fact that the numerator of the argument of the floor (·) function, A×C- [B×floor ( (A×C) /B) ] , is also an integer. Thus, the argument of the floor (·) functionis a rational number, but the final resultsis an integer.

Alternatively, if the DRX cycle is represented as a rational number and the DRX cycle is a short DRX cycle, the first device 110 may obtain the target start time offset by applying the predefined formula. In this case, the predefined formula may be represented as:

where A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the DRX cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.

In some example embodiments, if the DRX cycle is an integer number, the first device 110 may determine whether the DRX cycle is a short DRX cycle or a long DRX cycle. In this case, if the DRX cycle is the short DRX cycle, the first device 110 may obtain the target start time offset of the short DRX cycle by applying the predefined formula. In this case, the predefined formula may be represented as:

where SFN represents a system frame number, drx-ShortCycle represents the short DRX cycle, drx-StartOffset represents the target start time offset.

Alternatively, if the DRX cycle is an integer number and the DRX cycle is the long DRX cycle, the first device 110 may obtain the target start time offset of the long DRX cycle by applying the predefined formula. In this case, the predefined formula may be represented as:

where SFN represents a system frame number, drx-LongCycle represents the long DRX cycle, drx-StartOffset represents the target start time offset.

Alternatively, the predefined formula to perform the floor, division and product operations directly may lead to the modifications of the current DRX formula together with DRX hyper-cycle configuration in RRC domain. For example, Table 2 below shows an example of how to apply the predefined formula, which can be in technical specification (TS) . It is noted that Table 2 is only an example.

Table 2

For example, the configuration of the DRX indicates a hyper DRX cycle and the number of DRX cycles within the hyper DRX cycle. In this case, the DRX cycle may be represented as the hyper DRX cycle divided by the number of DRX cycles within the hyper DRX cycle. By way of example, the configuration of the DRX may indicate a tuple of DRX hyper cycle configuration that includes an integer hyper cycle, i.e., drx-HyperCycle and the number of cycles within the hyper cycle, i.e, drx-NumberOfCyclesPerHyperCycle. In this case, for example, with the floor operation, it may result in the pattern of 17, 17, 16 without introducing the counter to check at which DRX cycle when an adjustment is needed. For example, a combination of the hyper DRX cycle and the number of DRX cycles per hyper DRX cycle may include one of: (100, 3) , (200, 9) , (50, 3) , (125, 9) , (100, 9) , (25, 3) , which may cover the frame rate of 30fps, 45fps, 60fps, 72fps, 90fps, 120fps.

In an example embodiment, if the DRX cycle is a long DRX cycle, the first device 110 may obtain the target start time offset of the long DRX cycle by applying the predefined formula. In this case, the predefined formula may be represented as:

where SFN represents a system frame number drx-NumberOfCyclesPerHyperCycle represents the number of DRX cycles within the hyper DRX cycle, drx-HyperCycle represents the hyper DRX cycle, and drx-StartOffset represents the target start time offset.

In another example embodiment, if the DRX cycle is a short DRX cycle, the first device 110 may obtain the target start time offset of the long DRX cycle by applying the predefined formula. In this case, the predefined formula may be represented as:

Referring back to FIG. 3, the first device 110 performs 3050 the DRX based on the determined target start time offset. In this way, it can reduce the latency for performing the DRX by not skipping DRX cycle.

According to embodiments of the present disclosure, there are no rounding errors. For example, as shown in FIG. 2, there may be rounding errors by using formula (3) for determination of drx-StartOffset. In this numerical example in FIG. 2, DRX hyper cycle is B = 50 ms, and number of cycles per hyper cycle C = 3, so drxLongCycle is represented as a rational number 50/3 ms. In this case, it is clearly show that there are 3 numbers calculated as -1 for drx-StartOffset. However, by using the formula according to embodiments of the present disclsoure, the numerical errors can be overcome.

FIG. 5 shows a flowchart of an example method 500 implemented at a first device in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the first device 110 in FIG. 1.

At block 510, the fist device 110 receives, from a second device 120, a configuration of a discontinuous reception. The configuration of the discontinuous reception indicates at least one of a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle.

At block 520, the fist device 110 determines, based on a predefined formula, a target start time offset for an on duration of the discontinuous reception cycle without rounding errors. The target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number.

At block 530, the fist device 110 performs the discontinuous reception based on the determined target start time offset.

