CN111357223B

CN111357223B - Communication method, device and computer readable storage medium

Info

Publication number: CN111357223B
Application number: CN201780096924.8A
Authority: CN
Inventors: S·图尔蒂南; 吴春丽; R·R·克里希纳穆尔蒂
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy
Priority date: 2017-11-16
Filing date: 2017-11-16
Publication date: 2022-09-13
Anticipated expiration: 2037-11-16
Also published as: CN111357223A; WO2019095228A1

Abstract

A method, comprising: receiving a plurality of data packets; cause transmission of a first status report, the first status report including at least one of an acknowledgement and a negative acknowledgement for one or more of the plurality of data packets; and subsequently: starting a first timer; before expiration of the first timer: inhibiting further transmission of acknowledgements and negative acknowledgements included in the first status report; allowing transmission of at least one of an acknowledgement and a negative acknowledgement for one or more of the plurality of data packets that are not included in the first status report.

Description

Communication method, device and computer readable storage medium

Technical Field

The present application relates to a method, apparatus, system and computer program, particularly but not exclusively to radio link control status reporting in New Radios (NRs).

Background

A communication system can be seen as a facility that enables communication sessions between two or more entities, such as user terminals, base stations, and/or other nodes, by providing carriers between the various entities involved in a communication path. A communication system may be provided, for example, by means of a communication network and one or more compatible communication devices. For example, the communication session may comprise a communication of data for carrying communications such as voice, video, electronic mail (email), text messages, multimedia and/or content data. Non-limiting examples of services provided include two-way or multi-way calls, data communication or multimedia services, and access to data network systems, such as the internet.

In a wireless communication system, at least a portion of a communication session between at least two stations occurs over a wireless link. Examples of wireless systems include Public Land Mobile Networks (PLMNs), satellite-based communication systems, and different wireless local networks, e.g., Wireless Local Area Networks (WLANs). Wireless systems can generally be divided into cells and are therefore often referred to as cellular systems.

A user may access the communication system by means of a suitable communication device or terminal. The user's communication device may be referred to as User Equipment (UE) or user equipment. The communication device is provided with suitable signal receiving and transmitting means to enable communication, e.g. to enable access to a communication network or direct communication with other users. A communication device may access a carrier provided by a station (e.g., a base station of a cell) and transmit and/or receive communications on the carrier.

A communication system and associated devices typically operate in accordance with a given standard or specification which sets out what the various entities associated with the system are permitted to do and how that should be achieved. Communication protocols and/or parameters that should be used for the connection are also typically defined. An example of a communication system is UTRAN (3G radio). Other examples of communication systems are the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology and the so-called 5G or New Radio (NR) networks. Standardization of 5G or new radio networks is currently under discussion. LTE is being standardized by the third generation partnership project (3 GPP).

Disclosure of Invention

In a first aspect, there is provided a method comprising: receiving a plurality of data packets; cause transmission of a first status report, the first status report including at least one of an acknowledgement and a negative acknowledgement for one or more of the plurality of data packets; and subsequently: starting a first timer; before expiration of the first timer: inhibiting further transmission of acknowledgements and negative acknowledgements included in the first status report; and allowing transmission of at least one of an acknowledgement and a negative acknowledgement for one or more of the plurality of data packets that are not included in the first status report.

In one embodiment, the method comprises: before expiration of the first timer: inhibit transmission of a negative acknowledgement for a data packet having a higher sequence number than any of a plurality of data packets received prior to initiation of the first timer.

In one embodiment, the method comprises: before expiration of the first timer: the transmission of a negative acknowledgement having a lower sequence number than any of the plurality of data packets received prior to the start of the first timer is allowed.

In one embodiment, the method comprises: transmission of an acknowledgement for a data packet received after the start of the first timer is prohibited.

In one embodiment, the method comprises: the highest sequence number of the one or more data packets for which acknowledgements and negative acknowledgements are included in the first status report is determined.

In one embodiment, inhibiting further transmissions comprises: transmission of an acknowledgement or negative acknowledgement for any data packet having a sequence number less than or equal to the highest sequence number is prohibited.

In one embodiment, allowing the transmission comprises: transmission of at least one of an acknowledgement or a negative acknowledgement for any data packet having a sequence number greater than the highest sequence number is allowed.

In one embodiment, the transmission of at least one of an acknowledgement or a negative acknowledgement for the one or more data packets before the expiration of the first timer comprises: at least one of an acknowledgement or a negative acknowledgement for one or more data packets having sequence numbers less than the first limit is transmitted.

In one embodiment, the method comprises: the first limit is increased after expiration of the second timer.

In one embodiment, the transmission of the negative acknowledgement comprises: a negative acknowledgement is transmitted in the status report, the negative acknowledgement comprising a sequence number of a data packet that has not been received.

In one embodiment, the transmission of the negative acknowledgement comprises: transmitting a negative acknowledgement in the status report, the negative acknowledgement comprising an indication of one or more segments of the partially received data packet that have not been received.

In one embodiment, the indication of one or more segments comprises an indication of a start point and an end point of a set of consecutive segments in the data packet that have not been received.

According to a second aspect, there is provided a computer program product for a computer, the computer program product comprising software code portions for performing the steps of the first aspect when the product is run on a computer.

According to a third aspect, there is provided an apparatus comprising: at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to: receiving a plurality of data packets; cause transmission of a first status report, the first status report including at least one of an acknowledgement and a negative acknowledgement for one or more of the plurality of data packets; and subsequently: starting a first timer; before expiration of the first timer: inhibiting further transmission of acknowledgements and negative acknowledgements included in the first status report; and allowing transmission of at least one of an acknowledgement and a negative acknowledgement for one or more of the plurality of data packets that are not included in the first status report.

In one embodiment, the apparatus is configured to: before expiration of the first timer: the transmission of a negative acknowledgement of a data packet having a higher sequence number than any of the plurality of data packets received prior to the start of the first timer is inhibited.

