Branch : Computer Science and Engineering
Subject : Wireless Communication
Cellular System
Introduction:
The cellular system offers mobile and portable telephone stations the same service provided fixed stations over conventional wired loops.It has the capacity to serve tens of thousands of subscribers in a major metropolitan area
Major components:
- The cellular communications system consists of the following four major components that work together to provide mobile service to subscribers
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Public switched telephone network (PSTN):
- The PSTN is made up of local networks, the exchange area networks, and thelong-haul network that interconnect telephones and other communicationdevices on a worldwide basis.
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Mobile telephone switching office (MTSO)
- The MTSO is the central office for mobile switching. It houses the mobile switching center (MSC), field monitoring and relay stations for switching callsfrom cell sites to wire line central offices (PSTN). In analog cellular networks, the
- MSC controls the system operation. The MSC controls calls, tracks billing information, and locates cellular subscribers.
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Cell site with antenna system:
- The term cell site is used to refer to the physical location of radio equipment thatprovides coverage within a cell.
- A list of hardware located at a cell site includes power sources, interface equipment, radio frequency transmitters and receivers, and antenna systems
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Mobile subscriber unit (MSU):
- The mobile subscriber unit consists of a control unit and a transceiver that transmits and receives radio transmissions to and from a cell site. Three types of
- MSUs are available:
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The mobile telephone (typical transmit power is 4.0 watts)
- The portable (typical transmit power is 0.6 watts)
- The transportable (typical transmit power is 1.6 watts)