Systems and methods for PDCP sn gap reporting

Abstract

Systems and methods for consolidating Packet Data Convergence Protocol sequence number gap reports in wireless communication systems are disclosed. When multiple packet discard timers expire within a short time period, conventional approaches generate separate gap reports for each discarded packet, resulting in significant signaling overhead. The disclosed techniques consolidate information about multiple sequence number gaps into a single report. A user equipment determines temporal proximity of at least two packet discard timer expiries and generates a consolidated report. The consolidation may use a wait timer approach, delaying gap report transmission to determine if additional discard timers will expire. Alternatively, a consolidation timer approach determines gap report content at the end of a consolidation period. The methods reduce signaling overhead while maintaining efficient packet delivery optimization, particularly for high packet rate applications like extended reality and cloud gaming.

Description

SYSTEMS AND METHODS FOR PDCP SN GAP REPORTINGTECHNICAL FIELD

[0001] The present disclosure relates generally to reporting discarded packets.BACKGROUND

[0002] 5G is the fifth generation of mobile communications, addressing a wide range of use cases from enhanced mobile broadband (eMBB) to ultra-reliable low-latency communications (URLLC) to massive machine type communications (mMTC). 5G includes the New Radio (NR) access stratum interface and the 5G Core Network (5GC). The NR physical and higher layers are reusing parts of the LTE specification, and to that add needed components when motivated by new use cases.

[0003] Low-latency high-rate applications such as extended Reality (XR) and cloud gaming are important in 5G era. XR may refer to all real-and- virtual combined environments and humanmachine interactions generated by computer technology and wearables. It is an umbrella term for different types of realities including Virtual reality (VR), Augmented reality (AR), Mixed reality (MR), and the areas interpolated among them. The levels of virtuality range from partially sensory inputs to fully immersive VR.

[0004] 5G NR is designed to support applications demanding high rate and low latency in line with the requirements posed by the support of XR and cloud gaming applications in NR networks. 3GPP Release 17 contains a study item on XR Evaluations for NR. The main objectives are to identify the traffic model for each application of interest, the evaluation methodology and the key performance indicators of interest for relevant deployment scenarios, and to carry out performance evaluations accordingly in order to investigate possible standardization enhancements in potential follow-up SI / WI.

[0005] The low-latency applications like XR and cloud gaming require bounded latency, not necessarily ultra-low latency. The end-to-end latency budget may be in the range of 20-80 ms, which needs to be distributed over several components including application processing latency, transport latency, radio link latency, etc. For these applications, short transmission time intervals (TTIs) or mini-slots targeting ultra-low latency may not be effective.

[0006] Figure 1 shows an example of frame latency measured over radio access network (RAN), excluding application & core network latencies. It can be seen that there exist frame latency spikes in RAN. The sources for the latency spikes may include queuing delay, time-varyingradio environments, time-varying frame sizes, among others. Tools that can help to remove latency spikes are beneficial to enable better 5G support for this type of traffic.

[0007] In addition to bounded latency requirements, the applications like XR and cloud gaming also require high rate transmission. This can be seen from the large frame sizes originated from this type of traffic. The typical frame sizes may range from tens of kilobytes to hundreds of kilobytes. The frame arrival rates may be 60 or 120 frames per second (fps). As a concrete example, a frame size of 100 kilobytes and a frame arrival rate of 120 fps can lead to a rate requirement of 95.8 Mbps.

[0008] A large video frame is usually fragmented into smaller IP packets and transmitted as several transport blocks (TBs) over several TTIs in RAN. Figure 2 shows an example of the cumulative distribution functions of the number of transport blocks required to deliver a video frame with size ranging from 20 KB to 300 KB. For example, Figure 2 shows that for delivering the frames with a size of 200 KB each, the median number of needed TBs is 5.

[0009] The characteristics of XR traffic arrival are quite distinct from typical web-browsing and VoIP traffic as shown in Figure 3. It is well expected that the arrival time is quasi-periodic and largely predictable as VoIP. However, its data size is order of magnitude larger than VoIP, as discussed above. In addition, similar to web-browsing, the data size is different at every application PDU arrival instance due to dynamics of contents and human motion.

[0010] As mentioned above, many XR applications will generate traffic periodically with a variable size. When the application packet enters the internet, the initial packet may be transmitted into a single PDU in the network or may be segmented into several PDUs. One application packet could, for instance, correspond to one or several IP packets.

[0011] IP packets will arrive at the PDCP layer i.e., PDCP SDUs, and the PDCP layer will create PDCP PDUs and will deliver them to lower layers. When an IP packet arrives to PDCP, the PDCP layer starts a PDCP discard timer. When this timer expires, the PDCP discards the PDCP SDU as well as the corresponding PDCP Data PDU. If the PDCP PDU was delivered to lower layers, PDCP indicates the discard to lower layers. Lower layers e.g., RLC will discard the PDCP PDUs (RLC SDU) if these RLC SDU or any segment of the RLC SDU has not yet been transmitted to lower layers.

[0012] As discussed above, an application PDU e.g., a video frame, is divided into multiple IP packets. All these IP packets which belong to one video frame can be defined as PDU Set.

[0013] SA2 in [23700-60] identified that PDU sets could be assigned with a PDU Set Importance indicator. This parameter can be used to identify the importance of a PDU Set within a QoS flow. RAN may use it for PDU Set level packet discarding in presence of congestion.

[0014] *PDU Set as defined by 23.700-60: PDU Set: A PDU Set is composed of one or more PDUs carrying the payload of one unit of information generated at the application level (e.g. a frame or video slice for XRM Services, as used in TR 26.926

[0027] ). In some implementations all PDUs in a PDU Set are needed by the application layer to use the corresponding unit of information. In other implementations, the application layer can still recover parts all or of the information unit, when some PDUs are missing.