In one embodiment, the apparatus is configured to: before expiration of the first timer: the transmission of a negative acknowledgement having a lower sequence number than any of the plurality of data packets received prior to the start of the first timer is allowed.

In one embodiment, the apparatus is configured to: transmission of an acknowledgement for a data packet received after start of the first timer is inhibited.

In one embodiment, the apparatus is configured to: the highest sequence number of the one or more data packets for which acknowledgements and negative acknowledgements are included in the first status report is determined.

In one embodiment, the transmission of at least one of an acknowledgement or a negative acknowledgement for the one or more data packets prior to expiration of the first timer comprises: at least one of an acknowledgement or a negative acknowledgement for one or more data packets having sequence numbers less than a first limit is transmitted.

In one embodiment, the apparatus is configured to: the first limit is increased after expiration of the second timer.

According to a fourth aspect, there is provided a computer program embodied on a non-transitory computer readable storage medium, the computer program comprising program code for controlling a process to perform a process, the process comprising: receiving a plurality of data packets; cause transmission of a first status report, the first status report including at least one of an acknowledgement and a negative acknowledgement for one or more of the plurality of data packets; and subsequently: starting a first timer; before expiration of the first timer: inhibiting further transmission of acknowledgements and negative acknowledgements included in the first status report; and allowing transmission of at least one of an acknowledgement and a negative acknowledgement for one or more of the plurality of data packets that are not included in the first status report.

In one embodiment, the process includes: before expiration of the first timer: inhibit transmission of a negative acknowledgement for a data packet having a higher sequence number than any of a plurality of data packets received prior to initiation of the first timer.

In one embodiment, the process includes: before expiration of the first timer: the transmission of a negative acknowledgement having a lower sequence number than any of the plurality of data packets received prior to the start of the first timer is allowed.

In one embodiment, the process includes: transmission of an acknowledgement for a data packet received after start of the first timer is inhibited.

In one embodiment, the process includes: the highest sequence number of the one or more data packets for which acknowledgements and negative acknowledgements are included in the first status report is determined.

In one embodiment, the transmission of at least one of an acknowledgement or a negative acknowledgement for the one or more data packets before the expiration of the first timer comprises: at least one of an acknowledgement or a negative acknowledgement for one or more data packets having sequence numbers less than a first limit is transmitted.

In one embodiment, the process includes: the first limit is increased after expiration of the second timer.

In one embodiment, the transmission of the negative acknowledgement comprises: a negative acknowledgement is transmitted in the status report, the negative acknowledgement comprising the sequence number of the data packet that has not been received.

According to a fifth aspect, there is provided an apparatus comprising: means for receiving a plurality of data packets; means for causing transmission of a first status report, the first status report comprising at least one of an acknowledgement and a negative acknowledgement for one or more of a plurality of data packets; and means for subsequently: starting a first timer; before expiration of the first timer: inhibiting further transmission of acknowledgements and negative acknowledgements included in the first status report; and allowing transmission of at least one of an acknowledgement and a negative acknowledgement for one or more of the plurality of data packets not included in the first status report.

In the foregoing, a number of different embodiments have been described. It will be appreciated that further embodiments may be provided by a combination of any two or more of the above embodiments.

Drawings

Embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which:

fig. 1 shows a schematic diagram of an example communication system comprising a base station and a plurality of communication devices;

FIG. 2 shows a schematic diagram of an example mobile communication device;

FIG. 3 shows a schematic diagram of an example control apparatus;

figure 4 shows a schematic diagram of an LTE protocol stack;

FIG. 5a shows an example of PDCP PDUs;

FIG. 5b shows an example of an RLC PDU;

FIG. 5c shows an example of a MAC PDU;

FIG. 6a shows an example of a status report;

FIG. 6b shows an example of a status report;

FIG. 7 shows an example of a method according to an embodiment; and

fig. 8 shows an example of a status report.

Detailed Description

Before explaining the examples in detail, certain general principles of wireless communication systems and mobile communication devices are briefly explained with reference to fig. 1 to 2 to help understand the underlying technology of the described examples.

In a wireless communication system 100 such as that shown in fig. 1, mobile communication devices or User Equipment (UE)102, 104, 105 provide wireless access via at least one base station or similar wireless transmission and/or reception node or point. The base stations are typically controlled by at least one suitable controller means to enable operation and management of the mobile communications devices in communication with the base stations. The controller device may be located in a radio access network (e.g., wireless communication system 100) or in a Core Network (CN) (not shown), and may be implemented as one central device or its functionality may be distributed over multiple devices. The controller device may be part of the base station and/or provided by a separate entity such as a radio network controller. In fig. 1,

control devices

108 and 109 are shown as controlling respective

macro base stations

106 and 107. The control equipment of the base station may be interconnected with other control entities. The control device is typically provided with memory capacity and at least one data processor. The control means and functions may be distributed between a plurality of control units. In some systems, the control means may additionally or alternatively be provided in the radio network controller.

In fig. 1,

base stations

106 and 107 are shown connected to a wider communications network 113 via a gateway 112. Further gateway functionality may be provided to connect to another network.

Smaller base stations

116, 118 and 120 may also be connected to the network 113, for example, through separate gateway functions and/or via controllers of macro-level stations.

Base stations

116, 118, and 120 may be pico or femto base stations, and the like. In an example,

stations

116 and 118 are connected via gateway 111, while station 120 is connected via controller device 108. In some embodiments, smaller stations may not be provided. The

smaller base stations

116, 118, and 120 may be part of a second network (e.g., a WLAN) and may be WLAN APs.

