To achieve WLAN performance optimization, network managers and administrators must use new WLAN measurement and testing tools that are able to check network performance based on the type of applications running in the network.
Finding these tools forces network administrators to look for more innovative products beyond current vendors and testing methods.
Since these tools can be expensive, they can cost several times more.
Early wireless Lans were often designed as a rule of thumb, using an AP coverage circle, where the radius range represented the minimum signal strength.
The actual signal strength is then mapped using a site scan and measured either passively (scanning) or actively (association).
The tools used to perform the scan are manual and labor intensive; For example, one method requires testers to take two measurements in the field to collect both passive and active measurements.
It is clear that these methods do not work well on larger wireless local area networks.
More importantly, they do not reflect the actual capabilities of 802.11n and a growing variety of applications that rely on high bandwidth and low latency.
By using 802.11n, transmission rates in different directions can be controlled, and signal strength is not necessarily an acceptable indicator of application performance. Wlan performance Measurement tools Determine application requirements This is where new performance measurement tools designed specifically for 802.11n and critical mobile business applications can play a major role.
For example, the AirMagnet Survey not only uses iPerf to measure uplink and downlink performance, but it can be used for analysis to provide 802.11n recommended Settings and fast voice evaluations.
Veriwave WaveDeploy is a proxy-based site evaluation tool that generates test streams that can be sent to real client devices to measure not only TCP throughput but also Web, voice, and video \"quality of experience.\"
By testing a device with WaveDeploy, the tester can generate an overlay of the area that meets the requirements of the application.
This is determined by measurement metrics (e.g., MOS and sound jitter) for each application. Wlan Performance Optimization: Continuous client testing Optimizing WLAN performance is a complex business. These new scanning tools continue to be used after WLAN deployment to verify that performance goals have been met and to assess the impact of program adjustments and updates.
Over time, you may find that different clients have vastly different data rates and throughput, even when sending the same type of traffic from nearly the same location.
For example, where possible, a client encountering abnormally low data rates may refuse to roam to a better AP.
These \"difficult\" clients not only have low throughput, but they require more bandwidth time to send the same amount of data.
When there is a lot of competition for bandwidth usage time, every client will suffer because of this difficult client.
This is where you need to use a mobility tool such as AirMagnet WiFi Analyzer, which analyzes client roaming activity to identify troublesome clients and their actual impact on application performance (e.g., MOS score).
Regular test results using airtime fair algorithms for RF measurements are useful for fine-tuning processes, such as disabling low-data rate clients found to be causing problems, or enabling useful 802.11n options on clients. However, some performance issues are temporary and sensitive to client mix and location.
If a visitor brings a faulty device to the office, or simply tries to use the wireless LAN from a distant location, a slow client can appear that slows down other clients.
The only effective way to deal with this type of problem is to constantly measure through real-time responses.
Some wireless LAN vendors currently offer \"airtime fair\" algorithms that perform real-time RF tests and use them to automatically adjust client transmission opportunities.
For example, when Aerohive's Dynamic Airtime Scheduling is enabled, transmission opportunities are allocated based on the actual bandwidth time occupied by each client.
When a client's data rate starts to drop, faster clients get more transmission opportunities, optimizing overall throughput.
Aerohive's Performance Sentinel then closely correlates these real-time measurements with each user's needs and actual throughput goals.
If the SLA does not meet the requirements of a high-traffic client, the NOC operator receives a compliance alert. Integrating automated and segmented WLAN testing tools Finally, most organizations are integrating automated\/centralized and mobile\/segmented testing tools and methods.
For some tasks, it makes sense to utilize wireless LAN and WIPS infrastructure for continuous testing and near-real-time adjustments.
This approach is very effective in large distributed networks where regular testing is not possible.