WO2019029961A1

WO2019029961A1 - Scheduling technique for a data communication

Info

Publication number: WO2019029961A1
Application number: PCT/EP2018/069512
Authority: WO
Inventors: Andreas HÖGLUND
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2017-08-11
Filing date: 2018-07-18
Publication date: 2019-02-14

Abstract

A technique for transmitting data in a data communication scheduled by a radio access network, RAN, is described. As to a method aspect of the technique, at least one configuration message (502; 504) indicative of radio resources granted for transmissions according to a semi-persistent scheduling, SPS, that is configured for selectively skipping (508) the transmissions is received from the RAN. On at least one of the radio resources granted according to the SPS, a buffer status report, BSR (510) is selectively transmitted if new data to be transmitted in the data communication is available.

Description

Scheduling Technique for a Data Communication

Technical Field

The present disclosure generally relates to a scheduled data communication. More specifically, and without limitation, methods and devices are provided for a data communication that is scheduled by a radio access network.

Background

The 3rd Generation Partnership Project (3GPP) has been specifying technologies tailored for machine-to-machine (M2M) communications and use-cases related to the so-called Internet of Things (loT). Most recent work for 3GPP releases 13 and 14 includes enhancements to support machine-type communications (MTC) with radio device categories Cat-Mi and Cat-M2 for user equipments (UEs) supporting a reduced bandwidth of 6 physical resource blocks (PRBs) with up to 24 PRBs for Cat- M2 as well as UEs using a specific radio interface for narrowband loT (NB-loT) according to radio device categories Cat-NBl and Cat-NB2.

For NB-loT, short-lived connections and a stripped-down design was the main focus and, hence, subsequent traffic in a connected mode (e.g. RRC_CONNECTED mode) with a dedicated SR was not supported. However, in 3GPP release 15, the intention is to support more diverse traffic and to reduce latency and UE power consumption.

Therefore, a scheduling request (SR) is currently a work item objective in an approved work item for NB-loT in 3GPP release 15. In conventional LTE, if the UE is in the idle mode or does not have a dedicated PUCCH resource, the SR instead triggers a random access (RA) procedure. Further details as to the SR in conventional LTE can be found in the subclause 10.1.5 of the document 3GPP TS 36.213, V13.6.0, in the subclause 5.4.4 of the document 3GPP TS 36.321 and in the subclause 6.3.2 in the document 3GPP TS 36.331, e.g., V14.3.0 in each case.

Since the radio access network (RAN) controls the scheduling of radio resources, a straightforward scheduling technique for eMTC and NB-loT would use a physical layer SR analogously to conventional LTE. Therefore, the dedicated SR in the connected mode when the UEs are in uplink synchronization is one of the included working item objectives. First, data arriving in an uplink buffer of the UE would trigger such an SR. In conventional LTE, UEs in connected mode have a dedicated physical uplink control channel (PUCCH) resource in which the SR is transmitted. The SR does not contain any information. The SR is just an indication to the RAN that the UE wants to transmit data. The evolved Node B (eNB) of the RAN knows the UE-identity from the unique periodic resource used for the SR. Second, the eNB would typically provide an uplink grant to the UE, which is at least big enough for the UE to transmit a buffer status report (BSR), and possibly some user-plane data. However, above two steps for the conventional SR cause a significant signaling overhead, delay the actual data transmission, thus contributing to the latency in the data communication, and consume power in the multiple exchanges of control signaling. Summary

Accordingly, there is a need for a data communication technique that accurately schedules radio resources with less delay and power consumption. More

specifically, there is a need for a technique that reduces at least one of power consumption and latency in at least some situations.

As to one aspect, a method of transmitting data in a data communication scheduled by a radio access network (RAN) is provided. The method comprises or triggers a step of receiving, from the RAN, at least one configuration message indicative of radio resources granted for transmissions according to a semi-persistent scheduling (SPS) that is configured for selectively skipping the transmissions. The method further comprises or triggers a step of selectively transmitting, on at least one of the radio resources granted according to the SPS, a buffer status report, BSR, if data (e.g., new data) to be transmitted in the data communication is available.

The one method aspect may be implemented at or performed by a radio device. The radio device may encompass any transmitting station that is configured to wirelessly access the RAN. As to another aspect, method of scheduling a data communication involving a radio device is provided. The method comprises or triggers a step of transmitting, to the radio device, at least one configuration message indicative of radio resources granted for transmissions according to a semi-persistent scheduling (SPS) that is configured for selectively skipping the transmissions. The method further comprises or triggers a step of selectively receiving, on at least one of the radio resources granted according to the SPS, a buffer status report (BSR) if data (e.g., new data) to be transmitted (e.g., by the radio device) in the data communication is available.

The other method aspect may be implemented at the RAN. The other method aspect may be performed by a base station or a cell of the RAN. The base station may encompass any scheduling station that is configured to provide radio access to the radio device.

The other method aspect may further comprise or trigger any feature or step, or any corresponding feature or step, disclosed herein in the context of the one method aspect.

The radio device may be configured for peer-to-peer communication (e.g., on a sidelink) and/or for accessing the RAN (e.g. an UL and/or downlink, DL). The radio device may be a user equipment (UE, e.g., a 3GPP UE), a mobile or portable station (STA, e.g. a Wi-Fi STA), a device for machine-type communication (MTC), a NB-loT device or a combination thereof. Examples for the UE and the mobile station include a mobile phone and a tablet computer. Examples for the portable station include a laptop computer and a television set. Examples for the MTC device and the NB-loT device include robots, sensors and/or actuators, e.g., in manufacturing, automotive communication and home automation. The MTC device or the NB-loT device may be implemented in household appliances and consumer electronics. Examples for the combination include a self-driving vehicle, a door intercommunication system and an automated teller machine.

Examples for the base station may include a 3G base station or Node B, 4G base station or eNodeB, a 5G base station or gNodeB, an access point (e.g., a Wi-Fi access point) and a network controller (e.g., according to Bluetooth, ZigBee or Z-Wave).

The RAN may be implemented according to the Global System for Mobile

Communications (GSM), the Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE) and/or New Radio (NR).

The technique may be implemented on a Physical Layer (PHY), a Medium Access Control (MAC) layer, a Radio Link Control (RLC) layer and/or a Radio Resource Control (RRC) layer of a protocol stack for the data communication. The technique may be implemented as a technique for configuring a radio device for the SPS in combination with the selective skipping of transmissions.

As to another aspect, a computer program product is provided. The computer program product comprises program code portions for performing any one of the steps of the method aspects disclosed herein when the computer program product is executed by one or more computing devices. The computer program product may be stored on a computer-readable recording medium. The computer program product may also be provided for download via a data network, e.g., via the RAN and/or via the Internet and/or by the base station. Alternatively or in addition, any of the method aspects may be encoded in a Field-Programmable Gate Array (FPGA) and/or an Application-Specific I ntegrated Circuit (ASIC), or the functionality may be provided for download by means of a hardware description language.

As to one device aspect, a device for transmitting data in a data communication scheduled by a radio access network (RAN) is provided. The device is configured to perform or trigger the one method aspect. Alternatively or in addition, the device may comprise a receiving unit configured to receive, from the RAN, at least one configuration message indicative of radio resources granted for transmissions according to a semi-persistent scheduling (SPS) that is configured for selectively skipping the transmissions. The device may further comprise a transmitting unit configured to selectively transmit, on at least one of the radio resources granted according to the SPS, a buffer status report (BSR) if data (e.g., new data) to be transmitted in the data communication is available.

As to a further device aspect, a device for scheduling a data communication involving a radio device is provided. The device is configured to perform or trigger the other method aspect. Alternatively or in addition, the device may comprise a transmitting unit configured to transmit, to the radio device, at least one configuration message indicative of radio resources granted for transmissions according to a semi-persistent scheduling (SPS) that is configured for selectively skipping the transmissions. The device may further comprise a receiving unit configured to selectively receive, on at least one of the radio resources granted according to the SPS, a buffer status report (BSR) if data (e.g., new data) to be transmitted (e.g., by the radio device) in the data communication is available. As to a still further aspect, a device for transmitting data in a data communication scheduled by a radio access network (RAN) is provided. The device comprises at least one processor and a memory. Said memory comprises instructions executable by said at least one processor whereby the device is operative to receive, from the RAN, at least one configuration message indicative of radio resources granted for

transmissions according to a semi-persistent scheduling (SPS) that is configured for selectively skipping the transmissions. The device is further operative to selectively transmit, on at least one of the radio resources granted according to the SPS, a buffer status report (BSR) if data (e.g., new data) to be transmitted in the data

communication is available.

