Everyone looks for the Killer App. At 7signal, we not only found the “Killer App for Wi-Fi”, but also the “App that Kills Wi-Fi.”
It turns out that the Killer App is voice. Enterprises are starting to realize it is expensive and undesirable to make the desk phone the primary means for office communications. People want to be mobile and they want to bring and use their own device. The unified communications vendors are providing the applications for smartphones to provide the productivity features people are used to with their desktop phones.
This suits the enterprise CIOs – they want to stop paying for phones and the infrastructure required to support wired communications. In fact, the desktop phone is the last holdout to completely untether the desktop and keep the need for cabling. The enterprise can shift to one in which the WLAN is the main communications network. In addition, if the WLAN can support voice well, the need to provide mobile coverage in difficult spots goes away.
The challenge with Voice over Wi-Fi (VoWiFi) replacing the desk phone is Quality of Experience (QoE). IP phones on the desk had the same issue, but well designed and managed wired networks addressed the quality concerns. A well designed and managed WLAN can also allay any fear of migrating to a wireless-centric architecture. But an unmanaged WLAN carrying voice can exacerbate existing Wi-Fi challenges and create a poor experience for everyone. For example, voice as an application does not create a lot of bandwidth, but each conversation creates more packets and more attempts to access the shared spectrum. Many times an extra SSID is used for voice, increasing management overhead. Roaming users may also impact the processing power of WLAN access points.
None of these challenges are insurmountable when you can measure performance and understand the network. For Voice over WLAN (VoWLAN), it is imperative to have a Quality of Experience metric such as the Mean Opinion Score (MOS). MOS depends on many factors but provides a useful way to characterize the QoE:
|4||Good||Perceptible but not annoying|
An accompanying blog by Martin Varella discusses MOS and the Quality of Experience further. 7signal has long been successful in helping institutions such as hospitals where the workforce is very mobile and the WLAN carries voice and data. The MOS metric has been an important Key Performance Indicator for analyzing the network. As more enterprises move to a similar wireless-centric architecture, make sure MOS plays a role in your Wi-Fi performance management.