Specifications

General 9
Combination of Data and Voice Channel Assignments
The handset supports both a and b/g, and it is recommended to have the data and voice traffic on
different bands, but not necessary have data on the -a band.
Depending on the existing data and/or voice network, and choice of new installation preferences,
the WLAN can be set up as follows, see tables below:
Legacy Network Not Using Any 802.11n APs
Customer Is Running Dual Radios a/b/g APs
b/g a Comment
Customer is running single radio APs. Most vendors single radio APs are using the b/g band.
Data/Voice - Due to the limited amount of channels available, any WiFi device must
share the airtime. Since voice requires a steady access to the media,
it is important to minimize the impact of the other devices in the WLAN
by changing the randomness of getting access to the channel.
Standard 802.11 implementation does not support any type of admis-
sion or congestion control; data is served to clients on a “best effort“
basis. The adoption of WiFi alliance's WMM specification will help, but
not solve all of the problems with admission/congestion control.
If data clients must operate in the same band as handsets, they must
be Wi-Fi Multimedia (WMM) compliant and support 802.11g. Any
802.11b only clients will reduce the overall performance and is not rec-
ommended to use.
If any legacy b/g-client causes heavy traffic or does not support WMM
(QoS), this device should possibly be phased out, be replaced with
more modern equipment and moved over to the a-radio band.
b/g a Comment
Data (b-radio) Data + Voice This scenario is common with older APs that use only 
b-radio in the 2.4 GHz band.
Sharing the bandwidth for data and voice on the a-band is essen-
tially the same as for the b/g radio. Since the bandwidth is shared
by the two traffic types, WMM shall be used.
This leaves the b-radio free for any legacy clients like bar-code
scanners. Most bar-code scanners send little amounts of data.
There are more non-overlapping channels to choose from in the 5
GHz band, but special considerations must be taken to plan for the
limitations of the available channels due to the use of radars in the
same band. (See Section , “802.11a Radar Protection, Dynamic
Frequency Selection (DFS)”, on page -13.)