In some example embodiments, the method 500 further comprises: determining whether the discontinuous reception cycle is represented as a rational number; and in accordance with a determination that the discontinuous reception cycle is represented as a rational number and the discontinuous reception cycle is a long discontinuous reception cycle, obtaining the target start time offset by applying the predefined formula that is represented as: and wherein A represnets [ (SFN× 10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the long discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.

In some example embodiments, the method 500 further comprises: determining whether the discontinuous reception cycle is represented as a rational number; and in accordance with a determination that the discontinuous reception cycle is represented as a rational number and the discontinuous reception cycle is a short discontinuous reception cycle, obtaining the target start time offset by applying the predefined formula that is represented as: and wherein A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the short discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.

In some example embodiments, the method 500 further comprises: determining whether the discontinuous reception cycle is represented as a rational number; and in accordance with a determination that the discontinuous reception cycle is an integer number, determining whether the discontinuous reception cycle is a short discontinuous reception cycle or a long discontinuous reception cycle.

In some example embodiments, the method 500 further comprises: in accordance with a determination that the discontinuous reception cycle is the short discontinuous reception cycle, obtaining the target start time offset of the short discontinuous reception cycle by applying the predefined formula that is represented as: flooring ( [ (SFN × 10) + subframe number] modulo (drx-ShortCycle) ) = floor ( (drx-StartOffset) modulo (drx-ShortCycle) ) , and wherein SFN represents a system frame number, drx-ShortCycle represents the short discontinuous reception cycle, drx-StartOffset represents the target start time offset.

In some example embodiments, the method 500 further comprises: in accordance with a determination that the discontinuous reception cycle is the long discontinuous reception cycle, obtaining the target start time offset of the long discontinuous reception cycle by applying the predefined formula that is represented as: flooring ( [ (SFN × 10) + subframe number] modulo (drx-LongCycle) ) = drx-StartOffset, and wherein SFN represents a system frame number, drx-LongCycle represents the long discontinuous reception cycle, drx-StartOffset represents the target start time offset.

In some example embodiments, the configuration of the discontinuous reception indicates a hyper discontinuous reception cycle and the number of discontinuous reception cycles within the hyper discontinuous reception cycle, and wherein the discontinuous reception is represented as the hyper discontinuous reception cycle divided by the number of discontinuous reception cycles within the hyper discontinuous reception cycle.

In some example embodiments, the method 500 further comprises: in accordance with a determination that the discontinuous reception cycle is a long discontinuous reception cycle, obtaining the target start time offset of the long discontinuous reception cycle by applying the predefined formula that is represented as: flooring ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) / (drx-HyperCycle) ) ] ) ) / (drx-NumberOfCyclesPerHyperCycle) ) = drx-StartOffset, and wherein SFN represents a system frame number, drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.

In some example embodiments, the method 500 further comprises: in accordance with a determination that the discontinuous reception cycle is a short discontinuous reception cycle, obtaining the target start time offset of the short discontinuous reception cycle by applying the predefined formula that is represented as: flooring ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) = floor ( (drx-StartOffset × drx- NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( (drx-StartOffset × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) , and wherein SFN represents a system frame number, drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.

FIG. 6 shows a flowchart of an example method 600 implemented at a second device in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described from the perspective of the second device 120 in FIG. 1.

At block 610, the second device 120 transmits, to a first device 110, a configuration of a discontinuous reception indicating at least one of a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle, wherein a target start time offset for an on duration of the discontinuous reception cycle is determined based on a predefined formula, without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number.

In some example embodiments, if the discontinuous reception cycle is represented as a rational number and the discontinuous reception is a long discontinuous reception cycle, the target start time offset is obtained by applying the predefined formula that is represented as: and wherein A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the long discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.

In some example embodiments, if the discontinuous reception cycle is represented as a rational number and the discontinuous reception is a short discontinuous reception cycle, the target start time offset is obtained by applying the predefined formula that is represented as: and wherein A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the short discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.

In some example embodiments, if the discontinuous reception cycle is an integer number and the discontinuous reception cycle is the short discontinuous reception cycle, the target start time offset of the short discontinuous reception cycle is obtained by applying the predefined formula that is represented as: flooring ( [ (SFN × 10) + subframe number] modulo (drx-ShortCycle) ) = floor ( (drx-StartOffset) modulo (drx-ShortCycle) ) , and wherein SFN represents a system frame number, drx-ShortCycle represents the short discontinuous reception cycle, drx-StartOffset represents the target start time offset.

