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USERS GUIDE
www.auroramm.com
Wi-Fi channel selection
Wireless communication signals travel over the air. As a result, two devices transmitting at the same time, on
the same frequency, and within range of one another, will disturb each other. When the interference caused by
other devices is too strong, the packets transmitted by the Wi-Fi transmitter get so distorted that they are no
longer correctly understood by the receiver, and as a result these packets must be retransmitted. This causes a
decrease in the actual data rate achieved between the transmitting and the receiving Wi-Fi devices.
To limit the effect of interference between Wi-Fi devices, the 802.11 standard makes use of the CSMA / CA and
Clear-Channel Assessment (CCA) algorithms. Before sending a packet, the device checks whether another
transmission is currently going on. If this is not case, the device can use the channel and sends some packets.
Otherwise, the device will do a random back-off and retry to access the channel after a short period of time.
Even with the use of the CSMA/CA and CCA algorithms, the presence of too many Wi-Fi devices on the same
channel will have a negative impact on the maximum achievable data rate. Moreover, these algorithms are
inefficient against interferences coming from non Wi-Fi devices or from Wi-Fi devices operating on
overlapping channels. Therefore, it is strongly recommended to select a Wi-Fi channel with little to no
congestion.
Site survey
Ideally, the selection of the Wi-Fi channel should be made after conducting a wireless site survey. This site
survey maps out the different sources of interference and the active RF systems.
Based on the results from the site survey, the least occupied channel can be found and selected for each
meeting room. The Wi-Fi Analyzer includes two modes:
Simple Mode
(to deeply check one Wi-Fi hotspot) and
Expert Mode
(to check the Wi-Fi spectrum signal strength).
Generic configuration rules
In case no site survey can be made, the following rules of thumb should allow for a correct configuration:
The TS-100 access point in a particular meeting room should not re-use a Wi-Fi channel that overlaps with
one of the channels used in the corporate WLAN infrastructure. Ideally, at least two channels in the
corporate WLAN should be reserved exclusively for TS-100. In the case that many TS-100 systems are