YD/T 2689-2014Technical Requirement for LTE based Broadband Trunking Communication(B-TrunC) (English PDF)

3.1 Terms and definitions

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

3.1.1 Dispatcher

A special terminal that connects to the TD-LTE broadband trunking core network via wired or wireless means can initiate trunking scheduling services. Its service privileges are higher than those of ordinary terminals.

3.1.2 Broadband Trunking

A broadband wireless communication system based on broadband wireless mobile communication technology, supporting broadband data transmission services, voice and multimedia trunking command and dispatch services.

4.1 Backward compatibility

The system is based on 3GPP Release 9 and maintains backward compatibility with

Release 9.

Under the condition that the system's operating frequency band is supported, terminals of 3GPP R9 and R8 shall be able to use data services normally in the system. 3GPP R9 base stations can access the system through the SI interface.

4.2 Scalability

The system architecture and protocol design shall have good scalability to support functional and performance enhancements in subsequent stages, including large-scale networking and roaming, and interoperability with other networks.

4.3 Modularization

Under the condition of conforming to the overall system architecture, the system can be decomposed into multiple logical entities, and each logical entity is independent of the others. The various logical entities of the system can be flexibly combined to form actual network elements.

4.4 Interface accessibility

The system shall have good interoperability. It shall support interoperability between different equipment manufacturers using standard-defined accessible interfaces, such as air interfaces.

4.5 Safety

The system shall have a high level of security to ensure the security of broadband data and trunking services.

5.1 Business

The system shall support basic IP packet data transmission services and broadband trunking services. The system's broadband trunking service requirements are shown in

Table 1.The broadband trunking service function definitions are in Section 6.2.

Broadband trunking voice services implement session management through extended

NAS protocol messages.

5.2 Network topology

5.2.1 Local networking

The first phase of the B-Trunc broadband trunking system shall support local networking. Interoperability with other networks, large-scale and roaming networking shall be specified in subsequent phases and are not within the scope of this Standard.

5.2.2 Networking of fixed stations and mobile stations

The system shall support one or more of the following networking methods.

- Fixed-site networking. deploy one or more base stations at fixed sites, and terminals access the system wirelessly.

- Mobile base station networking. miniature mobile base stations deployed on vehicles, ships, and other carriers. These mobile base stations can connect to the core network via satellite links or long-range wireless communication technologies such as shortwave.

5.2.3 Fault mitigation (optional)

The system shall support fault mitigation capabilities. When communication between the system's wireless access subsystem and network subsystem is interrupted, or when the network subsystem fails, the base station shall be able to handle service requests from users within its coverage area, supporting services such as individual calls, group calls, and broadcast calls. Once the communication link is restored, the base station shall be able to switch back to normal operating status.

5.2.4 Virtual private network

The system shall have Virtual Private Network (VPN) functionality, enabling a single physical network to serve multiple organizations, with each organization's VPN operating independently. The system shall also support prioritization of VPNs.

5.3 Coverage

The system shall support transmission environments such as densely populated urban areas, urban areas, suburbs, and rural areas.

5.4 Terminal

Functionally, there are two types of terminals.

- TD-LTE data terminal. a terminal that supports IP-based packet data transmission.

- TD-LTE broadband trunking terminal. a terminal that simultaneously supports IP- based packet data transmission and broadband trunking functions.

In terms of form, terminals can include fixed terminals, handheld terminals, and vehicle-mounted terminals, with vehicle-mounted terminals being terminals installed on vehicles, ships, and other means of transportation.

6.1 TD-LTE basic functions

6.1.1 TD-LTE broadband trunking base station

To achieve IP-based packet data transmission, TD-LTE broadband trunking base stations shall support the functions listed in Table 2.The definitions of relevant functions and their mandatory/optional requirements shall be consistent with the requirements of YD/T 2571.Functions related to inter-system interoperability are not required by this Standard.

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