11.5.1 Wireless Networking

Learn how wireless networks operate and the standards behind them.

There are a lot of things behind wireless networking standards.

Wireless Communication

The FCC has jurisdiction over the specific radio frequencies that can be used by wireless networking devices. There are two frequencies, 2.4 GHz and 5 GHz. 2.4 GHz has shorter, wider waves, which means that they can travel farther but the data transfer speeds are a bit slow. 5 GHz have narrower, longer waves, meaning that they can't travel as far but the data transfer speeds get a boost compared to 2.4 GHz.

2.4 GHz and 5 GHz are considered unlicensed frequencies, meaning that you don't need permission from some government entity to use these frequencies. These unlicensed frequencies cannot exceed a certain EIRP limit defined by the FCC. The issue that arises from this is that interference might result from other devices using the same frequency. To get around this, we finetune our frequency to use a channel, or a smaller range of 20 MHz. For example, a router using Channel 11 might be running on the 2.45-2.47 GHz range. However, even then we might run into interference due to devices using adjacent channels to ours.

The only non-overlapping channels in the 2.4 GHz range are Channels 1, 6, and 11. However, since they don't overlap, every device will want to use them. This results in those channels being crowded, resulting in much slower network speeds.

Compared to 2.4 GHz, the 5 GHz range 45 channels to choose from, with 24 of them being exclusive and non-overlapping.

802.11 Standards

All wireless devices using 802.11 standards are backwards compatible with each other, it's just that if the versions are mismatched, they'll operate at the lowest speed supported.

Long-Range Wireless

For long-range wireless connections, you're forced to use a licensed frequency, typically either 900 MHz or 3.65 GHz (WiMAX runs on 3.65 GHz).

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