As to a still further aspect, a device for scheduling a data communication involving a radio device is provided. The device comprises at least one processor and a memory. Said memory comprises instructions executable by said at least one processor whereby the device is operative to transmit, to the radio device, at least one configuration message indicative of radio resources granted for transmissions according to a semi-persistent scheduling (SPS) that is configured for selectively skipping the transmissions. The device is further operative to selectively receive, on at least one of the radio resources granted according to the SPS, a buffer status report (BSR) if data (e.g., new data) to be transmitted (e.g., by the radio device) in the data communication is available.

As to a still further aspect, a device for transmitting data in a data communication scheduled by a radio access network (RAN) is provided. The device comprises a reception module for receiving, from the RAN, at least one configuration message indicative of radio resources granted for transmissions according to a semi-persistent scheduling (SPS) that is configured for selectively skipping the transmissions. The device further comprises a selective transmission module for selectively transmitting, on at least one of the radio resources granted according to the SPS, a buffer status report (BSR) if data (e.g., new data) to be transmitted in the data communication is available.

As to a still further aspect, a device for scheduling a data communication involving a radio device is provided. The device comprises a transmission module for

transmitting, to the radio device, at least one configuration message indicative of radio resources granted for transmissions according to a semi-persistent scheduling (SPS) that is configured for selectively skipping the transmissions. The device further comprises a selective reception module for selectively receiving, on at least one of the radio resources granted according to the SPS, a buffer status report (BSR) if data (e.g., new data) to be transmitted (e.g., by the radio device) in the data

communication is available.

The device (or any node or station for embodying the technique) may further include any feature disclosed in the context of the corresponding method aspect. Particularly, any one of the units and modules, or a dedicated unit or module, may be configured to perform or trigger one or more of the steps of any one of the method aspects.

Brief Description of the Drawings

Further details of embodiments of the technique are described with reference to the enclosed drawings, wherein:

Fig. 1 shows a schematic block diagram of a device for transmitting data in a data communication scheduled by a radio access network;

Fig. 2 shows a schematic block diagram of a device for scheduling a data

communication involving a radio device;

Fig. 3 shows a flowchart for a method of transmitting data in a data communication scheduled by a radio access network, which method is implementable by the device of Fig. 1;

Fig. 4 shows a flowchart for a method of scheduling a data communication

involving a radio device, which method is implementable by the device of Fig. 2;

Fig. 5 shows a schematic first signaling diagram for embodiments of the devices of Figs. 1 and 2 in communication;

Fig. 6 shows a schematic second signaling diagram for embodiments of the devices of Figs. 1 and 2 in communication;

Fig. 7 shows a flowchart for operating an embodiment of the device of Fig. 1;

Fig. 8 shows a schematic block diagram of a first embodiment of the device of

Fig. 1; Fig. 9 shows a schematic block diagram of a second embodiment of the device of Fig. 1;

Fig. 10 shows a schematic block diagram of a first embodiment of the device of Fig. 2; and

Fig. 11 shows a schematic block diagram of a second embodiment of the device of Fig. 2; and

Fig. 12 schematically illustrates a signaling diagram for a 3GPP NB-loT PHY

implementation.

Detailed Description

In the following description, for purposes of explanation and not limitation, specific details are set forth, such as a specific network environment in order to provide a thorough understanding of the technique disclosed herein. It will be apparent to one skilled in the art that the technique may be practiced in other embodiments that depart from these specific details. Moreover, while the following embodiments are primarily described for a 5G New Radio (NR) implementation, it is readily apparent that the technique described herein may also be implemented in any other radio network, including 3GPP LTE or a successor thereof, Wireless Local Area Network (WLAN) according to the standard family IEEE 802.11, Bluetooth according to the Bluetooth Special Interest Group (SIG), particularly Bluetooth Low Energy and Bluetooth broadcasting, and/or ZigBee based on IEEE 802.15.4.

Moreover, those skilled in the art will appreciate that the functions, steps, units and modules explained herein may be implemented using software functioning in conjunction with a programmed microprocessor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), a Digital Signal Processor (DSP) or a general purpose computer, e.g., including an Advanced RISC Machine (ARM). It will also be appreciated that, while the following embodiments are primarily described in context with methods and devices, the invention may also be embodied in a computer program product as well as in a system comprising at least one computer processor and memory coupled to the at least one processor, wherein the memory is encoded with one or more programs that may perform the functions and steps or implement the units and modules disclosed herein. Fig. 1 schematically illustrates a block diagram of a device for transmitting data in a data communication scheduled by a radio access network (RAN). The device is generically referred to by reference sign 100. The device 100 comprises a reception module 102 that receives, from the RAN, at least one configuration message indicative of radio resources granted for

transmissions according to a semi-persistent scheduling (SPS). The SPS (e.g., a parameter for the SPS received at the device 100 in the at least one configuration message) is configured for selectively skipping the transmissions, i.e., the device 100 can skip the transmission on any of the SPS-granted radio resources. When the transmission is skipped, it is not necessary that a packet data unit (PDU) with a zero service data unit (SDU) or padding bits be transmitted. A power amplifier of the device 100 may be switched-off during the skipped SPS-granted radio resource. The device 100 further comprises a selective transmission module 104 that selectively transmits, if data to be transmitted in the data communication (e.g., only if new data to be transmitted in the data communication) is available, a buffer status report (BSR) for the data communication on one or more of the radio resources granted according to the SPS.

Optionally, the device 100 comprises a further reception module 106 that receives, from the RAN, at least one further configuration message indicative of a change in the SPS-granted radio resources or further radio resources granted in response to the transmitted BSR.

The device 100 may be embodied by or at a radio device, e.g., a 3GPP UE or any transmitting station. The radio device 100 may be configured for wireless

communication with the RAN according to a protocol stack for the data

communication.

Fig. 2 schematically illustrates a block diagram of a device for scheduling a data communication involving a radio device. The device is generically referred to by reference sign 200. The device 200 comprises a transmission module 202 that transmits, to the radio device, at least one configuration message indicative of radio resources granted for transmissions according to a SPS. The SPS (e.g., a parameter for the SPS at the device 200 and/or a parameter for the SPS transmitted in the at least one configuration message) is configured for selectively skipping the transmissions. E.g., the device 200 and/or the RAN may refrain from triggering a retransmission if the radio device skips its transmission on any of the SPS-granted radio resources.

The device 200 further comprises a selective reception module 204 that selectively receives, if data to be transmitted in the data communication (e.g., only if new data to be transmitted in the data communication) is available, a BSR for the data communication on one or more of the radio resources granted according to the SPS.

Optionally, the device 200 comprises a further transmission module 206 that changes the SPS-granted radio resources or grants further radio resources in response to the received BSR.

The device 200 may be connected to and/or part of the RAN. The device 200 may be embodied by or at a scheduling station, e.g., a base station of the RAN, one or more nodes connected to the RAN (e.g., for controlling the base station) or a combination thereof. The RAN may schedule the data communication with or without being a receiver of the data transmissions from the radio device in the data communication. For example, the RAN may receive only the BSRs.

Any of the modules of the device 100 may be implemented by units configured to provide the corresponding functionality.

The device 200 may embody the RAN (e.g., as a base station of the RAN) in communication with the device 100. The device 100 may embody the radio device in communication with the device 200.

