Cellular

Sirindhorn International Institute of Technology Thammasat University School of Information, Computer and intercourse Technology ECS 445: Mobile Communications The Cellular Concept Prapun Suksompong, Ph.D. prapun@siit.tu.ac.th November 22, 2009 This bank bill covers fundamental cellular receiving set concepts which are at the centre of attention of providing wireless dialogue service to subscribers on the move exploitation deposited radio spectrum. Contents 1 Cellular Teleph peerless organizations 2 Frequency use 3 Cell planing with hexagonal cells 4 Co-Channel Interference 5 Trunking 6 Improving Coverage and aptitude 1 4 7 10 13 14 1 Cellular Telephone strategys 1.1. receiving set telephone governance should be structured to achieve high school susceptibility with molded radio spectrum while at the uniform beat covering very large areas. 1 1.2. Older System: Achieve a large coverage area by using a simple, high powered transmitter. ? Put BS on top of mountains or tall towers, so that it could make coverage for a large area. The next BS was so far away that interference was not an issue. Severely limit the number of users that could communicate synchronicly. Noise-limited system with few users.

The Bell alert system in New York City in the mid-seventies could only support a maximum of twelve cooccurring calls over a thousand square miles. 1.3. The number of cooccurring calls a mobile wireless system can spoil is essentially determined by the total spectral terminus allocation for that system and the heapwidth required for transmitting signals used in treatment a call. Example 1.4. Using a common running(a ) system, each channel needs to have a grad! e insigniawidth of most 25 kHz to enable su?cient audio quality to be carried, as well as allowing for a guard band between adjacent signals to ensure there are no undue levels of interference. Using this concept, it is possible to accommodate only cardinal users in a frequency band 1-MHz wide. Even if one C MHz were allocated to the system, this would enable only 4000 users...If you want to get down a full essay, order it on our website: OrderEssay.net

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