In some example embodiments, if the discontinuous reception cycle is an integer number and the discontinuous reception cycle is the long discontinuous reception cycle, the target start time offset of the long discontinuous reception cycle is obtained by applying the predefined formula that is represented as: flooring ( [ (SFN × 10) + subframe number] modulo (drx-LongCycle) ) = drx-StartOffset, and wherein SFN represents a system frame number, drx-LongCycle represents the long discontinuous reception cycle, drx-StartOffset represents the target start time offset.

In some example embodiments, if the discontinuous reception cycle is a long discontinuous reception cycle, the target start time offset of the long discontinuous reception cycle is obtained by applying the predefined formula that is represented as: flooring ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) / (drx-HyperCycle) ) ] ) ) / (drx-NumberOfCyclesPerHyperCycle) ) = drx-StartOffset, and wherein SFN represents a system frame number, drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.

In some example embodiments, if the discontinuous reception cycle is a short discontinuous reception cycle, the target start time offset of the short discontinuous reception cycle is obtained by applying the predefined formula that is represented as: flooring ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) = floor ( (drx-StartOffset × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( (drx-StartOffset × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) , and wherein SFN represents a system frame number, drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.

In some example embodiments, the second apparatus comprises a network device, and the first apparatus comprises a terminal device.

In some example embodiments, a first apparatus capable of performing any of the method 500 (for example, the first device 110 in FIG. 1) may comprise means for performing the respective operations of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first device 110 in FIG. 1.

In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a configuration of a discontinuous reception indicating at least one of a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle; means for determining, based on a predefined formula, a target start time offset for an on duration of the discontinuous reception cycle without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number; and means for performing the discontinuous reception based on the determined target start time offset.

In some example embodiments, the first apparatus further comprises: means for determining whether the discontinuous reception cycle is represented as a rational number; and in accordance with a determination that the discontinuous reception cycle is represented as a rational number and the discontinuous reception cycle is a long discontinuous reception cycle, obtaining the target start time offset by applying the predefined formula that is represented as: and wherein A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the long discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.

In some example embodiments, the first apparatus further comprises: means for determining whether the discontinuous reception cycle is represented as a rational number; and in accordance with a determination that the discontinuous reception cycle is represented as a rational number and the discontinuous reception cycle is a short discontinuous reception cycle, obtaining the target start time offset by applying the predefined formula that is represented as: and wherein A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.

In some example embodiments, the first apparatus further comprises: means for determining whether the discontinuous reception cycle is represented as a rational number; and means for in accordance with a determination that the discontinuous reception cycle is an integer number, determining whether the discontinuous reception cycle is a short discontinuous reception cycle or a long discontinuous reception cycle.

In some example embodiments, the first apparatus further comprises: in accordance with a determination that the discontinuous reception cycle is the short discontinuous reception cycle, obtaining the target start time offset of the short discontinuous reception cycle by applying the predefined formula that is represented as: means for flooring ( [ (SFN × 10) + subframe number] modulo (drx-ShortCycle) ) = floor ( (drx-StartOffset) modulo (drx-ShortCycle) ) , and wherein SFN represents a system frame number, drx-ShortCycle represents the short discontinuous reception cycle, drx-StartOffset represents the target start time offset.

In some example embodiments, the first apparatus further comprises: in accordance with a determination that the discontinuous reception cycle is the long discontinuous reception cycle, obtaining the target start time offset of the long discontinuous reception cycle by applying the predefined formula that is represented as: means for flooring ( [ (SFN × 10) + subframe number] modulo (drx-LongCycle) ) = drx-StartOffset, and wherein SFN represents a system frame number, drx-LongCycle represents the long discontinuous reception cycle, drx-StartOffset represents the target start time offset.

In some example embodiments, the first apparatus further comprises: in accordance with a determination that the discontinuous reception cycle is a long discontinuous reception cycle, obtaining the target start time offset of the long discontinuous reception cycle by applying the predefined formula that is represented as: means for flooring ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) / (drx-HyperCycle) ) ] ) ) / (drx-NumberOfCyclesPerHyperCycle) ) = drx-StartOffset, and wherein SFN represents a system frame number, drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.

In some example embodiments, the first apparatus further comprises: in accordance with a determination that the discontinuous reception cycle is a short discontinuous reception cycle, obtaining the target start time offset of the short discontinuous reception cycle by applying the predefined formula that is represented as: means for flooring ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) = floor ( (drx-StartOffset × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( (drx-StartOffset × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) , and wherein SFN represents a system frame number, drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.

In some example embodiments, the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

In some example embodiments, the first apparatus further comprises means for performing other operations in some example embodiments of the method 500 or the first device 110. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the first apparatus.

In some example embodiments, a second apparatus capable of performing any of the method 600 (for example, the second device 120 in FIG. 1) may comprise means for performing the respective operations of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second device 120 in FIG. 1.

In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus, a configuration of a discontinuous reception indicating at least one of a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle, wherein a target start time offset for an on duration of the discontinuous reception cycle is determined based on a predefined formula, without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number.

In some example embodiments, if the discontinuous reception cycle is represented as a rational number and the discontinuous reception cycle is a long discontinuous reception cycle, the target start time offset is obtained by applying the predefined formula that is represented as: and wherein A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the long discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.

In some example embodiments, if the discontinuous reception cycle is represented as a rational number and the discontinuous reception cycle is a short discontinuous reception cycle, the target start time offset is obtained by applying the predefined formula that is represented as: and wherein A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the short discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.

In some example embodiments, if the discontinuous reception cycle is an integer number and the discontinuous reception cycle is the short discontinuous reception cycle, the target start time offset of the short discontinuous reception cycle is obtained by applying the predefined formula that is represented as: means for flooring ( [ (SFN × 10) +subframe number] modulo (drx-ShortCycle) ) = floor ( (drx-StartOffset) modulo (drx-ShortCycle) ) , and wherein SFN represents a system frame number, drx-ShortCycle represents the short discontinuous reception cycle, drx-StartOffset represents the target start time offset.

In some example embodiments, if the discontinuous reception cycle is an integer number and the discontinuous reception cycle is the long discontinuous reception cycle, the target start time offset of the long discontinuous reception cycle is obtained by applying the predefined formula that is represented as: means for flooring ( [ (SFN × 10) + subframe number] modulo (drx-LongCycle) ) = drx-StartOffset, and wherein SFN represents a system frame number, drx-LongCycle represents the long discontinuous reception cycle, drx-StartOffset represents the target start time offset.

In some example embodiments, if the discontinuous reception cycle is a long discontinuous reception cycle, the target start time offset of the long discontinuous reception cycle is obtained by applying the predefined formula that is represented as: means for flooring ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) / (drx-HyperCycle) ) ] ) ) / (drx-NumberOfCyclesPerHyperCycle) ) = drx-StartOffset, and wherein SFN represents a system frame number, drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.

In some example embodiments, if the discontinuous reception cycle is a short discontinuous reception cycle, the target start time offset of the short discontinuous reception cycle is obtained by applying the predefined formula that is represented as: means for flooring ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) = floor ( (drx-StartOffset × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( (drx-StartOffset × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) , and wherein SFN represents a system frame number, drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.

In some example embodiments, the second apparatus further comprises means for performing other operations in some example embodiments of the method 600 or the second device 120. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the second apparatus.

FIG. 7 is a simplified block diagram of a device 700 that is suitable for implementing example embodiments of the present disclosure. The device 700 may be provided to implement a communication device, for example, the first device 110 or the second device 120 as shown in FIG. 1. As shown, the device 700 includes one or more processors 710, one or more memories 720 coupled to the processor 710, and one or more communication modules 740 coupled to the processor 710.

The communication module 740 is for bidirectional communications. The communication module 740 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 740 may include at least one antenna.

The processor 710 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 700 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

The memory 720 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 724, an electrically programmable read only memory (EPROM) , a flash memory, a hard disk, a compact disc (CD) , a digital video disk (DVD) , an optical disk, a laser disk, and other magnetic storage and/or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 722 and other volatile memories that will not last in the power-down duration.

A computer program 730 includes computer executable instructions that are executed by the associated processor 710. The instructions of the program 730 may include instructions for performing operations/acts of some example embodiments of the present disclosure. The program 730 may be stored in the memory, e.g., the ROM 724. The processor 710 may perform any suitable actions and processing by loading the program 730 into the RAM 722.

The example embodiments of the present disclosure may be implemented by means of the program 730 so that the device 700 may perform any process of the disclosure as discussed with reference to FIG. 2 to FIG. 6. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some example embodiments, the program 730 may be tangibly contained in a computer readable medium which may be included in the device 700 (such as in the memory 720) or other storage devices that are accessible by the device 700. The device 700 may load the program 730 from the computer readable medium to the RAM 722 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory, ” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM) .

FIG. 8 shows an example of the computer readable medium 800 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 800 has the program 730 stored thereon.

Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions/operations specified in the flowcharts and/or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM) , a read-only memory (ROM) , an erasable programmable read-only memory (EPROM or Flash memory) , an optical fiber, a portable compact disc read-only memory (CD-ROM) , an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

Further, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable sub-combination.

Although the present disclosure has been described in languages specific to structural features and/or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

An apparatus comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to:

receive, from a network device, a configuration of a discontinuous reception indicating at least one of: a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle;

determine, based on a predefined formula, a target start time offset for an on duration of the discontinuous reception cycle without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number; and

perform the discontinuous reception based on the determined target start time offset.
The apparatus of claim 1, wherein the apparatus is caused to:

determine whether the discontinuous reception cycle is represented as a rational number; and

in accordance with a determination that the discontinuous reception cycle is represented as a rational number and the discontinuous reception cycle is a long discontinuous reception cycle, obtaining the target start time offset by applying the predefined formula that is represented as:

and

wherein A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the long discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.
The apparatus of claim 1, wherein the apparatus is caused to:

determine whether the discontinuous reception cycle is represented as a rational number; and

in accordance with a determination that the discontinuous reception cycle is represented as a rational number and the discontinuous reception cycle is a short discontinuous reception cycle, obtaining the target start time offset by applying the predefined formula that is represented as:

and

wherein A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the short discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.
The apparatus of claim 1, wherein the apparatus is caused to:

determine whether the discontinuous reception cycle is represented as a rational number; and

in accordance with a determination that the discontinuous reception cycle is an integer number, determine whether the discontinuous reception cycle is a short discontinuous reception cycle or a long discontinuous reception cycle.
The apparatus of claim 4, wherein the apparatus is caused to:

in accordance with a determination that the discontinuous reception cycle is the short discontinuous reception cycle, obtaining the target start time offset of the short discontinuous reception cycle by applying the predefined formula that is represented as:

floor ( [ (SFN × 10) + subframe number] modulo (drx-ShortCycle) ) = floor ( (drx-StartOffset) modulo (drx-ShortCycle) ) , and

wherein SFN represents a system frame number, drx-ShortCycle represents the short discontinuous reception cycle, drx-StartOffset represents the target start time offset.
The apparatus of claim 4, wherein the apparatus is caused to:

in accordance with a determination that the discontinuous reception cycle is the long discontinuous reception cycle, obtaining the target start time offset of the long discontinuous reception cycle by applying the predefined formula that is represented as:

floor ( [ (SFN × 10) + subframe number] modulo (drx-LongCycle) ) = drx-StartOffset, and

wherein SFN represents a system frame number, drx-LongCycle represents the long discontinuous reception cycle, drx-StartOffset represents the target start time offset.
The apparatus of claim 1, wherein the configuration of the discontinuous reception indicates a hyper discontinuous reception cycle and the number of discontinuous reception cycles within the hyper discontinuous reception cycle, and

wherein the discontinuous reception cycle is represented as the hyper discontinuous reception cycle divided by the number of discontinuous reception cycles within the hyper discontinuous reception cycle.
The apparatus of claim 7, wherein the apparatus is caused to:

in accordance with a determination that the discontinuous reception cycle is a long discontinuous reception cycle, obtaining the target start time offset of the long discontinuous reception cycle by applying the predefined formula that is represented as:

floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) / (drx-HyperCycle) ) ] ) ) / (drx-NumberOfCyclesPerHyperCycle) ) = drx-StartOffset, and

wherein SFN represents a system frame number drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.
The apparatus of claim 7, wherein the apparatus is caused to:

in accordance with a determination that the discontinuous reception cycle is a short discontinuous reception cycle, obtaining the target start time offset of the short discontinuous reception cycle by applying the predefined formula that is represented as:

floor ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) = floor ( (drx-StartOffset × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( (drx-StartOffset × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) , and

wherein SFN represents a system frame number drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.
The apparatus of any of claims 1-9, wherein the apparatus comprises a terminal device.
A second apparatus comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to:

transmit, to a first apparatus, a configuration of a discontinuous reception indicating at least one of: a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle, wherein a target start time offset for an on duration of the discontinuous reception cycle is determined based on a predefined formula, without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number.
The second apparatus of claim 11, wherein if the discontinuous reception cycle is represented as a rational number and the discontinuous reception is a long discontinuous reception cycle, the target start time offset is obtained by applying the predefined formula that is represented as:

and

wherein A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the long discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.
The second apparatus of claim 11, wherein if the discontinuous reception cycle is represented as a rational number and the discontinuous reception is a short discontinuous reception cycle, the target start time offset is obtained by applying the predefined formula that is represented as:

