Proximity Services (ProSe), first introduced in Release 12 of the 3GPP specifications, is a D2D (Device-to-Device) technology that allows LTE devices to detect each other and to communicate directly.
In comparison to existing D2D and proximity networking technologies, ProSe offers a number of distinct benefits including better scalability, manageability, privacy, security and battery-efficiency. Current efforts to commercialize ProSe are being spearheaded by the public safety and critical communications sector. However, although initial investments in ProSe-enabled devices will be driven by these two sectors, there also exists a much larger opportunity in the commercial arena. Mobile operators can leverage ProSe to offer a range of B2B, B2B2C and B2C services that rely on proximity, including advertising, social networking, gaming, relaying traffic for wearables and V2X (Vehicle-to-Everything) connectivity, among others.
The National Institute of Standards and Technology (NIST) said in a report that “a cardinal requirement of public safety communications is to provide a direct communication capability that does not require any infrastructure and allows first responders to communicate effectively. Direct communications are essential when infrastructure-based communication is not available or when policy dictates that direct communication should be used.”
According to a report by First Responder Network Authority, technical groups at 3GPP had previously agreed that the scope of 5G ProSe in Release 17 would include direct UE-to-UE communication as well as UE-to-network relay. “5G ProSe UE-to-UE relay will be considered for Release 18 scope, and there is significant discussion to expand the scope to include multiple-hop relays to further extend off-network coverage which is important to public safety,” FirstNet Authority said.
“For 5GS, the proximity services are expected to be an important system wide enabler to support various applications and services. In Rel-16 the PC5 based architecture and communications are developed to support advanced V2X services. However, there are more proximity related service requirements than service requirements covered by the existing Rel-16 eV2X work,” 3GPP said.
“In order to support proximity services in 5GS based on SA1 requirements, SA2 has initiated the study item “Study on System enhancement for Proximity based Services in 5GS”. In addition, SA2 will develop a new framework for supporting proximity services in 5GS, i.e. using a common framework for supporting both public safety and commercial proximity services. This maywill make 5G’s proximity service security process different from 4G and require new functionality in addition to that in the existing ProSe and eV2X specifications,” 3GPP added.
3GPP added that the goal of the study on system enhancement for proximity-based services in 5GS was to provide support for ProSe Direct discovery, ProSe Direct communication, UE-to-Network Relay, UE-to-UE Relay, direct communication path selection between PC5 and Uu, and PC5 Service Authorization and Policy/Parameter Provisioning.