An example of a wireless communication system is the architecture standardized by the third generation partnership project (3 GPP). The 3 GPP-based development is commonly referred to as the Long Term Evolution (LTE) of the Universal Mobile Telecommunications System (UMTS) radio access technology. Various development stages of the 3GPP specifications are referred to as releases. A newer development of LTE is often referred to as LTE-advanced (LTE-a). LTE employs a mobile architecture known as evolved universal terrestrial radio access network (E-UTRAN). The base stations of such systems are referred to as evolved or enhanced node bs (enbs) and provide E-UTRAN features such as user plane packet data convergence/radio link control/medium access control/physical layer protocol (PDCP/RLC/MAC/PHY) and control plane Radio Resource Control (RRC) protocol termination to the communication devices. Other examples of radio access systems include those provided by base stations of systems based on technologies such as Wireless Local Area Network (WLAN) and/or WiMax (worldwide interoperability for microwave access). A base station may provide coverage for an entire cell or similar radio service area.

Examples of suitable communication systems are the 5G or NR concepts. The network architecture in NR may be similar to that of LTE-advanced. The base stations of the NR system may be referred to as next generation node bs (gnbs). The network architecture may vary depending on the need to support various radio technologies and better QoS support, as well as some on-demand requirements for QoS levels, e.g., to support QoE from a user perspective. Moreover, network-aware services and applications and service-and application-aware networks may introduce changes to the architecture. These are related to Information Centric Networking (ICN) and user centric content delivery networking (UC-CDN) approaches. NR may use multiple-input multiple-output (MIMO) antennas, more base stations or nodes than LTE (the so-called small cell concept), include macro stations operating in cooperation with smaller stations, and may employ various radio technologies for better coverage and higher data rates.

Future networks may use Network Function Virtualization (NFV), which is a network architecture concept that proposes virtualizing network node functions as "building blocks" or entities that may be operably connected or linked together to provide services. A Virtualized Network Function (VNF) may comprise one or more virtual machines running computer program code using standard or generic types of servers instead of custom hardware. Cloud computing or data storage may also be used. In radio communication, this may mean that the node operation is performed at least partly in a server, host or node operatively coupled to the remote radio head. It is also possible that node operations will be distributed among multiple servers, nodes or hosts. It should also be understood that the workload distribution between core network operation and base station operation may be different from LTE or even non-existent.

A possible mobile communication device will now be described in more detail with reference to fig. 2, which shows a schematic partial cross-sectional view of a communication device 200. Such communication devices are often referred to as User Equipment (UE) or terminals. Suitable mobile communication devices may be provided by any device capable of sending and receiving radio signals. Non-limiting examples include a Mobile Station (MS) or a mobile device such as a mobile phone or a so-called 'smart phone', a computer provided with a wireless interface card or other wireless interface facility (e.g., a USB dongle), a Personal Digital Assistant (PDA) or tablet computer provided with wireless communication capabilities, or any combination of these, etc. For example, mobile communication devices may provide for communication of data for carrying communications such as voice, electronic mail (email), text messages, multimedia and so on. Many services can be offered and provided to the user via their communication device. Non-limiting examples of such services include two-way or multi-way calls, data communications or multimedia services, or simply access to a data communications network system, such as the internet. Broadcast or multicast data may also be provided to the user. Non-limiting examples of content include downloads, television and radio programs, videos, advertisements, various alerts, and other information.

The

communication devices

102, 104, 105 may access the communication system based on various access technologies, such as Code Division Multiple Access (CDMA) or wideband CDMA (wcdma). Other non-limiting examples include Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), and various schemes thereof, such as Interleaved Frequency Division Multiple Access (IFDMA), single carrier frequency division multiple access (SC-FDMA), and Orthogonal Frequency Division Multiple Access (OFDMA), Spatial Division Multiple Access (SDMA), and the like.

The mobile device 200 may receive signals over the air interface or radio interface 207 via appropriate means for receiving and may transmit signals via appropriate means for transmitting radio signals. In fig. 2, a transceiver device is schematically designated by block 206. For example, the transceiver device 206 may be provided by means of a radio and an associated antenna arrangement. The antenna arrangement may be arranged inside or outside the mobile device.

The mobile device is typically provided with at least one data processing entity 201, at least one memory 202 and possibly other components 203 for software and hardware assistance in performing tasks designed to be performed, including controlling access to and communication with access systems and other communication devices. The data processing, storage and other related control means may be provided on a suitable circuit board and/or in a chipset. This feature is denoted by reference numeral 204. The user may control the operation of the mobile device by means of a suitable user interface, such as a keypad 205, voice commands, touch sensitive screen or pad, combinations thereof or the like. A display 208, a speaker, and a microphone may also be provided. Furthermore, the mobile communication device may comprise suitable connectors (wired or wireless) to other devices and/or for connecting external accessories (e.g. hands-free devices) to it.

Fig. 3 shows an example of a control arrangement for a communication system, e.g. a station, e.g. a base station, (e) a node B or 5G AP, or a node or server or host of a core network, such as an MME or S-GW, coupled to and/or for controlling an access system, such as a RAN node. The method may be implanted in a single control device or on more than one control device. The control means may be integrated with or external to the nodes or modules of the core network or RAN. In some embodiments, the base station comprises a separate control device unit or module. In other embodiments, the control device may be another network element, such as a radio network controller or a spectrum controller. In some embodiments, each base station may have such control means as well as control means provided in the radio network controller. The control means 300 may be arranged to provide control of communication in the service area of the system. The control device 300 comprises at least one memory 301, at least one data processing unit 302, 303 and an input/output interface 304. Via the interface, the control device may be coupled to a receiver and a transmitter of the base station. The receiver and/or transmitter may be implemented as a radio front end or a remote radio head.

Referring now to fig. 4, an illustration of a UE protocol stack (protocol stack) as part of the LTE standard is provided. As can be seen in the figure, the stack (stack) comprises 3 different layers, a data packet passing on the uplink when the data packet is ready to be transmitted over the network, and a data packet passing on the downlink when received from the network for transmission to the host.