and

wherein A represnets [ (SFN×10) +subframe number] which is an integer number, SFN represents a system frame number, B/C represents the short discontinuous reception cycle which is a rational number represented by a ratio of two integers that are represented as B and C, Z represents the target start time offset which is an integer number, and floor represents a floor operation.
The second apparatus of claim 11, wherein if the discontinuous reception cycle is an integer number and the discontinuous reception cycle is the short discontinuous reception cycle, the target start time offset of the short discontinuous reception cycle is obtained by applying the predefined formula that is represented as:

floor ( [ (SFN × 10) + subframe number] modulo (drx-ShortCycle) ) = floor ( (drx-StartOffset) modulo (drx-ShortCycle) ) , and

wherein SFN represents a system frame number, drx-ShortCycle represents the short discontinuous reception cycle, drx-StartOffset represents the target start time offset.
The second apparatus of claim 11, wherein if the discontinuous reception cycle is an integer number and the discontinuous reception cycle is the long discontinuous reception cycle, the target start time offset of the long discontinuous reception cycle is obtained by applying the predefined formula that is represented as:

floor ( [ (SFN × 10) + subframe number] modulo (drx-LongCycle) ) = drx-StartOffset, and

wherein SFN represents a system frame number, drx-LongCycle represents the long discontinuous reception cycle, drx-StartOffset represents the target start time offset.
The second apparatus of claim 11, wherein the configuration of the discontinuous reception indicates a hyper discontinuous reception cycle and the number of discontinuous reception cycles within the hyper discontinuous reception cycle, and

wherein the discontinuous reception is represented as the hyper discontinuous reception cycle divided by the number of discontinuous reception cycles within the hyper discontinuous reception cycle.
The second apparatus of claim 16, wherein if the discontinuous reception cycle is a long discontinuous reception cycle, the target start time offset of the long discontinuous reception cycle is obtained by applying the predefined formula that is represented as:

floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) / (drx-HyperCycle) ) ] ) ) / (drx-NumberOfCyclesPerHyperCycle) ) = drx-StartOffset, and

wherein SFN represents a system frame number drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.
The second apparatus of claim 16, wherein if the discontinuous reception cycle is a short discontinuous reception cycle, the target start time offset of the short discontinuous reception cycle is obtained by applying the predefined formula that is represented as:

floor ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( ( [ (SFN × 10) + subframe number] × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) = floor ( (drx-StartOffset × drx-NumberOfCyclesPerHyperCycle - [drx-HyperCycle × floor ( ( (drx-StartOffset × drx-NumberOfCyclesPerHyperCycle) ) /drx-HyperCycle) ] ) /drx-NumberOfCyclesPerHyperCycle) , and

wherein SFN represents a system frame number drx-NumberOfCyclesPerHyperCycle represents the number of discontinuous reception cycles within the hyper discontinuous reception cycle, drx-HyperCycle represents the hyper discontinuous reception cycle, and drx-StartOffset represents the target start time offset.
The second apparatus of any of claims 11-18, wherein the second apparatus comprises a network device, and the first apparatus comprises a terminal device.
A method comprising:

receiving, at a first apparatus and from a second apparatus, a configuration of a discontinuous reception indicating at least one of a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle;

determining, based on a predefined formula, a target start time offset for an on duration of the discontinuous reception cycle without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number; and

performing the discontinuous reception based on the determined target start time offset.
A method comprising:

transmitting, at a second apparatus and to a first apparatus, a configuration of a discontinuous reception indicating at least one of: a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle, wherein a target start time offset for an on duration of the discontinuous reception cycle is determined based on a predefined formula, without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number.
A first apparatus comprising:

means for receiving, from a second apparatus, a configuration of a discontinuous reception indicating at least one of: a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle;

means for determining, based on a predefined formula, a target start time offset for an on duration of the discontinuous reception cycle without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number; and

means for performing the discontinuous reception based on the determined target start time offset.
A second apparatus comprising:

means for transmitting, to a first apparatus, a configuration of a discontinuous reception indicating at least one of: a discontinuous reception cycle of the discontinuous reception or a start time offset of the discontinuous reception cycle, wherein a target start time offset for an on duration of the discontinuous reception cycle is determined based on a predefined formula, without rounding errors, wherein the target start time offset is ensured to match the start time offset of the discontinuous reception cycle when the discontinuous reception cycle is represented as a rational number.
A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of any of claims 20-21.