Patent Description:
Since Long Term Evolution (LTE) Rel-<NUM>, to assist the scheduler, the evolved NodeB (eNodeB or eNB) can configure User Equipment (UE) to send Buffer Status Reports (BSR) and Power Headroom Reports (PHR) in uplink. BSR indicates the amount of data the UE has available for transmission, while PHR provides the eNB with information about the difference between the nominal UE maximum transmit power and the estimated power for Uplink Shared Channel (UL-SCH) transmission. BSR are typically used by the eNB to choose an appropriate transport block size while PHR are typically used to select and appropriate coding scheme (MCS) and number of allocated Physical Resource Blocks (PRBs).

If the UE has no allocation available on the Physical Uplink Shared Channel (PUSCH) for the transmission time interval (TTI) where the BSR is triggered, a Scheduling Request (SR) is then triggered. The SR is transmitted on the Physical Uplink Control Channel (PUCCH) using dedicated resources which are allocated on a UE basis with a certain periodicity. Also note that BSRs/SRs can also be triggered based on configurations of periodical BSR.

In both LTE and <NUM> NR, different types of BSR are defined to minimize overhead when possible and maximize the information provided to the scheduler when needed. For instance, in NR, four types of BSR are defined, namely, Short BSR, Short truncated BSR, Long BSR, Long truncated BSR. The Short BSR minimizes overhead and is currently used when there is only one LCG with data buffered. R2-<NUM> describes the UE reports long BSR when an UL grant can accommodate the long BSR plus its subheader; otherwise, the UE reports short BSR (page <NUM> Proposal <NUM>). R2-<NUM> describes a UE using long BSR reporting when only a single LCG has data available and the number of padding bits is equal to or larger than the size of the long BSR plus its subheader (page <NUM> last paragraph).

As used herein, the term "communication network" refers to a network that follows any suitable communication standards or protocols such as long term evolution (LTE), LTE-Advanced (LTE-A) and <NUM> NR, and employs any suitable communication technologies, including, for example, Multiple-Input Multiple-Output (MIMO), OFDM, time division multiplexing (TDM), frequency division multiplexing (FDM), code division multiplexing (CDM), Bluetooth, ZigBee, machine type communication (MTC), eMBB, mMTC and uRLLC technologies. For the purpose of discussion, in some embodiments, the LTE network, the LTE-A network, the <NUM> NR network or any combination thereof is taken as an example of the communication network.

As used herein, the term "network device" refers to any suitable device at a network side of a communication network. The network device may include any suitable device in an access network of the communication network, for example, including a base station (BS), a relay, an access point (AP), a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a gigabit NodeB (gNB), a Remote Radio Module (RRU), a radio header (RH), a remote radio head (RRH), a low power node such as a femto, a pico, and the like. Further, the function of a gNB can be split into different locations, for example, in central units (CU) and distributed units (DU), in various deployment options. For the purpose of discussion, in some embodiments, the eNB is taken as an example of the network device.

The network device may also include any suitable device in a core network, for example, including multi-standard radio (MSR) radio equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), Multi-cell/multicast Coordination Entities (MCEs), Mobile Switching Centers (MSCs) and MMEs, Operation and Management (O&M) nodes, Operation Support System (OSS) nodes, Self-Organization Network (SON) nodes, positioning nodes, such as Enhanced Serving Mobile Location Centers (E-SMLCs), and/or Mobile Data Terminals (MDTs).

As used herein, the term "terminal device" refers to a device capable of, configured for, arranged for, and/or operable for communications with a network device or a further terminal device in a communication network. The communications may involve transmitting and/or receiving wireless signals using electromagnetic signals, radio waves, infrared signals, and/or other types of signals suitable for conveying information over air. In some embodiments, the terminal device may be configured to transmit and/or receive information without direct human interaction. For example, the terminal device may transmit information to the network device on predetermined schedules, when triggered by an internal or external event, or in response to requests from the network side.

Examples of the terminal device include, but are not limited to, user equipment (UE) such as smart phones, wireless-enabled tablet computers, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), and/or wireless customer-premises equipment (CPE). For the purpose of discussion, in the following, some embodiments will be described with reference to UEs as examples of the terminal devices, and the terms "terminal device" and "user equipment" (UE) may be used interchangeably in the context of the present disclosure.

