Polycom H340 - Manual (Page 8)

8
© 2010 Polycom, Inc. All rights reserved. POLYCOM ® , the Polycom “Triangles” logo and the names and marks associated with Polycom’s products are trademarks and/or service marks of Polycom, Inc.
and are registered and/or common law marks in the United States and various other countries. All other trademarks are property of their respective owners. No portion hereof may be reproduced or
transmitted in any form or by any means for any purpose other than the recipient’s personal use without the express written permission of Polycom
Deploying SpectraLink e340, h340 and i640 Wireless Telephones BEST PRACTICES GUIDE
October 2010
required levels will provide an adequate buffer for these propagation challenges, enabling a more reliable and
consistent level of performance with low retry rates.
2.2 Access Point Configuration Considerations
There are several fundamental access point configuration options that must be considered prior to performing a site
survey and deploying a voice-capable WLAN infrastructure. In general, adjacent APs in three dimensions (above,
below and beside) must use different non-overlapping radio channels to prevent interference between them.
This document does not cover all issues or considerations for WLAN deployment. It is strongly recommended that
Polycom Professional Service, or another suitable professional services organization, with wireless voice deployment
experience be engaged to answer additional questions about configurations that may affect voice quality or wireless
telephone performance. In addition, VIEW Configuration Guides for WLAN infrastructure, which are available from
the Polycom web site, should be followed closely.
2.2.1 Channel Selection
The 802.11b standard provides for three non-interfering, non-overlapping frequency channels - channels one, six
and eleven in North America. Access points within range of each other should always be set to non-interfering
channels to maximize the capacity and performance of the wireless infrastructure. Figure 2 illustrates the correct
deployment methodology for 802.11b deployments.
Figure 2 - 802.11b Non-interfering Channels with Overlapping Cell Coverage
If adjacent access points in three dimensions (above, below or beside) are set to the same channel, or utilize
channels with overlapping frequency bands, the resulting interference will cause a significant reduction in the
network performance and throughput, and will degrade overall voice quality. A space of twenty five MHz, or 5
channels or greater should be used to configure neighbor APs for non-interfering channels Figure 3 represents the
2.4 GHz frequency range, indicating the overlap in channel frequencies.