[0015] RAN2 also agreed on a new feature called PDCP SN Gap report. Using this report, the PDCP transmitter can inform the PDCP receiver of missing PDCP SN numbers, i.e., the PDCP SDUs that have been discarded and thus will not be transmitted. The information about missing SN will enable the receiver side to move the receiving window forward faster (reduce the waiting time of reordering timers) and allow for faster delivery of received packets to higher layers. Upon receiving the PDCP SN gap report, the receiver state variables (RX_NEXT, RX_DELIV and RX_REORD) are updated. It was also agreed that how to limit the frequency of the PDCP SN gap reporting is left to UE implementation.SUMMARY

[0016] The present disclosure addresses challenges in PDCP sequence number gap reporting for wireless communication systems, particularly in scenarios involving XR and cloud gaming applications where multiple packets may be discarded in quick succession.

[0017] In wireless communications, when a transmitting entity discards a packet with an assigned sequence number while a higher sequence number is buffered, a "gap" is created in the sequence numbers. The transmitting entity generates a PDCP SN gap report to inform the receiving entity of the missing sequence numbers, enabling the receiver to advance its receiving window and reduce packet delivery delays. However, when multiple discard timers expire within a short time interval, multiple gap reports may be generated in quick succession, causing significant signaling overhead.

[0018] The present disclosure provides systems and methods for consolidating multiple PDCPSN gap reports to reduce signaling overhead while maintaining efficient packet delivery. In some embodiments, a User Equipment (UE) combines information about multiple sequence number gaps into a single consolidated report using timer-based mechanisms. The consolidation may be based on the timing relationship between multiple packet discard events and the remaining time at the receiving entity.

[0019] In some embodiments, a method may include determining, based on temporal proximity of the expiration of at least two packet discard timers, to generate a consolidated report for the expiration of the at least two packet discard timer; and generating the consolidated report.

[0020] In some embodiments, a method may include receiving a consolidated Packet Data Convergence Protocol Sequence Number, PDCP SN, gap report from a user equipment, the consolidated PDCP SN gap report indicating missing sequence numbers for at least two packet discard timer expiries that occurred within a time period; and processing the consolidated PDCP SN gap report to update receiver state variables.

[0021] In some embodiments, a UE may include: processing circuitry configured to detect expiration of at least two packet discard timers within a time period; timer circuitry configured to determine temporal proximity of the expiries; and a communication interface configured to transmit a consolidated PDCP SN gap report for the at least two packet discard timer expiries based on the temporal proximity determination.

[0022] In other embodiments, a network node include: a communication interface configured to receive a consolidated PDCP SN gap report from a user equipment, the consolidated PDCP SN gap report indicating missing sequence numbers for at least two packet discard timer expiries that occurred within a time period; processing circuitry configured to process the consolidated PDCP SN gap report and update receiver state variables; and memory configured to store the receiver state variables.

[0023] In some embodiments, a method performed by a UE may include: receiving a first packet associated with a first discard timer; receiving a second packet associated with a second discard timer; and transmitting a gap report at a transmission time that is subsequent to expiration of the first discard timer and the second discard timer, the gap report indicating at least the expiration of the first discard timer and the second discard timer.

[0024] The disclosed techniques enable more efficient PDCP SN gap reporting by reducing the frequency of signaling messages while maintaining the benefits of gap reporting for packet delivery optimization. This is particularly advantageous for applications with high packet rates and variable packet sizes, such as XR and cloud gaming, where multiple packets may be discarded in rapid succession due to stringent latency requirements.BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0026] Figure 1 illustrates an example of frame latency measured over Radio Access Network (RAN);

[0027] Figure 2 illustrates an example of the cumulative distribution functions of the number of transport blocks required to deliver a video frame with size ranging from 20 KB to 300 KB ;

[0028] Figure 3 illustrates extended Reality (XR) traffic characteristics compared to Voice over IP (VoIP) and Web-browsing;

[0029] Figure 4 illustrates an operation of a User Equipment device (UE) in accordance with some embodiments of the present disclosure;

[0030] Figure 5 illustrates an operation of a network node in accordance with some embodiments of the present disclosure;

[0031] Figure 6 shows an example of a communication system in accordance with some embodiments of the present disclosure;

[0032] Figure 7 shows a UE in accordance with some embodiments of the present disclosure;

[0033] Figure 8 shows a network node in accordance with some embodiments of the present disclosure;

[0034] Figure 9 is a block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized in accordance with some embodiments of the present disclosure; and

[0035] Figure 10 illustrates an operation of a User Equipment device (UE) in accordance with some embodiments of the present disclosure.DETAILED DESCRIPTION

[0036] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0037] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0038] There currently exist certain challenge(s). As described above, a Tx entity generates a PDCP SN gap report when a packet assigned a sequence number (SN) and queued in the buffer is discarded, whilst a higher SN is buffered thereby creating a “gap” in SNs. When the Rx entityreceives this SN gap report, it can advance the lower edge of the Rx window past the discarded SN and stop the corresponding timer (T-Reordering), which indicates how long it should wait to receive a certain packet before advancing the window to the next unreceived packet. By stopping the T-Reordering timer early upon reception of the PDCP SN gap report, the Rx entity can ideally reduce the delay to submit packets to the higher layers by the length of T-Reordering.

[0039] The packet arriving in a protocol entity (e.g., PDCP layer) and assigned a SN is discarded based on a configured discard timer which dictates when the packet shall be discarded if it has not yet been transmitted. A single report (e.g., in the form of the PDCP SN gap report) can be sent to the Rx entity. However, multiple discard timers may be running in parallel for different packets which might expire within a certain time interval rendering multiple packets with assigned SNs to be discarded in quick succession and hence multiple reports would also be sent to the network in quick succession. These multiple reports would cause significant overhead.

[0040] Some embodiments of the current disclosure relate to how the UE would handle the scenario where the discard timer for more than one packet may expire within a short period of time and how the reporting is performed to indicate the SN gap.

[0041] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. The UE combines information about multiple sequence number gaps in to one report for example by a timer-based solution allowing for combining of PDCP SN gap reports depending on the remaining time at the Rx entity (T-Reordering) and the time between the discards of multiple packets. The other option to combine the PDCP SN gap report is based on if a certain number of packets are discarded in a similar timeframe considering the remaining T-Reordering timer. In some embodiments, a timer-based solution enables combining of the reports for multiple discarded packets.

[0042] Certain embodiments may provide one or more of the following technical advantage(s). Some embodiments help to reduce the frequency of the gap report signaling especially for multiple discarded packets. The teachings of certain embodiments may improve the e.g., data rate, latency, power consumption, etc.

[0043] The following description is written in the form of UE sending a report to the network in the uplink (UL). However, the procedures as described are equally applicable to the downlink (DL).

[0044] It will be discussed herein how timers are started and restarted. It should be appreciated when reading this that timers described here can be started if they are not running, and restarted if they are already running. For example, if the used timer duration is 1 second, the timer could be started with a 1 second duration and restarted with the same duration, i.e. if the timer is not runningand is started it would expire 1 second after the start and if instead the timer is already running and is restarted the timer would expire 1 second after the restart.

[0045] The behavior described herein is described such that the UE applies these embodiments as a whole. But the UE can communicate multiple types of traffic, e.g. multiple bearers. The embodiments described herein can be performed per flow, bearer, instance of protocol entity (PDCP / RLC entity), etc. Meaning that it may be so that packets associated with a first bearer may not be impacting by packets associated with a second bearer.

[0046] Systems and methods for PDCP SN GAP reporting are provided. In some embodiments, a method performed by a UE includes determining to perform consolidation of reports based on a trigger condition. In some embodiments, determining is based on one or more timers and / or counters. In some embodiments, determining comprises: determining that there are two expiries of discard timers; if the expiries are closer than a time T apart: generating one report; and if the expiries are further away than the time T apart: generating two reports. In some embodiments, a method may be performed by a network node, the method including receiving a consolidation of reports based on a trigger condition.

[0047] Some embodiments of the current disclosure relate to the scenario wherein a packet arrives in a protocol entity (e.g., a PDCP entity) in the UE and, in response to this, the UE starts a discard timer which dictates when the UE shall discard the packet in case the packet has not yet been transmitted. Further, if there is at least one packet which the UE has already initiated the transmission of, the UE shall send a report to indicate that the UE has discarded the packet. Some embodiments of the current disclosure relate to how the UE would handle the scenario where the discard timer for more than one packet may expire.

[0048] In some embodiments, each new discard timer expiration postpones the report a time Twait. In one embodiment the UE will determine if a second discard timer for a second packet will expire within a time Twait after the expiration of a first discard timer for a first packet. If this is the case, the UE will trigger sending a report to the network in response to the expiration of the second discard timer, otherwise the UE will trigger the sending of a report to the network in response to the expiration of the first discard timer. The UE can determine that the second discard timer will not expire within a time Twait after the expiration of a first discard timer either due to the second discard timer is expected to expire later than Twait. Or, that there is no second packet or there is no second packet with a second discard timer that exists or applies.

[0049] And as can be appreciated, this algorithm allows for further packets: for example, if a third discard timer for a third packet will expire within a time Twait after the expiration of a second discard timer, the UE will instead trigger sending a report to the network in response to theexpiration of the third discard timer, otherwise (i.e., if the third timer expires after a time Twait or the third timer does not exist / apply) the UE will trigger sending a report to the network in response to the expiration of the second discard timer. Another way to interpret Twait is that all packets whose discard timers expire within Twait can be considered to trigger sending the report. This can be applicable to packets marked as both low and high importance (according to the Rel-18 specified classification of packets using PDU set importance (PSI)).

[0050] In one embodiment the order does not matter among the first, second and third packet, i.e., it could be so that the first packet in the above is sent first, then the third packet, then the second packet, or any other order of the packets or the expiration of their timers. This is especially the case for packets of low importance which although might arrive after the high importance packets, have much shorter discard timers thereby these low importance packets are more likely to fall with Twait.

[0051] This embodiment allows for the UE to keep on postponing sending the report as long as new packets’ discard timers expire within a time Twait from an earlier packet’s discard timer expire. However, this may result in the report never being sent if discard timers keep on expiring close enough in time. Therefore, in one embodiment the UE will trigger sending the report at latest a time TLongest_deiay after the first discard timer expired. The length of TLongest_deiay could be of the order of T-Reordering i.e., essentially the delay at the Rx entity before the received packets are submitted to higher layers.

[0052] In another approach, the UE will allow for at most a certain number of N packets to trigger the postponing of the report. For example, if N is 2 then the UE will only allow packet 2 and packet 3 to postpone sending the report, but a fourth packet would not trigger further postponing of the report.

[0053] This embodiment can be implemented with a timer Ti which is started or restarted whenever a discard timer expires for a packet. If the timer Ti expires, the UE sends the report to the network. And to achieve the TLongest_deiay behavior described above, the UE starts a timer T2 in response to starting (not restarting) the timer Ti, and the UE sends the report in response to either TI expiry or T2 expiry (whichever happens first). Expiry of TI may trigger expiry of T2 and vice versa.

[0054] One approach of implementing this is that the UE would trigger / generate the first report immediately upon discard timer expiration, but that report is not sent immediately, instead that report is kept the time Twait and unless the discard timer for a second packet expires (i.e. a second report is triggered), the UE sends the first report. However, if a second packet's discardtimer expires the UE will generate the report due to the second packet's discard timer expiring and also discard, make obsolete, or otherwise refrain from sending the first report.

[0055] Above it was described that each time a discard timer expires the UE will wait a time Twait to see if other discard timers expire and if this is the case the UE postpones sending the report until a timer Twait after that new time.

[0056] In another embodiment the UE will, in response to a discard timer expires for a first packet, start a timer Tconsoiidate- In contrast to the approach with Twait described above, the UE will trigger sending a report after Tconsoiidate- However, the report content will be determined at the end of the Tconsoiidate which means that if other packets have been discarded during this time duration, the UE will set the report accordingly, i.e. the report will indicate that also the newly discarded packets has been discarded. In contrast, if the report would be set at the time of expiration of the first discard timer, the report would only indicate that the first packet was discarded.

[0057] In one version of this embodiment, when the report is sent (i.e. at the end of Tconsoiidate), the UE will wait until a subsequent packet is discarded due to expiry of a discard timer, and in response to this the UE would start the Tconsoiidate timer again and wait to generate a consolidated report after that timer duration.

[0058] In another version of this embodiment, the UE would start the Tconsoiidate timer another time in response to that it expires, and the UE would generate a report at the end of this timer duration to send a consolidated report with information about all discard during that timer duration, however, the UE may chose to refrain from sending a report if there has been no discards during the timer duration.

