With the expansion of the daily business of public security organs, the application of wireless communication system on the diversity of the proposed higher requirements, as the daily use of the cluster network in some special scenes can not meet the needs of public security business. Therefore, the demand for public security wireless emergency communications backup network is gradually referred to an urgent construction of the height.
Public security wireless emergency communication backup network as the daily routine service communication system backup and supplement, in large security activities to achieve emergency command and dispatch communications. The city is increasingly prosperous and its scale is expanding. The public security system may encounter a large number of security activities different from the daily work, such as the guarding work of important leaders or foreign guests, the security activities of large-scale rallies and the sudden event rescue, etc., in the public security departments to deal with similar emergencies, the demand for communication services have a certain degree of particularity.
The following are the same as the "Public security wireless emergency communications backup network “requires a wide range of coverage, call clear, stable and reliable. The cluster communication system is based on the daily police work development, complex network construction, limited signal coverage, the application of large user volume grouping applications, high construction costs, the need for more frequent frequency resources, so the cluster system can not be appropriate and emergency communications backup network Construction.
The same frequency of the same network for a wide range of wireless coverage, the number of users of the wireless communications command and dispatch network, the network structure is simple, network construction costs and relatively low cycle, while saving the frequency of public resources, is the most suitable construction mode of public security wireless emergency communication backup network.
As shown in the figure, the co-frequency broadcasting system is a wireless communication device that uses a central link base station to connect a plurality of co-broadcasting base stations using the same pair of frequency calls. The same frequency of the same network system issolve the large area within the scope of the formation of efficient wireless communication network.
(1) Communication coverage: a number of inter-base station interconnection, covering the sum of each station;
(2) With the frequency of broadcasting, saving frequency resources: multi-station sharing a pair of frequencies, to solve the problem of frequency resource bottlenecks;
(3) User automatic roaming: walkie-talkie switch base station without changing the channel, automatic roaming;
(4) Walkie-talkie simple operation: walkie-talkie using conventional
(5) Overlapping coverage area interference: When multiple base stations simultaneously cover a region, will have overlapping interference problem, the same frequency broadcast system using related technology can eliminate these interference, get a clear voice quality.
(6) Computer-aided scheduling applications: the whole network can be computer management and auxiliary scheduling.
(7) Extended mobile video applications: the same frequency broadcast base station to install mobile video receiver equipment and shared base station shared E1 link transmission.
(8) The use of conventional walkie-talkie, to protect the early radio investment: the existing cluster walkie-talkie switch to the conventional mode can be used in the same frequency broadcast network. Taking into account the various levels of cities in the communication coverage and urban area on the different, public security wireless emergency communications backup network will be divided into provincial capital city, city, county three categories, respectively, to develop emergency network construction planning.