17 lines
844 B
Markdown
17 lines
844 B
Markdown
# Channel access method for shared mediums
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## Time Division (TDMA)
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assigns time-slots to each transmitter in which they are allowed to send.
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Dynamic slots can be used to adjust for variable bit-rate streams.
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## Frequency Division (FDMA)
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assigns parts of the total bandwidth into multiple channels.
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## Code Division (CDMA)
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Uses orthogonal codes assigned to transmitters, allowing them to send on the same time and frequency.
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Both TDMA and FDMA need guard intervals that remain relatively fixed with rising numbers of participants.
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CDMA in comparison is directly limited by the Shannon-Hartley channel capacity,
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meaning that an increased noise floor introduced by an increasing number of transmitters results in temporarily decreased call quality,
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whereas other channel division methods would usually result in permanently decreased quality. |