Re: Wireless LAN Deployment

rossdm · ‎06-11-2003

We are currently in the process of deploying a wireless LAN. We are considering using the AP 1200. However our main headache lies with the overflowing of our signal outside the desired area. According to information gathered so far, it would seem that the AP 1200 is directional at 802.11b, however when upgraded (Firmware) to support 802.11a the AP 1200 becomes omni directional. To begin with, is this accurate? If it is, how can we then support 802.11b and possibly migrate to 802.11a while maintaining our directional restrictions on overflow.

cm7894 · ‎06-11-2003

One thing that will help control the signal propagation is adjusting the power settings in the AP. Often, there may be channel issues or the signal may be bleeding into unwanted areas. The ability to adjust the power settings is dependent on what power level the site was surveyed at (for example 30mW).

Antennas will also help determine the type of signal pattern. Many people use the 2.2 omni antenna, and some prefer a directional antenna such as a patch antenna. The signal with vary depending on the type and gain used. 1200’s (I believe) “may” be purchased with both A and B options. I am not sure if there is a G Cisco solution.

rossdm · ‎06-12-2003

We have been doing extensive research on this issue. Our latest findings suggest that a specific positioning of the 5-Ghz radio module (which also carries the AP Antenna) would guarantee a directional spectrum. I have been looking at the installation guides for the AP 1200 and the 5-Ghz radio module and have not been able to find any specific indication as relates to specific positions that would ensure a directional spectrum. If anyone knows about any documentation that lists and or details the specifications for obtaining a directional spectrum using the 5-Ghz radio module with the AP 1200 please direct me to it. I am very grateful. Thanks

gilmo · ‎06-17-2003

At this point 802.11a (5-Ghz ) spec does not allow the user to change the antenna. So that's the reason why manufacturers are shipping the units with no option for external antennas and therefore all 802.11a units bring omni antennas. However as an experiment you could create your own deflector, the deflector will help you to direct the signal.

rossdm · ‎06-17-2003

Thanks a whole heap guys for all your assistance. We have decided to go with 802.11b with directional patch antennas for the time being. We will look into moving to 802.11a in the future. Thanks again for the help, I really do appreciate it.