阅读说明：本技术 用于带宽部分的预配置无线电链路切换 (Pre-configured radio link switching for bandwidth segments ) 是由 D·拉塞尔瓦 M·琴泰纳罗 于 2019-03-28 设计创作，主要内容包括：提供了一种方法,该方法包括：指示发送方在第一传输时间在载波的第一活跃带宽部分上向接收方传输第一分组数据单元；基于切换规则确定延迟和载波的第二带宽部分；其中切换规则定义第二带宽部分不同于第一带宽部分；并且该方法还包括：如果发送方被指示传输第一分组数据单元,则指示发送方在指示传输第一分组数据单元之后在延迟已经过去之后的第二传输时间在第二活跃带宽部分上向接收方传输第二分组数据单元。(There is provided a method comprising: instructing the sender to transmit a first packet data unit on a first active bandwidth portion of a carrier to the receiver at a first transmission time; determining a delay and a second bandwidth portion of the carrier based on the handover rule; wherein the switching rule defines the second bandwidth portion to be different from the first bandwidth portion; and the method further comprises: if the sender is instructed to transmit the first packet data units, the sender is instructed to transmit second packet data units to the receiver over the second active bandwidth portion at a second transmission time after the delay has elapsed after instructing to transmit the first packet data units.)

1. An apparatus, comprising:

an indication component configured to indicate to a sender to transmit a first packet data unit on a first active bandwidth portion of a carrier to a receiver at a first transmission time;

a determining component configured to determine a delay and a second bandwidth portion of the carrier based on a handover rule; wherein

The switching rule defines that the second bandwidth portion is different from the first bandwidth portion; and

the indication component is configured to: if the sender is instructed to transmit the first packet data units, the sender is instructed to transmit second packet data units to the receiver over the second active bandwidth portion at a second transmission time after the delay has elapsed after instructing to transmit the first packet data units.

2. The apparatus of claim 1, further comprising:

a notification component configured to notify the receiver of the switching rule.

3. The apparatus according to any one of claims 1 and 2, wherein the sender is a cell and the receiver is a terminal.

4. The apparatus of claim 1, further comprising:

a monitoring component configured to monitor whether a message including the handover rule is received from the recipient;

a derivation component configured to: if the message is received, the handover rule is derived from the message.

5. The apparatus according to any one of claims 1 and 4, wherein the sender is a terminal and the receiver is a cell.

6. The apparatus of any of claims 1 to 5, further comprising:

a command component configured to command copying of the received packet data unit into the first packet data unit having a first sequence number and the second packet data unit having a second sequence number, wherein the first sequence number is the same as the second sequence number.

7. The apparatus of claim 6, further comprising:

a notification component configured to: if the command means commands the copying, the receiver is informed that the received packet data unit is copied.

8. The apparatus according to any of claims 6 and 7 when dependent on claim 3, wherein the received packet data unit is received from a core network.

9. The apparatus according to any of claims 6 and 7 when dependent on claim 5, wherein the received packet data unit is received from an application on the terminal.

10. The apparatus of any one of claims 1 to 9,

the indication means is configured to indicate that a first packet data unit of a flow is transmitted on the first bandwidth portion at the first transmission time and that a second packet data unit of the flow is transmitted on the second bandwidth portion at the second transmission time;

the first packet data unit has a first sequence number;

the second packet data unit has a second sequence number; and

the second sequence number is subsequent to the first sequence number.

11. The apparatus according to any of claims 1 to 10, wherein the instructing means is configured to instruct the sender to transmit the second packet data unit within a predefined duration after the delay has elapsed after instructing the transmission of the first packet data unit.

12. The apparatus of any one of claims 1 to 11,

the handover rules include at least one of: absolute timing of the second transmission time; a dependency of the second bandwidth part on the first bandwidth part; and a time difference between the second transmission time and the first transmission time, the time difference varying according to a semi-persistent allocation timing.

13. The apparatus of any one of claims 3 and 5,

the terminal is configured to notify the cell of a minimum delay; and

the cell is configured to set the delay equal to or greater than the minimum delay.

14. An apparatus, comprising:

a first monitoring component configured to monitor whether a first packet data unit is received from a sender on a first active bandwidth portion of a carrier at a first reception time;

a determining component configured to determine a delay and a second bandwidth portion of the carrier based on a handover rule; wherein

The switching rule defines that the second bandwidth portion is different from the first bandwidth portion; and

the first monitoring component is configured to: if the first packet data unit is received, monitoring whether a second packet data unit is received from the sender on the second active bandwidth portion at a second reception time after the delay has elapsed after the first packet data unit is received.

15. The apparatus of claim 14, further comprising:

a notification section configured to notify the sender of the switching rule.

16. The apparatus according to any one of claims 14 and 15, wherein the sender is a terminal and the receiver is a cell.

17. The apparatus of claim 14, further comprising:

a second monitoring section configured to monitor whether a message including the handover rule is received from the sender;

a derivation component configured to: if the message is received, the handover rule is derived from the message.

18. The apparatus according to any of claims 14 and 17, wherein the sender is a cell and the receiver is a terminal.

19. The apparatus of any one of claims 14 to 18,

the first packet data unit has a first sequence number;

the second packet data unit has a second sequence number; and the apparatus further comprises:

a first checking section configured to check whether the first serial number and the second serial number are the same;

a processing component configured to: processing the second packet data unit as a duplicate of the first packet data unit if the first sequence number is the same as the second sequence number.

20. The apparatus of claim 19, further comprising:

a supervision component configured to supervise whether information is received regarding the sender copying the received packet data units into the first packet data units and the second packet data units;

a prohibition component configured to: if the information is not received, the first checking means is prohibited from performing the check.

21. The apparatus of claim 20 when dependent on claim 16, wherein the sender receives the received packet from an application on the terminal.

22. The apparatus according to claim 20 when dependent on claim 18, wherein the sender receives the received packet from a core network.

23. The apparatus of any one of claims 14 to 22,

the first packet data unit has a first sequence number;

the second packet data unit has a second sequence number; and the apparatus further comprises:

a second checking means configured to check whether the second sequence number is subsequent to the first sequence number;

means for arranging the second packet data unit in a packet data unit flow after the first packet data unit if the second sequence number is after the first sequence number.