The inventors find that in both LTE and <NUM> NR network, the motivation of using Short Buffer Status Reports (BSR) when there is only one logical channel group (LCG) with data buffered is to reduce signaling overhead and hence increase coverage, especially for low bit rate services such as Voice over Internet Protocol (VoIP) where one byte overhead matters. The problem with NR is that due to the increase of LCGs to be reported, the number of bits which can be used to report the buffer size (BS) decreases in order to keep the short BSR one byte long. It is to be noted that in NR, <NUM> bits is used for BS field (instead of <NUM> bits in LTE). Further, the <NUM> bits BS field are also to be compared with the <NUM> bits for Long BSR.

An obvious solution would be to make the short BSR two bytes long to accommodate a longer BS field. However, this would defeat the purpose of having a short BSR in the first place as well as increase overhead compared to LTE.

Another obvious solution would be to configure the UE to either report short or long. However, such a solution is not flexible and makes radio resource control (RRC) reconfiguration frequent depending on the traffic mix. Indeed with such a solution, it is not possible to fulfill the opposite requirements occurring when e.g. VoIP is mixed with background data: on one hand, a short BSR is needed to limit overhead, on the other hand, a long BSR is needed to increase reporting accuracy.

It was also proposed to use Long BSR for the single LCG case as long as the grant is big enough for the Long BSR to provide more information to a NR NodeB (gNB). Unfortunately, because in logical channel prioritization the BSR format is first selected, this solution is equivalent to using the Long BSR always, which introduces extra overhead for VoIP and requires the gNB to always provide big enough for both Long BSR plus speech frame, thereby reducing the coverage.

It was also proposed to rely on the amount of buffered data to select the BSR format and/or rely on the number of configured carriers. However, this does not help in this scenario as the gNB would still have to consider the worst case to avoid segmenting speech frames. It was also proposed introduce threshold based BSR table selection, so that when the BS threshold is above the maximum value of the first table it can indicate, then the second table with larger maximum value will be selected. However, such solution has the same drawback (that is, the gNB would still have to consider the worst case to avoid segmenting speech frames).

Embodiments of the present disclosure provide a new scheme for optimizing BSR for limited traffic mix. The basic idea is that when only one LCG is being reported in a regular or periodic BSR (that is, when there is data available for transmission for only one LCG), whether a short or long BSR being reported is up to the network configuration. Specifically, in various embodiments of the present disclosure, whether a short or long BSR being reported is up to the configuration of LCG or the configuration of LCH within LCG, depending on the granularity of the RRC configuration being per LCG or per LCH.

<FIG> illustrates an example communication network <NUM> in which embodiments of the present disclosure can be implemented. The communication network <NUM> may comply with any suitable protocol or standard that already exists or will be developed in the future. In some embodiments, the communication network <NUM> may be the LTE (or LTE-A) network, the NR network or combination thereof.

The communication network <NUM> comprises a network device <NUM>. The network device <NUM> serves two terminal devices (including a first terminal device <NUM>-<NUM> and a second terminal device <NUM>-<NUM>, collectively referred to as a terminal device <NUM>) in a cell <NUM>. It is to be understood that the numbers of network devices and terminal devices are shown only for the purpose of illustration without suggesting any limitation. The network <NUM> may include any suitable numbers of network devices and terminal devices.

The first and second terminal devices <NUM>-<NUM> and <NUM>-<NUM> may communicate with the network device <NUM> or with each other via the network device <NUM>. The communication may utilize any suitable technology that already exists or will be developed in the future.

The network device <NUM> can configure the terminal device <NUM> to send BSR in uplink. As discussed above, BSR indicates the amount of data that the terminal device <NUM> has available for transmission. BSR are typically used by the network device <NUM> to choose an appropriate transport block size. In the context, the BSR can be a regular BSR or a periodic BSR.

<FIG> shows a flowchart of an example method <NUM> in accordance with a claimed embodiment of the present disclosure. The method <NUM> is implemented at the terminal device <NUM> as shown in <FIG>. For the purpose of discussion, the method <NUM> will be described with reference to <FIG>.

Method <NUM> describes the determination of the format of BSR when the granularity of the RRC configuration is per LCG. At block <NUM>, when the terminal device <NUM> detects that a BSR is to be triggered, whether data buffered at the terminal device <NUM> and available for transmission is included in a single LCG or a plurality of LCGs is detected.

Among other conditions, a BSR is to be triggered in the terminal device <NUM>:.

