Introduction
Change the Transmitter Power Level Parameter of the Existing AP to Extend the Coverage
Resolution
You can extend the radio coverage area of an AP when you modify the transmitter power level parameter.
The transmitter power (mW) setting determines the power level of the radio transmitter. The default power setting is the highest transmit power allowed in a regulatory domain. Government regulations define the highest power level for radio devices.
Caution: The transmitter power level setting must conform to the established standards of the country in which the setting is used.
Generally, the transmitted power is reduced to limit the effect of RF interference. The reduction has a negative effect on the radio coverage. The transmitted power is directly proportional to the radio coverage area. Therefore, the weaker the transmitted power, the smaller is the radio coverage area.
If you perform a proper site survey, and remove possible sources of RF interference, you can use the highest possible transmitted power value to extend the radio coverage area.
This CLI command under the radio interface changes the transmitted power level to the maximum on an AP:
Access Point (config)# interface dot11radio 0
Access Point (config-if)# power local maximum
Use this command to set the power level to maximum. Then, check how much throughput you have, and move the power level to a lower value until you reach a high throughput rate that stays consistent. You can also start from the lowest possible power level and increase the level until you reach a consistent throughput. This is because in some cases, if you do not boost the signal to the maximum level, the throughput and signal strength can change continuously and not remain consistent.
Configuring Radio Transmit Power
Beginning in privileged EXEC mode, follow these steps to set the transmit power on access point radios:
Purpose
Step 1 | configure terminal | Enter global configuration mode. |
Step 2 | interface dot11radio { 0 | 1 } | Enter interface configuration mode for the radio interface. The 2.4-GHz radio is radio 0, and the 5-GHz radio is radio 1. |
Step 3 | power local These options are available for the 802.11b, 2.4-GHz radio: { 1 | 5 | 20 | 30 | 50 | 100 | maximum } These options are available for the 5-GHz radio: { 5 | 10 | 20 | 40 | maximum } | Set the transmit power for the 802.11b, 2.4-GHz radio or the 5-GHz radio to one of the power levels allowed in your regulatory domain. All settings are in mW. Note |
Step 4 | power local These options are available for the 802.11g, 2.4-GHz radio: power local cck settings: { 1 | 5 | 10 | 20 | 30 | 50 | 100 | maximum } power local ofdm settings: { 1 | 5 | 10 | 20 | 30 | maximum } | Set the transmit power for the 802.11g, 2.4-GHz radio to one of the power levels allowed in your regulatory domain. All settings are in mW. On the 2.4-GHz, 802.11g radio, you can set Orthogonal Frequency Division Multiplexing (OFDM) power levels and Complementary Code Keying (CCK) power levels. CCK modulation is supported by 802.11b and 802.11g devices. OFDM modulation is supported by 802.11g and 802.11a devices. Note Note |
Step 5 | end | Return to privileged EXEC mode. |
Step 6 | copy running-config startup-config | (Optional) Save your entries in the configuration file. |
Use the no form of the power command to return the power setting to maximum, the default setting.
For more information on how to change the transmitter power level parameter, refer to the Change the Transmitter Power Level Parameter of the Existing Access Point to Extend the Coverage section of WLAN Radio Coverage Area Extension Methods.
Problem Type
The signal quality varies on machine the same distance away
Products
Access point
Reference
Refer to
Configure Radio Transmit Power for more information on how to configure the power level setting on the AP section of Configuring Radio Settings
.