24. The apparatus of any of claims 14 to 23, wherein the first monitoring component is configured to: monitoring whether the second packet data unit is received if the first packet data unit is received within a predefined duration after the delay has elapsed after the first packet data unit is received.

25. The apparatus of any one of claims 14 to 24,

the handover rules include at least one of: absolute timing of the second receive time; a dependency of the second bandwidth part on the first bandwidth part; and a time difference between the second receive time and the first receive time, the time difference varying according to a semi-persistent allocation timing.

26. The apparatus of any one of claims 16 and 18,

the terminal is configured to notify the cell of a minimum delay; and

the cell is configured to set the delay equal to or greater than the minimum delay.

27. A method, comprising:

instructing the sender to transmit a first packet data unit on a first active bandwidth portion of a carrier to the receiver at a first transmission time;

determining a delay and a second bandwidth portion of the carrier based on a handover rule; wherein the content of the first and second substances,

the switching rule defines that the second bandwidth portion is different from the first bandwidth portion; and the method further comprises:

if the sender is instructed to transmit the first packet data units, the sender is instructed to transmit second packet data units to the receiver over the second active bandwidth portion at a second transmission time after the delay has elapsed after instructing to transmit the first packet data units.

28. The method of claim 27, further comprising:

notifying the receiver of the switching rule.

29. The method according to any of claims 27 and 28, wherein the sender is a cell and the receiver is a terminal.

30. The method of claim 27, further comprising:

monitoring whether a message including the handover rule is received from the recipient;

if the message is received, the handover rule is derived from the message.

31. The method according to any of claims 27 and 30, wherein the sender is a terminal and the receiver is a cell.

32. The method of any of claims 27 to 31, further comprising:

ordering a duplication of the received packet data unit into the first packet data unit having a first sequence number and the second packet data unit having a second sequence number, wherein the first sequence number is the same as the second sequence number.

33. The method of claim 32, further comprising:

if the copying is commanded, the receiver is notified that the received packet data unit is copied.

34. A method according to any of claims 32 and 33 as dependent on claim 29, wherein the received packet data unit is received from a core network.

35. A method according to any of claims 32 and 33 as dependent on claim 31, wherein the received packet data unit is received from an application on a terminal.

36. The method of any one of claims 27 to 35,

the indication comprises an indication that a first packet data unit of a flow is transmitted on the first bandwidth portion at the first transmission time and a second packet data unit of the flow is transmitted on the second bandwidth portion at the second transmission time;

the first packet data unit has a first sequence number;

the second packet data unit has a second sequence number; and

the second sequence number is subsequent to the first sequence number.

37. The method according to any of claims 27 to 36, wherein the indicating comprises indicating to the sender to transmit the second packet data unit within a predefined duration after the delay has elapsed after indicating to transmit the first packet data unit.

38. The method of any one of claims 27 to 37,

the handover rules include at least one of: absolute timing of the second transmission time; a dependency of the second bandwidth part on the first bandwidth part; and a time difference between the second transmission time and the first transmission time, the time difference varying according to a semi-persistent allocation timing.

39. The method of any one of claims 29 and 31,

the terminal is configured to notify the cell of a minimum delay; and

the cell is configured to set the delay equal to or greater than the minimum delay.

40. A method, comprising:

monitoring whether a first packet data unit is received from a sender on a first active bandwidth portion of a carrier at a first reception time;

determining a delay and a second bandwidth portion of the carrier based on a handover rule; wherein

The switching rule defines that the second bandwidth portion is different from the first bandwidth portion; and the method further comprises:

if the first packet data unit is received, monitoring whether a second packet data unit is received from the sender on a second active bandwidth portion at a second reception time after the delay has elapsed after the first packet data unit is received.

41. The method of claim 40, further comprising:

notifying the sender of the handover rule.

42. The method according to any of claims 40 and 41, wherein the sender is a terminal and the receiver is a cell.

43. The method of claim 40, further comprising:

monitoring whether a message including the handover rule is received from the sender;

if the message is received, the handover rule is derived from the message.

44. The method according to any of claims 40 and 43, wherein the sender is a cell and the receiver is a terminal.

45. The method of any one of claims 40 to 44,

the first packet data unit has a first sequence number;

the second packet data unit has a second sequence number; and the method further comprises:

checking whether the first sequence number is the same as the second sequence number;

processing the second packet data unit as a duplicate of the first packet data unit if the first sequence number is the same as the second sequence number.

46. The method of claim 45, further comprising:

whether supervision information is received, said information regarding the sender copying the received packet data units into the first packet data units and the second packet data units;

if the information is not received, the checking is disabled.

47. A method according to claim 46 as dependent on claim 42, wherein the sender receives the received packet from an application on the terminal.

48. A method according to claim 46 as dependent on claim 44, wherein the sender receives the received packet from a core network.

49. The method of any one of claims 40 to 48,

the first packet data unit has a first sequence number;

the second packet data unit has a second sequence number; and the method further comprises:

checking whether the second sequence number is subsequent to the first sequence number;

the second packet data unit is arranged in the packet data unit flow after the first packet data unit if the second sequence number is after the first sequence number.

50. A method according to any one of claims 40 to 49, wherein if the first packet data unit is received within a predefined duration after the delay has elapsed after the first packet data unit is received, monitoring whether the second packet data unit is received.

51. The method of any one of claims 40 to 50,

the handover rules include at least one of: absolute timing of the second receive time; a dependency of the second bandwidth part on the first bandwidth part; and a time difference between the second receive time and the first receive time, the time difference varying according to a semi-persistent allocation timing.

52. The method of any one of claims 42 and 44,

the terminal is configured to notify the cell of a minimum delay;

and the cell is configured to set the delay equal to or greater than the minimum delay.

53. A computer program product comprising a set of instructions which, when executed on an apparatus, is configured to cause the apparatus to perform the method of any of claims 27 to 52.

54. The computer program product of claim 53, embodied as a computer-readable medium or directly loadable into a computer.

Technical Field

The invention relates to a pre-configured radio link switching for bandwidth parts. In particular cases, the invention relates to data replication, which is particularly useful in the context of URLLC.

