TECHNICAL FIELD
5 [0001] Embodiments of the present disclosure generally relate to the field of
telecommunication, and in particular, to methods, devices and computer storage media of
communication for data transmission in an inactive state of a terminal device.
BACKGROUND
10 [0002] Typically, a terminal device in an inactive state may still have small and infrequent
data traffic (also referred to as small data transmission (SDT) hereinafter) to be transmitted.
Until the third generation partnership project (3GPP) Release 16, the inactive state cannot
support data transmission, and the terminal device has to resume connection (i.e., enter a
connected state) for any downlink and uplink data. Connection setup and subsequently
15 release to the inactive state happens for each data transmission whatever small and
infrequent the data packets are. This will result in unnecessary power consumption and
signaling overhead.
[0003] In this event, 3GPP Release 17 has approved SDT based on a random access
channel (RACH) in the inactive state and also approved SDT based on pre-configured
20 physical uplink shared channel (PUSCH) resources in the inactive state. Thereby, the
signaling overhead can be reduced. In this case, how to perform SDT has become a hot
ISSUe.
SUMMARY
25 [0004] In general, embodiments of the present disclosure provide methods, devices and
computer storage media for communication.
[0005] In a first aspect, there is provided a method of communication. The method
comprises: determining, at a terminal device in an inactive state, whether one or more data
radio bearers (DRBs) with uplink data to be transmitted support data transmission in the
30 inactive state; in accordance with a determination that the one or more DRBs support the
data transmission in the inactive state, determining, based on a payload size associated with
the uplink data and a threshold associated with the one or more DRBs, whether the uplink
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data is to be transmitted in the inactive state; and in accordance with a determination that
the uplink data is to be transmitted in the inactive state, transmitting the uplink data to a
first network device in the inactive state.
[0006] In a second aspect, there is provided a method of communication. The method
5 comprises: receiving, at a first network device, uplink data transmitted by a terminal device
in an inactive state; and transmitting, to a third network device, a request for relocating an
anchor for a context of the terminal device, the request comprising a first indication as to
whether there is remaining data to be transmitted, the third network device maintaining the
context of the terminal device.
10 [0007] In a third aspect, there is provided a method of communication. The method
comprises: receiving, at a second network device and from a terminal device, a first request
for resuming connection upon cell reselection of the terminal device from a first cell of a
first network device to a second cell of the second network device during data transmission
in an inactive state of the terminal device; and transmitting, to a fourth network device
15 maintaining the context of the terminal device, a second request for relocating an anchor for
a context of the terminal device.
[0008] In a fourth aspect, there is provided a method of communication. The method
comprises: receiving, at a third network device and from a first network device, a request
for relocating an anchor for a context of a terminal device in an inactive state, the request
20 comprising a first indication as to whether there is remaining data other than uplink data to
be transmitted, the third network device maintaining the context of the terminal device;
determining, based on the first indication, whether the anchor is to be relocated; and in
accordance with a determination that the anchor is not to be relocated, transmitting, to the
first network device, at least a part of the context for transmission of the uplink data in the
25 inactive state.
[0009] In a fifth aspect, there is provided a method of communication. The method
comprises: receiving, at a fourth network device and from a second network device, a
second request for relocating an anchor for a context of a terminal device, the fourth
network device maintaining the context; in accordance with a determination that the anchor
30 is to be relocated, transmitting, to the second network device, information about sequence
number and hyper frame number of data packets associated with uplink data to be
transmitted; and transmit the data packets to the second network device.
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[0010] In a sixth aspect, there is provided a terminal device. The terminal device
comprises a processor and a memory coupled to the processor. The memory stores
instructions that when executed by the processor, cause the terminal device to perform the
method according to the first aspect of the present disclosure.
5 [0011] In a seventh aspect, there is provided a first network device. The first network
device comprises a processor and a memory coupled to the processor. The memory stores
instructions that when executed by the processor, cause the first network device to perform
the method according to the second aspect of the present disclosure.
[0012] In an eighth aspect, there is provided a second network device. The second
10 network device comprises a processor and a memory coupled to the processor. The
memory stores instructions that when executed by the processor, cause the second network
device to perform the method according to the third aspect of the present disclosure.
[0013] In a ninth aspect, there is provided a third network device. The third network
device comprises a processor and a memory coupled to the processor. The memory stores
15 instructions that when executed by the processor, cause the transmitting device to perform
the method according to the fourth aspect of the present disclosure.
[0014] In a tenth aspect, there is provided a fourth network device. The fourth network
device comprises a processor and a memory coupled to the processor. The memory stores
instructions that when executed by the processor, cause the fourth network device to
20 perform the method according to the fifth aspect of the present disclosure.
[0015] In an eleventh aspect, there is provided a computer readable medium having
instructions stored thereon. The instructions, when executed on at least one processor,
cause the at least one processor to perform the method according to the first aspect of the
present disclosure.
25 [0016] In a twelfth aspect, there is provided a computer readable medium having
instructions stored thereon. The instructions, when executed on at least one processor,
cause the at least one processor to perform the method according to the second aspect of the
present disclosure.
[0017] In a thirteenth aspect, there is provided a computer readable medium having
30 instructions stored thereon. The instructions, when executed on at least one processor,
cause the at least one processor to perform the method according to the third aspect of the
present disclosure.
3
[0018] In a fourteenth aspect, there is provided a computer readable medium having
instructions stored thereon. The instructions, when executed on at least one processor,
cause the at least one processor to perform the method according to the fourth aspect of the
present disclosure.
5 [0019] In a fifteenth aspect, there is provided a computer readable medium having
instructions stored thereon. The instructions, when executed on at least one processor,
cause the at least one processor to perform the method according to the fifth aspect of the
present disclosure.
[0020] Other features of the present disclosure will become easily comprehensible
10 through the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Through the more detailed description of some embodiments of the present
disclosure in the accompanying drawings, the above and other objects, features and
15 advantages of the present disclosure will become more apparent, wherein:
[0022] FIG. 1 illustrates an example communication network in which some embodiments
of the present disclosure can be implemented;
[0023] FIG. 2 illustrates a schematic diagram illustrating a process for communication
during SDT according to embodiments of the present disclosure;
20 [0024] FIG. 3 illustrates a schematic diagram illustrating a process for communication
upon cell reselection according to embodiments of the present disclosure.

WHAT IS CLAIMED IS:
1. A method of communication, comprising:
determining, at a terminal device in an inactive state, whether one or more data
radio bearers (DRBs) with uplink data to be transmitted support data transmission in the
5 inactive state;
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in accordance with a determination that the one or more DRBs support the data
transmission in the inactive state, determining, based on a payload size associated with the
uplink data and a threshold associated with the one or more DRBs, whether the uplink data
is to be transmitted in the inactive state; and
in accordance with a determination that the uplink data is to be transmitted in the
inactive state, transmitting the uplink data to a first network device in the inactive state.
2. The method of claim 1, wherein determining whether the uplink data is to be
transmitted in the inactive state comprises:
15 determining a total payload size of the uplink data; and
in accordance with a determination that the total payload size is less than a first
threshold size, determining that the uplink data is to be transmitted in the inactive state.
3. The method of claim 1, wherein determining whether the uplink data is to be
20 transmitted in the inactive state comprises:
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determining a payload size of data in the uplink data corresponding to each of the
one or more DRBs; and
in accordance with a determination that the payload size is less than the second
threshold size, determining that the uplink data is to be transmitted in the inactive state.
4. The method of claim 3, wherein the second threshold size is set in association
with each of the DRBs.
5. The method of claim 1, wherein transmitting the uplink data comprises:
30 receiving, from the first network device, a configuration about a bandwidth part
(BWP) for the data transmission in the inactive state; and
performing, based on the configuration, a random access procedure for transmission
of the uplink data.
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6. The method of claim 1, further comprising:
transmitting, to the first network device, an indication as to whether remaining data
other than the uplink data is to be transmitted.
7. The method of claim 1, further comprising:
determining whether the data transmission in the inactive state can be performed in
a second cell of a second network device upon cell reselection from a first cell of the first
network device to the second cell;
in accordance with a determination that the data transmission in the inactive state
can be performed in the second cell, maintaining in the inactive state; and
transmitting the uplink data to the second cell in the inactive state.
8. The method of claim 7, further comprising:
performing, while maintaining in the inactive state, at least one of the following:
a reset of a media access control (MAC) entity of a MAC layer of the terminal
device;
a release of a MAC cell group configuration for the MAC entity;
a re-establishment of a radio link control (RLC) entity of a RLC layer of the
20 terminal device for data radio bearers associated with the terminal device that are not
suspended; or
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a re-establishment of a packet data convergence protocol (PDCP) entity of a PDCP
layer of the terminal device for the data radio bearers associated with the terminal device
that are not suspended.
9. The method of claim 8, further comprising:
transmitting, to the second cell, a PDCP status report for a DRB in an acknowledge
mode (AM) of the RLC layer.
10. The method of claim 7, further comprising:
in accordance with a determination that the data transmission in the inactive state
cannot be performed in the second cell, suspending, while maintaining in the inactive state,
DRBs associated with the terminal device; and
performing a random access procedure for transmission of the uplink data in a
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connected state.
11. The method of claim 1, further comprising:
determining whether further uplink transmission comprises an uplink signaling;
5 in accordance with a determination that the further uplink transmission comprises
10
the uplink signaling, suspending DRBs associated with the terminal device; and
performing the further uplink transmission in a connected state based on a random
access procedure.
12. The method of claim 11, further comprising:
in accordance with a determination that the further uplink transmission does not
comprise the uplink signaling, determining whether a further DRB with the further uplink
transmission is different from each of the one or more DRBs and the further DRB supports
the data transmission in the inactive state;
15 in accordance with a determination that the further DRB does not support the data
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transmission in the inactive state, suspending DRBs associated with the terminal device;
and
performing the further uplink transmission in a connected state based on a random
access procedure.
13. The method of claim 12, further comprising:
performing, in the connected state and based on the random access procedure,
transmission of data in the uplink data that is not transmitted successfully.
14. The method of claim 12, further comprising:
in accordance with a determination that the further DRB is different from each of
the one or more DRBs and supports the data transmission in the inactive state, determining
whether the further uplink transmission is to be performed in the inactive state; and
in accordance with a determination that the further uplink transmission is to be
30 performed in the inactive state, performing the further uplink transmission to the first
network device in the inactive state.
15. The method of claim 14, further comprising:
performing, in the inactive state, transmission of data in the uplink data that is not
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transmitted successfully.
16. A method of communication, comprising:
receiving, at a first network device, uplink data transmitted by a terminal device in
5 an inactive state; and
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15
transmitting, to a third network device, a request for relocating an anchor for a
context of the terminal device, the request comprising a first indication as to whether there
is remaining data to be transmitted, the third network device maintaining the context of the
terminal device.
17. The method of claim 16, wherein the indication comprises at least one of the
following:
user plane transport network layer (UP TNL) information for downlink transmission;
or
a buffer status report (BSR) from the terminal device.