[0059] If the UE determines that no additional discard timers will expire during the remaining time of timer Twait / Tconsoiidate,the UE sends the report earlier, i.e. before Twait / Tconsoiidate has expired. The UE can determine this by identifying that all the running discard timers have a longer remaining duration than the remaining duration of Twait / Tconsoiidate-

[0060] In some embodiments, the UE determines temporal proximity between discard timer expiries using a predetermined time threshold T. If two or more discard timer expiries occur within time T of each other, they are considered temporally proximate and suitable for consolidation into a single gap report. The value of time T may be configured based on system requirements, expected traffic patterns, or the remaining duration of T-Reordering timers at the receiving entity.

[0061] Figure 4 illustrates a method 400 performed by a user equipment (UE) in accordance with some embodiments of the present disclosure. The method includes determining (step 410) to perform consolidation of reports based on a trigger condition. In some embodiments, the determining step is based on one or more timers and / or counters that track temporal proximity ofpacket discard timer expiries. The temporal proximity may be determined using one or more consolidation timers and / or one or more counters that track a number of expirations of packet discard timers within a time period.

[0062] The method further includes generating (step 420) a consolidated report when the trigger condition is satisfied. In some embodiments, the determining step 410 comprises determining that there are at least two expiries of discard timers, and if the expiries occur closer than a predetermined time T apart, generating one consolidated report in step 420. If the expiries are further away than the time T apart, the method generates separate reports.

[0063] The consolidation may be implemented using various approaches. In one embodiment, if a second packet discard timer for a second packet will expire within a time Twait after the expiration of a first packet discard timer for a first packet, the UE triggers sending a consolidated report to the network in response to the expiration of the second packet discard timer. The UE may determine that the second packet discard timer will not expire within the time Twait after the expiration of the first packet discard timer due to either: the second packet discard timer being expected to expire later than Twait; or, no second packet existing or no second packet with a second packet discard timer existing.

[0064] In some embodiments, if a third packet discard timer for a third packet will expire within the time Twait after the expiration of the second packet discard timer, the UE triggers sending the consolidated report to the network in response to the expiration of the third packet discard timer. All packets whose packet discard timers expire within Twait may be considered for triggering the sending of the consolidated report. The temporal order of packet transmission does not affect the determination of the time Twait.

[0065] The UE may postpone sending the consolidated report as long as new packet discard timers expire within the time Twait from the expiration of an earlier packet discard timer. However, to prevent indefinite postponement, the UE may send the consolidated report at latest a time TLongest_deiay after a first packet discard timer of the at least two packet discard timers expired. The length of TLongest_deiay may be approximately the duration of a T-Reordering timer. The UE may also allow at most a predetermined number N packets to trigger postponing sending of the consolidated report.

[0066] In another embodiment, the UE starts a consolidation timer Tconsoiidate in response to a first packet discard timer expiration, and triggers sending the consolidated report after the expiration of the timer Tconsoiidate- The content of the consolidated report is determined at the end of the timer Tconsoiidate, and if other packets have been discarded during the duration of the timer Tconsoiidate, the consolidated report indicates that other packets have also been discarded. When theconsolidated report is sent at the end of the timer Tconsoiidate, the UE may wait until a subsequent packet is discarded due to expiration of a subsequent packet discard timer, and in response start the timer Tconsoiidate again. Alternatively, the UE may restart the timer Tconsoiidate in response to the expiration of the timer Tconsoiidate and generate a subsequent consolidated report at the end of the restarted timer Tconsoiidate with information about all packet discards during the restarted timer duration.

[0067] If the UE determines that no additional packet discard timers will expire during a remaining time of a consolidation timer, the UE may send the consolidated report before the consolidation timer expires.

[0068] Figure 5 illustrates a method 500 performed by a network node in accordance with some embodiments of the present disclosure. The method includes receiving (step 510) a consolidated Packet Data Convergence Protocol Sequence Number (PDCP SN) gap report from a user equipment. The consolidated PDCP SN gap report indicates missing sequence numbers for at least two packet discard timer expiries that occurred within a time period.

[0069] The method further includes processing (step 520) the consolidated PDCP SN gap report to update receiver state variables. In some embodiments, processing the consolidated PDCP SN gap report comprises updating at least one of RX_NEXT, RX_DELIV, and RX_REORD state variables based on the missing sequence numbers indicated in the consolidated report.

[0070] The network node may advance a receive window based on the missing sequence numbers indicated in the consolidated PDCP SN gap report. The consolidated PDCP SN gap report may comprise sequence number gap information for multiple packets that were discarded by the user equipment within temporal proximity of each other.

[0071] The network node may also stop a T-Reordering timer corresponding to at least one of the missing sequence numbers indicated in the consolidated PDCP SN gap report. The consolidated reporting approach reduces signaling overhead compared to receiving separate gap reports for each individual packet discard timer expiration. By receiving the consolidated PDCP SN gap report, the network node achieves reduced signaling overhead compared to receiving separate gap reports for each of the at least two packet discard timer expiries.

[0072] Figure 10 illustrates a method performed by a user equipment (UE) in accordance with some embodiments of the present disclosure. In a first step 1010 the UE receives a first packet associated with a first discard timer. The UE may receive the first packet for transmission and associate it with a first discard timer that dictates when the packet may be discarded if it has not yet been transmitted. In a second step 1020, the UE receives a second packet associated with a second discard timer. Similar to the first packet, the UE may receive the second packet andassociate it with a second discard timer. In a third step 1030, the UE transmits a gap report at a transmission time that is subsequent to expiration of the first discard timer and the second discard timer. The gap report indicates at least the expiration of the first discard timer and the second discard timer.

[0073] In some embodiments, the method further comprises receiving additional packets each associated with respective discard timers that expire within a predetermined time period of the first discard timer and the second discard timer. In such cases, the gap report indicates expiration of the respective discard timers for the additional packets, enabling consolidation of multiple discard events into a single report.

[0074] The gap report may be transmitted as a single consolidated Packet Data Convergence Protocol Sequence Number (PDCP SN) gap report. This consolidated approach reduces signaling overhead compared to transmitting separate gap reports for each individual packet discard timer expiration.