At block <NUM>, when it is determined that the data is included in a single LCG, the format of the BSR is determined based on a configuration of the LCG. The format of the BSR is selected from a group consisting of short BSR and long BSR. Short BSR (and also Short Truncated BSR) is only one byte long with <NUM> bits for the BS field, while Long (and also Long Truncated BSR) is at least <NUM> bytes long with <NUM> bits for the BS field.

In some embodiments, when the single LCG with data buffered is configured to enable long BSR, the long BSR for the LCG is selected. Otherwise, the short BSR for the LCG is selected. That is to say, once the configuration of the LCG is "long-BSR-enabled", the terminal device <NUM> will report Long BSR, even if there is only one LCG has the buffered data.

In some embodiments, when the data is determined to be included in a plurality of LCGs (that is, more than one LCG), the long BSR for the plurality of LCGs will be selected. Otherwise, the short BSR is reported.

In the claimed embodiment, a transport block size allocated for the amount of the data may be determined. Then the format of the BSR can be determined based on the configuration of the single LCG and a comparison between the transport block size with a predefined first transport block size threshold.

For example, when determining that the LCG is configured to enable long BSR (that is, the configuration of the LCG is "long-BSR-enabled") and that the transport block size is larger than the predefined first transport block (TB) size threshold (may also referred to as "long BSR TB threshold"), the long BSR is selected. Otherwise, the short BSR for the LCG is selected.

In some other embodiments, the format of the BSR can be determined only based on the comparison between the TB size with the predefined first transport block size threshold, regardless of the configuration of the LCG. For example, Long BSR is used when the transport block size is larger than a predefined number of bits, and Short BSR is used when the transport block size is smaller than the predefined number of bits.

It is to be understood that alternatively, in some embodiments, the default behavior could be changed so that the long BSR is sent unless a "short-BSR-enabled" is configured.

<FIG> which shows a flowchart of another example method <NUM> in accordance with the claimed embodiment of the present disclosure. The method <NUM> can likewise be implemented at the terminal device <NUM> as shown in <FIG>. For the purpose of discussion, the method <NUM> will also be described with reference to <FIG>. The difference between method <NUM> and method <NUM> is that method <NUM> describes the determination of the format of BSR when the granularity of the RRC configuration is per LCH within the LCG.

Referring to <FIG>, at block <NUM>, when the terminal device <NUM> detects that a BSR is to be triggered, whether data buffered at the terminal device <NUM> and available for transmission is included in a single LCG or a plurality of LCGs is detected. The act implemented at block <NUM> is the substantially same as that implemented at block <NUM> in <FIG>.

At block <NUM>, when it is determined that that the data is included in a single LCG, whether the data is included in a single LCH or included in a plurality of LCHs within the LCG needs to be further determined. If it is determined, at block <NUM>, that the data is included in a single LCH, the format of the BSR will be determined based on configuration of the LCH. If it is determined, at block <NUM>, that the data is included in a plurality of LCHs within the LCG, the format of the BSR will be determined based on configuration of an LCH with data buffered that has a higher priority than the other LCHs (i.e. the LCH having the highest priority).

In some embodiments, when the LCH with data buffered that has a higher priority than the other LCHs is configured to enable long BSR (that is, the configuration of the LCH having the highest priority with data is "long-BSR-enabled"), the long BSR will be selected for the LCG. When the LCH with data buffered that has a higher priority than the other LCHs is configured to not enable long BSR (that is, the configuration of the LCH having the highest priority is not "long-BSR-enabled"), the Short BSR will be selected for the LCG.

<FIG> illustrate some example BSR format selection according to some embodiments of the present disclosure. As illustrated in <FIG>, two LCHs are included in an LCG. The LCH1 <NUM> (that is, the first LCH) is configured for a voice service, and the LCH2 <NUM> (that is, the second LCH) is configured for an enhanced broadband (eMBB) service. LCH1 has higher priority than LCH2 and LCH2 is configured with long-BSR-enabled.

Referring to <FIG>, in this example, the data <NUM> is only included in a single LCG <NUM> (also referred to as "LCG1"), and the data <NUM> is further only included in a radio link control (RLC) service data unit (SDU) buffer <NUM> associated with the single LCH1 <NUM>. In other words, only LCH1 <NUM> within the LCG1 <NUM> has the data <NUM> available for transmission. Accordingly, the format of the BSR will determined based on the configuration of LCH1 <NUM> having the data <NUM>. In this case, media access control (MAC) entity <NUM> will trigger Short BSR.