Abbreviations

3G/4G/5G third generation/fourth generation/fifth generation

3GPP third generation partnership project

ACK acknowledgement

BLER Block error Rate

BW bandwidth

BWP bandwidth portion

BWPCI Bandwidth portion configuration index

BWPI bandwidth portion indicator

CA carrier aggregation

CC component carrier

CE control element

CG configuration authorization

CQI channel quality information

CSI channel state information

CSI-RS channel state information reference signal

DC dual connection

DCI downlink control information

DL downlink

DRB data radio bearer

EESM exponential effective SINR mapping

eMB enhanced mobile broadband

eNB evolution NodeB (base station of 4G)

FDD frequency division duplex

gNBgNodeB (base station of 5G)

HARQ hybrid automatic repeat request

HetNet heterogeneous network

ICIC inter-channel interference cancellation

IE information element

IIoT industrial Internet of things

IoT Internet of things

LCH logical channel

LTE Long term evolution

MAC multiple access channel

MC multi-connection

MCS modulation coding scheme

mMTC massive machine type communication

MTC machine type communication

NACK negative acknowledgement

NR new radio

PBCCH physical broadcast control channel

PCell primary cell

PDCCH physical downlink control channel

PDCP packet data convergence protocol

PDSCH physical downlink shared channel

PDU packet data unit

PHY physical layer

Pkt packet

PRB physical resource block

PSCell main and auxiliary cell

QPSK quadrature phase shift keying

RAN radio access network

Rel version

RF radio frequency

RLC radio link control

RRC radio resource control

SA system architecture

SCell secondary cell

SCS subcarrier spacing

SDAP service data adaptation protocol

SIB system information block

SINR signal-to-interference-and-noise ratio

SN Serial number

SPS semi-persistent scheduling

TB transport block

TR technical report

TRS tracking reference signal

TS technical Specification

TSN time sensitive network

TXM transmission

UE user equipment

UL uplink

UPF user plane functionality

URLLC ultra-reliable low-delay communication

vCC virtual component carrier

Interface between XngNB (base station)

Background

Research project 3GPP RP-182090 (NR industrial internet of things research for Rel-16 industrial internet of things (IIoT)) included the following goals:

"L2/L3 enhancement:

data replication and multi-connection enhancements, including (RAN2/RAN 3):

resource efficient DCP replication, e.g., PDCP replication activation and coordination between nodes for resource efficiency assurance (origin), avoiding unnecessary duplicate transmissions, etc.

PDCP replication with more than 2 copies, with DC and CA (combination thereof), so data transmission is done from at most two nodes: the revenue is evaluated and, if beneficial, relevant solutions are investigated.

The potential impact of the high-level multi-connectivity studied by SA 2. "

More information is provided in the 3GPP TR 38.825 and subsequent Rel-16 work item (RP-190728).

Therefore, data replication of the PDCP layer is considered to be a driver of the IIoT paradigm. Indeed, PDCP data replication provides transmit diversity enhancement, thereby reducing the error probability of replicated packets, since errors occurring on both transmission paths are generally somewhat uncorrelated. 3GPP release 15 supports PDCP data replication across different Component Carriers (CCs) in the same network node (i.e., when combined with carrier aggregation CA), or across two different nodes (i.e., when combined with dual connectivity DC). In addition, in future releases, Multiple Connections (MC) may also be considered. MC allows for participating in transmission/reception operations to User Equipment (UE) using more than two nodes at a time and/or more than two radio links, e.g., where the radio links are a combination of DC and CA.

In a gNB intra-deployment of PDCP data replication, two (or more) transmission paths for transmitting a copy of a packet are instantiated at the same gNB. Even assuming a heterogeneous network (hetnet) deployment (requiring DC), the intra-gbb scenario is quite important, as only a small fraction of UEs in the network may benefit from DC because they are physically close to one primary serving cell. For example, in the hetnet scenario defined by 3GPP for performance evaluation, this realistic effect is modeled assuming that only about 30% of the UEs in the macro cell area are dropped around the small cell cluster. This results in only about 30% of UEs that can benefit from DC with both macro and small cells, while the remaining about 70% of UEs can only be served via macro cells. The latter UE can use PDCP replication to improve reliability only when the macro cell splits its bandwidth into more than one CC by using CA, as shown in fig. 1.

Figure 1 shows release 15 (prior art) PDCP data replication for downlink by CA in a gbb intra-deployment. The gNB receives data packets (shown as black boxes) from the core network (e.g., UPF), encapsulates them as PDCP PDUs and assigns them Sequence Numbers (SNs). If PDCP data replication is deemed necessary/requested, the gmb replicates the packet at the PDCP layer. One copy (shown as a black box) is pushed down to the RLC entity controlling the first component carrier (denoted as CC1) and the other copy (shown as a dashed box) is pushed down to the RLC entity controlling the second component carrier (denoted as CC 2). The same data packets (i.e., PDCP PDUs with a given SN) are then transmitted independently to the UE over both CCs. The repeated entries have the same SN.

For the purposes of this application, each cell is unambiguously associated with a carrier (having a center frequency and a bandwidth surrounding the center frequency). Since each cell is also unambiguously identified by its cell identifier, the carrier is also unambiguously identified by the cell identifier.

The following additional background and prior art concepts are relevant in the context of the present application:

PDCP replication in a 5G New Radio (NR) according to 3GPP release 15:

-duplication allows PDCP PDUs to be duplicated and sent over two different RLC entities;

the RLC entities may belong to the same cell group (via CA replication) or to different cell groups (via DC replication);

when using the same cell group, restrictions are imposed in the MAC to ensure that two copies never end up on the same carrier. If two copies end on the same carrier, they will fail at the same time, losing (cancel) any benefit of the duplicate packet;

when using different cell groups, the carrier of the first cell must be different from the carrier of the second cell, i.e. an inter-frequency scenario;

-replication is enabled at RRC and controlled at MAC by MAC Control Element (CE) of uplink direction.

In the context of NR, the concept of bandwidth part (BWP) is introduced. Simply stated, BWP is the subband within the wider NR carrier. BWP is defined in NR Rel-15 in 3GPP TS 38.300 (see section 6.10), 3GPP TS 38.211 (see section 4.4.5) and 3GPP TS 38.331 (see BWP information element IE), while the configuration of BWP is described in chapter 12 of 3GPP TS 38.213. The definition and basic features of BWP are as follows:

the carrier bandwidth part is defined as follows (see section 4.4.5 of 3GPP TS 38.211): "A Carrier Bandwidth Part is a resource set of physical resource blocks, selected from a resource subset of the common resource blocks for a given parameter set and cyclic prefix on a given Carrier" (the Carrier Bandwidth Part is a set of contiguous physical resource blocks selected from a contiguous subset of common resource blocks on a given Carrier for a given parameter set and cyclic prefix.)