[0075] In some embodiments, the transmission time occurs after expiration of all discard timers for packets received within a consolidation time window. This timing relationship ensures that the gap report captures all relevant discard events within the consolidation period.

[0076] The gap report indicates missing sequence numbers corresponding to the first packet and the second packet, as well as any additional packets whose discard timers expired within the consolidation period. This information enables the receiving entity to advance its receiving window and update receiver state variables accordingly.

[0077] The method described in Figure 10 is particularly suitable for testing and verification purposes, as each step involves externally observable actions that can be detected and measured by test equipment. This addresses the need for testable UE implementations while maintaining the benefits of consolidated gap reporting for reducing signaling overhead.

[0078] Figure 6 shows an example of a communication system 600 in accordance with some embodiments.

[0079] In the example, the communication system 600 includes a telecommunication network 602 that includes an access network 604, such as a Radio Access Network (RAN), and a core network 606, which includes one or more core network nodes 608. The access network 604 includes one or more access network nodes, such as network nodes 610A and 610B (one or more of which may be generally referred to as network nodes 610), or any other similar Third Generation Partnership Project (3GPP) access nodes or non-3GPP Access Points (APs). Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by asingle vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 602 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 602 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 602, including one or more network nodes 610 and / or core network nodes 608.

[0080] Examples of an ORAN network node include an Open Radio Unit (O-RU), an Open Distributed Unit (O-DU), an Open Central Unit (O-CU), including an O-CU Control Plane (O- CU-CP) or an O-CU User Plane (O-CU-UP), a RAN intelligent controller (near-real time or non- real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O-2 interface defined by the O-RAN Alliance or comparable technologies. The network nodes 610 facilitate direct or indirect connection of User Equipment (UE), such as by connecting UEs 612A, 612B, 612C, and 612D (one or more of which may be generally referred to as UEs 612) to the core network 606 over one or more wireless connections.

[0081] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 600 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 600 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0082] The UEs 612 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 610 and other communication devices. Similarly, the network nodes 610 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 612 and / or with other network nodes or equipment in the telecommunication network 602 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 602.

[0083] In the depicted example, the core network 606 connects the network nodes 610 to one or more hosts, such as host 616. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 606 includes one more core network nodes (e.g., core network node 608) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 608. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-Concealing Function (SIDE), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0084] The host 616 may be under the ownership or control of a service provider other than an operator or provider of the access network 604 and / or the telecommunication network 602, and may be operated by the service provider or on behalf of the service provider. The host 616 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0085] As a whole, the communication system 600 of Figure 6 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 600 may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable Second, Third, Fourth, or Fifth Generation (2G, 3G, 4G, or 5G) standards, or any applicable futuregeneration standard (e.g., Sixth Generation (6G)); Wireless Local Area Network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any Low Power Wide Area Network (LPWAN) standards such as LoRa and Sigfox.

[0086] In some examples, the telecommunication network 602 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunication network 602 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 602. For example, the telecommunication network 602 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing enhanced Mobile Broadband (eMBB) services to other UEs, and / or massive Machine Type Communication (mMTC) / massive Internet of Things (loT) services to yet further UEs.

[0087] In some examples, the UEs 612 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 604 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 604. Additionally, a UE may be configured for operating in single- or multi-Radio Access Technology (RAT) or multi-standard mode. For example, a UE may operate with any one or combination of WiFi, New Radio (NR), and LTE, i.e. being configured for Multi-Radio Dual Connectivity (MR-DC), such as Evolved UMTS Terrestrial RAN (E-UTRAN) NR - Dual Connectivity (EN-DC).

[0088] In the example, a hub 614 communicates with the access network 604 to facilitate indirect communication between one or more UEs (e.g., UE 612C and / or 612D) and network nodes (e.g., network node 610B). In some examples, the hub 614 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 614 may be a broadband router enabling access to the core network 606 for the UEs. As another example, the hub 614 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 610, or by executable code, script, process, or other instructions in the hub 614. As another example, the hub 614 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 614 may be a content source. For example, for a UE that is a Virtual Reality (VR) headset, display, loudspeaker or other media delivery device, the hub 614 may retrieve VRassets, video, audio, or other media or data related to sensory information via a network node, which the hub 614 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 614 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0089] The hub 614 may have a constant / persistent or intermittent connection to the network node 61 OB. The hub 614 may also allow for a different communication scheme and / or schedule between the hub 614 and UEs (e.g., UE 612C and / or 612D), and between the hub 614 and the core network 606. In other examples, the hub 614 is connected to the core network 606 and / or one or more UEs via a wired connection. Moreover, the hub 614 may be configured to connect to a Machine-to-Machine (M2M) service provider over the access network 604 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 610 while still connected via the hub 614 via a wired or wireless connection. In some embodiments, the hub 614 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 610B. In other embodiments, the hub 614 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and the network node 610B, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0090] Figure 7 shows a UE 700 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged, and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, Voice over Internet Protocol (VoIP) phone, wireless local loop phone, desktop computer, Personal Digital Assistant (PDA), wireless camera, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, Laptop Embedded Equipment (LEE), Laptop Mounted Equipment (LME), smart device, wireless Customer Premise Equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3GPP, including a Narrowband Internet of Things (NB-IoT) UE, a Machine Type Communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0091] A UE may support Device-to-Device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), Vehicle-to- Vehicle (V2V), Vehicle-to-Infrastructure (V2I), or Vehicle- to-Everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a devicethat is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0092] The UE 700 includes processing circuitry 702 that is operatively coupled via a bus 704 to an input / output interface 706, a power source 708, memory 710, a communication interface 712, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Figure 7. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0093] The processing circuitry 702 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 710. The processing circuitry 702 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general purpose processors, such as a microprocessor or Digital Signal Processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 702 may include multiple Central Processing Units (CPUs).

[0094] In the example, the input / output interface 706 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 700. Examples of an input device include a touch-sensitive or presence- sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0095] In some embodiments, the power source 708 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 708 may further include power circuitry for delivering power from the power source 708 itself, and / or an external power source, to the various parts of the UE 700 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 708. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 708 to make the power suitable for the respective components of the UE 700 to which power is supplied.

