Systems, methods, and devices for device-to-device relay communication

1. A user equipment (UE) configured to:

receive a relay discovery request from a first peer UE, wherein the relay discovery request includes an identifier that identifies a second peer UE;

determine that the second peer UE is within a communication range of the UE;

in response to the relay discovery request and that the second peer UE is within the communication range of the UE, transmit a first IP address for the first peer UE and a second IP address for the second peer UE to the second peer UE in a link establishment request or a link update request, wherein the first IP address is different than the second IP address;

establish a first link with the first peer UE;

establish a second link with the second peer UE based on the request; and

based on the first IP address and the second IP address, relay internet protocol (IP) packets from the first peer UE to the second peer UE and relay IP packets from the second peer UE to the first peer UE.

2. The UE of claim 1 , wherein the relay discovery request from the first peer UE comprises a request for link establishment or link update with the UE.

3. The UE of claim 2 , wherein the request for link establishment or link update from the first peer UE comprises an indication that the request is for communication with the second peer UE.

4. The UE of claim 1 , wherein the UE is configured to send a link establishment request or link update request to the second peer UE.

5. The UE of claim 1 , wherein the UE is further configured to act as one or more of a dynamic host configuration protocol (DHCP) server and a default internet protocol (IP) router for communication between the first peer UE and the second peer UE.

6. The UE of claim 5 , wherein the UE is configured to transmit assigned IP version 4 addresses to the first peer UE and the second peer UE.

7. The UE of claim 1 , wherein the UE is configured to transmit the IP address for the first peer UE and the IP address for the second peer UE to the first peer UE in a link establishment response or link update response.

8. The UE of claim 1 , wherein the UE is further configured to perform a discovery procedure to discover the first peer UE and the second peer UE and to discover user information corresponding to each of the first peer UE and the second peer UE.

9. User equipment (UE) comprising:

a processor;

a memory in electronic communication with the processor; and

instructions stored in the memory that when executed by the processor cause the processor to:

process a message from a proximate UE comprising a direct communication relay discovery request to communicate with a remote UE, wherein the message includes an identifier that identifies the remote UE, and wherein the message further comprises a link establishment request;

transmit a message to the proximate UE indicating acceptance of the direct communication relay discovery request to communicate with the remote UE;

determine a first internet protocol (IP) address assigned to the remote UE by the proximate UE and a second IP address assigned to the UE by the proximate UE using information included in the link establishment request, wherein the first IP address is different than the second IP address; and

using the first IP address and the second IP address, communicate with the remote UE via the proximate UE.

10. The UE of claim 9 , wherein the message to the proximate UE indicating acceptance comprises a link establishment response.

11. The UE of claim 9 , wherein the message from a proximate UE comprises an indication that the direct communication relay discovery request is for communication with a source user corresponding to the remote UE.

12. The UE of claim 9 , wherein the instructions are further executable by the processor to perform service discovery to determine an IP address for the remote UE.

13. The UE of claim 9 , wherein the message from the proximate UE comprises an IP version 4 address for the UE assigned by the proximate UE and an IP version 4 address for the remote UE assigned by the proximate UE, wherein the instructions are further executable by the processor to determine an IP address assigned to the UE based on the message from the proximate UE and wherein the instructions are further executable by the processor to send packets to the remote UE using the IP version 4 address for the remote UE assigned by the proximate UE.