NR version 15 supports BWP sizes between 24 and 275 PRBs (400MHz, 120kHz SCS).

NR supports 4 parameter sets: 15, 30, 60kHz for SCS in FR1(<6GHz), and 60, 120kHz for SCS in FR2(>6 GHz).

For paired spectrum (FDD), the UE may be configured with an initial downlink/uplink BWP plus up to 4 downlink BWPs and up to 4 uplink BWPs in the serving cell.

Only one carrier BWP is active at a given time.

UE is not expected to transmit or receive PDSCH, PDCCH, CSI-RS or TRS outside of active BWP. This means that the frequency resource allocation for the UE should be within its active BWP using the relevant parameter set.

The bandwidth part is indicated by a bandwidth part indicator, which may comprise 1 or 2 bits:

table 1: bandwidth part indicator (BWPI), taken from 3GPP TS 38.212 v15.3.0-Table 7.3.1.1.2-1

To summarize:

the prior art is as follows: PDCP replication in LTE/NR requires multiple frequency layers: two instances (i.e., two copies) of the PDCP packet should be sent on different serving cells operating at different frequencies:

in a single gbb scenario, this is achieved by CA-based replication, i.e. copies are sent over two component carriers in the same gbb (i.e. PCell @ F1+ SCell @ F2, where F1/F2 denotes the carrier frequency, e.g. 2.1 GHz).

In a multi-gNB scenario, this is achieved by dual connectivity based replication, i.e. the replica is sent by two nodes operating at different frequencies (i.e. PCell @ F1 on the primary cell group plus PSCell @ F2 on the secondary cell group).

There is a requirement to avoid that the two serving CCs of the UE interfere with each other.

In the related art, a carrier may include a plurality of configured BWPs. However, in release 15, only one BPW can be active at a time for a pair of transmitter/receivers (downlink and uplink). Switching between different active BWPs may be done using one of the following mechanisms:

1. downlink Control Information (DCI) signaling: the configured BWP may be activated by a bandwidth part indicator (see above) in DCI Format 0_1(UL grant) and DCI Format 0_1(DL time scheduling);

2. a Radio Resource Control (RRC) configuration;

3. timer-based configuration: the timer controls the automatic switch to the default BWP. The automatic switching is based on inactivity.

4. By the MAC entity itself in response to initiating the random access procedure.

Earlier patent applications (PCT/EP2019/053714) proposed using two active BWPs simultaneously to achieve PDCP data replication in either an intra-gbb scenario (no CA) or an inter-frequency gbb scenario. This proposal has a considerable impact on UE complexity and 3GPP technical specifications.

Disclosure of Invention

It is an object of the present invention to improve the prior art.

According to a first aspect of the present invention, there is provided an apparatus comprising: an indication component configured to indicate to a sender to transmit a first packet data unit on a first active bandwidth portion of a carrier to a receiver at a first transmission time; and determining means configured to determine a delay and a second bandwidth portion of the carrier based on a handover rule; wherein the switching rule defines the second bandwidth portion to be different from the first bandwidth portion; and the indicating means is configured to: if the sender is instructed to transmit the first packet data units, the sender is instructed to transmit second packet data units to the receiver over the second active bandwidth portion at a second transmission time after the delay has elapsed after instructing to transmit the first packet data units.

According to a second aspect of the present invention, there is provided an apparatus comprising: a first monitoring component configured to monitor whether a first packet data unit is received from a sender on a first active bandwidth portion of a carrier at a first reception time; and determining means configured to determine a delay and a second bandwidth portion of the carrier based on a handover rule; wherein the switching rule defines the second bandwidth portion to be different from the first bandwidth portion; and the first monitoring component is configured to: if the first packet data unit is received, it is monitored whether a second packet data unit is received from the sender on a second active bandwidth portion at a second reception time after the delay has elapsed after receiving the first packet data unit.

According to a third aspect of the invention, there is provided a method comprising: instructing the sender to transmit a first packet data unit on a first active bandwidth portion of a carrier to the receiver at a first transmission time; determining a delay and a second bandwidth portion of the carrier based on a handover rule; wherein the switching rule defines the second bandwidth portion to be different from the first bandwidth portion; and the method further comprises: if the sender is instructed to transmit the first packet data units, the sender is instructed to transmit second packet data units to the receiver over the second active bandwidth portion at a second transmission time after the delay has elapsed after instructing to transmit the first packet data units.

According to a fourth aspect of the present invention, there is provided a method comprising: monitoring whether a first packet data unit is received from a sender on a first active bandwidth portion of a carrier at a first reception time; determining a delay and a second bandwidth portion of the carrier based on a handover rule; wherein the switching rule defines the second bandwidth portion to be different from the first bandwidth portion; and the method further comprises: if the first packet data unit is received, it is monitored whether a second packet data unit is received from the sender on a second active bandwidth portion at a second reception time after the delay has elapsed after the first packet data unit is received.

Each of the methods of the third and fourth aspects may be a radio link handover method.

According to a fifth aspect of the present invention, there is provided a computer program product comprising a set of instructions which, when executed on an apparatus, is configured to cause the apparatus to perform the method according to any one of the third and fourth aspects.

According to some example embodiments of the invention, at least one of the following advantages may be achieved:

reduced signaling overhead to achieve greater flexibility in utilizing available bandwidth;

omicron in particular: bandwidth splitting for PDCP replication does not affect the available bandwidth for traffic without PDCP replication;

furthermore, bandwidth splitting involves inserting guard bands between CCs (i.e., at both edge frequencies of each component carrier) to avoid cross interference, but at the cost of these parts of the carrier not being used.

Reduced energy consumption at the UE and the gNB;

the transmission reliability can be enhanced.

Further advantages will become clear from the detailed description below.

It should be understood that any of the above-described modifications may be applied to the various aspects to which they refer, alone or in combination, unless they are explicitly stated to exclude alternatives.

