The MPT 1327 signaling is designed by British Telecom Service for BANDIII (174 - 225 MHZ) trunking frequency band, and the transmission on private or public control information channels is conducted in FFSK mode, which, however, is also applicable to other frequencies and other modulation modes. Besides, it is a kind of public signaling with many manufacturers using the standard manufacturing equipment. In this case, it has benefited users a lot: more options in the device configuration and more convenient for users to expand and network, etc. in the future.
Applicability: The signaling can be applied both in small systems of the single base station and large network systems of more base stations; it has no much limitation to such system equipment as channel machines and mobile stations and technically has strong compatibility, with system equipment between regions being able to vary.
Complete functionality: The standard presents the full functions: in addition to the basic function such as group call necessary for dispatch, other functions such as selective call, data call, state information, all call, inclusive call, wired/wireless switch and callback, roaming, etc. are all designed to undergo a rigorous signal transmission process, and manufacturers and the users can choose functions according to their own needs.
Much room for development, user autonomy, and full guarantee for flexibility: The definitely stated code words in the signaling are only part of the available encoding and there are a lot of code words not defined so as to facilitate the future additional new functions and the users’ demand for different parameters. For example, if there are only two kinds of defined information in the status information, other 30 kinds of information are self-defining information; there are also a lot of spare codes and reserve codes in the address code words.
Suitable for popularization: The format is clear and easy to understand due to the fact that the signaling between base stations and mobile stations in the up-link and down-link control channel is transmitted in a way similar question-and-answer.
High communication reliability: Highly efficient error-correction includes using 15 BCH (63, 48) cyclic code + 1 bit parity check bit, with strong error correction ability, high reliability, and convenience for computer processing.
High system capacity: The maximum capacity for each system can accommodate 1,036,800 user numbers, 1,024 channel numbers, 3,2768 system identification numbers. In 1998, China's Ministry of Public Security promulgated the GAT, 176-1998, the Specification for Police Automation Level, Public Security Mobile Radio Communication Network, which stipulates that the MPT 1327 signaling format and code word structure be used and CPS technology specification be used for the user number.
At present, most of the trunking communication systems used by China's public security industry follow the MPT 1327 technical specification to construct the local public security 350 million wireless private networks in provinces and cities, with tens of thousands of existing analog base stations, about 16,000 analog trunking channels, and more than 1 million analog trunking terminals.
