Chapter 24 - Wi-Fi Range: Impact on Data Rates, Coverage, and Capacity

Summary

Introduction

In the wired Ethernet environment, distance limitations and data rates are fully defined. This is a result of specific transmitter and receiver standards and a controlled media, i.e. the wire. A controlled media (such as wired Ethernet) is the key point here because a defined data rate can be maintained over a specified distance.

Things change significantly with wireless communications and once again the key is a controlled media, or lack there of. Physical media will always return fixed results; distances and data rates can vary greatly when using Radio Frequency (RF) as the transmission medium. It is because of this “fluid” nature of RF that deploying a Wi-Fi network can be fraught with issues, miss met expectations and a generally unhappy group of users.

It is also important to note the range, or the coverage area of a Wi-Fi Access Point is impacted by several items including data rate, capacity, interference and other variables so there are many things to contend with when going wireless.

However, with an understanding of a few basic principles such as antenna design and gain along with some information on items that impact a Wi-Fi network, you will be in a position to better create a higher performing, longer range wireless network.

Defining Range and Coverage

Before the RF signal leaves the antenna, a digital signal processor will convert the data stream into complex symbols that carry it over the air as it is transmitted.