This is a guest post from Rick Steiner. He’s a Senior Systems Engineer for Airopath, a leading Wireless System Integrator based in Seattle, WA. He has over 25 years in the telecommunications industry with over 15 years designing, implementing and troubleshooting Wireless networks for a variety of clients across diverse verticals in Manufacturing, Distribution, Industrial, Medical, Education, Retail and Office Environments. He holds many certifications from various sources within the industry including Cisco, Aruba, and CWNP.
No matter what term any particular vendor uses to title it, the automatic radio management features found on controllers today are very appealing especially when your IT staff is overworked.
Offloading certain tasks such as AP power level and channel assignments to an automated responsive system, the “set it and forget it” mentality, offers benefits that are easily seen when compared to having to perform manual changes to the system. But I am seeing a trend that can no longer be maintained when it comes to implementing a WLAN system with the default settings applied.
In today’s WLAN markets there is an emphasis on using the 5GHz space – rightly so due to the several benefits that are obtained from the increased numbers of channels, the ability to perform channel bonding, the smaller potential with outside interference, and more. When implementing such a system, however, typically the number of AP units increase and their overall spacing gets closer in order to support the physical changes experienced when moving from 2.4GHz to 5GHz, most notably higher attenuation. Often this introduces challenges to the environment that weren’t experienced before like co-channel interference in the 2.4GHz space brought on by this closer physical placement.
Additionally, many radio management systems rely on listening to the AP-to-AP signal strength and measurement factors as their only or primary resource for determining AP settings. When differing physical environments being controlled by a signal controller unit such as office space, high ceiling warehouses, and outdoor locations are included as part of the algorithm used to determine these settings automatically, customers experience areas where client devices have troubles within one type of physical space versus not having issues within the others.
Since many of my clients assume the defaults to be the best “one size fits all” solution for these variations they leave all these settings within their controllers alone and do not perform any type of tuning to the system. In an underutilized environment this usually does not present an issue since the lack of utilization masks many issues that are encountered. But now that several of these systems are being tested with the influx of devices and reliance on wireless as the main avenue to the access layer any hidden issues become glaringly troublesome when the system is operating at a higher capacity.
It is for these reasons that the defaults for the automatic radio management settings are no longer acceptable when deploying a WLAN system. Tuning minimum and maximum power limits, mandatory and supported data rates and even the dB levels the AP units use to evaluate their settings are key to a successful deployment especially with diverse environments being covered by only one controller. Utilizing features like AP groupings and radio profiles that are part of the controller software help to narrow down specific settings that can be applied to the different situations that these AP units are deployed within. By breaking up deployments into logical sections or groups where the same conditions can be applied, the system can evaluate each subset appropriately and have a much better chance to “automagically” set the system up for success.
To help understand what is occurring within the environment and to better facilitate modifying the automatic settings appropriately, an RF validation of the network should be performed. RF Validations come in different forms but most will include a coverage validation or “heat map” showing signal strengths as received by a client device and a spectrum analysis of the RF or Layer 1 to identify potential interference and bandwidth utilization at a minimum. Additional checks can also include verification of controller configurations and settings in accordance with best practices and recommendations from the manufacturer or a wireless professional based upon your implementation goals and usage.
Leveraging the knowledge and experience of wireless professionals through the use of RF validations and configuration verification services will give you the information needed to tune your controller appropriately. This means happy users, less trouble tickets and more time for your already overworked IT support staff to work on other issues than spending time manually tuning the system reactively.
This is not going to resolve everything but using the tools available you can increase the odds of success for your WLAN deployment.