Referring to <FIG>, in this example, the data <NUM> is likewise only included in the single LCG <NUM>, and further only included in a RLC SDU buffer <NUM> associated with a single LCH2 <NUM> within LCG <NUM>. In other words, only LCH2 <NUM> within the LCG1 <NUM> has the data <NUM> available for transmission. Accordingly, the format of the BSR will be determined based on the configuration of LCH2 <NUM> having the data <NUM>. In this case, MAC entity <NUM> will trigger Long BSR.

Referring to <FIG>, in this scenario, the data is likewise only included in the single LCG <NUM>, but further included in both RLC SDU buffer <NUM> associated with the LCH1 <NUM> and RLC SDU buffer <NUM> associated with the LCH2 <NUM>. In other words, both LCH1 <NUM> and LCH2 <NUM> within the LCG1 <NUM> have the data <NUM> available for transmission. Accordingly, the format of the BSR is determined based on configuration of the LCH that has higher priority. In this case, the voice service has the higher priority than the eMBB service. Therefore, MAC entity <NUM> will trigger Short BSR.

Alternatively, or in addition, a transport block size that is allocated for the amount of the data can be determined. Accordingly, in some embodiments, the format of the BSR can be determined based on the configuration of the LCH and a comparison between the transport block size with a predefined second transport block size threshold.

For example, when determining that the LCH is configured to enable long BSR and that the transport block size is larger than the predefined second transport block size threshold, the long BSR is selected. In some embodiments, the second transport block size threshold can be the same as the first transport block size threshold. In some other embodiments, the second transport block size threshold can be different from the first transport block size threshold.

In some other embodiments, the format of the BSR can be determined only based on the comparison between the transport block size with the predefined second transport block size threshold, regardless of the configuration of the LCH. For example, Long BSR is used when the transport block size is larger than a predefined number of bits and Short BSR is used when the transport block size is smaller than the predefined number of bits.

Again, it is to be understood that alternatively, the default behavior could be changed so that the long BSR is sent unless a "short-BSR-enabled" is configured.

Alternatively, in some embodiments, two short BSR MAC CEs are used with <NUM> bits BS field and <NUM> bits LCG ID field as in LTE (compared with <NUM> bits BS field and <NUM> bits LCG ID field), and the Logical Channel Identifier (LCID) of the MAC CE signals the last or first bit of the LCG ID field. For instance, only the <NUM> least significant bit (LSB) bits of the LCG ID are signaled in the LCG ID field in the BSR MAC CE and the first MAC CE (with LCID x) represents "<NUM>" for the most significant bit (MSB) of the LCG ID and the second MAC CE (with LCID y) represents "<NUM>" for MSB of the LCG ID. Finally, instead of using two different LCIDs for MAC CEs to convey the MSB of the LCG ID, an R bit in the MAC subheader could also be used.

According to various embodiments of the present disclosure, reduced overhead (and thus enhanced coverage) for low bit rate services can be achieved, while high BSR reporting granularity for other services can be maintained as the short and long BSR have different granularities and different maximum values.

Moreover, when there are, for example, one LCH for VoIP and one LCH for eMBB configured at the same time, configuring them into same LCG would provide less overhead than configuring them into two separate LCGs, as based on the proposal whenever there is data for VoIP, Short BSR will be reported regardless of whether there is eMBB data in the buffer.

In addition, determining the format based on the available grant/TB size prioritizes the use of short format always when the number of available bits to transmit is small. In turns, when there are more bits available, the relative overhead introduced of reporting the Long format BSR is not critical anymore.

In some embodiments, an apparatus capable of performing the method <NUM> and method <NUM> (for example, the terminal device <NUM>) may comprise means for performing the respective steps of the method <NUM> and method <NUM>. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the apparatus comprises: means for determining whether data buffered at the terminal device and available for transmission is included in a single logical channel group, LCG, in response to detecting, at a terminal device, that a buffer state report, BSR, is to be triggered, the BSR indicating amount of the data; and means for determining a format of the BSR based on a configuration of the LCG or a configuration of a logical channel, LCH, within the LCG, in response to determining that the data is included in a single LCG, the format of the BSR selected from a group consisting of short BSR and long BSR.

In some embodiments the BSR is regular BSR or periodic BSR.

In some embodiments, the means for determining the format of the BSR comprises: means for selecting the long BSR for the LCG, in response to the LCG is configured to enable long BSR.

In some embodiments, the apparatus further comprises: means for selecting long BSR for the plurality of LCGs, in response to determining that the data is included in a plurality of LCGs.

In one claimed embodiment, the means for determining the format of the BSR comprises:
means for determining a transport block size allocated for the amount of the data; and means for determining the format of the BSR based on the configuration of the LCG and a comparison between the transport block size with a predefined first transport block size threshold.

In some embodiments, the means for determining the format of the BSR based on the configuration of the LCG and a comparison between the transport block size with a predefined first transport block size threshold comprises: means for selecting the long BSR, in response to determining that the LCG is configured to enable long BSR and that the transport block size is larger than the predefined first transport block size threshold.

In the claimed embodiment, the means for determining the format of the BSR comprises:
means for determining whether the data is included in a single LCH within the LCG in response to determining that the data is included in a single LCG; means for determining the format of the BSR based on configuration of the LCH in response to determining that the data is included in a single LCH; and means for determining the format of the BSR based on configuration of an LCH that has highest priority among the plurality of LCHs in response to determining that the data is included in a plurality of LCHs within the LCG.

In some embodiments, the means for determining the format of the BSR comprises: means for selecting the long BSR for the LCG in response to the LCH that has the highest priority among the plurality of LCHs is configured to enable long BSR; and means for selecting the Short BSR for the LCG in response to the LCH that has the highest priority among the plurality of LCHs with data is not configured to enable long BSR.

In some embodiments, the means for determining the format of the BSR comprises: means for determining the format of the BSR based on configuration of the first LCH, in response to determining that the data is included in a first LCH and a second LCH within the LCG, wherein the first LCH has a higher priority than the second LCH.

In some embodiments, the means for determining the format of the BSR comprises: means for determining a transport block size that is allocated for the amount of the data; and means for determining the format of the BSR based on the configuration of the LCH and a comparison between the transport block size with a predefined second transport block size threshold.

In some embodiments, the means for determining the format of the BSR based on the configuration of the LCH and a comparison between the transport block size with a predefined second transport block size threshold comprises: means for selecting the long BSR in response to determining that the LCH is configured to enable long BSR and that the transport block size is larger than the predefined second transport block size threshold.

<FIG> is a simplified block diagram of a device <NUM> that is suitable for implementing embodiments of the present disclosure. The device <NUM> can be implemented at or as at least a part of the terminal device <NUM> as shown in <FIG>.

As shown, the device <NUM> includes a processor <NUM>, a memory <NUM> coupled to the processor <NUM>, a communication module <NUM> coupled to the processor <NUM>, and a communication interface (not shown) coupled to the communication module <NUM>. The memory <NUM> stores at least a program <NUM>.

The program <NUM> is assumed to include program instructions that, when executed by the associated processor <NUM>, enable the device <NUM> to operate in accordance with the embodiments of the present disclosure, as discussed herein with reference to <FIG>. The embodiments herein may be implemented by computer software executable by the processor <NUM> of the device <NUM>, or by hardware, or by a combination of software and hardware. The processor <NUM> may be configured to implement various embodiments of the present disclosure.

The memory <NUM> may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory <NUM> is shown in the device <NUM>, there may be several physically distinct memory modules in the device <NUM>. The processor <NUM> may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples.

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

Examples of the carrier include a signal, computer readable media.

Claim 1:
A method comprising:
in response to detecting, at a terminal device, that a buffer state report, BSR, is to be triggered, determining whether data buffered at the terminal device and available for transmission is included in a single logical channel group, LCG, the BSR indicating amount of the data buffered;
characterised in that
in response to determining that the data buffered is included in a single LCG, determining a format of the BSR based on:
determining a transport block size allocated for the amount of the data buffered, a configuration of the LCG, and a comparison between the transport block size with a predefined first transport block size threshold; or
determining whether the data buffered is included in a single LCH within the LCG and determining the format of the BSR based on a configuration of the LCH in response to the determination that the data buffered is included in the single LCH within the LCG, and determining the format of the BSR based on the configuration of the LCH that has a highest priority among a plurality of LCHs in response to determining that the data buffered is included in the plurality of LCHs within the LCG.