[0096] The memory 710 may be or be configured to include memory such as Random Access Memory (RAM), Read Only Memory (ROM), Programmable ROM (PROM), Erasable PROM (EPROM), Electrically EPROM (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 710 includes one or more application programs 714, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 716. The memory 710 may store, for use by the UE 700, any of a variety of various operating systems or combinations of operating systems.

[0097] The memory 710 may be configured to include a number of physical drive units, such as Redundant Array of Independent Disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, High Density Digital Versatile Disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, Holographic Digital Data Storage (HDDS) optical disc drive, external mini Dual In-line Memory Module (DIMM), Synchronous Dynamic RAM (SDRAM), external micro-DIMM SDRAM, smartcard memory such as a tamper resistant module in the form of a Universal Integrated Circuit Card (UICC) including one or more Subscriber Identity Modules (SIMs), such as a Universal SIM (USIM) and / or Internet Protocol Multimedia Services Identity Module (ISIM), other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as a ‘SIM card.’ The memory 710 may allow the UE 700 to access instructions, application programs, and the like stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system, may be tangibly embodied as or in the memory 710, which may be or comprise a device-readable storage medium.

[0098] The processing circuitry 702 may be configured to communicate with an access network or other network using the communication interface 712. The communication interface 712 may comprise one or more communication subsystems and may include or becommunicatively coupled to an antenna 722. The communication interface 712 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 718 and / or a receiver 720 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 718 and receiver 720 may be coupled to one or more antennas (e.g., the antenna 722) and may share circuit components, software, or firmware, or alternatively be implemented separately.

[0099] In the illustrated embodiment, communication functions of the communication interface 712 may include cellular communication, WiFi communication, LPWAN communication, data communication, voice communication, multimedia communication, short- range communications such as Bluetooth, NFC, location-based communication such as the use of the Global Positioning System (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband CDMA (WCDMA), GSM, LTE, NR, UMTS, WiMax, Ethernet, Transmission Control Protocol / Internet Protocol (TCP / IP), Synchronous Optical Networking (SONET), Asynchronous Transfer Mode (ATM), Quick User Datagram Protocol Internet Connection (QUIC), Hypertext Transfer Protocol (HTTP), and so forth.

[0100] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 712, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected, an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0101] As another example, a UE comprises an actuator, a motor, or a switch related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0102] A UE, when in the form of an loT device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology,extended industrial application, and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a television, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or VR, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 700 shown in Figure 7.

[0103] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship, an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0104] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator and handle communication of data for both the speed sensor and the actuators.

[0105] In some embodiments, the processing circuitry 702 includes timer circuitry configured to manage consolidation operations. The timer circuitry may be configured to determine temporal proximity of packet discard timer expiries and may implement one or more consolidation timers,such as a Twait timer that defines a consolidation window, or a Tconsoiidate timer that defines when to generate consolidated reports.

[0106] In some embodiments, the processing circuitry 702 further comprises counter circuitry configured to track a number of packet discard timer expiries within a time period. The counter circuitry enables the UE 700 to determine when sufficient discard events have occurred to warrant report consolidation.

[0107] The memory 710 may be configured to store timer states associated with the consolidation operations and sequence number gap information for multiple packet discard timer expiries. The communication interface 712 is configured to transmit consolidated PDCP SN gap reports to reduce signaling overhead compared to transmitting separate gap reports for each individual packet discard timer expiration.

[0108] Figure 8 shows a network node 800 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged, and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment in a telecommunication network. Examples of network nodes include, but are not limited to, APs (e.g., radio APs), Base Stations (BSs) (e.g., radio BSs, Node Bs, evolved Node Bs (eNBs), NR Node Bs (gNBs)), and O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

[0109] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node), and / or Remote Radio Units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such RRUs may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a Distributed Antenna System (DAS).

[0110] Other examples of network nodes include multiple Transmission Point (multi-TRP) 5G access nodes, Multi-Standard Radio (MSR) equipment such as MSR BSs, network controllers such as Radio Network Controllers (RNCs) or BS Controllers (BSCs), Base Transceiver Stations (BTSs), transmission points, transmission nodes, Multi-Cell / Multicast Coordination Entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0111] The network node 800 includes processing circuitry 802, memory 804, a communication interface 806, and a power source 808. The network node 800 may be composed of multiple physically separate components (e.g., a NodeB component and an RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 800 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair may in some instances be considered a single separate network node. In some embodiments, the network node 800 may be configured to support multiple RATs. In such embodiments, some components may be duplicated (e.g., separate memory 804 for different RATs) and some components may be reused (e.g., a same antenna 810 may be shared by different RATs). The network node 800 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 800, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, Long Range Wide Area Network (LoRaWAN), Radio Frequency Identification (RFID), or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within the network node 800.

[0112] The processing circuitry 802 may comprise a combination of one or more of a microprocessor, controller, microcontroller, CPU, DSP, ASIC, FPGA, or any other suitable computing device, resource, or combination of hardware, software, and / or encoded logic operable to provide, either alone or in conjunction with other network node 800 components, such as the memory 804, to provide network node 800 functionality.

[0113] In some embodiments, the processing circuitry 802 includes a System on a Chip (SOC). In some embodiments, the processing circuitry 802 includes one or more of Radio Frequency (RF) transceiver circuitry 812 and baseband processing circuitry 814. In some embodiments, the RF transceiver circuitry 812 and the baseband processing circuitry 814 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of the RF transceiver circuitry 812 and the baseband processing circuitry 814 may be on the same chip or set of chips, boards, or units.

[0114] The memory 804 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid state memory, remotely mounted memory, magnetic media, optical media, RAM, ROM, mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD), or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device -readable,and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 802. The memory 804 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 802 and utilized by the network node 800. The memory 804 may be used to store any calculations made by the processing circuitry 802 and / or any data received via the communication interface 806. In some embodiments, the processing circuitry 802 and the memory 804 are integrated.

