YD/T 3400-2018General Technical Requirements of LTE-Based Vehicular Communication (English PDF)

3.1 Terms and Definitions

For the purpose of this document, the following terms and definitions apply.

3.1.1 Road side unit (RSU)

An entity that supports V2I services and may communicate with UE. The RSU may appear as an eNB or a stationary UE. When the RSU appears as a stationary UE, it may be in or out of the LTE network coverage.

3.2 Abbreviations

For the purpose of this document, the following abbreviations apply.

C-TEID. Common-Tunnel Endpoint IDentifier;

EPS. Evolved Packet System;

E-UTRAN. Evolved UTRAN;

HPLMN. Home Public land Mobile Network;

L.MBMS. Local MBMS;

MBMS. Multimedia Broadcast/Multicast Service;

ME. Mobile Equipment;

5.1 Basic requirements

Requirement 1.When the sending terminal is served by E-UTRAN that supports V2X, the message transmission shall be controlled by the 3GPP network.

Requirement 6.

5.2 Effective communication distance

Requirement 16.E-UTRA shall be able to provide sufficient effective communication distance to ensure that the driver has sufficient response time (for instance, 4s).

5.3 Movement speed

Requirement 17.Regardless of whether the Vehicle-to-Everything terminal uses the

Vehicle-to-Everything communication service that is provided by E-UTRAN that supports V2X communication, the 3GPP system shall be able to support messages sending between vehicles at a maximum relative speed of 500km/h.

5.4 Communication delay

Requirement 19.For terminals that support vehicle-to-vehicle and vehicle-to- pedestrian communication, whether it is sent directly or forwarded by a road side unit,

E-UTRA (N) shall ensure that the maximum communication delay not exceed 100ms.

Requirement 20.Only for special use cases (such as collision detection), the maximum delay of sending V2V messages between E-UTRA (N) Vehicle-to-Everything terminals should not exceed 20ms.

5.5 Transmission reliability

Requirement 23.The E-UTRAN network shall not rely on application layer retransmission to provide highly reliable transmission.

5.6 Requirements for information security

Requirement 24.When the Vehicle-to-Everything terminal uses the service that is provided by E-UTRAN that supports V2X communication, the 3GPP network shall provide a method for the operator to authorize the Vehicle-to-Everything terminal to perform V2X communication.

5.7 Requirements for coverage

Requirement 30.V2X services shall be supported both with and without operator network coverage.

5.8 Requirements for message sending frequency

Requirement 31.E-UTRAN shall be able to support road side units and Vehicle-to-

Everything terminals with a message sending frequency of up to 10Hz.

NOTE. The messages transmitted by V2X applications to 3GPP may be either periodic or triggered by specific events.

5.9 Requirements for message size

Requirement 32.Excluding security-related message units, for periodic messages, E-

UTRAN shall be able to support a maximum of 50~300 bytes of messages that are transmitted between two UEs that support V2X applications.

6.1 Architecture model

6.1.1 Overview

V2X communication has two mutually independent and complementary working modes; namely, V2X communication based on PC5 direct mode and V2X communication based on LTE-Uu. The working mode based on LTE-Uu may be unicast or MBMS. The UE may use these two working modes to receive and transmit, respectively. For example. A UE may use MBMS to receive V2X messages, but send

V2X messages without using LTE-Uu. A UE may also receive V2X messages through

LTE-Uu downlink unicast.

6.1.2 V2X communication architecture based on PC5 and LTE-Uu

6.1.2.1 V2X communication architecture based on PC5 and LTE-Uu in non-

roaming scenarios

6.1.2.2 V2X communication architecture based on PC5 and LTE-Uu in roaming

scenarios

6.2 Introduction of the interface

Each interface is introduced as follows.

6.3 Functional entities

6.3.1 UE

The UE may support the following functions.

7.1 High-level functional requirements

7.1.1 Authorization and provision function

7.1.1.1 Authorization and provision of V2X communication on the PC5 interface

7.1.1.1.1 Overview

The authorization of V2X communication based on the PC5 interface shall follow the following principles.

7.1.1.1.2 Provision of the strategy/parameter

The V2X communication based on the PC5 interface needs to provide the following information to the UE.

7.1.1.1.3 Configuration principles for the parameters of the V2X communication on the PC5 interface

For V2X communication based on the PC5 interface, the operator may pre-configure the parameters required for V2X communication to the UE without the need for the UE to connect to the V2X control function to obtain the initial configuration, and follow the following principles.

7.1.2 Sending and receiving messages on PC5 interface

The PC5 interface (as defined in 3GPP TS 23.303) is used to send and receive V2X messages. V2X communication based on the PC5 interface supports roaming and cross-PLMN operations. The UE may support V2X communication based on the PC5 interface in the scenarios of "using E-UTRAN services" and "not using E-UTRAN services".

7.1.5 QoS processing

7.1.5.1 QoS management on PC5 interface

The MME sends the UE-PC5-AMBR as part of the UE context information to the eNB based on the subscription information.

7.2 Requirements of the radio function

7.2.1 Overview

Supports the provision of V2X services through the PC5 interface and/or Uu interface.

The UE may support V2X communication based on the PC5 interface in the scenarios of "using E-UTRAN services" and "not using E-UTRAN services".

7.3 Identification

On the PC5 interface, each UE has a Layer-2 ID for V2X communication, which is included in each frame as the source Layer-2 ID on the Layer-2 link. The UE self- configures Layer-2 ID for V2X communication.

7.4 Function description and message flow

7.4.1 Control plane and user plane protocol stack

The PC5-U protocol stack defined in the proximity communication (see 3GPP TS

23.303) is used for V2X communication transmission based on the PC5 interface. The

V2X communication transmission based on the PC5 interface supports IP and non-IP

PDCP SDU.

7.4.5.4 X2 handover

For handover with X2, the "V2X service authorized" indication and UE-PC5-AMBR are sent to the target eNB.

7.4.5.5 Tracking area update (TAU)

The TAU process has the following modifications.

7.4.5.6 Acquire subscription data

The subscription data acquisition process has the following modifications. If the "V2X services authorized" indication and the UE-PC5-AMBR subscription change, and the

S1 bearer has been established, the MME sends the modified "V2X services authorized" indication and UE-PC5-AMBR to the eNB through the S1-AP UE Context

Modification Request message.

......