Layer 2 of the protocol stack comprises a first protocol layer 401, a second protocol layer 402 and a zeroth protocol layer 403. In this example, the first protocol layer 401 is a Radio Link Control (RLC) layer 401, the second protocol layer 402 is a Medium Access Control (MAC) layer 402, and the zeroth protocol layer 403 is a Packet Data Convergence Protocol (PDCP) layer 403. The protocol stack may also include a Service Data Adaptation Protocol (SDAP) layer (not shown).

The RLC layer 401 is configured to receive data packets from the PDCP 403. RLC 401 then performs the necessary processing to produce a data packet that is passed to MAC layer 402. The data packets that the RLC layer 401 passes to the MAC layer 402 may be referred to as RLC Protocol Data Units (PDUs) or MAC Service Data Units (SDUs). The term "service data unit" refers to packets received by one layer of the stack, while packets output by one layer of the stack are referred to as "protocol data units". Therefore, when the term "RLC PDU" is used, this may also be understood to mean "MAC SDU" and vice versa.

The PDCP layer 403 receives PDCP SDUs, and may then perform at least some of the following functions to generate PDCP PDUs: header compression and decompression, transfer of user data, reordering and in-order delivery, encryption and decryption, and timer SDU based discard. PDCP may also perform reordering when dual connectivity is configured.

The RLC layer 401 receives PDCP PDUs from the PDCP layer 303, and may then perform some of the following functions to generate RLC PDUs: transmitting upper layer PDU; error correction is performed through ARQ; segmentation and reassembly of RLC SDUs; re-segmenting the RLC SDU segment; repeating the detection; and protocol error detection.

The MAC layer 402 receives RLC PDUs from the RLC layer 401, and may then perform some of the following functions to generate MAC PDUs: mapping between logical channels and transport channels; multiplexing/demultiplexing MAC SDUs belonging to one or different logical channels into/from a Transport Block (TB) transferred to/from a physical layer on a transport channel; scheduling information reporting; error correction is performed through HARQ; priority handling between logical channels of one UE; priority handling between UEs by means of dynamic scheduling; selecting a transmission format; and filling.

The protocol stack may include a third protocol layer 404, which in this example is a physical layer 404. However, it is understood that the physical layer is merely an example, and the third protocol layer may take forms other than the physical layer 404. When the MAC layer 402 has processed the RLC PDU 401 to produce a MAC PDU 402, the MAC layer 402 may then pass the MAC PDU to the physical layer 404. The physical layer is configured to prepare and transmit data packets over the network to the receiving entity.

The transport entity performing the above-described processing and transmission of data packets may comprise a User Equipment (UE), such as the user equipment described above with reference to fig. 2. Likewise, the receiving entity receiving the data packets from the network may comprise a User Equipment (UE), such as the user equipment described above with reference to fig. 2.

Reference is made to fig. 5a, 5b and 5 c. Figure 5a illustrates an example of a PDCP PDU 510. The PDCP PDU 510 includes a PDCP SDU 520 received by the PDCP layer 403 and a PDCP header 530 attached to the PDCP SDU by the PDCP layer.

Fig. 5b shows an example of an RLC PDU 540. The RLC PDU 540 includes an RLC payload 550 and an RLC header 560, which is attached by the RLC layer 401 to the RLC payload 550. The RLC payload 550 includes a complete PDCP PDU 510 or a segment of a PDCP PDU 510.

Fig. 5c shows an example of a MAC PDU 570. The MAC PDU 570 includes a MAC payload 580 and a MAC header 590, the MAC header 590 being attached to the MAC payload 580 by the MAC layer 402. The MAC payload 580 includes one or more RLC PDUs 540.

Radio Link Control (RLC) is a layer 2 protocol. The main task of the RLC protocol is to transmit upper layer Protocol Data Units (PDUs) in one of three modes: acknowledged Mode (AM), Unacknowledged Mode (UM), and Transmission Mode (TM).

The receiving entity, which may be referred to as an RLC entity, may operate in an Acknowledged Mode (AM). In AM, the receiving entity is configured to send a STATUS report (which may be referred to as a STATUS PDU) to the transmitting entity (which may be referred to as a peer AM RLC entity), from which data packets (which may be RLC PDUs and/or RLC SDUs) are received. The status report may include a positive Acknowledgement (ACK) of a data packet (or portion thereof) that has been received from the transmitting entity. The status report may additionally include Negative Acknowledgements (NACKs) of data packets (or portions thereof) that are expected to be received from the transmitting entity or that have been determined to be lost. In some cases, the status report may include only a single explicit ACK value used to indicate to the transmitting entity the acknowledgement of multiple data packets that have been received at the receiving entity. For example, the ACK may include a sequence number that indicates to the transmitting entity that there are all data packets that have been successfully received at the receiving entity, have not been negatively acknowledged, but do not include the sequence number.

It should be appreciated that although the term STATUS PDU is used in the specification, this is merely an example, and where this term is used, a broader STATUS report may be intended. The description relates to a procedure for transmitting a status report from a receiving entity. Part of the process includes passing to a lower protocol layer (e.g., physical layer 404) of the status report for transmission over the network to the transport entity.

The receiving entity may be configured to transmit the status report in response to a poll from the transmitting entity. For example, when an indication is received at the receiving entity from the transmitting entity that a data packet containing a status report should be transmitted (e.g., this may be an AMD (acknowledged mode data) PDU with a Sequence Number (SN) ═ x and a polling field set to "1"), the receiving entity should transmit the status report in response. If the PDU is to be discarded, a status report may be transmitted. Additionally or alternatively, if the sequence number of a data packet is less than a limit (which may be referred to as RX _ Highest _ Status in some examples), the receiving entity should transmit a Status report after receiving such a data packet. Otherwise, the transmission of the status report is delayed until the sequence number of the data packet is less than the limit. This may occur when the receiving entity increases the limit. Additionally or alternatively, if the sequence number of a data packet is greater than or equal to RX _ Next + AM _ Window _ Size, the receiving entity should transmit a status report after receiving such a data packet. Otherwise, transmission of the status report is delayed until the sequence number is greater than or equal to RX _ Next + AM _ Window _ Size. RX Next is a receive state variable that holds the value of SN after the last in-order received data packet and which serves as the lower edge of the receive window. It is initially set to 0 and is updated each time the receiving entity receives data with SN RX _ Next. In other words, RX _ Next is the sequence number after the highest sequence number of all received data packets. AM _ Window _ Size is a constant used by both the transmission side and the reception side of each reception entity. The value of which varies according to the number of bits used to represent the sequence number. For example, when 12-bit SN is used, AM _ Window _ Size is 2048, and when 18-bit SN is used, AM _ Window _ Size is 131072.

