scope:

The present document specifies the protocols for Proximity-based Services (ProSe) in 5G system as specified in 3GPP TS 23.304 [2] for:

a) 5G ProSe direct discovery;

b) 5G ProSe communication over the PC5 interface; and

c) 5G ProSe UE-to-network relay.

The present document defines the associated procedures for 5G ProSe service authorization and configuration, 5G ProSe direct discovery, 5G ProSe direct communication, and 5G ProSe UE-to-network relay.

The present document also defines the message format, message contents, error handling and system parameters applied by the protocols for ProSe in 5GS.