Drawings

Further details, features, objects and advantages will become apparent from the following detailed description of preferred exemplary embodiments of the invention, taken in conjunction with the accompanying drawings, in which:

FIG. 1 illustrates PDCP data replication according to 3GPP Rel-15;

figure 2 illustrates the concept of PDCP data replication in the uplink according to some example embodiments of the present invention.

Fig. 3 illustrates a concept of PDCP data replication in downlink according to some exemplary embodiments of the present invention.

FIG. 4 shows a flow diagram according to an example embodiment of the invention;

FIG. 5 shows an apparatus according to an example embodiment of the invention;

FIG. 6 illustrates a method according to an example embodiment of the invention;

fig. 7 shows an apparatus according to an exemplary embodiment of the invention.

FIG. 8a shows a method according to an example embodiment of the invention;

FIG. 8b shows a method according to an example embodiment of the invention; and

fig. 9 shows an apparatus according to an example embodiment of the invention.

Detailed Description

Certain exemplary embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein features of the exemplary embodiments may be freely combined with each other unless otherwise specified. It should be clearly understood, however, that the description of certain exemplary embodiments is given by way of example only and is not intended to limit the invention to the details disclosed.

Further, it should be understood that the apparatus is configured to perform a corresponding method, although in some cases only the apparatus or only the method is described.

Some example embodiments of the present invention improve radio resource efficiency when operating PDCP data replication for URLLC in a deployment within a gNB, i.e., instantiating two (or more) transmission paths for communicating packet replication at the same gNB. In the PDCP replication of Rel-15, it is impossible to use the replication through only one carrier. According to some example embodiments of the invention, this limitation is overcome.

When PDCP data replication is supported in an intra-gbb scenario, the adoption of CA may impose severe limitations on frequency deployment due to the need to divide the available bandwidth into multiple blocks (i.e., CCs). For example, given a (small) cell with an overall system bandwidth B of 20MHz, two CCs need to be deployed to operate in CA, each CC having e.g. a half bandwidth B₁And B₂So that B is₁+B₂B. In particular, it is possible to use, for example,

the center frequency of CC1 may be F₁3.495GHz, wherein B₁10MHz, and

the center frequency of CC2 may be F₂3.505GHz, where B₂＝10MHz。

This bandwidth partitioning may result in sub-optimal system performance as well as end-user performance. For example, the same (small) cell may be serving other types of traffic than URLLC, and therefore have heterogeneous requirements. For example, enhanced movesA mobile broadband (eMBB) user or a large-scale machine type communication (mMTC) device may need to use more than B₁Or B₂To receive large amounts of data, e.g. for video streaming and firmware updates, respectively. However, if CA is not used, they cannot use the total bandwidth B. Thus, eMBB/mtc users may be forced to use CA (if supported by the UE) to meet their capacity requirements, which may result in greater UE power consumption due to CA operation.

The prior art results in severe limitations on frequency deployment due to the need to partition (segment) the available bandwidth into at least two blocks (i.e., CCs) in order to operate replication. For devices that may require the use of transmission bandwidth exceeding the segment size (e.g., video streaming and firmware updates), such bandwidth partitioning may result in sub-optimal system performance as well as end-user performance. These users may be forced to use CA (if supported by the UE) to meet their capacity requirements, which may result in greater UE power consumption and more signaling (for measurement configuration and reporting, CA settings) and have to rely on a slow mechanism for adjusting the used CCs.

Some example embodiments of the present invention implement CA within a carrier by dividing radio resources into "virtual" CCs according to a handover rule assigned to a UE without splitting it into component carriers. For a UE, there may be one or more handover rules, e.g., as a function of service type, etc. Accordingly, some example embodiments of the present invention address the negative impact of hard (hard) radio resource partitioning by CA. Conventional NR BWP is assumed and used in some example embodiments of the invention (as explained in the prior art section), but the invention is not limited to the detailed values defined for any 3GPP release.

In more detail, according to some example embodiments of the present invention, both the gNB and the UE use pre-configured rules to switch active BWPs between configured BWPs. In some example embodiments, the transmission for the copy of the packet (the packet copied at the PDCP) is switched to increase transmit diversity.

For example, focusing on the downlink direction, the network will first schedule one instance of the packet in the current active BWP (e.g., BWP1) and switch the active BWP (i.e., to BWP2) before scheduling another instance (i.e., a duplicate) of the packet to BWP 2. Accordingly, the UE switches from BWP1 to BWP2 according to the same switching rule after receiving the first packet. The network takes into account BWP handoff delays (e.g., as defined by RAN 4) when scheduling packets/allocations. The proposed method can be applied to both uplink and downlink transmissions.

Note that the purpose of pre-configured switching of active BWPs is to minimize signaling overhead and avoid signaling misdetections, which are detrimental to delay/reliability targets for e.g. URLLC and/or TSN traffic.

Furthermore, the UE is allocated semi-persistent radio resources (semi-persistent scheduling (SPS) in DL and Configuration Grant (CG) in UL) on different BWPs, which may be used according to a pre-configured handover of BWPs.

The pre-configured BWP switching according to some embodiments of the present invention may be used for transmission of packets of a packet stream and their (direct) subsequent packets in order to improve the transmission diversity of the subsequent transmissions. That is, the packet is not a duplicate. Thus, the lifetime, i.e. the maximum number of subsequent errors that an application can tolerate, may be considered.

Some methods according to some example embodiments of the present invention are preferably applicable to applications with more relaxed latency requirements than BWP handover latency.

Figure 2 shows a schematic diagram of some embodiments of the invention for the uplink case. Figure 3 shows a schematic diagram of some embodiments of the invention for the downlink case. In both cases, the transmitting entity (sender, i.e., UE in fig. 2 and gNB in fig. 3) implements PDCP data replication by BWP aggregation. That is, according to fig. 2, the PDCP layer of the UE receives a packet from an application (black frame) and copies it (black diagonal frame). According to fig. 3, the PDCP layer of the gNB receives packets from the core network (e.g., UPF) (black boxes) and copies them (black diagonal boxes). The respective sender transmits the first copy on BWP1 and the second copy on BWP 2. Packet transmissions on both BWPs occur at subsequent times (direct subsequent times) that are pre-configured by the network on both the UE and the gNB. Accordingly, the respective recipients receive the copies on the respective BWPs.