By imposing one or more of these conditions on the transmission of the status report, it can be ensured that the receiving entity transmits the status report after HARQ reordering.

The status report may be used by the transmitting entity to detect a failure to receive the AMD PDU at the receiving entity.

As explained, conditions may be imposed to allow time for HARQ reordering before transmitting the status report. A timer (which may be referred to as t-reassembly) may be used for this purpose. At various points in the description, this timer is referred to as a second timer. The receiving entity may be configured to transmit the status report upon expiration of the time period for reordering (t-reassembly). For example, when the time period/timer expires, the limit (i.e., RX _ Highest _ Status) may be increased such that the sequence number of the packet for which no ACK or NACK has been transmitted is now below the limit, and thus a new Status report including an ACK or NACK for these data packets may be transmitted.

Typically, a further timer (which may be referred to as t-statuproshibit) is used to determine whether to allow or disallow status reporting. At various points in the description, this timer may be referred to as a first timer. If the timer is not running, the receiving entity may be configured to transmit a status report including both ACK and NACK to the transmitting entity. The receiving serving entity may perform such transmission by constructing and transmitting a STATUS PDU to a lower layer (e.g., physical layer) at a first transmission occasion indicated by the lower layer. However, if the timer is running, the receiving entity may generally block the transmission of ACKs and NACKs until the first timer expires.

When the receiving entity has transmitted the status report, the receiving entity may be configured to start a first timer such that the receiving entity will not transmit further status reports until the timer expires.

In one particular example, if t-statuppriohibit is running, even after triggering STATUS reports multiple times, the receiving side of the AM RLC entity should construct a single STATUS PDU at the first transmission occasion indicated by the lower protocol layer after the t-statuppriohibit expires while the t-statuppriohibit is running and transmitting it to the lower layer for transmission to the transmitting entity. When the STATUS PDU has been transferred to a lower protocol layer, the receiving side of the AM RLC entity should start t-statupprechibit.

Since the New Radio (NR) RLC will not concatenate RLC SDUs into larger RLC PDUs, the size of the STATUS PDU may be increased compared to other radio access technologies, as multiple RLC SDUs may need to be NACK. For example, if a single MAC PDU includes 30 RLC PDUs and is lost, each RLC PDU will require a negative acknowledgement. However, there may be a limit on the size of the status report (and thus the number of ACK/NACKs) that may be transmitted. Such size limitations may be imposed by the size specified for the UL grant. Thus, in some cases, more RLC PDUs may be lost than can be indicated. This may exceed the size allowed for the STATUS PDU.

Therefore, in a single status report, it may not be possible to include all ACKs or NACKs up to the limit. If only a portion of the ACKs or NACKs are included in the status report, then all ACKs or NACKs will not be transmitted to the transmitting entity when the first timer is started, which will prohibit sending other status reports. Thus, since no NACK is received at the transmitting entity, data packets not received at the receiving entity may not be retransmitted until after the first timer expires.

One proposed solution to this problem is to prevent the first timer from starting until all NACKs for a failed transmission have been transmitted in the status report. In this proposed solution, when the receiving entity has transmitted a STATUS report, the receiving entity may not start t-statuproshibit if the complete information of all missing PDUs has not been included in the STATUS PDU. However, this approach has a problem that when a new UL grant is received and a new STATUS PDU is constructed, the new UL grant may not include all details to be reported, as with the previous UL grant. In practice, the same information will be set first according to the RLC specification (lowest NACK _ SN). In other words, a NACK may be sent for the same missing data packet that had been NACK in the previous status report. The receiving entity may resend the same NACK because the new grant received does not include all the details indicating which data packets the receiving entity needs to report.

Examples according to the present application may address this issue. According to such an example, the first timer is started when the transmission of the status report is performed. The receiving entity is configured to not transmit ACKs and NACKs for one or more data packets for which ACKs or NACKs have been previously sent (i.e., in the first status report) before the timer expires. However, the receiving entity is configured to transmit at least a second status report before the expiration of the first timer, the second status report comprising ACKs and NACKs for one or more data packets for which no ACK or NACK was transmitted in the first status report, either an acknowledgement data packet received before the timer started or a negative acknowledgement data packet expected to be received before the timer started. Thus, the receiving entity is allowed to transmit the remaining ACK/NACKs that are not suitable in the first status report. However, after starting the timer, the receiving entity may still be prohibited from transmitting ACK/NACKs for received (or expected to be received in the case of a NACK) data packets. In some cases, if the capacity of the second status report exceeds a threshold (i.e., there is sufficient space in the second status report), the ACKSs may be allowed to be included in the second status report with data packets received at the start of the timer. The transmitting entity may receive the NACK at least in the second status report and perform the necessary retransmissions.

The receiving entity may determine that a data packet is expected to be received before the timer starts if the sequence number of the data packet is lower than the sequence number of a data packet that was successfully received at the receiving entity before the timer started.

When the receiving entity constructs a Status report, if the Highest sequence number of any packet reported (i.e. including an ACK or NACK in the Status report) is less than a limit (e.g. RX _ Highest _ Status), which may occur due to insufficient space in the UL grant, the receiving entity is only prohibited from reporting data packets that have been reported in the first Status report (i.e. data packets with sequence numbers less than or equal to the Highest sequence number of the data packets reported in the first Status report) when the first timer is active. These data packets can be said to satisfy the condition SN < ACK _ SN _ reported, where ACK _ SN _ reported is the SN immediately following the highest SN of the reported data packet.

