Cluster system and satellite communication lifting mobile communication system

Time：2020-12-31 View：

Mobile communication system is a kind of radio communication system mainly including cellular system, cluster system, AdHoc network system, satellite communication system, packet wireless network, cordless telephone system, radio paging system, etc.
The characteristics of mobile communication system include that mobile communication must use radio waves for information transmission, communication operates in complex interference environment, and the demand for mobile communication traffic is increasing day by day.

Cellular system
Cellular system is the most extensive land public mobile communication system. In a cellular system, the coverage area is generally divided into multiple cells like a cell. Fixed base stations are set in each cell to provide users with access and information forwarding services. Communication between mobile users and non-mobile users must be conducted through the base station. Base stations are generally connected to backbone switching networks mainly composed of switches through wired lines. A cellular system is a connected network. Once a channel is assigned to a user, the channel can always be used by the user. Cellular systems are generally used for voice communication.

 

Cluster System
The cluster system is similar to the cellular system and is also a connected network. It is generally a private network with a small scale and mainly provides voice communication for mobile users.

Satellite communication
The satellite communication system has the widest communication range and can provide communication services for users in every corner of the world. In this system, the satellite plays a similar function as the base station. The satellite communication system can be divided into three types according to the position of the satellite: stationary orbit, middle orbit and low orbit. Satellite communication system has the disadvantages of high cost, large transmission delay and limited transmission bandwidth.
All the above mobile communication systems need the support of wired network communication infrastructure, such as base stations, switches, satellites, etc. The establishment and operation of these facilities require a lot of manpower and material resources, so the cost is relatively high and the construction cycle is also long. Ad Hoc the network does not need the support of the base station, and the host network is established by itself. Therefore, the network establishment cost is low and the time is short. Generally, it only takes a few seconds or minutes. In the above communication system, mobile terminals do not directly communicate with each other, and mobile terminals only have the sending and receiving function and do not have the forwarding function. The Ad Hoc network consists of mobile hosts, which can communicate directly with each other, while the mobile hosts not only send and receive data, but also forward data. In addition, the mobile communication system mainly provides users with voice communication function, usually using circuit switching, and the topology is relatively stable. However, Ad Hoc networks use packet forwarding technology to provide data communication services for users, and the topology is easy to change.