Study on Key Protocols of Shanghai Metro B-TrunC Network Interconnection

Abstract

[Objective] The B-TrunC (broadband trunking communication) network of Shanghai Metro adopts the architecture of multi-line shared hot standby trunking core network, which needs access to the base stations and terminals of multiple lines from different vendors. In order to realize network interconnection, it is necessary to standardize the design of the interface protocol between the trunking core network and the base station/terminals. [Method] On the basis of B-TrunC standards, some interface protocols between the trunking core network and base stations/terminals are refined and supplemented. For the hot standby trunking core network, the interface between the trunking core network and the base stations needs to supplement the switchover process protocols between the main and the standby trunking core networks. Based on a comprehensive analysis of the advantages and disadvantages of the above two existing switchover schemes, the optimized functional requirements and process protocols are proposed. To meet the requirements for interconnection of terminals trunking functions, the detailed configuration schemes of relevant protocols are proposed to realize the interconnection of the functions including terminal loading call groups, centralized audio and video recording, and multimedia messaging. [Result & Conclusion] After supplementing and refining the interface protocols, the B-TrunC hot standby trunking core network of Shanghai Metro connecting with the base station/terminals of two vendors, realizes not only the corresponding switchover of all base station/terminals accompanying the switchover of the core network, but also the interconnection of the functions including trunking call, real-time short data, and multimedia messaging. It breaks through the key technical bottleneck of B-TrunC network resource sharing.

Keywords

• metro
• b-trunc
• interconnection
• protocol standard