On the other hand, the receiving entity does not prohibit reporting of the remaining data packets in at least the second status report (i.e. the data packets having a sequence number larger than the highest sequence number of the data packets reported in the first status report). It can be said that these data packets satisfy the condition ACK _ SN _ ported < ═ SN < RX _ Highest _ Status.

After the partial STATUS PDU has been sent, it may be considered to trigger a STATUS report for the remaining partial/unreported information (previously reported SN > -ACK _ SN _ reported). It should be appreciated that multiple partial STATUS PDUs may be transmitted consecutively, where ACK _ SN _ reported is defined as a sequence number higher than the highest sequence number of the data packet reported in the last partial STATUS report. A partial status report is a status report that includes partial information (i.e., ACK/NACK), which may be constructed based on data packets received at the receiving entity. The partial status report cannot include all ACK/NACKs, and therefore, at least the second status report needs to be transmitted after starting the first timer to send the remaining ACK/NACKs.

When the first timer is active, a status report may be constructed and sent to acknowledge or not acknowledge the data packet until the sequence number of the positively or negatively acknowledged data packet reaches the limit, i.e. until a status report is sent comprising a sequence number of the data packet equal to the limit. In some examples, the limit may be referred to as RX _ Highest _ Status, which may be recorded during construction of the first Status report.

In some examples, the first timer may be restarted in response to a status report transmitted from the receiving entity while the first timer is running.

In some examples, while the first timer is active, data packets with sequence numbers above the limit (e.g., RX _ Highest _ Status) may be received. In this case, for data packets whose sequence number does not exceed the limit, the receiving entity may be configured to transmit an ACK and/or NACK only when the first timer is active, even if other data packets are available for acknowledgement. The restriction may be considered to have been set when the receiving entity transmits the first status report. In other examples, the receiving entity may be configured to report ACKs and/or NACKs for data packets that arrive while the first timer is active. This may occur as long as the status report includes a report of data packets with sequence numbers below the limit (i.e., remaining status information). This may occur as long as the status report comprises a report of data packets that have been received or determined to have not been successfully received at the receiving entity at the time the first status report was transmitted.

In some examples, the at least second status report includes an indication of a lowest sequence number that may be considered for acknowledgement in the at least second status report. Thus, if the transmission of the first status report fails, the transmitting entity does not interpret all sequence numbers below the indicated lowest sequence number as acknowledged. In some examples, the range of sequence numbers is included in the at least second status report, indicating a range of sequence numbers to which the at least second status report applies.

If during this procedure t-statupphibit expires, the report is initialized in order to take into account RX _ Next < ═ SN < RX _ Highest _ Status, i.e. according to the general rules of Status reporting. This is because RLC SN RX _ Next may have been lost again.

An advantage of examples of the present application is that they allow a receiving entity to report lost data packets when not all information can fit into one status report. This may help to mitigate stalling of the transmitting entity (i.e., transmission window stalling) during high data rate scenarios.

When the STATUS report has been triggered, if the first timer is not running on the first transmission occasion (possibly indicated by the lower protocol layer), the receiving entity shall construct a STATUS PDU and transmit it to the lower layer for transmission. On the other hand, if the first timer is running and part of the state information is waiting to be transmitted: at a first transmission opportunity, a STATUS PDU is constructed and transmitted to a lower layer for transmission.

When a status report has been triggered, at a first transmission occasion (possibly indicated by a lower layer) after expiration of the first timer, the receiving entity is configured to construct and transmit a single status report to the transmitting entity, even if multiple status reports are transmitted while the first timer is active.

Examples of the present application will be explained in more detail with reference to the following drawings.

Referring to fig. 7, illustrated is a method 700 that may be performed in a device, such as a user equipment or network node, that receives a data packet from a transmitting entity and transmits an Acknowledgement (ACK) to indicate successful receipt of the data packet or transmits a Negative Acknowledgement (NACK) to indicate that the data packet has not been successfully received from the transmitting entity. The term data packet as used herein may refer to an RLC SDU which is acknowledged separately. Alternatively, the term data packet may refer to a segment of an RLC SDU, such as a PDCP PDU. Alternatively, the term data packet may refer to an RLC PDU.

Those skilled in the art will appreciate that method 700 is provided as an example, and in other examples, one or more steps of the method may be omitted.

At S710, the receiving entity transmits a status report to the transmitting entity. This STATUS report may be referred to as a STATUS PDU. The status report may include one or more ACKs received for the data packet at the receiving entity. The status report may include one or more NACKs corresponding to data packets not all or partially received that are expected to be received from the transmitting entity. The receiving entity may be configured to transmit an ACK or NACK for data packets up to the sequence number limit. The sequence number limit may be referred to as RX _ Highest _ Status. The limit may be set to ensure that the status report is transmitted after HARQ reordering. However, as explained, in the examples of the present application, due to the limited space, especially in high data rate scenarios, it may not be possible to include all ACK/NACKs up to the limited data packet in the status report. Thus, in this case, even if the RX _ Highest _ Status limit is not reached, the receiving entity is configured to include an ACK/NACK for a data packet in a Status report, there is room in the first Status report of the data packet, and to transmit the Status report to the receiving entity.

At S720, a first timer is started. This timer may be referred to as a t-StatusProhibit timer.

At S730, it is determined whether the first timer has expired. In response to determining that the first timer has not expired, the receiving entity transmits an ACK/NACK for the unreported data packet to the transmitting entity at S740. The ACK/NACK may be transmitted for data packets having a sequence number less than or equal to the highest sequence number of the data packets received before the timer was started. Therefore, the data packet received after the timer is started may not be acknowledged. However, data packets received at the receiving entity prior to the start of the timer are acknowledged, which data packets are not included in the previous status report. Likewise, a negative acknowledgement for a data packet that was not received at the receiving entity but has a lower sequence number than the data packet received at the receiving entity before the timer started.