[0115] The communication interface 806 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 806 comprises port(s) / terminal(s) 816 to send and receive data, for example to and from a network over a wired connection. The communication interface 806 also includes radio front-end circuitry 818 that may be coupled to, or in certain embodiments a part of, the antenna 810. The radio front-end circuitry 818 comprises filters 820 and amplifiers 822. The radio front-end circuitry 818 may be connected to the antenna 810 and the processing circuitry 802. The radio front-end circuitry 818 may be configured to condition signals communicated between the antenna 810 and the processing circuitry 802. The radio front-end circuitry 818 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 818 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of the filters 820 and / or the amplifiers 822. The radio signal may then be transmitted via the antenna 810. Similarly, when receiving data, the antenna 810 may collect radio signals which are then converted into digital data by the radio front-end circuitry 818. The digital data may be passed to the processing circuitry 802. In other embodiments, the communication interface 806 may comprise different components and / or different combinations of components.

[0116] In certain alternative embodiments, the network node 800 does not include separate radio front-end circuitry 818; instead, the processing circuitry 802 includes radio front-end circuitry and is connected to the antenna 810. Similarly, in some embodiments, all or some of the RF transceiver circuitry 812 is part of the communication interface 806. In still other embodiments, the communication interface 806 includes the one or more ports or terminals 816, the radio front-end circuitry 818, and the RF transceiver circuitry 812 as part of a radio unit (not shown), and the communication interface 806 communicates with the baseband processing circuitry 814, which is part of a digital unit (not shown).

[0117] The antenna 810 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 810 may be coupled to the radio front-end circuitry 818 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 810 is separate from the network node 800 and connectable to the network node 800 through an interface or port.

[0118] The antenna 810, the communication interface 806, and / or the processing circuitry 802 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node 800. Any information, data, and / or signals may be received from a UE, another network node, and / or any other network equipment. Similarly, the antenna 810, the communication interface 806, and / or the processing circuitry 802 may be configured to perform any transmitting operations described herein as being performed by the network node 800. Any information, data, and / or signals may be transmitted to a UE, another network node, and / or any other network equipment.

[0119] The power source 808 provides power to the various components of the network node 800 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 808 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 800 with power for performing the functionality described herein. For example, the network node 800 may be connectable to an external power source (e.g., the power grid or an electricity outlet) via input circuitry or an interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 808. As a further example, the power source 808 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0120] Embodiments of the network node 800 may include additional components beyond those shown in Figure 8 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 800 may include user interface equipment to allow input of information into the network node 800 and to allow output of information from the network node 800. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 800. In some embodiments providing a core network node, such as core network node 108 of FIG. 6, some components, such as the radio front-end circuitry 818 and the RF transceiver circuitry 812 may be omitted.

[0121] The processing circuitry 802 is configured to process consolidated PDCP SN gap reports and update receiver state variables, including at least one of RX_NEXT, RX_DELIV, and RX_REORD state variables. The processing circuitry 802 may also be configured to advance a receive window based on missing sequence numbers indicated in consolidated PDCP SN gap reports.

[0122] In some embodiments, the network node 800 includes timer circuitry configured to manage T-Reordering timers. The timer circuitry may stop a T-Reordering timer corresponding to at least one of the missing sequence numbers indicated in a consolidated PDCP SN gap report.

[0123] The memory 804 is configured to store receiver state variables and may maintain window state information for efficient packet processing. The communication interface 806 is configured to receive consolidated PDCP SN gap reports from user equipment, thereby achieving reduced signaling overhead.

[0124] Figure 9 is a block diagram illustrating a virtualization environment 900 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices, and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more Virtual Machines (VMs) implemented in one or more virtualization environments 900 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, a UE, a core network node, or a host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 900 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface. Virtualization may facilitate distributed implementations of a network node, a UE, a core network node, or a host.

[0125] Applications 902 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 900 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0126] Hardware 904 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices asdescribed herein, such as a network interface, an input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 906 (also referred to as hypervisors or Virtual Machine Monitors (VMMs)), provide VMs 908A and 908B (one or more of which may be generally referred to as VMs 908), and / or perform any of the functions, features, and / or benefits described in relation with some embodiments described herein. The virtualization layer 906 may present a virtual operating platform that appears like networking hardware to the VMs 908.

[0127] The VMs 908 comprise virtual processing, virtual memory, virtual networking, or interface and virtual storage, and may be run by a corresponding virtualization layer 906. Different embodiments of the instance of a virtual appliance 902 may be implemented on one or more of VMs 908, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as Network Function Virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers and customer premise equipment.

[0128] In the context of NFV, a VM 908 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 908, and that part of the hardware 904 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 908 on top of the hardware 904 and corresponds to the application 902.

[0129] The hardware 904 may be implemented in a standalone network node with generic or specific components. The hardware 904 may implement some functions via virtualization. Alternatively, the hardware 904 may be part of a larger cluster of hardware (e.g., such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 910, which, among others, oversees lifecycle management of the applications 902. In some embodiments, the hardware 904 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 912 which may alternatively be used for communication between hardware nodes and radio units.

[0130] Although the computing devices described herein (e.g., UEs, network nodes) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions, and methods disclosed herein. Determining, calculating, obtaining, or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0131] The disclosed techniques may be implemented in various apparatus configurations. A user equipment may include dedicated timer circuitry for managing consolidation operations, or timer functionality may be implemented within general processing circuitry. Similarly, counter functionality for tracking discard events may be implemented as specialized counter circuitry or as software-implemented counters within processing circuitry.

[0132] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processingcircuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.

[0133] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.CLAIMS1. A method performed by a user equipment, the method comprising: determining, based on temporal proximity of the expiration of at least two packet discard timers, to generate a consolidated report for the expiration of the at least two packet discard timer; and generating the consolidated report.2. The method of claim 1, wherein the temporal proximity is determined using one or more consolidation timers and / or one or more counters that track a number of expirations of packet discard timers within the time period.3. The method of claim 1, wherein determining comprises: if the expiration of the at least two packet discard timers occurs closer than a time T apart: generating one consolidated report.4. The method of claim 1, wherein determining comprises: if a second packet discard timer for a second packet will expire within a time Twait after the expiration of a first packet discard timer for a first packet, triggering the sending of a report to a network in response to the expiration of the second packet discard timer.5. The method of claim 4, further comprising: determining that the second packet discard timer will not expire within a time Twait after the expiration of a first packet discard timer due to either: the second packet discard timer being expected to expire later than Twait; or no second packet existing or no second packet with a second packet discard timer existing.6. The method of claim 4, further comprising: if a third packet discard timer for a third packet will expire within a time Twait after the expiration of a second packet discard timer, triggering the sending of a report to the network in response to the expiration of the third packet discard timer.7. The method of claim 4, wherein all packets whose packet discard timers expire within Twait are considered for triggering the sending of the report.8. The method of claim 4, wherein the temporal order of packet transmission does not affect the determination of the time Twait.

