Interference with Other Users

Overview

Wi-Fi is governed by rules embodied in Federal law, in a document people refer to informally as 'Part 15.' Technically, this document is 'Part 15 of Title 47 of the Code of Federal Regulations,' and it's the rules and regulations imposed by the Federal Communications Commission (FCC) on unlicensed use of the radio spectrum. Devices that fall under Part 15's jurisdiction include microwave ovens, shortwave diathermy medical devices, cordless phones, low-power 'walkie talkie' 2-way radios, and of course, 802.11 wireless networking gear.

What I want to do here is walk you through some of the jargon, regulations, and issues that you may have to confront as Wi-Fi users. The burden of following the rules mostly falls on equipment manufacturers, unless you begin setting up high-gain antenna systems or in some other way boost the effective power of your Wi-Fi signals. And even if you follow Part 15's rules to the letter, there may be issues involving interference, both to your network and from your network, which may not be easy to understand, much less solve. Knowing where you stand in terms of government regulations may prove helpful in working out difficulties as a citizen in the greater Wi-Fi community.

Part 15 itself is an immense body of government legalese, and until you have some practice reading government regulations, it's hard to pick out the portions of the law that apply to ordinary Wi-Fi operations. In this topic I'll summarize the most significant points. One thing to keep in mind is that if you use Wi-Fi equipment unmodified and as it was intended to be used, there's almost nothing in the law that you need to know. It's the technical enthusiast who works with antennas and broad-ranging, outdoor installations who has to keep certain restrictions and limits in mind.