Mobile phone development Combat 4--GSM System composition 1

System composition

GSM (Global System for Mobile communication)the network structure of the global mobile communication system, from the physical entity, mainly includes: Mobile terminal,BSSsubsystems andMSSsubsystems, and other parts. Mobile Terminals andBSSthe subsystem passes the standardUmWireless interface Communication,BSSSubsystem andMSSthe subsystem passes the standardAinterface Communication.

 Mobile Station (MS)

The mobile station is a public GSM The device used by the user in the mobile communication network is also the user can directly contact the entire GSM the only device in the system. The types of mobile stations include not only handheld stations, but also car and portable stations. With the GSM Standard Digital handheld station further small, lightweight and increase the development trend of functions, handheld users will occupy a large part of the entire user.

in addition to access via wireless interfaceGSMthe system's usual wireless and processing functions, the mobile station must provide the interface with the user. For example, the microphone, speakers, display, and keys needed to complete a call call. or provide an interface to some other terminal equipment. For example, the interface between a personal computer or a fax machine, or both of these interfaces. Therefore, depending on the application and service situation, the mobile station can be a separate mobile terminal (MT), handheld, on-board or by mobile terminals (MT) directly with the terminal equipment (TEThe fax machine is connected or is made up of a mobile terminal (MT) via the relevant terminal adapter (TA) and terminal equipment (TE) are connected to each other. These are categorized as one of the important components of the mobile station--mobile devices.

Another important component of the mobile station is the user identification module (SIM), it is basically a matchISOStandard of"Wisdom"Card, itcontains information about all users and certain wireless interfaces, including authentication and encryption information. UseGSMstandard mobile stations need to be plugged inSIMonly when handling abnormal emergency calls, the card can beSIMoperation of the mobile station in case of a card. SIMthe application of the card makes the mobile station not tied to a user in a fixed way, soGSMsystem is throughSIMcard to identify mobile phone users, which lays the foundation for future personal communications.

MT : Mobile Terminal TA : Terminal Adapter TE : Terminal Equipment

BSS subsystem

base station subsystem BSS for plmn The fixed and wireless portions of the network provide trunking, On the one hand BSS communicate directly with mobile station via wireless interface, on the other hand Span style= "font-size:12pt" >BSS mss msc 500m --35km Span style= "font-size:12pt".

Base Station Subsystem BSS can be divided into two parts. BTS, which is connected to the mobile station via wireless interface,and the base station controller (BSC) connected to the mobile switching center, is responsible for wireless transmission ,BSC is responsible for control and management.

aBSSsystem consists of aBSCwith one or moreBTScomposition,BSSA subsystem can be made up of multipleBSCand theBTScomposition. One base station controllerBSCaccording to traffic needs can control dozens ofBTS. BTScan be directly related toBSCand can also be connected via a base station interface deviceBIEwith the remoteBSCconnected. The base station subsystem should also include code converters (TC) and sub-multiplexing devices (SM).

Mobile phone development Combat 4--GSM System composition 1