The numbers on the arrows in fig. 2 and 3 indicate the sequence of actions performed at both transmission ends (sender, receiver).

1. The packet arrives at an upper layer of the sender and is transferred to the PDCP layer.

2. The PDCP layer of the sender duplicates the packet.

3. The first copy is transmitted over an associated radio resource (e.g., CG or SPS) at time t over BWP1, and the recipient receives them and attempts to decode them over BWP 1.

4. Both the sender and the receiver switch the active BWP from BWP1 to BWP2 according to the switching rules.

5. The second copy is transmitted at time t + Δ over BWP2, where Δ is the minimum BWP switching delay or another delay period that is longer than the BWP switching delay. The receiver attempts to decode the signal received on BWP 2.

6. The PDCP layer of the receiving entity receives the copy and operates in accordance with conventional procedures. For example, the PDCP layer may discard one of the copies, typically the later received copy (i.e., the copy received on BWP2), or merge the two copies.

In the following, exemplary embodiments of the present invention relating to uplink transmission are explained in more detail. In this use case, a reliable uplink transmission from the UE to the cell represented by the gNB is required. To maximize transmission diversity, PDCP data replication is enabled to utilize different BWPs (instead of different CCs as in conventional replication by CA), which are sequentially activated according to a handover rule as a means to increase network flexibility and efficiency.

A UE with up to N (e.g., 4 in Rel-15) configured BWPs can potentially be activated, with the limitation that only one BWP is active at a time. In this example, two BWPs (BWP1 and BWP2) are configured. The network activates/configures PDCP data replication at the UE side, provides an indication of BWP (e.g., BWP1) to associate with a Logical Channel (LCH) (e.g., LCH1) corresponding to a first instance of the packet, and provides an indication of BWP (e.g., BWP2) to associate with an LCH (e.g., LCH2) corresponding to a second instance of the packet. The configuration also indicates that BWP1 and BWP2 are mapped to RLC entities associated with PDCP entities for which PDCP data replication is configured.

A Configuration Grant (CG) configuration may also be associated with a given BWP and LCH. Therefore, the timing of CG activation must follow the BWP switching pattern. In particular, a configuration tailored for LCH1 is denoted by CG1, which is defined by transmission timing including, for example, an offset o1 and a period p 1. The configuration tailored to LCH2 (for duplicate packets) is denoted by CG2, which is defined by transmission timing including, for example, an offset o1+ Δ (Δ being the minimum BWP switching delay or longer predefined delay) and a period p1 (same as CG 1).

A flow chart of a method according to this use case is provided in fig. 4. As shown in fig. 4, as action "0", the network denoted by the gNB configures the UE (here, URLLC UE is taken as an example, but the method of fig. 4 is not limited to URLLC UE). In particular, the network configures the LCH and the corresponding BWP and provides the UE with handover rules for transmission of PDCP duplicate packets.

The actions of numerals 1 to 6 correspond to numerals 1 to 6 of fig. 2, and refer to the description of fig. 2.

In some example embodiments of the present invention, to reduce the overall signaling overhead, the BWP handover rules are provided by the network to the UE in a semi-static manner, e.g., via RRC/MAC CE as part of the aforementioned BWP configuration. However, regardless of how the UE acquires the BWP switching rule, the UE automatically switches between BWPs as instructed to transmit the corresponding LCH. The pre-configured BWP handover rules avoid transmitting dedicated signaling to indicate each individual BWP handover.

In one example embodiment, the BWP switching pattern is defined by the absolute timing of the switching and the BWP to be switched at a given time, as illustrated in the examples below.

Example 1 relates to PDCP replication with two BWPs.

The BWP switching rule is configured as follows:

instructed to switch from BWP1 to BWP2 after t0+2n × p1

Instructed to switch from BWP2 to BWP1 after t0+ (2n +1) × p1

Wherein

-t0 is the start time of the first transmission of LCH1

pI is the period of CG1

N is an integer ranging from 0, 1, 2, … …

This switching rule results in:

pkt #1(LCH1) > TXM on BWP1 at t 0; CG1 (offset o1, period p1)

> BWP switch from BWP1 to BWP2 after t0

Pkt # 1' (LCH2) > TXM on BWP2 at t0+ Δ; CG2 (offset o1+ delta, period p1)

Pkt #2(LCH1) > TXM on BWP2 at t0+ p 1; CG1 (offset o1, period p1)

> BWP switch from BWP2 to BWP1 after t0+ p1

Pkt # 2' (LCH2) > TXM on BWP1 at t0+ p1+ Δ; CG2 (offset o1+ delta, period p1)

Pkt #3(LCH1) > TXM on BWP1 at t0+2p 1; CG1 (offset o1, period p1)

> BWP switch from BWP1 to BWP2 after t0+2pl

Pkt # 3' (LCH2) > TXM on BWP2 at t0+2p1+ Δ; CG2 (offset o1+ delta, period p1)

Etc. of

In this example, the switching delay Δ is shorter than the period p 1.

Example 2 relates to transmitting subsequent packets using 4 BWPs to meet a time-to-live target.

The BWP switching rule is configured as follows:

instructed to switch from BWP1 to BWP2 after t0+4n × p1

Instructed to switch from BWP2 to BWP3 after t0+ (4n +1) × p1

Instructed to switch from BWP3 to BWP4 after t0+ (4n +2) × p1

Instructed to switch from BWP4 to BWP1 after t0+ (4n +3) × p1

Wherein

-p1 is the period of CG1

N is an integer ranging from 0, 1, 2, … …

This switching rule results in:

pkt #1(LCH1) > TXM on BWP1 at t 0; CG1 (offset o1, period p1)

> BWP switch from BWP1 to BWP2 after t0

Pkt #2(LCH1) > TXM on BWP2 at t0+ p 1; CG1 (offset o1, period p1)

> BWP switch from BWP2 to BWP3 after t0+ p1

Pkt #3(LCH1) > TXM on BWP3 at t0+2p 1; CG1 (offset o1, period p1)

> BWP switch from BWP3 to BWP4 after t0+2pl

Pkt #4(LCH1) > TXM on BWP4 at t0+3p 1; CG1 (offset o1, period p1)

> BWP switch from BWP4 to BWP1 after t0+3p1

Pkt #5(LCH1) > TXM on BWP1 at t0+4p 1; CG1 (offset o1, period p1)

> BWP switch from BWP1 to BWP2 after t0+4p1

Etc. of

As a function of the traffic period, the timing of BWP handover may be further optimized to accommodate the potential HARQ retransmissions that can occur in the same BWP (i.e., before switching to a different BWP).

In another example, the PDCP entity may provide a handover indication to the PHY layer based on packet duplication.

According to some example embodiments of the present invention, a single cell may implement PDCP replication without dividing its bandwidth among multiple CCs (i.e., without CA), but by sequential activation with different BWPs. In this way, the gbb may utilize maximum scheduling flexibility to serve delay tolerant downlink traffic, since the entire downlink radio resource pool is available. On the other hand, for URLLC downlink transmission, for example, the gNB may allocate multiple active BWPs (these BWPs represent virtual component carriers) for the transmission of the replica using frequency diversity.

Some example embodiments of the present invention address the overhead of active BWP switching, proposing a preconfigured switch between active BWPs for a given transmitter/receiver pair to reduce the total signaling overhead.

Enabling coexistence between regular operation and PDCP replication through virtual CCs

Hereinafter, the gNB operation is described, including a scheduling operation for URLLC (as an example of BWP handover) and eMBB/mtc (as an example of no BWP handover) UE coexistence.

The allocation of active BWP for various UEs is done as a function of e.g. their applications (or QoS required by the applications). Furthermore, the quality of the active BWP may be considered (e.g., radio signal strength/quality, SINR, achievable BLER, etc.). For example, among dedicated BWPs, the gNB will allocate:

one large active BWP, which may be up to the entire available bandwidth of delay tolerant downlink traffic (e.g., eMBB and mtc),

two or more active bwps (vccs) to URLLC UEs, which benefit from data replication.

During scheduling operations, if a UE must be allocated frequency resources (PRBs), the MAC scheduler will apply an appropriate mask to certain BWPs when scheduling the UE to account for the UE's active BWPs and their potential limitations.

In this way, the gbb has maximum flexibility in scheduling downlink traffic for delay tolerant applications (background traffic) over the entire radio resource pool, such that the background traffic reaches maximum system capacity. This goal may be achieved by defining a single active BWP (bandwidth equal to e.g. the entire transmission bandwidth) for UEs requiring broadband downlink traffic and having low delay requirements. On the other hand, when scheduling URLLC downlink transmissions, the gNB is allowed to define different transmission paths by vCC (BWP1 and BWP2), the aforementioned vCC exploiting frequency diversity to improve transmission reliability.

Note that two independent transmissions using, for example, half bandwidth (N/2) may have benefits over one unique transmission using, for example, full bandwidth due to the following circumstances and reasons:

since replication will be used for URLLC applications, which typically have smaller payload sizes (e.g., 20B), half the bandwidth may be sufficient to operate at the lowest MCS allowed by the standard (e.g., QPSK 1/8) in most cases. Therefore, having more bandwidth can only be achieved using additional coding means (such as padding), which is quite inefficient. Note that encoding typically becomes inefficient at the lowest encoding rate.

The bandwidth supported by the UE may be much smaller than the system bandwidth of the serving cell, and therefore the UE cannot benefit from a larger bandwidth unless some example embodiments of the invention are used, if the spectrum is not split in the component carriers. Especially in the mmwave scenario, the available spectrum is rather large (e.g. hundreds of MHz) and from a complexity point of view it is simpler for the UE to have 4 receivers operating e.g. at maximum bandwidth 100MHz than to have one receiver operating at 400 MHz. Note that mmW scenarios are currently considered promising in Rel-16 URLLC SI (see 3GPP R1-1900976 or 3GPP R1-1900171).

Furthermore, the two main sources of packet errors are link adaptation errors (i.e. estimated MCS errors) and interference (SINR at transmission is degraded by interference). By having two independent transmissions, more diversity in terms of both errors can be achieved than by having one unique transmission. Details of combining received PDUs at the UE side are explained for example in PCT/FI 2018/050918. The method proposes a lightweight coordinated transmission of PDCP PDUs and their copies at both nodes/component carriers and their combination at the receiver side, where the combination is applied at the PHY by soft information combining the TBs carrying the original and copy PDCP PDUs.

In some example embodiments, the UE considers only the first received PDU of the doubled (duplicated) PDUs and discards later received duplicates. Therefore, the waiting time can be reduced.

Furthermore, for two independent transmissions, their MCS may be optimized separately, while the MCS level for the only transmission will be sub-optimal, since the effective SINR (determining the actual MCS) over the entire transmission bandwidth may be degraded. That is, PRBs with lower SINR will negatively impact the effective SINR calculated by EESM.

Fig. 5 shows an apparatus according to an example embodiment of the invention. The apparatus may be a sender (e.g., a gNB or a UE) or an element thereof. Specifically, it may be a base station in downlink communication or a terminal in uplink communication. Fig. 6 shows a method according to an example embodiment of the invention. The apparatus according to fig. 5 may perform the method of fig. 6, but is not limited to this method. The method of fig. 6 may be performed by the apparatus of fig. 5, but is not limited to being performed by the apparatus.

The device comprises an indication means 10 and a determination means 20. The indication means 10 and the determination means 20 may be an indication module and a determination module, respectively. The indicating means 10 and the determining means 20 may be an indicating party and a determining party, respectively. The indication means 10 and the determination means 20 may be an indication processor and a determination processor, respectively.

The instructing means 10 instructs the transmitting side to transmit the first packet data unit on the first active bandwidth portion of the carrier to the receiving side at the first transmission time (S10).

The determining section 20 determines the delay and the second bandwidth part of the carrier based on the handover rule (S20). The switching rule defines the second bandwidth portion to be different from the first bandwidth portion.

S10 and S20 may be performed in any order. S10 and S20 may be performed in full or partial parallel.

If the sender is instructed to transmit the first packet data units (S10), the instructing means 10 instructs the sender to transmit the second packet data units on the second active bandwidth portion to the receiver at the second transmission time (S30). In particular, the instructing means instructs the sender to transmit the second packet data unit after the determined delay has elapsed after instructing the transmission of the first packet data unit (S10). For example, the instructing means 10 may instruct the sender to transmit a second packet data unit to indicate the applicable delay immediately after instructing the transmission of the first packet data unit. As another example, the instructing means 10 may instruct the sender to transmit the second packet data unit only after the delay has elapsed after instructing the transmission of the first packet data unit. In this case, the indication of the transmission means that the indication is transmitted immediately (as soon as possible). The switching rule may additionally comprise a maximum duration during which the transmission of the second packet data unit may be performed after the delay has elapsed.

Fig. 7 shows an apparatus according to an example embodiment of the invention. The apparatus may be a sender (e.g., a gNB or a UE) or an element thereof. Specifically, it may be a base station in uplink communication or a terminal in downlink communication. Fig. 8a and 8b illustrate a method according to an exemplary embodiment of the invention. The apparatus according to fig. 7 may perform the methods of fig. 8a and 8b, but is not limited to these methods. The method of fig. 8a and 8b may be performed by the apparatus of fig. 7, but is not limited to being performed by the apparatus.

The apparatus includes a monitoring component 110 and a determining component 120. The monitoring component 110 and the determining component 120 can be a monitoring module and a determining module, respectively. The monitoring component 110 and the determining component 120 can be a monitoring party and a determining party, respectively. The monitoring component 110 and the determining component 120 can be a monitoring processor and a determining processor, respectively.

The monitoring section 110 monitors whether a first packet data unit is received from the sender on a first active bandwidth portion of the carrier at a first reception time (S110).

The determining part 120 determines the delay and the second bandwidth part of the carrier based on the handover rule (S120). The switching rule defines the second bandwidth portion to be different from the first bandwidth portion.

S110 and S120 may be performed in any order. S110 and S120 may be performed in full or in part in parallel. If S120 is performed after S110, S120 may be performed only in case the first PDU is received (yes in S110), or S120 may be performed in any case regardless of whether the first PDU is received. Different examples are shown in fig. 8a and 8 b.

If the first packet data unit is received (yes at S110), the monitoring component 110 monitors whether a second packet data unit is received from the sender on the second active bandwidth portion at a second reception time (S130). Specifically, the monitoring section 110 monitors whether or not the second packet data unit is received after the delay has elapsed after the first packet data unit is received (S110). For example, monitoring component 110 can begin monitoring whether a second packet data unit is received immediately after receiving a first packet data unit and evaluate the delay later. As another example, monitoring component 110 can monitor whether a second packet data unit is received after the delay has elapsed only after the first packet data unit is received. The switching rule may additionally comprise a maximum duration during which the second packet data unit is expected to be received after the delay has elapsed.

Fig. 9 shows an apparatus according to an example embodiment of the invention. The apparatus comprises at least one processor 810 and at least one memory 820 comprising computer program code, and the at least one processor 810 together with the at least one memory 820 and the computer program code are arranged to cause the apparatus at least to perform at least one of the methods according to fig. 6, 8a and 8b and the related description.

Some example embodiments of the present invention are described based on a 3GPP network (e.g., NR). However, the present invention is not limited to NR. It can be applied to any generation (3G, 4G, 5G, etc.) 3GPP network.

Some example embodiments of the present invention are described in detail for uplink transmission. However, some example embodiments of the present invention are applicable to downlink where a cell transmits on two or more active bandwidth portions according to a handover rule.

In some example embodiments of the present invention, the network provides the applicable handover rules to the UE before applying BWP handover. In other example embodiments, a set of handover rules is available at the UE and the network provides an indication of applicable handover rules in addition to the set of handover rules. The set of switching rules may be pre-configured in the UE or the network may provide the set of switching rules to the UE.

In some example embodiments, a single handover rule is defined in both the network and the UE. In some example embodiments, a plurality of handover rules are defined in both the network and the UE, and applicable handover rules are automatically defined by each of the network (gNB) and the UE based on certain conditions, such as a higher layer application that needs to apply BWP handover or a time of day. In these embodiments, the network does not need to inform the UE of the applicable handover rules.

The UE is an example of a terminal. However, the terminal (UE) may be any device capable of connecting to a (3GPP) radio network, such as an MTC device, an IoT device, and so on.

The cell may be part of a base station. A base station may include one or more cells. The base station may be, for example, a gNB, eNB, or NodeB. As described above, a cell (and its carrier) is identified by its cell identifier. However, the transmission chain (transmission chain) of a cell (e.g., a gNB) is not limited to a particular implementation. For example, it may comprise remote radio head(s), antenna panel (s)/element(s), TRP(s) (transmission and reception point (s)). Each radio unit is connected to an antenna(s) serving a particular direction and thus forms a cell.

The definitions indicated in this specification are based on current 3GPP standards. However, they do not limit the present invention. Other definitions according to the same or corresponding concepts also apply to some example embodiments of the invention.

A piece of information may be transmitted from one entity to another in one or more messages. Each of these messages may include additional (different) information.

The names of the network elements, protocols and methods are based on current standards. In other versions or other technologies, the names of these network elements and/or protocols and/or methods may be different as long as they provide the corresponding functionality.

Two physically different statements mean that they perform different functions, unless stated otherwise or clear from the context otherwise. This does not necessarily mean that they are based on different hardware. That is, each entity described in this specification may be based on different hardware, or some or all of the entities may be based on the same hardware. This does not necessarily mean that they are based on different software. That is, each entity described in this specification may be based on different software, or some or all of the entities may be based on the same software. Each of the entities described in this specification may be implemented in a cloud.

From the above description it is thus evident that the exemplary embodiments of this invention provide, for example, a terminal (such as a UE) or a component thereof, an apparatus implementing the same, a method for controlling and/or operating the same, and a computer program(s) controlling and/or operating the same, as well as a medium carrying such computer program(s) and forming a computer program product(s). From the above description it is thus evident that the exemplary embodiments of this invention provide, for example, a satellite or a component thereof acting as a base station (e.g., a gNB or eNB), an apparatus embodying the same, methods for controlling and/or operating the same, and computer programs controlling and/or operating the same, as well as media carrying such computer program(s) and forming computer program product(s).

By way of non-limiting example, implementations of any of the above blocks, apparatus, systems, techniques or methods include implementation as hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

It should be understood that the foregoing is what is presently considered to be the preferred exemplary embodiment of the invention. It should be noted, however, that the description of the preferred exemplary embodiment is given by way of example only and that various modifications may be made without departing from the scope of the invention as defined by the appended claims.