Fig. 3 shows a flowchart for a method 300 of transmitting data in a data

communication scheduled by a RAN. The method 300 comprises or triggers a step 302 of receiving, from the RAN, at least one configuration message indicative of radio resources granted for transmissions according to an SPS configured for selectively skipping the transmissions. The method 300 further comprises or triggers a step 304 of selectively transmitting, on at least one of the radio resources granted according to the SPS, a BSR if (e.g., new) data to be transmitted in the data communication is available. Optionally, a change in the configuration of the SPS and/or a grant for further radio resources for the data communication is received in a step 306. The change and/or the grant may depend on the BSR transmitted in the step 304. The method 300 may be performed by the device 100, e.g., at or using the radio device. For example, the modules 102, 104 and, optionally, 106 may perform the steps 302, 304 and, optionally, 306, respectively.

The technique can be embodied for transmitting the BSR without the need of transmitting a scheduling request for inducing a scheduling grant for the BSR. The BSR can be transmitted straightaway, i.e., without an intermediate step for achieving the scheduling grant for transmitting the BSR. Thus, at least one of latency in the data communication, radio resources of the RAN and power consumption of embodiments of the technique can be reduced.

The method may be implemented as a method of requesting radio resources scheduled based on a BSR, e.g., without a scheduling request (e.g., as a physical control signal or a control element on a physical control channel) for requesting radio resources for the BSR. Embodiments can eliminate or reduce the need for a dedicated scheduling request. Herein, "dedicated" may refer to a scheduling request that is specifically triggered by the new data. Alternatively or in addition, "dedicated" may refer to a scheduling request that requests for radio resources, wherein the payload or usage of such radio resources is determined at the time of triggering or transmitting the scheduling request. In preferred implementations, the radio resources for transmitting at least the BSRs (e.g., those BSRs triggered by new data) are not dynamically scheduled.

Herein, "new data" may encompass data for a new transmission, e.g., as opposed to previously transmitted data and/or data for a retransmission. The availability of the new data may also be referred to as arrival of new data. The arrival may trigger the selective transmission of the BSR. The selectivity in the selective transmission of the BSR may depend on the availability of the new data.

The radio resources granted according to the SPS may comprise a plurality of radio resources, e.g., temporally separate radio resources. The plurality of radio resources may be preemptively scheduled according to the SPS, e.g., all at once (i.e., in one of the one or more configuration messages). The payload or usage of at least some of radio resources granted according to the SPS may be not yet determined at the time of receiving the at least one configuration message indicative of the radio resources.

The plurality of radio resources granted according to the SPS may comprise separate physical resource blocks (PRBs) or separate pairs of PRBs. In the time domain, the plurality of radio resources may comprise separate subframes or separate

transmission time intervals (TTI).

For example, the radio resources granted according to the SPS may be periodically scheduled according to the SPS. The periodicity of the scheduling may be referred to as SPS interval, e.g., semiPersistSchedlntervalUL (e.g., according to 3GPP TS 36.321, subclause 5.10.2, e.g., V14.3.0) or semiPersistSchedlntervalSL for an uplink data communication or a sidelink data communication, respectively. The plurality of radio resources granted according to the SPS may be on the same set of subcarriers and/or spatial streams.

The BSR may be indicative of the data (e.g., user data or payload data) to be transmitted in the data communication. The BSR may be indicative of at least one of new data (e.g., data not yet transmitted in the data communication),

unacknowledged data (e.g., data potentially to be retransmitted in the data communication) or negatively acknowledged data (e.g., data to be retransmitted in the data communication).

The technique may be applied to multiple instances of the BSR (briefly referred to as a plurality of BSRs), e.g., for each occurrence of new data. A plurality of BSRs may be transmitted on (e.g., a proper subset of) the radio resources granted according to the SPS. The BSRs may be selectively transmitted according to the current availability of new data to be transmitted in the data communication.

One of the configuration messages may be indicative of a configuration for the SPS. Another one of the configuration messages may be indicative of a configuration for the selective skipping.

The data communication may include a machine-type communication (MTC). The radio device may comprise, or may be implemented by, a user equipment (UE) or a device for MTC according to 3GPP Long Term Evolution or a successor thereof, e.g., 3GPP release 13, 14 or 15, which is also referred to as an enhanced MTC (eMTC). Alternatively or in addition, the data communication may include a narrowband Internet-of-Things (NB-loT) communication. The radio device may comprise, or may be implemented by an NB-loT device, e.g., according to 3GPP release 13, 14 or 15.

The method may further comprise or trigger a step of receiving, from the RAN in response to the transmitted BSR, a scheduling grant for one or more further radio resources for the data communication and/or a further configuration message indicative of a change in the SPS depending on the BSR. For example, the SPS interval may be changed depending on the BSR.

Based on the transmitted BSR, the RAN may grant further radio resources for transmitting the data in the data communication. The further granted radio resources may be dynamically granted or semi-persistently scheduled. The data to be transmitted (e.g., the new data) may be transmitted (e.g., partly) in the same radio resource (e.g., temporally contiguous with the radio resource) used for transmitting the BSR, (e.g., partly) in at least one subsequent radio resource granted according to the SPS and/or (e.g., partly) in radio resources further granted by the RAN in response to the BSR.

The selective transmission on the radio resources granted according to the SPS includes selectively skipping the transmission of the BSR if no new data is available.

If no new data is available, any transmission on the corresponding radio resource granted according to the SPS may be skipped. Alternatively, the corresponding radio resource may be used differently, e.g., for retransmitting data in the data

communication.

Multiple instances of the BSR (i.e., a plurality of BSRs) may be selectively transmitted on the radio resources granted according to the SPS depending on whether or not new data is available at the time of the corresponding radio resources.

The SPS may be configured according to an SPS-ConfigUL information element (IE), e.g., according to the document 3GPP TS 36.331, V14.3.0. Alternatively or in addition, the at least one configuration message may be indicative of an SPS configuration for a sidelink in the data communication, e.g., analogously to the SPS-ConfigUL IE according to the document 3GPP TS 36.331, V14.3.0.

The radio resources granted according to the SPS may also be referred to as SPS- granted radio resources. A transmission on an SPS-granted radio resource may also be referred to as an SPS-granted transmission.

The SPS according to the at least one configuration message may be configured for skipping (i.e., for selectively skipping) any one of the transmissions on the radio resources granted according to the SPS, if no data is available for the corresponding one of the transmissions. That is, the SPS (e.g., the radio device using the SPS) may be configured to skip a transmission on the radio resources granted according to the SPS in case no data is available for the corresponding transmissions. Configuring the SPS for the selective skipping may include configuring the RAN (e.g., the serving BS) not to trigger a retransmission and/or not to transmit a negative acknowledgment (NACK) signal when a transmission on an SPS-granted radio resource is skipped.

In the context of selectively skipping an SPS-granted transmission, the unavailability of "data" may encompass an unavailability of the BSR or may encompass a zero service data unit (SDU), e.g., on a medium access control (MAC) layer. The data to be transmitted in the data communication and the BSR may be transmitted on the same physical channel, e.g., a physical uplink shared channel (PUSCH) of the RAN.

The SPS may be configured for skipping the transmission on a radio resource granted according to the SPS, if no data (e.g., no BSR) is available for the transmission. For example, the grant according to the SPS may be ignored for one or some of the periodically scheduled radio resources.

The selective skipping may be configured by setting a parameter of a MAC- MainConfig IE for the MAC layer. For example, the selective skipping may be configured according to the document 3GPP TS 36.331, V14.3.0 and/or the document 3GPP TS 36.321, V14.3.0.

The plurality of BSRs may be exclusively transmitted on the radio resources granted according to the SPS. For example, each BSR triggered by new data may be transmitted exclusively on the SPS-granted radio resources of the RAN. Preferably, none of the BSRs (e.g., no BSR that is triggered by new data) is transmitted on a dynamically scheduled radio resource of the RAN.

A dynamically scheduled radio resource may encompass a radio resource that is granted in response to a (e.g., dedicated) scheduling request. Alternatively or in addition, a dynamically scheduled radio resource may comprise only one radio resource or one temporally contiguous set of radio resources, e.g., one PRB or one pair of PRBs.

The method may be performed by a radio device served by the RAN. The radio device may be any device configured for accessing the RAN, synchronizing with the RAN and/or receiving configuration messages from the RAN. The at least one configuration message may be received at the radio device. The radio resources may be granted for transmissions from and/or at the radio device. The BSR may be transmitted from the radio device served by the RAN.

