cellular communications
CELLULAR COMMUNICATIONS
PAPER PRESENTED BY D. Jyothsna Jyothsna_magical@yahoo.co.in G. Anusha anusha_gollapudi@yahoo.co.in
ABSTRACT
A cellular mobile communications system uses a large number of low-power wireless transmitters to create cells—the basic geographic service area of a wireless communications system. Variable power levels allow cells to be sized according to the subscriber density and demand within a particular region. As mobile users travel from cell to cell, their conversations are handed off between cells to maintain seamless service. Channels (frequencies) used in one cell can be reused in another cell some distance away. Cells can be added to accommodate growth, creating new cells in unserved areas or overlaying cells in existing areas.
Now we are going to discuss about -
1.Mobile communication principles
2.Mobile telephone system using the cellular concept
3.Cellular system architecture
4.North American analog cellular system
5.Cellular system components
6.Digital systems
1. Mobile Communications Principles
Each mobile uses a separate, temporary radio channel to talk to the cell site. The cell site talks to many mobiles at once, using one channel per mobile. Channels use a pair of frequencies for communication—one frequency (the forward link) for transmitting from the cell site and one
Figure 1. Basic Mobile Telephone Service Network frequency (the reverse link) for the cell site to receive calls from the users. Radio energy dissipates over distance, so mobiles must stay near the base station to maintain communications. The basic structure of mobile
PAPER PRESENTED BY D. Jyothsna Jyothsna_magical@yahoo.co.in G. Anusha anusha_gollapudi@yahoo.co.in
ABSTRACT
A cellular mobile communications system uses a large number of low-power wireless transmitters to create cells—the basic geographic service area of a wireless communications system. Variable power levels allow cells to be sized according to the subscriber density and demand within a particular region. As mobile users travel from cell to cell, their conversations are handed off between cells to maintain seamless service. Channels (frequencies) used in one cell can be reused in another cell some distance away. Cells can be added to accommodate growth, creating new cells in unserved areas or overlaying cells in existing areas.
Now we are going to discuss about -
1.Mobile communication principles
2.Mobile telephone system using the cellular concept
3.Cellular system architecture
4.North American analog cellular system
5.Cellular system components
6.Digital systems
1. Mobile Communications Principles
Each mobile uses a separate, temporary radio channel to talk to the cell site. The cell site talks to many mobiles at once, using one channel per mobile. Channels use a pair of frequencies for communication—one frequency (the forward link) for transmitting from the cell site and one
Figure 1. Basic Mobile Telephone Service Network frequency (the reverse link) for the cell site to receive calls from the users. Radio energy dissipates over distance, so mobiles must stay near the base station to maintain communications. The basic structure of mobile