To best understand the RF environment both pre and post-deployment of wireless infrastructure, it is strongly encouraged to perform site surveys and make changes based on the result. This article outlines some tools and best practices for performing site surveys with an MR wireless deployment.
Cisco Meraki Access Points can be configured to broadcast a dedicated SSID for Site Surveys, without the access point requiring an active Internet connection to the cloud controller. Clients can then connect to this SSID in order to conduct passive or active site surveys. An MR in site survey mode will be denoted by a blinking green status LED on the unit.
The following instructions outline how to enable site survey mode on an MR access point:
Optional: After the site survey SSID has been enabled, the channel and power usage of the survey SSID can be manually set on a per-radio basis.
After setting the access point for Site Survey mode, the AP starts broadcasting an open SSID, "site_survey-<Mac address of the AP>" as shown below:
While in Site Survey Mode, the access point will no longer be able to serve connectivity for any wireless clients and can be used only for site survey purposes. The access point is now ready to be used at the location where the site survey needs to be performed. The AP can be powered using a PoE injector or a PoE switch and does not need to have wired connectivity to the internet.
The survey SSID being broadcast from the access point can now be used to perform active/passive site surveys using any professional site survey tool. Examples include:
These tools have the coverage patterns for Cisco Meraki access points built-in, enabling predictive survey functionality as well.
Site surveys should be performed using the same Cisco Meraki access point model as that would be used in the customer infrastructure.
Ensure that the AP is not mounted close to any metal or concrete walls that can contribute to heavy attenuation of RF signals.
Have a blueprint of the location being surveyed handy, to document the signal readings, data rates and record any interference sources during the survey.
With so many variables that can affect the RF propagation of an AP and in turn affect the client performance and roaming behaviors, it is always recommended to have an onsite site survey performed to ensure optimal coverage and performance. Those who do not have access to a site survey tool can still leverage the statistics provided on the local status page on the access point. Admins can see signal-to-noise ratio for the client that is connected to the survey SSID. A classic approach is to design for a voice-grade network which uses cell edges around -67dBm and a consistent SNR (Signal to Noise Ratio) of 25dB or more. This is generally sufficient for normal data clients, while allowing for VoIP infrastructure to be introduced later.
The local status page also provides info about channel utilization on current channels. It also describes the amount of time that both WiFi and non-WiFi (interference) are present on each of those channels, and provides a list of all the other access points (Meraki and non-Meraki) that it can hear on the same channel (under the Neighbors tab). These statistics can help provide a good estimate of the coverage provided by the access point, along with any interference that may be present across those channels.
The following article outlines how to perform a full site survey, in-depth, and is strongly recommended for additional guidelines:
Please refer to the following articles for additional information about wireless behavior and troubleshooting: