User equipment, comprising: a receiver, configured to receive a discovery message sent by a second user equipment, wherein the discovery message indicates cell information of the second user equipment and the discovery message is using at least one of a codeword resource, a frequency resource and a time resource; a processor, configured to acquire the cell information of the second user equipment; and a transmitter, configured to send a communication request to a network device according to the discovery message, wherein the communication request is used to request to communicate with the second user equipment, and the communication request indicates the cell information of the second user equipment, so that the network device sends a paging message to the second user equipment according to the communication request and the cell information of the second user equipment, characterized in that the cell information of the second user equipment is a discovery area identifier of the second user equipment, the discovery area identifier includes one or multiple cells, and the discovery area identifier is shorter than a cell identifier, wherein the discovery message indicates the discovery area identifier of the second user equipment by using the codeword resource used by the discovery message; and the processor is specifically configured to determine the discovery area identifier of the second user equipment according to a correspondence between a discovery area identifier and a codeword resource, and the codeword resource used by the discovery message, or wherein the discovery message indicates the discovery area identifier of the second user equipment by using the frequency resource used by the discovery message; and the processor is specifically configured to determine the discovery area identifier of the second user equipment according to a correspondence between a discovery area identifier and a frequency resource, and the frequency resource used by the discovery message, or wherein the discovery message indicates the discovery area identifier of the second user equipment by using the time resource used by the discovery message; and the processor is specivically configured to determine the discovery area identifier of the second user equipment according to a correspondence between a discovery area identifier and a time resource, and the time resource used by the discovery message. a receiver, configured to receive a discovery message sent by a second user equipment, wherein the discovery message indicates cell information of the second user equipment and the discovery message is using at least one of a codeword resource, a frequency resource and a time resource; a processor, configured to acquire the cell information of the second user equipment; and a transmitter, configured to send a communication request to a network device according to the discovery message, wherein the communication request is used to request to communicate with the second user equipment, and the communication request indicates the cell information of the second user equipment, so that the network device sends a paging message to the second user equipment according to the communication request and the cell information of the second user equipment, characterized in that the cell information of the second user equipment is a discovery area identifier of the second user equipment, the discovery area identifier includes one or multiple cells, and the discovery area identifier is shorter than a cell identifier, wherein the discovery message indicates the discovery area identifier of the second user equipment by using the codeword resource used by the discovery message; and the processor is specifically configured to determine the discovery area identifier of the second user equipment according to a correspondence between a discovery area identifier and a codeword resource, and the codeword resource used by the discovery message, or wherein the discovery message indicates the discovery area identifier of the second user equipment by using the frequency resource used by the discovery message; and the processor is specifically configured to determine the discovery area identifier of the second user equipment according to a correspondence between a discovery area identifier and a frequency resource, and the frequency resource used by the discovery message, or wherein the discovery message indicates the discovery area identifier of the second user equipment by using the time resource used by the discovery message; and the processor is specivically configured to determine the discovery area identifier of the second user equipment according to a correspondence between a discovery area identifier and a time resource, and the time resource used by the discovery message.