According to the at least one configuration message, at least one of the radio device, the RAN and the SPS may be configured for selectively skipping a transmission on one or more of the radio resources granted according to the SPS when no data (e.g., no BSR) to be transmitted is available at the radio device.

The BSR may be generated and/or selectively transmitted only if new data to be transmitted is or becomes available at the radio device. The BSR may be selectively transmitted depending on whether or not new data to be transmitted in the data communication is available at the radio device. The data communication may relate to one of a plurality of a hybrid automatic repeat request (HARQ) entities at the radio device. The technique may be implemented for one or each of the HARQ entities or each of a subset of the HARQ entities.

The radio device may be served by a base station of the RAN. The RAN may comprise one or more base stations. The data and/or the BSR may be transmitted to the RAN, e.g., to the base station. The data communication may comprise an uplink (UL) from the radio device to the RAN, e.g., to the base station.

For example, the MAC-MainConfig IE may comprise a parameter, skipUplinkTxSPS, that indicates whether the radio device supports skipping (e.g., selectively skipping) of an UL transmission for a configured uplink grant if no data (e.g., user data and/or the BSR) is available for transmission, e.g., as described in the document 3GPP TS 36.321, V14.3.0, particularly in subclause 5.4.2.

Alternatively or in addition, the data may be transmitted to another radio device. The other radio device may be within coverage of the RAN (i.e., served by the RAN, e.g., another radio device served by the same base station) or may be out of coverage of the RAN (and within range of the radio device). The data communication may comprise a sidelink (SL) from the radio device to the other radio device. For example, the SPS may be configured for the SL according to the document 3GPP TS 36.321, V14.3.0, e.g., subclause 5.14.1. Alternatively or in addition, the BSR may be a SL BSR, e.g., according to the document 3GPP TS 36.321, V14.3.0, e.g., subclause 5.4.4.

Alternatively or in addition, the skipping (i.e., the selective skipping) of SL

transmissions may be configured in the MAC-MainConfig IE, e.g., by setting a parameter skipSidelinkTxSPS in the MAC-MainConfig IE, which may be structured analogously to the parameter skipUplinkTxSPS.

The data to be transmitted in the data communication may be available in a buffer of the radio device. The BSR may indicative of a filling status of the buffer. For example, the radio device may comprise a HARQ buffer for each of the HARQ entities.

The filling status of the buffer may also be referred to as the size of the buffer or the amount of data available in the buffer for transmission in the data communication. The buffer may comprise the data (e.g., user data or payload data) to be transmitted from the radio device in the data communication. The buffer may store at least one of the new data and the unacknowledged data originating from the radio device in the data communication.

The data communication may comprise an UL. The buffer may comprise an UL buffer storing the data to be transmitted in the UL. Alternatively or in addition, the data communication may comprise a SL. The buffer may comprise an SL buffer storing the data to be transmitted in the SL.

In the case of a SL for the data communication, the data in the SL buffer may be transmitted to the other radio device using radio resources scheduled by the RAN (e.g., the base station) in response to and/or based on the SL BSR. The SL BSR may be selectively transmitted to the RAN (e.g., the base station) according to the technique.

The BSR may be triggered by new data arriving in the buffer. The buffer may be a buffer on the MAC, layer (e.g., of a protocol stack used for the data communication) of the radio device. Furthermore, the buffer may be a HARQ buffer of an HARQ entity at the MAC layer of the radio device.

At least some or all of the new data in the buffer may be transmitted on the radio resources granted according to the SPS. For example, the BSR and some or all of the new data may be transmitted in one of the SPS-granted radio resources. The data transmitted on at least some of the radio resources granted according to the SPS may include data that is retransmitted in response to a negative acknowledgement.

Alternatively or in addition, data retransmission may be dynamically scheduled. The radio device may refrain from transmitting on the radio resources granted according to the SPS unless new data is available for transmission in the data communication.

The radio device may remain in a radio resource control (RRC) connected mode. Alternatively or in addition, the SPS may be canceled once a timer for a time alignment of the radio device with the RAN (e.g., the serving base station) expires. The RRC connected mode may be triggered and/or completed in a random access (RA) procedure. Alternatively or in addition, the time alignment may be received and/or established in RA procedure.

The method may further comprise or trigger a step of transmitting, to the RAN, at least one first request triggering at least one of configuring the SPS for the data communication and configuring the selective skipping for the data communication. The SPS configured for the selective skipping (i.e., the combi ned configuration of the SPS and the selective skipping) may also be referred to as SPS with skipping. The at least one first request may trigger or may be indicative of SPS with skipping.

The method may be triggered by the at least one first request. For example, the at least one first request may trigger the at least one configuration message indicative of the radio resources granted for transmissions according to the SPS configured for the selectively skipping. Alternatively or in addition, the at least one first request may be transmitted prior to receiving the at least one configuration message indicative of radio resources granted for transmissions according to the SPS configured for the selectively skipping. The at least one configuration message may be received in response to transmitting the at least one first request.

The method may further comprise or trigger a step of transmitting, to the RAN, at least one second request triggering the RA procedure with the RAN. The at least one second request may imply a scheduling request to the RAN and/or the at least one first request.

The at least one second request may include a RA preamble. The RA preamble may be transmitted on a physical random access channel (PRACH), e.g., for the radio device implementing a user equipment (UE) or a device for MTC or eMTC.

Alternatively or in addition, the RA preamble may be transmitted on a NB-loT PRACH (NPRACH), e.g., for the radio device implementing an NB-loT device. The RA procedure with the RAN may comprise a step of receiving, from the RAN, a scheduling grant for a further radio resource that is scheduled prior to the next radio resource granted according to the SPS. The scheduling grant may be received in response to the at least one second request. By triggering the RA procedure for dynamically scheduling the further radio resource, a latency requirement of the data communication may be selectively and/or temporarily fulfilled. For example, SPS- granted radio resources may limit the latency in the data communication (e.g., when transmitting user data and/or the BSR according to the SPS). The latency limit may be a lower limit on the latency, which depends on the SPS interval. By triggering the RA procedure, the latency limit may be selectively and/or temporarily circumvented.

The at least one second request may be selectively transmitted if the time between the radio resources granted according to the SPS (e.g., the SPS interval) or the time until the next radio resource granted according to the SPS (e.g., the difference between the current TTI and the TTI of the next SPS-granted radio resource) violates a latency requirement of the data communication (e.g., by being greater than an upper latency limit).

The at least one second request may be transmitted in addition to (e.g., after) transmitting the at least one first request and/or if the SPS is configured for the selective skipping in the data communication.

The method may further comprise or trigger a step of determining to either reduce power consumption of the radio device or reduce latency in the data communication. The determination may depend on at least one of a latency requirement (e.g., of the data communication and/or the radio device) and a power constraint (e.g., of the radio device).

The method may further comprise or trigger a step of indicating a result of the determination to the RAN. Indicating, to the RAN, the reduction of the power consumption may comprise transmitting, to the RAN, the at least one first request. For reducing the power consumption, the radio device may transmit the first request, trigger the configuration of the SPS with skipping and/or indicate, to the RAN, a preference for the SPS with skipping. Alternatively or in addition, indicating, to the RAN, the reduction of the latency may comprise transmitting, to the RAN, the at least one second request. For reducing the latency, the radio device may transmit the second request, trigger the RA procedure and/or indicate, to the RAN, a preference for the RA procedure. The radio device may be operated (e.g., according to the result of the determination) selectively in a first operating state and a second operating state. The first operating state may comprise any one of the steps including or related to configuring and/or using the SPS with skipping. The second operating state may comprise any one of the steps including or related to requesting and/or using the further radio resource. The indication may include transmitting the first and second requests for switching to the first and second operating states, respectively.

The first operating state may reduce the power consumption relative to the second operating state. The second operating state may reduce the latency relative to the first operating state.

At a first point in time, at least one of the new data becomes available (e.g., at the radio device and/or in the buffer) for the transmission. Alternatively or in addition, at the first point in time, the BSR may be triggered. The BSR is transmitted at a second point in time according to the SPS. The second point in time may be after the first point in time. The first point in time may be between the times (i.e., subframes or TTIs) of the radio resources granted according to the SPS. The second point in time may correspond to the radio resource granted according to the SPS subsequently to the first point in time. For example, the second point in time may correspond to the TTI or subframe of the next SPS-granted radio resource after the first point in time.