An unreported data packet is a data packet for which no ACK or NACK has been transmitted to the transmitting entity. The receiving entity may determine whether a data packet has not been reported by checking the highest sequence number value included in a previous status report sent to the transmitting entity. The highest sequence number value provides an indication of the next sequence number for a data packet that was not reported as lost in the previous status report. The receiving entity at S740 may check the highest sequence number value and transmit an ACK/NACK for any data packet having a sequence number value equal to or higher. The receiving entity may transmit sequence numbers up to the ACK/NACK of the restricted data packet.

By transmitting the ACK/NACK for the unreported data packet, the transmitting entity is able to receive the ACK/NACK and in response perform a retransmission of the NACK (negative acknowledgement) data packet. If the receiving entity must wait until the first timer expires before beginning to transmit the ACK/NACK, a retransmission delay will result, since the transmitting entity will not be aware of the failure of the transmission of the relevant data packet until the timer expires.

After S740, if it is determined that the first timer has expired, the method proceeds to S750. At S750, it is determined that a second timer (e.g., t-reassembly) has expired. In S760, the receiving entity stored limit (e.g., RX _ Highest _ Status) is updated in response to determining that the second timer has expired. In response to determining that the limit has been updated, the method may again proceed to S710, where the receiving entity again transmits a further status report. Since the restriction has been raised, the receiving entity is configured to transmit an ACK or NACK for data packets with higher sequence numbers.

Referring to fig. 6a and 6b, examples of status reports are shown which may be transmitted by a receiving entity to a transmitting entity. Fig. 6a shows an example of a first status report 600 that may be transmitted when the first timer is inactive. Fig. 6a shows an example of a second status report 650, which may be subsequently transmitted when the first timer is active.

Fig. 6a shows a status report with a header 605. The header contains information necessary for correctly decoding the status report 600 at the transmitting entity, such as a control PDU type field (CPT). The status report 600 further comprises an ACK610 indicating that a data packet with a sequence number less than 4, which has not been negatively acknowledged, has been successfully received at the receiving entity. In this example, status report 600 does not contain an ACK or NACK for the first data packet with sequence number 1. However, the transmitting entity may be configured to interpret ACK610f as acknowledging any data packet (including the first data packet) having a sequence number less than SN-4, but not yet receiving a NACK. Therefore, even if an ACK with sequence number 1 is not included in the status report 600, the status report 600 can be understood as an "implicit" acknowledgement of the first data packet.

The status report 600 also includes a NACK 615 indicating that the third data packet has not been successfully received at the receiving entity (sequence number 3). In this case, all segments of the third data packet are not received at the receiving entity, and thus, the NACK 615 does not include an indication of which particular segments were not received, but rather indicates that the receiving entity has not received the entire data packet.

The status report 600 also includes a NACK 620 indicating that the receiving entity has not successfully received one or more segments of the second data packet (sequence number 2). In this case, the NACK includes an indication of the particular segment in which the transmission of the data packet failed. If the segment that failed transmission is in a continuous sequence, a NACK may contain an indication of the start of the sequence (SOstart) and the end of the sequence (SOend). Thus, the transmitting entity may determine which segments of the data packet have not been successfully transmitted and may then retransmit only those segments, rather than the entire data packet.

After transmission of the status report 600, the receiving entity is configured to start a first timer. Until the expiration of the first timer, the receiving entity may transmit a status report that includes ACK/NACKs for data packets for which an ACK or NACK has not been transmitted (i.e., unreported data packets). Such a status report is shown in fig. 6 b.

Fig. 6a shows a status report 650 with a header 655. The header 655 contains information required to correctly decode the status report at the transport entity, such as the control PDU type field (CPT). The status report 650 also includes an ACK 660 indicating that a data packet with a sequence number less than 8 has been successfully received at the receiving entity. As in the first status report 600, the presence of an ACK may implicitly acknowledge data packets with lower sequence numbers that have not been negatively acknowledged. Accordingly, ACK 660 may acknowledge to the transmitting entity that the fifth data packet was received at the receiving entity (sequence number 5) since a NACK for the fifth data packet was not included in status report 650.

The status report 650 also includes a NACK 665 indicating that the seventh data packet has not been successfully received at the receiving entity (sequence number 7). In this case, all segments of the seventh data packet have not been received at the receiving entity, and thus, NACK 665 does not include an indication of which particular segments were not received, but rather indicates that the receiving entity has not received the entire data packet.

The status report 650 also includes a NACK 670 indicating that the receiving entity has not successfully received one or more segments of the sixth data packet (sequence number 8). In this case, NACK 670 includes an indication of the particular segment in which transmission of the data packet failed. If the segment that failed transmission is in a continuous sequence, NACK 670 may contain an indication of the start of the sequence (SOstart) and the end of the sequence (SOend). Thus, the transmitting entity may determine which segments of the data packet have not been successfully transmitted and may then retransmit only those segments, rather than the entire data packet.

Fig. 6a and 6b show that when transmission of a sequence of consecutive segments of a data packet fails, the amount of space required to convey this information in a status report can be reduced by including an indication of the start and end points of the sequence. Likewise, when transmission of a sequence of consecutive data packets fails, this may be indicated in the status report by indicating the start and end points of the sequence. Referring to fig. 8, this is illustrated.

Fig. 8 shows an example of a status report 800. The header 605 and NACK 615 may be substantially the same as shown in fig. 6 a. ACK 810 is an acknowledgement with SN of 9. The status report also includes a NACK805 indicating a transmission failure of a data packet having sequence numbers 5 to 8. In this example, NACK805 indicates these data packets by including a value indicating the start of the range (NACK _ SN ═ 5) and a value indicating the size of the range (NACK range). In this example, NACK range 3 indicates that after a data packet with SN 5, there are 3 data packets with consecutive sequence numbers (i.e.,

SN

6, 7, and 8) that are negatively acknowledged by the presence of this NACK805 in the status report 800.