Claims

9. The method of claim 4, wherein the user equipment postpones sending the report as long as new packet discard timers expire within a time Twait from the expiration of an earlier packet discard timer expire.

10. The method of claim 9, further comprising: sending the report at latest a time TLongest_deiay after a first packet discard timer of the at least two packet discard timers expired.

11. The method of claim 10, wherein the length of TLongest_dei y is approximately the duration of a T-Reordering timer.

12. The method of claim 5, further comprising: allowing at most a predetermined number N packets to trigger postponing sending of the report.

13. The method of claim 1, further comprising: in response to a first packet discard timer of the at least two packet discard timers expiring for a first packet, starting a timer Tconsoiidate; and triggering the sending a report after the expiration of the timer Tconsoiidate.

14. The method of claim 13, wherein: the content of the report is determined at the end of the timer Tconsoiidate; and if other packets have been discarded during a duration of the timer Tconsoiidate, the report indicates that other packets have also been discarded.

15. The method of claim 14, wherein when the report is sent at the end of the timer Tconsoiidate, the user equipment waits until a subsequent packet is discarded due to expiration of a subsequent packet discard timer, and in response starts the timer Tconsoiidate again.

16. The method of claim 14, further comprising: restarting the timer Tconsoiidate in response to the expiration of the timer Tconsoiidate and generating a subsequent report at an end of the restarted timer Tconsoiidate with information about all packet discards during the restarted timer duration.

17. The method of claim 1, further comprising: if the user equipment determines that no additional packet discard timers will expire during a remaining time of a consolidation timer, sending the consolidated report before the consolidation timer expires.

18. A method performed by a network node, the method comprising: receiving a consolidated Packet Data Convergence Protocol Sequence Number, PDCP SN, gap report from a user equipment, the consolidated PDCP SN gap report indicating missing sequence numbers for at least two packet discard timer expiries that occurred within a time period; and processing the consolidated PDCP SN gap report to update receiver state variables.

19. The method of claim 18, wherein processing the consolidated PDCP SN gap report comprises updating at least one of RX_NEXT, RX_DELIV, and RX_REORD state variables.

20. The method of claim 18, further comprising: advancing a receive window based on the missing sequence numbers indicated in the consolidated PDCP SN gap report.21 The method of claim 18, wherein the consolidated PDCP SN gap report comprises sequence number gap information for multiple packets that were discarded by the user equipment within temporal proximity of each other.

22. The method of claim 18, further comprising: stopping a T-Reordering timer corresponding to at least one of the missing sequence numbers indicated in the consolidated PDCP SN gap report.

23. The method of claim 18, wherein receiving the consolidated PDCP SN gap report reduces signaling overhead compared to receiving separate gap reports for each of the at least two packet discard timer expiries.

24. A user equipment comprising: processing circuitry configured to detect expiration of at least two packet discard timers within a time period; timer circuitry configured to determine temporal proximity of the expiries; and a communication interface configured to transmit a consolidated PDCP SN gap report for the at least two packet discard timer expiries based on the temporal proximity determination.

25. The user equipment of claim 24, wherein the timer circuitry comprises one or more consolidation timers configured to measure the temporal proximity.

26. The user equipment of claim 24, wherein the processing circuitry comprises counter circuitry configured to track a number of packet discard timer expiries within the time period.

27. The user equipment of claim 24, wherein the timer circuitry is configured to implement a Twait timer that defines a consolidation window for determining whether to consolidate multiple gap reports.

28. The user equipment of claim 24, wherein the timer circuitry is configured to implement a Tconsoiidate timer that defines when to generate the consolidated PDCP SN gap report.

29. The user equipment of claim 24, further comprising: memory configured to store timer states and sequence number gap information for the at least two packet discard timer expiries.

30. The user equipment of claim 24, wherein the communication interface is configured to transmit the consolidated PDCP SN gap report to reduce signaling overhead compared to transmitting separate gap reports.

31. A network node comprising: a communication interface configured to receive a consolidated PDCP SN gap report from a user equipment, the consolidated PDCP SN gap report indicating missing sequence numbers for at least two packet discard timer expiries that occurred within a time period; processing circuitry configured to process the consolidated PDCP SN gap report and update receiver state variables; and memory configured to store the receiver state variables.

32. The network node of claim 31, wherein the processing circuitry is configured to update at least one of RX_NEXT, RX_DELIV, and RX_REORD state variables based on the consolidated PDCP SN gap report.

33. The network node of claim 31, wherein the processing circuitry is configured to advance a receive window based on missing sequence numbers indicated in the consolidated PDCP SN gap report.

34. The network node of claim 31, further comprising: timer circuitry configured to stop a T- Reordering timer corresponding to at least one of the missing sequence numbers indicated in the consolidated PDCP SN gap report.

35. A method performed by a user equipment, the method comprising: receiving a first packet associated with a first discard timer; receiving a second packet associated with a second discard timer; and transmitting a gap report at a transmission time that is subsequent to expiration of the first discard timer and the second discard timer, the gap report indicating at least the expiration of the first discard timer and the second discard timer.

36. The method of claim 35, further comprising: receiving additional packets each associated with respective discard timers that expire within a predetermined time period of the first discard timer and the second discard timer, wherein the gap report indicates expiration of the respective discard timers for the additional packets.

37. The method of claim 35, wherein the gap report is transmitted as a single consolidated Packet Data Convergence Protocol Sequence Number (PDCP SN) gap report.

38. The method of claim 35, wherein the transmission time occurs after expiration of all discard timers for packets received within a consolidation time window.

39. The method of claim 35, wherein the gap report indicates missing sequence numbers corresponding to the first packet and the second packet.

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