The BSR may be a short BSR, e.g., according to subclause 6.1.3 in the document 3GPP TS 36.321, V14.3.0. The radio device may comprise different buffers, e.g., for the data to be transmitted. The BSR (e.g., each BSR for each of the buffers) may be indicative of the filling status of one (e.g., the corresponding one) of the buffers. For example, the BSR may be indicative of the amount of data in the buffer only for one specific logical channel group (LCG).

The BSR may be a regular BSR. The regular BSR may encompass a BSR that is triggered by the new data, e.g., UL data or SL data for a logical channel which belongs to a LCG. Alternatively or in addition, the new data triggering the regular BSR may become available for the transmission in a radio link control (RLC) entity and/or in a packet data convergence protocol (PDCP) entity of the protocol stack at the radio device. The definition of what data shall be considered as available for transmission may be specified according to 3GPP TS 36.322, subclause 4.5, e.g., V13.3.0 and/or the document 3GPP TS 36.323, subclause 4.5, e.g., V13.6.0. Alternatively or in addition, the new data that triggers the regular BSR belongs to a logical channel with higher priority than the priorities of the logical channels which belong to any LCG and for which data is already available for transmission, or there is no data available for transmission for any of the logical channels which belong to a LCG. Moreover, the regular BSR may encompass a BSR that is trigged by the expiry of a retransmission timer for the BSR (e.g., a reixBS ?-Timer according to 3GPP TS 36.321, subclause 5.4.5, e.g., V14.3.0), e.g., while the MAC entity has data available for transmission for any of the logical channels which belong to a LCG.

The technique may be implemented, at least partly, on the MAC layer. The BSR may be implemented by a BSR MAC control element (CE).

The trigger or criterion "if new data to be transmitted in the data communication is available" may be implemented using any trigger or criterion described in the document 3GPP TS 36.321, e.g., V14.3.0, for a scheduling request. Particularly, any trigger or criterion for a scheduling request described in the context of MTC, NB-loT or wideband UEs may analogously applied for the selective transmission of the BSR on the SPS-granted radio resources. The selective transmission of the BSR may be triggered directly without the scheduling request.

The radio resources granted according to the SPS may be on a physical uplink control channel (PUSCH) or a physical sidelink shared channel (PSSCH) used for the data communication.

One or more, or all, of the at least one configuration message may be received on an MTC physical downlink control channel (MPDCCH), e.g., if the data communication includes an eMTC. Alternatively or in addition, one or more of the at least one configuration message may be received on a NB-loT physical downlink control channel (NPDCCH), e.g., if the data communication involves a NB-loT device as the radio device.

Fig. 4 shows a flowchart for a method 400 of scheduling a data communication involving a radio device. The method comprises or triggers a step 402 of transmitting, to the radio device, at least one configuration message indicative of radio resources granted for transmissions according to an SPS that is configured for selectively skipping the transmissions. In a step 404 of the method 400, a BSR is selectively received on at least one of the radio resources granted according to the SPS, if (e.g., new) data to be transmitted in the data communication is available. Optionally, a scheduling grant depending on the BSR and indicative of one or more further radio resources for the data communication and/or a further configuration message depending on the BSR and i ndicative of a change in the SPS is transmitted to the radio device in response to the received BSR in a step 406 of the method 400.

The method 400 may be performed by the device 200, e.g., at or using the base station of the RAN . For example, the modules 202, 204 and, optionally, 206 may perform the steps 402, 404 and, optionally, 406, respectively.

I nstead of introducing a dedicated physical scheduling request (SR), the technique may allow configuring radio devices (e.g., U Es) with SPS and a feature for selectively skipping the transmission (e.g., the skipUplink-feature), which is referred to as SPS with selective skipping. With the use of SPS with selective skipping, the BSR (e.g., a regular BSR) is transmitted whenever data arrives in the (e.g., uplink) buffer of the radio device. Embodiments of the technique maintain compatibility with the technical specification 3GPP TS 36.321, e.g., V14.3.0.

As a reference example, conventional 3GPP LTE would require a conventional first step of transmitting a dedicated physical SR and a conventional second step of receiving a grant for transmitting at least an BSR in response to the SR. At least some embodiments of the technique can eliminate, at least in some situations, one or both of the two conventional steps.

Optionally, a further functionality is added to the device 100, e.g., to the radio device, to select optimizing for low latency in a second operating state. I n the second operating state, the device 100 triggers a RA procedure, e.g., if an SR is triggered or if a conventional SR would be triggered. I n a first operating state of the device 100 (e.g., whenever the device 100 is not in the second operating state) the device 100 selects optimizing power consumption (e.g., the power consumption of the radio device). I n the first operating state, the subsequent SPS-granted radio resource may be used for transmitting the data and or the BSR, e.g., if an SR is triggered or if a conventional SR would be triggered. The device 100, e.g., the radio device, may transmit a request for an SPS grant with selective skipping (e.g., by configuring skipUplinkTX) for switching to the first operating state.

The method 400 may be performed by a RAN, e.g., a base station of the RAN . The RAN, e.g., the base station, may serve the radio device. The RAN may comprise multiple base stations and corresponding cells. The data communication may comprise an UL transmission of the radio device. The base station may receive the data and the BSR. Alternatively or in addition, the data communication may include a SL transmission of the radio device. The data may be received by one or more other radio devices, e.g., in the cell corresponding to the serving base station. The BSR may be received by the serving base station.

Herein, the "base station" may encompass a network controller (e.g., a Wi-Fi access point) or a radio access node (e.g. a 3G Node B, a 4G eNodeB or a 5G gNodeB) of the RAN. The base station may be configured to provide radio access. Alternatively or in addition, the one or more radio devices may include a mobile or portable station or a radio device wirelessly connectable to the RAN. Two or more instances of the radio devices may be configured to wirelessly connect to each other, e.g., in an ad-hoc radio network or via a 3GPP sidelink.

Fig. 5 shows a first example of a signaling diagram 500 for signals or messages exchanged in a radio communication between embodiments of the devices 100 and 200 as a result of performing implementations of the methods 300 and 400, respectively.

According to steps 301 and 401 of the methods 300 and 400, respectively, the at least one first request is transmitted from the device 100 to the device 200. The at least one first request comprises at least one of a request 502 for receiving a configuration for the SPS and a request 504 for receiving a configuration for the selective skipping, e.g., for the para meter SkipUplinkTxSPS.

According to the steps 302 and 402 of the methods 300 and 400, respectively, the at least one configuration message 506 is transmitted from the device 200 to the device 100. The at least one configuration message 506 may comprise a configuration message (and optionally an activation message) for the SPS and a configuration message (and optionally an activation message) for the selective skipping, e.g., by configuring the parameter SkipUplinkTxSPS.

The configuration of the SPS comprises the SPS interval, e.g.,

semiPersistSchedlntervalUL as a parameter. In each SPS interval, the SPS-granted radio resources is, according to the step 304 of the method 300, used for

transmission or the transmission is skipped. The latter is indicated at reference sign 508. One case of using the upcoming SPS-granted radio resource includes transmitting the BSR 510. The BSR may be a regular BSR. Transmitting the BSR on the upcoming SPS- granted radio resource may be triggered by the arrival of new data or the availability of data upon expiry of a timer. Accordingly, the device 200 selectively receives the BSR 510 in the step 404 of the method 400, wherein the selectivity relates to the BSR trigger at the device 100.

The radio communication between the devices 100 and 200 may or may not be part of the data communication. For example, the regular BSR 510 may be transmitted on the same physical channel used for transmitting the data. E.g., the BSR may be piggybacked as a MAC CE in a MAC PDU that includes a MAC SDU with data to be transmitted in the data communication. Alternatively or in combination, the data to be transmitted in the data communication may be addressed to another radio device, and the selectively transmitted BSR may be addressed to the device 200.

Fig. 6 shows a second example of a signaling diagram 500 for signals or messages exchanged between embodiments of the devices 100 and 200 in a radio

communication resulting from performing implementations of the methods 300 and 400, respectively. The second example may be a more detailed implementation of the first example. Features and steps that correspond to those of the first example or that are exchangeable with corresponding features and steps of the first example are indicated by like reference signs. The radio communication may or may not be part of the data communication.

According to the steps 301 and 401 of the methods 300 and 400, respectively, the device 100 transmits the at least one first request for the SPS (i.e., the request 502) with selective skipping (i.e., the request 504). The requests 502 and/ 504 may be carried on a RA channel (RACH) and/or using UE Assistance Information.

In the steps 302 and 402 of the methods 300 and 400, respectively, a first

configuration message 506 (e.g., using RRC signaling) is transmitted from the device 200 to the device 100 responsive to the request 502. The first configuration message 506 is indicative of the SPS configuration (e.g., the IE SPS-ConfigUL), particularly a Cell-Random Network Temporary Identifier for the SPS (e.g., SPS C-RNTI) and the SPS interval (e.g., semiPersistSchedlntervalUL) are defined. The further SPS parameter implicitReleaseAfter is not used in combination with the selective skipping, e.g., with the parameter skipUplinkTxSPS. A default SPS configuration is specified in 3GPP TS 36.331, V14.3.0, subclause 9.2.3.

Based on the received SPS configuration, the device 100 decodes the MPDCCH or the NPDCCH with a CRC value scrambled by the SPS C-RNTI.

Further in the steps 302 and 402, e.g., by means of RRC signaling, the IE MAC- MainConfig (e.g., for an eMTC implementation) or the IE MAC-MainConfig-NB (e.g., for an NB-loT implementation) is transmitted from the device 200 to the device 100 responsive to the request 504 as a second configuration message 506, which modifies a MAC main configuration so that a MAC entity at the device 100 is configured with the selective skipping, e.g., with the parameter skipUplinkTxSPS.

Based on the selective skipping configuration (e.g., the MAC entity being configured with skipUplinkTxSPS), the MAC entity ignores the uplink grant, if the uplink grant received on MPDCCH and/or NPDCCH was addressed to the SPS C-RNTI and if the HARQ buffer of the identified process is empty. For example, if skipUplinkTxSPS is configured, the radio device 100 skips UL transmissions for a configured uplink grant if no data is available for transmission in the UE buffer according to 3GPP TS 36.321 V14.3.0. E-UTRAN may always configures skipUplinkTxSPS when

semiPersistSchedlntervalUL is shorter than sflO.

Further in the steps 302 and 402 of the methods 300 and 400, respectively, the SPS configuration is activated by transmitting downlink control information (DCI)

Format 0 scrambled with the SPS C-RNTI on the MPDCCH or the NPDCCH (as a third configuration message 506). The activation causes initializes or reinitializes the configured uplink grant to start in this TTI or subframe, e.g., in accordance with 3GPP TS 36.321 V14.3.0, subclause 5.4.1.

According to 3GPP TS 36.321 V14.3.0, subclause 5.10.2, the N-th grant occurs according to the SPS in the TTI or subframe:

(10 * SFN + subframe) = [(10 * SFNstart time + subframestart time)

+ N * semiPersistSchedlntervalUL

+ Subframe_Offset * {N modulo 2)] modulo 10240. Herein, SFNstart time and subframestart time are the system frame number {SFN) and subframe, respectively, at the time the configured uplink grant was initialized or rei nitialized .

I n steps 303 and 403 of the methods 300 and 400, respectively, the MAC entity at the device 100 confirms the activation to device 200. To this end, an SPS confirmation MAC CE as defined in 3GPP TS 36.321, V14.3.0, subclause 6.1.3.11 may be generated. The SPS confirmation MAC CE is identified by a MAC PDU subheader with a certain Logical Channel ID (LCI D). The MAC entity may transmit the MAC PDU on the U L shared channel (U L-SCH).

3GPP TS 36.321 V14.3.0, Subclause 5.4.2.1: If the MAC entity is configured with skipUplinkTxSPS and if the uplink grant received on PDCCH was addressed to the SPS C-RNTI and if the HARQ buffer of the identified process is empty: ignore the uplink grant.

I n the step 404, due to the configuration for selective skipping, the device 200 (e.g., the base station) does not transmit a NACK in the absence 510 of a PUSCH

transmission from the device 100 in the step 304 on the SPS-granted radio resource.

As compared to a dedicated physical SR signal, it is better in at least some use cases if the eN B as the device 200 straightaway receives the BSRs in the step 404 from the U Es that remain in the RRC connected mode as instances of the device 100. There are periodic BSRs and regular BSRs. To minimize control signaling overhead, it may be not desired that all U Es in the RRC connected mode periodically report zero uplink buffer. Rather, the BSR is only triggered when new data arrives according to the step 304. Therefore, periodic BSRs are not good for replacing SR but regular BSRs are.

The BSR 510 is supported for N B-loT but only short BSR, and since there is no equivalent PUCCH for N B-loT, the BSR will always trigger a RA procedure unless the UE 100 already has an U L grant, that is prior to 3GPP release 15. However, if the regular BSR is transmitted using the SPS and the skipUplink-feature, the U Es has an U L grant available whenever data arrives in the uplink buffer. With the skipUplink- feature introduced in 3GPP release 14, the UEs 100 does not have to transmit anything (i.e. padding) unless new data arrives in the UL buffer and a corresponding MAC BSR CE 510 has been generated. That is, exactly like a dedicated SR signal, but there is no increase in U E power consumption when not used. A first implementation of the method 300 and/or 400 includes a combination of a regular BSR with SPS and the skipUplink-feature to avoid the need to introduce a new dedicated physical SR signal. In addition, the power consumption of the UE 100 is reduced.

In the same way as for a dedicated physical SR-signal, very frequent SPS resources (i.e. short semiPersistSchedlntervalUL) could lead to an unacceptably high system overhead. Therefore, it is not feasible to address both reduced latency and reduced UE power consumption (or efficient usage of radio resources) at the same time (e.g., in the same operating state of the UE 100).

Optionally, It is left up to an implementation of the UE 100 whether to optimize for latency or UE power consumption. If optimizing for latency in the second operating state, the UE 100 uses the RA when a SR is triggered as in 3GPP release 13 operation, i.e., when a conventional SR would be triggered according to 3GPP release 13.

Since the RA procedure is initialized immediately, a new dedicated physical SR-signal has no latency advantage for SR resource periodicities with acceptable system overhead in at least some scenarios. The latter would have reduced signaling, but on the other hand need to wait for the next upcoming SR resource, assuming the same periodicity for NPRACH and SR resources.

If optimizing for UE power consumption in the first operating state, the UE 100 wait for the subsequent SPS occasion (i.e., subsequent SPS-granted radio resource), and then transmits the BSR (hence avoiding the RA procedure).

Fig. 7 shows a flowchart for selectively operating the device 100 in the first and second operating states. Functionality 700 for the device 100 (e.g., a UE) to select what to optimize for may require a trigger 702 for the regular BSR (e.g., the arrival of new data to be transmitted in the data communication). In a determining step 704, the device 100 determines whether communication latency or power consumption should be reduced. For the reducing communication latency, the at least one second request is transmitted in a step 706. Otherwise, the at least one first request is transmitted to the RAN in the step 301, which commences the method 300.

The functionality 700 may be specified as follows, wherein features added to subclause 5.4.5 ("Buffer Status Reporting") in the document 3GPP TS 36.321, V14.3.0 are emphasized below in bold type: else if a Regular BSR has been triggered and logicalChannelSR-ProhibitTimer is not running:

- if an uplink grant is not configured or the UE is an NB-loT UE optimizing for latency or the Regular BSR was not triggered due to data becoming available for transmission for a logical channel for which logical channel SR masking

{logicalChannelSR-Mask) is setup by upper layers:

- a Scheduling Request shall be triggered.

Above trigger for the scheduling request is thus a trigger for the RA procedure.

A second implementation of the technique, which may be combined with the first implementation, enables the device 100 (e.g., a UE) to select to optimize for latency (e.g., the BSR triggers SR and, thus, a RA procedure) in the second operating state or UE power consumption (e.g., a configured SPS grant with skipUL -feature is used for BSR transmission) in the first operating state.

In a third implementation of the technique, which may be combined with the first and/or second implementations, the device 100 is configured to request to be configured with SPS (and the s/ /pL//.-feature) according to the step 301, so that the device 100 can optimize for a reduced power consumption and it is expected that the device 100 remains in the RRC connected mode after the initial data transmissions. Normally, SPS is used for specific services such as Voice-over-I P (VoIP) which are IMS services and/or identified by certain Quality-of-Service (QoS) Class Identifiers (QCI). However, NB-loT does not support QCI and there would be no way to distinguish the UEs 100 that would benefit from being configured with SPS (and the s/ /pL//.-feature). The RAN would then have to configure all UEs 100 with SPS (and the skipUL -feature) in order to have the above gains, but that would be unnecessarily expensive in terms of resource consumption.

Therefore, it is beneficial if a UE 100 requests the SPS (and the s/ /pL//.-feature) or informs the RAN about its preference according to the step 301.

Any one of the at least one first request (e.g., the requests 502 and/or 504) and/or the indication of the preference may be transmitted to the RAN (e.g., in the step 301) by at least one of the following measures:

- appending an indication in the so-called UE Assistance Information; - configuring and/or indicating by RRC signaling, which may exclude the control-plane optimization and/or data transfer over Non-Access-Stratum (DoNAS);

- configuring and/or indicating by Non-Access-Stratum (NAS) signaling, e.g. in the Service Request or RA procedure (e.g., "RRC Connection Setup Complete") from the UE 100 to the eNB 200; and/or (e.g., "Initial UE message") from the eNB 200 to the Mobility Management Entity (MME), which may include the control-plane optimization and/or DoNAS;

- adding information to UE context in MME; and

- indicating a preference in UE subscription information.

In the third implementation of the technique, the UE 100 is able to request, or indicate the preference for, the use of SPS (and s/ /pL//.-feature) for the transmission of the regular BSR 510 in the RRC connected mode, as the first operating state

Any of the three implementations may be combined with any embodiment.

Fig. 8 shows a schematic block diagram for an embodiment of the device 100. The device 100 comprises one or more processors 804 for performing the method 300 and memory 806 coupled to the processors 804. For example, the memory 806 may be encoded with instructions that implement at least one of the modules 102, 104 and 106.

The one or more processors 804 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and/or encoded logic operable to provide, either alone or in conjunction with other components of the device 100, such as the memory 806, radio device functionality and/or data transmitting functionality. For example, the one or more processors 804 may execute instructions stored in the memory 806. Such

functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 100 being configured to perform the action.

As schematically illustrated in Fig. 8, the device 100 may be embodied by a transmitting station 800, e.g., a radio device. The transmitting station 800 comprises a radio interface 802 coupled to the device 100 for data communication with the RAN and/or one or more other radio devices.

In a variant, e.g., as schematically illustrated in Fig. 9, the functionality of the device 100 is provided by a node of a user network linked to the station 800. That is, the node performs the method 300. The functionality of the device 100 is provided by the node to the transmitting station 800, e.g., via the interface 802 or a dedicated wired or wireless interface.

Fig. 10 shows a schematic block diagram for an embodiment of the device 200. The device 200 comprises one or more processors 1004 for performing the method 400 and memory 1006 coupled to the processors 1004. For example, the memory 1006 may be encoded with instructions that implement at least one of the modules 202, 204 and 206.

The one or more processors 1004 may be a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, microcode and/or encoded logic operable to provide, either alone or in conjunction with other components of the device 100, such as the memory 1006, base station functionality and/or scheduling functionality. For example, the one or more processors 1004 may execute instructions stored in the memory 1006. Such functionality may include providing various features and steps discussed herein, including any of the benefits disclosed herein. The expression "the device being operative to perform an action" may denote the device 200 being configured to perform the action.

As schematically illustrated in Fig. 10, the device 200 may be embodied by a scheduling station 1000, e.g., a base station. The scheduling station 1000 comprises a radio interface 1002 coupled to the device 200 for data communication with the RAN and/or one or more other radio devices.

In a variant, e.g., as schematically illustrated in Fig. 11, the functionality of the device 200 is provided by a node of the RAN or a core network linked to the RAN. That is, the node performs the method 400. The functionality of the device 200 is provided by the node to the scheduling station 1000, e.g., via the interface 1002 or a dedicated wired or wireless interface. In any embodiment, the technique may be implemented by transmitting a regular BSR on radio resources granted according to an SPS with selective skipping.

Transmitting a dedicated physical SR signal or a RA preamble for receiving a grant for transmitting the regular BSR may be avoided or may be used as a subsidiary measure, e.g., to fulfill a latency requirement. The radio device may be configured to request the SPS with selective skipping or to indicate its preference of the SPS with selective skipping for BSR transmission. Furthermore, the radio device may be configured to determine or select whether to transmit the regular BSR on the SPS- granted radio resources with selective skipping (e.g., for optimizing the power consumption) or trigger a RA procedure (e.g., for optimizing latency).

As has become apparent from above description, embodiments of the technique avoid or reduce the usage and/or the standardization of a dedicated physical SR signal. Same or further embodiments can reduce latency and/or power consumption, e.g., as compared to a dedicated physical SR signal since two transmissions can be omitted (namely, the transmission of the SR in the uplink, and the assignment of a grant for transmitting a BSR in the downlink). Embodiments of the technique may at least one of improve latency in the data communication, increase an effective usage of radio resources, reduce a signaling overhead, reduce power consumption in radio transmissions and reduce the number of standardized control signals. While a dedicated SR is just a flag and in this way requires intermediate steps to achieving an (e.g., UL or SL) grant with which the radio device can transmit the BSR in order for the RAN (e.g., an eNB) to give it an appropriate (e.g., UL or SL) grant for the transmission of the data (e.g., user-plane payload), the technique can be implemented to directly transmit the BSR in the next SPS-granted radio resources as the BSR is triggered (e.g., by the same trigger that would conventionally trigger the dedicated SR). Thus, some or all SRs can be replaced by the BSRs using the SRS with selective skipping.

Many advantages of the present invention will be fully understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the units and devices without departing from the scope of the invention and/or without sacrificing all of its advantages. Since the invention can be varied in many ways, it will be recognized that the invention covers particularly the scope of the enclosed enumerated embodiments and their combinations. Further embodiments of the technique are disclosed in the following appendix including a discussion of a 3GPP NB-loT PHY Scheduling Request.

Claims

1. A method (300) of transmitting data in a data communication scheduled by a radio access network, RAN, the method comprising or triggering the steps of:

receiving (302), from the RAN, at least one configuration message (502; 504) indicative of radio resources granted for transmissions according to a semi-persistent scheduling, SPS, that is configured for selectively skipping (508) the transmissions; and

selectively transmitting (304), on at least one of the radio resources granted according to the SPS, a buffer status report, BSR (510), if new data to be transmitted in the data communication is available (702).

2. The method of claim 1, further comprising or triggering the step of:

receiving, from the RAN in response to the transmitted BSR (510), at least one of a scheduling grant of one or more further radio resources for the data

communication and a further configuration message indicative of a change in the SPS depending on the BSR (510).

3. The method of claim 1 or 2, wherein the selective transmission on the radio resources granted according to the SPS includes selectively skipping (508) the transmission of the BSR (510) if no new data is available.

4. The method of any one of claims 1 to 3, wherein multiple instances of the BSR (510) are selectively transmitted on the radio resources granted according to the SPS depending on whether or not new data is available (702) at the time of the corresponding radio resources.

5. The method of claim 4, wherein the SPS according to the at least one configuration message (502; 504) is configured for skipping (508) the transmissions on the radio resources granted according to the SPS, if no data is available for the corresponding transmissions.

6. The method of claim 4 or 5, wherein the BSRs (510) are exclusively transmitted on the radio resources granted according to the SPS.

7. The method of any one of claims 1 to 6, wherein none of the BSRs (510) is transmitted on a dynamically scheduled radio resource of the RAN.

