Communication method and related product to establish a link between two communication devices

A communication method performed by a second user terminal, comprising:

• blindly searching for a first message sent by a first user terminal, wherein the first message comprises a first link configuration parameter, and the first link configuration parameter is used to establish a first link, wherein the first message is received at one of a plurality of first communication resource pools specified by a first communication resource pool set and the first communication resource pool set is used to determine the first link configuration parameter;
• sending a first acknowledgement message to the first user terminal, wherein the first acknowledgement message is used to indicate that the second user terminal completes establishment of the first link to the first user terminal;
• receiving a second message sent by the first user terminal through the first link, wherein the second message comprises a second link configuration parameter, and the second link configuration parameter is used to establish a second link;
• sending a second acknowledgement message to the first user terminal, wherein the second acknowledgement message is used to indicate that the second user terminal completes establishment of the second link to the first user terminal;
• and
• communicating with the first user terminal through the second link,
• wherein the first link is a link different than the second link.

A communication method performed in a communications system that comprises a first user terminal, a second user terminal, and an access network device, wherein the method comprises:

• determining, by the first user terminal, a first communication resource pool set specifying a plurality of first communication resource pools, wherein the first communication resource pool set is used to determine a first link configuration parameter;
• sending, by the first user terminal, a first message using the first communication resource pool set, wherein the first message comprises the first link configuration parameter, and the first link configuration parameter is used to establish a first link;
• blindly searching, by the second user terminal, for the first message;
• sending, by the second user terminal, a first acknowledgement message to the first user terminal, wherein the first acknowledgement message is used to indicate that the second user terminal completes establishment of the first link to the first user terminal;
• sending, by the first user terminal, a second message to the second user terminal, wherein the second message comprises a second link configuration parameter, and the second link configuration parameter is used to establish a second link;
• sending, by the second user terminal, a second acknowledgement message to the first user terminal, wherein the second acknowledgement message is used to indicate that the second user terminal completes establishment of the second link to the first user terminal;
• and
• communicating, by the first user terminal, with the second user terminal through the second link,
• wherein the first link is a link different than the second link.