COMMUNICATION DEVICE AND COMMUNICATION SYSTEM

1 . A communication device comprising:

a communicator configured to include a first wireless communication layer and a second wireless communication layer, with the second wireless communication layer having a first link layer protocol or a second link layer protocol, which is a radio link protocol, and perform radio communication with another communication device via the first wireless communication layer; and

a controller configured to control communication in transmission and reception of data of the second wireless communication layer by performing control on the data in accordance with whether a radio link protocol of the second wireless communication layer corresponds to the first link layer protocol or the second link layer protocol so that the transmission and reception of the data is performed.

2 . The communication device according to claim 1 , wherein when the second wireless communication layer does not support the first link layer protocol, in transmission and reception of data corresponding to the first link layer protocol from and to the other communication device, the controller adjusts a first parameter, which is a parameter of the first link layer protocol of the data, to a second parameter, which is a parameter of the second link layer protocol, in the control so that the data corresponds to the second link layer protocol, and passes the data to the second wireless communication layer.

3 . The communication device according to claim 2 , wherein

the parameter is information regarding a size of a packet that transmits the data, and

the controller configured to set, as a second parameter, a parameter indicating a size that is equal to or less than a data size of the first parameter and is the greatest with which the communication device is capable of handling.

4 . The communication device according to claim 2 , wherein

the parameter is information regarding a size of a packet that transmits the data, and

the controller configured to set, as a second parameter, a parameter indicating a size that is equal to or greater than a data size of the first parameter and is the smallest with which the communication device is capable of handling.

5 . The communication device according to claim 2 , wherein the parameter is information regarding subcarrier spacing of a packet that transmits the data.

6 . The communication device according to claim 5 , wherein the controller configured to set, as a second parameter, a parameter that is equal to the subcarrier spacing of the first parameter or that has a small difference from the subcarrier spacing of the first parameter.

7 . The communication device according to claim 5 , wherein the controller configured to receive a support parameter, which is a parameter of the first link layer protocol supported by the other communication device, select, from the support parameter, a parameter that is equal to or approximates to a parameter of the second link layer protocol supported by the communication device, and notify the other communication device of the parameter as a candidate parameter.

8 . The communication device according to claim 7 , wherein the support parameter is included in user equipment (UE) capability.

9 . The communication device according to claim 7 , wherein the support parameter is included in user equipment (UE) assistance information.

10 . The communication device according to claim 7 , wherein the notification is performed by radio resource control (RRC).

11 . The communication device according to claim 7 , wherein the notification is performed by medium access control (MAC), a control element (CE), or a physical data control channel (PDCCH).

12 . The communication device according to claim 7 , wherein the controller configured to perform the notification when the communication device detects that a state of the communication device or the other communication device has changed.

13 . A communication device comprising:

a communicator configured to include a first wireless communication layer and a second wireless communication layer, with the second wireless communication layer having a first link layer protocol or a second link layer protocol, which is a radio link protocol, and perform radio communication with another communication device via the first wireless communication layer; and

a controller configured to control communication in transmission and reception of data of the second wireless communication layer by performing control on the data in accordance with a parameter of the first link layer protocol or the second link layer protocol that is received from the other communication device so that the transmission and reception of the data is performed.

14 . A communication system comprising:

a first communication device and a second communication device, wherein

the first communication device configured to include a first wireless communication layer and a second wireless communication layer, with second wireless communication layer having a first link layer protocol, which is a radio link protocol,

the second communication device configured to include the first wireless communication layer and the second wireless communication layer, with second wireless communication layer including a second link layer protocol, which is a radio link protocol,

the second communication device configured to transmit, to the first communication device, data corresponding to the second link layer protocol, and

the first communication device configured to perform radio communication with the second communication device via the first wireless communication layer, and in reception of data of the second wireless communication layer, when the first communication device receives, from the second communication device, data corresponding to the second link layer protocol, the first communication device performs control on the data so that the data corresponds to the first link layer protocol.