8. The method of any one of claims 1 to 7, wherein the method is performed by a radio device (100) served by the RAN.

9. The method of claim 8, wherein the BSR (510) is generated and/or selectively transmitted only if new data to be transmitted is or becomes available (702) at the radio device (100).

10. The method of claim 8 or 9, wherein the data to be transmitted in the data communication is available in a buffer of the radio device (100), and the BSR (510) is indicative of a filling status of the buffer.

11. The method of claim 10, wherein the data communication comprises an uplink, UL, and the buffer comprises an UL buffer storing the data to be transmitted in the UL, and/or the data communication comprises a sidelink, SL, and the buffer comprises a SL buffer storing the data to be transmitted in the SL.

12. The method of claim 10 or 11, wherein the BSR (510) is triggered by new data arriving in the buffer.

13. The method of any one of claims 10 to 12, wherein the buffer is a buffer on a medium access control, MAC, layer of a protocol stack of the radio device (100).

14. The method of any one of claims 10 to 13, wherein the buffer is a hybrid automatic repeat request, HARQ, buffer of an HARQ entity at the MAC layer of the radio device (100).

15. The method of any one of claims 10 to 14, wherein at least some of the new data in the buffer is transmitted on the radio resources granted according to the SPS.

16. The method of any one of claims 8 to 15, wherein the radio device (100) refrains from transmitting on the radio resources granted according to the SPS unless new data is available (702) for transmission.

17. The method of any one of claims 8 to 16, wherein the radio device (100) remains in a radio resource control, RRC, connected mode.

18. The method of any one of claims 8 to 17, wherein the SPS is canceled once a timer for a time alignment of the radio device (100) with the RAN expires.

19. The method of any one of claims 1 to 18, further comprising:

transmitting, to the RAN, at least one first request triggering at least one of configuring the SPS and configuring the selective skipping (508) for the data communication.

20. The method of any one of claims 1 to 19, further comprising:

transmitting, to the RAN, at least one second request triggering a random access, RA, procedure with the RAN.

21. The method of claim 20, wherein the RA procedure with the RAN comprises the step of:

receiving, from the RAN, a scheduling grant for a further radio resource that is scheduled prior to the next radio resource granted according to the SPS.

22. The method of claim 20 or 21, wherein the at least one second request is selectively transmitted if the time between the radio resources granted according to the SPS or the time until the next radio resource granted according to the SPS violates a latency requirement of the data communication.

23. The method of any one of claims 1 to 22, further comprising:

determining to either reduce power consumption of the radio device (100) or reduce latency of the data communication; and

indicating a result of the determination to the RAN.

24. The method of claims 19, 20 and 23, wherein the radio device (100) is selectively operated, according to the result of the determination, in a first operating state comprising the steps of any one of claims 1 to 18 and a second operating state comprising the step of claim 21, wherein the indication includes transmitting the first and second requests for switching to the first and second operating states, respectively.

25. The method of any one of claims 1 to 24, wherein, at a first point in time, at least one of the new data becomes available (702) and the BSR (510) is triggered, and wherein the BSR (510) is transmitted at a second point in time according to the SPS.

26. The method of claim 25, wherein the second point in time corresponds to the radio resource granted according to the SPS subsequently to the first point in time.

27. The method of any one of claims 1 to 26, wherein the BSR (510) is a short BSR.

28. The method of any one of claims 1 to 27, wherein the BSR (510) is a regular BSR.

29. The method of any one of claims 1 to 28, wherein the radio resources granted according to the SPS are on a physical uplink control channel, PUSCH, or a physical sidelink shared channel, PSSCH, used for the data communication.

30. A method (400) of scheduling a data communication involving a radio device (100), the method comprising or triggering the steps of:

transmitting (402), to the radio device (100), at least one configuration message (502; 504) indicative of radio resources granted for transmissions according to a semi-persistent scheduling, SPS, that is configured for selectively skipping (508) the transmissions; and

selectively receiving (404), on at least one of the radio resources granted according to the SPS, a buffer status report, BSR (510), if new data to be transmitted in the data communication is available (702).

31. The method of claim 30, further comprising or triggering the step of:

transmitting, to the radio device (100) in response to the received BSR (510), at least one of a scheduling grant of one or more further radio resources for the data communication and a further configuration message indicative of a change in the SPS depending on the BSR (510).

32. The method of claim 30 or 31, further comprising any feature or step corresponding any of the claims 1 to 29.

33. A computer program product comprising program code portions for performing the steps of any one of the claims 1 to 32 when the computer program product is executed on one or more computing devices (804; 1004).

34. The computer program product of claim 33, stored on a computer-readable recording medium (806; 1006).

35. A device (100) for transmitting data in a data communication scheduled by a radio access network, RAN, the device (100) being configured to perform or trigger the steps of:

receiving, from the RAN, at least one configuration message (502; 504) indicative of radio resources granted for transmissions according to a semi-persistent scheduling, SPS, that is configured for selectively skipping (508) the transmissions; and

selectively transmitting, on at least one of the radio resources granted according to the SPS, a buffer status report, BSR (510), if new data to be transmitted in the data communication is available (702).

36. The device of claim 35, further configured to perform or trigger the steps of any one of claims 2 to 29.

37. A device (200) for scheduling a data communication involving a radio device (100), the device (200) being configured to perform or trigger the steps of:

transmitting, to the radio device (100), at least one configuration message (502; 504) indicative of radio resources granted for transmissions according to a semi- persistent scheduling, SPS, that is configured for selectively skipping (508) the transmissions; and

selectively receiving, on at least one of the radio resources granted according to the SPS, a buffer status report, BSR (510), if new data to be transmitted in the data communication is available (702).

38. The device of claim 37, further configured to perform or trigger the steps of claim 31 or 32.

39. A device (100) for transmitting data in a data communication scheduled by a radio access network, RAN, the device (100) comprising at least one processor (804) and a memory (806), said memory (806) comprising instructions executable by said at least one processor (804), whereby the device (100) is operative to:

receive, from the RAN, at least one configuration message (502; 504) indicative of radio resources granted for transmissions according to a semi-persistent scheduling, SPS, that is configured for selectively skipping (508) the transmissions; and

selectively transmit, on at least one of the radio resources granted according to the SPS, a buffer status report, BSR (510), if new data to be transmitted in the data communication is available (702).

40. The device of claim 39, further operative to perform the steps of any one of claims 2 to 29.

41. A device (200) for scheduling a data communication involving a radio device (100), the device (200) comprising at least one processor (1004) and a memory (1006), said memory (1006) comprising instructions executable by said at least one processor (1004), whereby the device (200) is operative to:

transmit, to the radio device (100), at least one configuration message (502; 504) indicative of radio resources granted for transmissions according to a semi- persistent scheduling, SPS, that is configured for selectively skipping (508) the transmissions; and

selectively receive, on at least one of the radio resources granted according to the SPS, a buffer status report, BSR (510), if new data to be transmitted in the data communication is available (702).

42. The device of claim 41, further operative to perform the steps of claim 31 to 32.

43. A device (100) for transmitting data in a data communication scheduled by a radio access network, RAN, the device (100) comprising:

a reception module (102) for receiving, from the RAN, at least one

configuration message (502; 504) indicative of radio resources granted for transmissions according to a semi-persistent scheduling, SPS, that is configured for selectively skipping (508) the transmissions; and

a selective transmission module (104) for selectively transmitting, on at least one of the radio resources granted according to the SPS, a buffer status report, BSR (510), if new data to be transmitted in the data communication is available (702).

44. The device of claim 43, further comprising one or more modules for performing the steps of any one of claims 2 to 29.

45. A device (200) for scheduling a data communication involving a radio device (100), the device (200) comprising:

a transmission module (202) for transmitting, to the radio device (100), at least one configuration message (502; 504) indicative of radio resources granted for transmissions according to a semi-persistent scheduling, SPS, that is configured for selectively skipping (508) the transmissions; and selective reception module (204) for selectively receiving, on at least one of the radio resources granted according to the SPS, a buffer status report, BSR (510), if new data to be transmitted in the data communication is available (702).

46. The device (200) of claim 45, further comprising one or more modules for performing the steps of claim 31 or 32.