Cisco 802.11 Wireless Networking Quick Reference

Chapter 11

Tuning AP Radio Parameters

Installing and configuring an access point (AP) is generally a straightforward affair.

Plug in the unit, establish some basic configuration settings, and you are ready.

However, your environment might require you to tweak more settings for optimal

performance. For example, in an effort to conserve laptop battery power, you might

reconfigure transceivers to operate less frequently. You might also find the need to

manually set radio channels or adjust the size of frames that are broadcast and received.

Cisco APs provide a way to manage these settings.

Power Tuning

When people buy APs, they tend to purchase the unit with the most power. Although

it’s great to get the best range, there might be times when you need less, not more. For

example, you might want to minimize a signal’s interference with your neighbor’s AP.

Power management has another useful purpose—it saves battery power. Many clients

are likely installed on laptop computers and other mobile devices. By the nature of

their design, these devices aren’t generally plugged into the wall. Rather, they rely on

battery power. If the 802.11 radio uses all the battery power, these devices cannot last

long.

Managing Power Settings on the AP

The configuration steps for this section and chapter are located on the Settings screen.

This page is reached from the AP’s home page, then you click Network Interfaces

from the menu on the left. Click the radio you want to change (Radio0-802.11G for

the 2.4-GHz radio and Radio1-802.11A for the 5-GHz radio). Finally, click on the

Settings tab.

Select the power level you wish, and then click Apply at the bottom of the screen. This

portion of the Settings tab is shown in Figure 11-1.

186 Power Tuning

Figure 11-1 Within the Settings Tab You Can Manage the AP’s Transmission Power

If you enter the commands described in Table 11-1, you can also adjust the AP’s

transmit power from the CLI. Use a console to access the CLI, or connect to the AP

with a terminal program and log on with the AP’s IP address.

Table 11-1 Configuring Transmit Power

Command Description

configure terminal Enters global configuration mode.

interface dot11radio {0 | 1} Enters configuration mode for the radio

interface. The 2.4-GHz radio is radio 0, and

the 5-GHz radio is radio 1.

power local

Power levels (expressed in milliwatts [mW])

available for the 2.4-GHz radio:

{1 | 5 | 20 | 30 | 50 | 100 | maximum}

Power levels available for the 5-GHz radio:

{5 | 10 | 20 | 40 | maximum}

Sets the transmit power to one of the powers

allowed in your regulatory domain.

end Returns to privileged EXEC mode.