Networking / Beginners

Broadcasting Frequency

One of the biggest issues with wireless communication is the potential for interference from other wireless devices. To solve this, different wireless devices must operate in specific broadcasting frequencies. Knowing these wireless frequency ranges will assist you in troubleshooting interference issues from other devices operating in the same wireless band. The original 802.11 standards use the 2.4-GHz frequency. Later standards use either 2.4-GHz or 5.0-GHz frequencies.

Broadcasting Methods

The original IEEE 802.11 wireless Ethernet standard defined methods by which devices may communicate using spread-spectrum radio waves. Spread-spectrum broadcasts data in small, discrete chunks over the different frequencies available within a certain frequency range.

802.11 defines three different spread-spectrum broadcasting methods: direct-sequence spread spectrum (DSSS), frequency-hopping spread spectrum (FHSS) and orthogonal frequency- division multiplexing (OFDM). DSSS sends data out on different frequencies at the same time, while FHSS sends data on one frequency at a time, constantly shifting (or hopping) frequencies. DSSS uses considerably more bandwidth than FHSS-around 22 MHz as opposed to 1 MHz. DSSS is capable of greater data throughput, but it's also more prone to interference than FHSS. OFDM is the latest method and combines the multiple frequencies of DSSS with FHSS's hopping capability. The 802.11 wireless networking implementation used DSSS and later OFDM.

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