7B Indirect 3GPP Communication
22.2783GPPService requirements for the Evolved Packet System (EPS)TS
7B.1 Feature description
Indirect 3GPP Communication enables an Evolved ProSe Remote UE (e.g. wearable device, UE) to connect to the 3GPP network via an Evolved ProSe UE-to-Network Relay. The connection between the Evolved Prose Remote UE and the Evolved ProSe UE-to-Network Relay can use E-UTRA or WLAN.
The Evolved ProSe Remote UE has the functionality to directly connect to the EPC without an Evolved ProSe UE-to-Network Relay.The Evolved ProSe Remote UE will be visible to and controlled by the 3GPP network when connected via an Evolved ProSe UE-to-Network Relay. The Evolved ProSe Remote UE can use Indirect 3GPP Communication either in E-UTRAN coverage or out of E-UTRAN coverage.
The requirements listed in this clause (7B) exclude GSM and UMTS. Indirect 3GPP Communication to the 3GPP network shall not impact either of GSM and UMTS.
The Evolved ProSe Remote UE and the Evolved ProSe UE-to-Network Relay are served by the same PLMN.
7B.2 General Requirements for Indirect 3GPP Communication
The 3GPP system shall be capable of supporting Indirect 3GPP Communications between an Evolved ProSe Remote UE and the 3GPP network via an Evolved ProSe UE-to-Network Relay. This requirement applies to any Indirect 3GPP Communication between an Evolved ProSe Remote UE and Evolved ProSe UE-to-Network Relay, including ProSe Group Communication and ProSe Broadcast Communication.
There shall be a maximum of one Evolved ProSe UE-to-Network Relay between an Evolved ProSe Remote UE and E-UTRAN.
The connection between an Evolved ProSe Remote UE and an Evolved ProSe UE-to-Network Relay shall be able to use E-UTRA or WLAN.
The Evolved ProSe Remote UE supporting only E-UTRA can use Indirect 3GPP Communication either in E-UTRAN coverage or out of E-UTRAN coverage.
The Evolved ProSe Remote UE supporting E-UTRA and other RAT(s) can use Indirect 3GPP Communication either in E-UTRAN coverage or out of coverage of all supported 3GPP RAT(s) of the UE.
A UE shall be capable of acting as an Evolved ProSe UE-to-Network Relay between an Evolved ProSe Remote UE and E-UTRAN if it is authorised by the3GPP network to act as a relay and served by this E-UTRAN.
An authorised Evolved ProSe UE-to-Network Relay shall be capable of being enabled/disabled by the 3GPP network to act as a relay to/from E-UTRAN for other Evolved ProSe Remote UEs unable to access E-UTRAN.
The 3GPP network shall control the Evolved ProSe Remote UE via an Indirect 3GPP Communication using E-UTRA or WLAN. This requirement applies to any Indirect 3GPP Communication between an Evolved ProSe Remote UE and Evolved ProSe UE-to-Network Relay, including ProSe Group Communication and ProSe Broadcast Communication.
The 3GPP network shall be able to identify, authenticate, address and reach an Evolved ProSe Remote UE when it accesses the 3GPP network via an Indirect 3GPP Communication.
The 3GPP network shall manage the E-UTRA(N) resources used for the communication path between the Evolved ProSe Remote UE and the network when it accesses the 3GPP network via an Indirect 3GPP Communication.
The 3GPP network shall provide efficient use of E-UTRA radio spectrum (i.e., not increase interference or power consumption of the in-coverage UE when shared with out-of-coverage UEs).
The 3GPP network shall provide resource efficient management of shared radio spectrum for all users (e.g., Public Safety, commercial).
Based on the preference of the end-user of the Evolved ProSe UE-to-Network Relay, the 3GPP network shall be able to allow/disallow access from an Evolved ProSe Remote UE to the network via an Evolved ProSe UE-to-Network Relay.
The 3GPP system shall support the real time user traffic session (e.g. Multimedia telephony and/or real time video) for an Evolved ProSe Remote UE when the Evolved ProSe Remote UE is connected to the 3GPP network via an Indirect 3GPP Communication.
The 3GPP systems shall support small data services (e,g, CIoT, eMTC) for an Evolved ProSe Remote UE when the Evolved ProSe Remote UE uses an Indirect 3GPP Communication.
The 3GPP systems shall support data services (e,g, non-real time data) for an Evolved ProSe Remote UE when the Evolved ProSe Remote UE uses an Indirect 3GPP Communication.
The 3GPP system shall enable emergency calls via the Evolved ProSe Relay UE in case that the Evolved ProSe Remote UE supports emergency calls.
The 3GPP system shall be able to support the change for an Evolved ProSe Remote UE from a direct 3GPP communication to an Indirect 3GPP Communication and vice-versa.
NOTE: Potential reasons for changing could be to achieve better QoS or battery efficiency, as well as either the Evolved ProSe Remote UE or Evolved ProSe UE-to-Network Relay moving in or out of E-UTRAN coverage.
The 3GPP network shall be able to ensure service continuity when the Evolved ProSe Remote UE changes from a direct 3GPP communication to an Indirect 3GPP Communication and vice-versa.
The 3GPP system shall be able to support QoS for a user traffic session even in Indirect 3GPP Communication using E-UTRA.
The support of Indirect 3GPP Communication shall not lead to a significant increase of complexity of the Evolved Prose Remote UE compared to direct communication to 3GPP network.
The use of Indirect 3GPP Communication should typically lead to a decrease in power consumption and shall not lead to an increase in power consumption at the Evolved ProSe Remote UE when compared to the Evolved ProSe Remote UE using the direct 3GPP communication for the same traffic.
An Evolved ProSe UE-to-Network Relay shall be able to relay data for a group of Evolved ProSe Remote UEs using ProSe Group Communications regardless of their group membership, if authorized by the 3GPP network.