It should be understood that each block of the flowchart of fig. 7, and any combination thereof, may be implemented by various means, such as hardware, software, firmware, one or more processors, and/or circuitry.

The method may be implemented on the mobile device described in relation to fig. 2 or on the control means shown in fig. 3.

The control functions may include: receiving a plurality of data packets; cause transmission of a first status report, the first status report including at least one of an acknowledgement and a negative acknowledgement of one or more of the plurality of data packets; and subsequently: starting a first timer; before expiration of the first timer: inhibiting further transmission of acknowledgements and negative acknowledgements included in the first status report; allowing transmission of at least one of an acknowledgement and a negative acknowledgement of one or more of the plurality of data packets not included in the first status report.

It is to be understood that the apparatus may comprise or be coupled to other units or modules or the like, such as a radio part or a radio head, for transmission and/or reception. Although the apparatus has been described as one entity, the different modules and memories may be implemented in one or more physical or logical entities.

It is to be noted that although embodiments have been described with respect to LTE/LTE-a and NR, similar principles may be applied with respect to other networks and communication systems. For example, the principles may be applied to device operation using multiple connections. Thus, although certain embodiments are described above by way of example with reference to certain example architectures for wireless networks, technologies and standards, embodiments may be applied to any other suitable form of communication system than that illustrated and described herein.

It is also noted herein that while the above describes exemplifying embodiments, there are several variations and modifications which may be made to the disclosed solution without departing from the scope of the present invention.

In general, the various embodiments may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects of the invention may be implemented in hardware, while other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device, although the invention is not limited thereto. While various aspects of the invention may be illustrated and described as block diagrams, flow charts, or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods 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.

Embodiments of the invention may be implemented by computer software executable by a data processor of a mobile device, such as in a processor entity, or by hardware, or by a combination of software and hardware. Computer software or programs (also known as program code, including software routines, applets, and/or macros) can be stored in any device-readable data storage medium and they include program instructions to perform particular tasks. The computer program product may include one or more computer-executable components that are configured to perform an embodiment when the program is run. The one or more computer-executable components may be at least one software code or portion thereof.

Further in this regard it should be noted that any block of the logic flow as in the figures may represent a program step or an interconnected logic circuit, block or function or a combination of a program step and a logic circuit, block or function. The software may be stored on such physical media as memory chips or memory blocks implemented within the processor, magnetic storage such as hard or floppy disks, and optical storage such as, for example, DVDs and their data variants CDs. The physical memory is a non-transitory medium.

The memory may be of any type suitable to the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The data processor may be of any type suitable to the local technical environment, and may include one or more of general purpose computers, special purpose computers, microprocessors, Data Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), FPGAs, gate level circuits and processors based on a multi-core processor architecture, as non-limiting examples.

Embodiments of the invention may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

The foregoing description provides by way of non-limiting example a full and informative description of the exemplary embodiments of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended claims. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention, as defined in the appended claims. Indeed, there is yet another embodiment that includes a combination of one or more embodiments with any other embodiments previously discussed.

Claims

1. A method of communication, comprising:

receiving a plurality of data packets;

cause transmission of a first status report comprising at least one of an acknowledgement and a negative acknowledgement for one or more of the plurality of data packets; and subsequently:

starting a first timer;

prior to expiration of the first timer:

inhibiting further transmission of acknowledgements and negative acknowledgements included in the first status report; and

allowing transmission of at least one of an acknowledgement and a negative acknowledgement for one or more of the plurality of data packets that are not included in the first status report.

2. The method of claim 1, comprising: prior to expiration of the first timer: inhibiting the transmission of negative acknowledgements for data packets having higher sequence numbers than any of the plurality of data packets received prior to the start of the first timer.

3. The method of claim 1, comprising, prior to expiration of the first timer: allowing the transmission of a negative acknowledgement having a lower sequence number than any of the plurality of data packets received prior to the start of the first timer.

4. The method of claim 1, inhibiting the transmission of acknowledgements for data packets received after the starting of the first timer.

5. The method of claim 1, comprising: determining a highest sequence number of the one or more data packets for which acknowledgements and negative acknowledgements are included in the first status report.

6. The method of claim 5, wherein inhibiting the further transmission comprises: refraining from the transmission of an acknowledgement or negative acknowledgement for any data packet having a sequence number less than or equal to the highest sequence number.

7. The method of claim 5, wherein allowing the transmission comprises: allowing the transmission of at least one of an acknowledgement or a negative acknowledgement for any data packet having a sequence number greater than the highest sequence number.

8. The method of claim 1, wherein the transmission of at least one of an acknowledgement or a negative acknowledgement for one or more data packets before the first timer expires comprises: at least one of an acknowledgement or a negative acknowledgement for one or more data packets having sequence numbers less than the first limit is transmitted.

9. The method of claim 8, comprising: increasing the first limit after expiration of a second timer.

10. The method of claim 1, wherein the transmission of negative acknowledgements comprises:

transmitting a negative acknowledgement in the status report, the negative acknowledgement comprising a sequence number of a data packet that has not been received.

11. The method of any preceding claim, wherein the transmission of a negative acknowledgement comprises:

transmitting a negative acknowledgement in the status report, the negative acknowledgement comprising an indication of one or more segments of the partially received data packet that have not been received.

12. The method of claim 11, wherein the indication of one or more segments comprises: an indication of a start point and an end point of a set of consecutive segments in the data packet that have not been received.

13. A computer readable storage medium having stored thereon program code configured to, when executed, cause an apparatus to perform the method of any of claims 1 to 12.

14. An apparatus for communication, comprising:

at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to:

receiving a plurality of data packets;

starting a first timer;

prior to expiration of the first timer: