1. A method of communication, comprising: transmitting, at a first network device and to a second network device, a request for configuring a secondary cell group (SCG) associated with the second network device, the 5 request comprising first information about a first activity state for the SCG; and receiving a response to the request from the second network device, the response indicating a current activity state of the SCG, the current activity state being determined based on the first information by the second network device. 10 2. The method of claim 1, wherein transmitting the request comprises: in accordance with a determination that the SCG is to be added, transmitting a secondary node (SN) addition request comprising the first information; and in accordance with a determination that the SCG is to be modified, transmitting a SN modification request comprising the first information. 15

3. The method of claim 1, wherein the first activity state for the SCG is activation or deactivation.

4. A method of communication comprising: 20 receiving, at a second network device and from a first network device, a request for configuring a secondary cell group (SCG) associated with the second network device, the request comprising first information about a first activity state for the SCG; and determining, a current activity state for the SCG based on the first information; and transmitting a response to the request to the first network device, the response 25 indicating the current activity state for the SCG.

5. The method of claim 4, wherein receiving the request comprises: in accordance with a determination that the SCG is to be added, receiving a secondary node (SN) addition request; and 30 in accordance with a determination that the SCG is to be modified, receiving a SN modification request.

6. The method of claim 4, wherein the first activity state for the SCG is activation or 45 deactivation.

7. A method of communication comprising: receiving, at a first network device and from a second network device, a first 5 message for configuring a secondary cell group (SCG) associated with the second network device, the first message comprising a parameter of a second activity state of the SCG; and transmitting, to the second network device, a second message to confirm the first message. 10 8. The method of claim 7, wherein the second activity state for the SCG is activation or deactivation.

9. A method of communication comprising: generating, at a second network device, a first message for configuring a secondary 15 cell group (SCG) associated with the second network device, the first message comprising a parameter about a second activity state of the SCG; and transmitting the first message to the first network device.

10. The method of claim 9, wherein the second activity state for the SCG is 20 activation or deactivation.

11. A method of communication comprising: in accordance with a determination that a condition for performing a configuration for a primary secondary cell (PScell) of a secondary cell group (SCG) of a second network 25 device is met, determining, at a terminal device served by a first network device, whether the SCG of the second network device is deactivated; and in accordance with a determination that the SCG is deactivated, transmitting a third message to the second network device of the SCG, the third message indicating that the configuration for the PSecll has been completed by the terminal device. 30

12. The method of claim 11, further comprising: receiving, from the first network device a first radio resource control (RRC) reconfiguration message for configuring the PScell of the SCG; and determining the condition for performing a configuration for the PScell of the SCG 46 is met.

13. The method of claim 12, wherein transmitting the third message comprises: 5 transmitting the third message to the first network device, such that the third message is transmitted to the second network device via the first network device; and wherein the method further comprises: suspending transmission with the second network device to avoid a random access (RA) procedure for the PScell. 10

14. The method of claim 12, wherein transmitting the third message comprises: transmitting the third message to the first network device, such that the third message is transmitted to the second network device via the first network device; and 15 wherein the method further comprises: enabling transmission with the second network device; performing a random access (RA) procedure for the PScell via the enabled transmission; and suspending the transmission with the second network device in response to a 20 completion of the RA procedure.

TECHNICAL FIELD
[0001] Embodiments of the present disclosure generally relate to the field of
telecommunication, and in particular, to methods of communication, network devices,
terminal devices and computer readable media.
10 BACKGROUND
[0002] Dual Connectivity (DC) is a mode of operation where a terminal device (for
example, user equipment, UE) can be configured to utilize radio resources provided by two
network devices, for example, two base stations (BSs). A first network device serves the
terminal device as a Master Node (MN), and a second network device serves the terminal
15 device as a Secondary Node (SN). In the traditional DC scenario, the MN and SN may be
associated with one or more serving cells usually, and further a carrier aggregation (CA)
technology could be implemented for efficient frequency usage. The group of serving
cells associated with the MN is referred to as a Master Cell Group (MCG) and the group of
serving cells associated with the SN is referred to as a Secondary Cell Group (SCG).
20 [0003] In a DC scenario, the terminal device needs to maintain the radio links with both
MN and SN simultaneously, which causes significant power consumption. For example,
the power consumption of a DC terminal device is multiple of that of a traditional terminal
device (such as, 3 to 4 times of a Long Term Evolution, LTE, terminal device). Further, it
is proposed that in some cases (such as, the data rate of the terminal device changes from
25 high to low, and so on), the SCG serving the terminal device may be suspended/deactivated
or may be configured in dormancy state to reduce power consumption. However, in case
that the SCG is suspended/deactivated, processes for some DC procedures, in particular the
procedures relating to configuration SCG, have not been stipulated.
30 SUMMARY
[0004] In general, example embodiments of the present disclosure provide a solution for
configuring SCG in case that the SCG is suspended/deactivated SCG.
3
[0005] In a first aspect, there is provided a method of communication. The method
comprises transmitting, at a first network device and to a second network device, a request
for configuring a SCG associated with the second network device. The request comprises
first information about a first activity state for the SCG. The method further comprises
5 receiving a response to the request from the second network device. The response
indicates a current activity state of the SCG. The current activity state is determined based
on the first information by the second network device.
[0006] In a second aspect, there is provided a method of communication. The method
comprises receiving, at a second network device and from a first network device, a request
10 for configuring a SCG associated with the second network device. The request comprises
first information about a first activity state for the SCG. The method further comprises
determining a current activity state for the SCG based on the first information. The
method also comprises transmitting a response to the request to the first network device.
The response indicates the current activity state for the SCG.
15 [0007] In a third aspect, there is provided a method of communication. The method
comprises receiving, at a first network device and from a second network device, a first
message for configuring a SCG associated with the second network device. The first
message comprises a requirement about a second activity state of the SCG. The method
further comprises transmitting, a second message to the second network device to confirm
20 the first message.
[0008] In a fourth aspect, there is provided a method of communication. The method
comprises generating, at a second network device, a first message for configuring a SCG
associated with the second network device. The first message comprises a parameter
about a second activity state of the SCG. The method further comprises transmitting the
25 first message to the first network device.
[0009] In a fifth aspect, there is provided a method of communication. The method
comprises in accordance with a determination that a condition for performing a
configuration for a primary secondary cell (PScell) of a SCG of a second network device is
met, determining, at a terminal device served by a first network device, whether the SCG of
30 the second network device is deactivated. The method further comprises in accordance
with a determination that the SCG is deactivated, transmitting a third message to the second
network device of the SCG. The third message indicates that the configuration for the
4
PSecll has been completed by the terminal device.
[0010] In a sixth aspect, there is provided a method of communication. The method
comprises receiving, at a terminal device and from a second network device, a fourth
message for configuring a SCG of the second network. The fourth message comprises a
5 second indication indicating the SCG is deactivated. The method further comprises
transmitting a fifth message to the second network device of the SCG. The fifth message
indicates that the configuration for the PSecll has been completed by the terminal device.
[0011] In a seventh aspect, there is provided a network device. The network device
includes a processing unit; and a memory coupled to the processing unit and storing
10 instructions thereon, the instructions, when executed by the processing unit, causing the
device to perform the method according to the first aspect.
[0012] In an eighth aspect, there is provided a network device. The network device
includes a processing unit; and a memory coupled to the processing unit and storing
instructions thereon, the instructions, when executed by the processing unit, causing the
15 device to perform the method according to the second aspect.
[0013] In a ninth aspect, there is provided a network device. The network device
includes a processing unit; and a memory coupled to the processing unit and storing
instructions thereon, the instructions, when executed by the processing unit, causing the
device to perform the method according to the third aspect.

WE CLAIM:
1. A method of communication, comprising:
transmitting, at a first network device and to a second network device, a request for
configuring a secondary cell group (SCG) associated with the second network device, the
5 request comprising first information about a first activity state for the SCG; and
receiving a response to the request from the second network device, the response
indicating a current activity state of the SCG, the current activity state being determined
based on the first information by the second network device.
10 2. The method of claim 1, wherein transmitting the request comprises:
in accordance with a determination that the SCG is to be added, transmitting a
secondary node (SN) addition request comprising the first information; and
in accordance with a determination that the SCG is to be modified, transmitting a
SN modification request comprising the first information.
15
3. The method of claim 1, wherein the first activity state for the SCG is activation or
deactivation.
4. A method of communication comprising:
20 receiving, at a second network device and from a first network device, a request for
configuring a secondary cell group (SCG) associated with the second network device, the
request comprising first information about a first activity state for the SCG; and
determining, a current activity state for the SCG based on the first information; and
transmitting a response to the request to the first network device, the response
25 indicating the current activity state for the SCG.
5. The method of claim 4, wherein receiving the request comprises:
in accordance with a determination that the SCG is to be added, receiving a
secondary node (SN) addition request; and
30 in accordance with a determination that the SCG is to be modified, receiving a SN
modification request.
6. The method of claim 4, wherein the first activity state for the SCG is activation or
45
deactivation.
7. A method of communication comprising:
receiving, at a first network device and from a second network device, a first
5 message for configuring a secondary cell group (SCG) associated with the second network
device, the first message comprising a parameter of a second activity state of the SCG; and
transmitting, to the second network device, a second message to confirm the first
message.
10 8. The method of claim 7, wherein the second activity state for the SCG is activation
or deactivation.
9. A method of communication comprising:
generating, at a second network device, a first message for configuring a secondary
15 cell group (SCG) associated with the second network device, the first message comprising a
parameter about a second activity state of the SCG; and
transmitting the first message to the first network device.
10. The method of claim 9, wherein the second activity state for the SCG is
20 activation or deactivation.
11. A method of communication comprising:
in accordance with a determination that a condition for performing a configuration
for a primary secondary cell (PScell) of a secondary cell group (SCG) of a second network
25 device is met, determining, at a terminal device served by a first network device, whether
the SCG of the second network device is deactivated; and
in accordance with a determination that the SCG is deactivated, transmitting a third
message to the second network device of the SCG, the third message indicating that the
configuration for the PSecll has been completed by the terminal device.
30
12. The method of claim 11, further comprising:
receiving, from the first network device a first radio resource control (RRC)
reconfiguration message for configuring the PScell of the SCG; and
determining the condition for performing a configuration for the PScell of the SCG
46
is met.
13. The method of claim 12,
wherein transmitting the third message comprises:
5 transmitting the third message to the first network device, such that the third
message is transmitted to the second network device via the first network device; and
wherein the method further comprises:
suspending transmission with the second network device to avoid a random access
(RA) procedure for the PScell.
10
14. The method of claim 12,
wherein transmitting the third message comprises:
transmitting the third message to the first network device, such that the third
message is transmitted to the second network device via the first network device; and
15 wherein the method further comprises:
enabling transmission with the second network device;
performing a random access (RA) procedure for the PScell via the enabled
transmission; and
suspending the transmission with the second network device in response to a
20 completion of the RA procedure.