Руководство По Проектированию для Cisco Cisco Aironet 350 Mini-PCI Wireless LAN Client Adapter
3-12
Enterprise Mobility 4.1 Design Guide
OL-14435-01
Chapter 3 WLAN Radio Frequency Design Considerations
Planning for RF Deployment
Figure 3-4
Planning Tool
Different Deployment Types of Overlapping WLAN Coverage
How much overlapping WLAN coverage you set in your wireless network depends on the usage, though
with limited exceptions, all designs should be deployed to minimize retransmission and data rate
shifting. Wireless networks can be deployed for location management, voice, or data-only networks, or
a combination of all three. The difference is in the pattern in which the APs are laid out, and the amount
of RF overlap in the coverage area. When planning a WLAN deployment consideration should be given
to future uses of the WLAN deployment.
with limited exceptions, all designs should be deployed to minimize retransmission and data rate
shifting. Wireless networks can be deployed for location management, voice, or data-only networks, or
a combination of all three. The difference is in the pattern in which the APs are laid out, and the amount
of RF overlap in the coverage area. When planning a WLAN deployment consideration should be given
to future uses of the WLAN deployment.
Converting a WLAN deployment to support additional services beyond a data-only deployment is not
simply a matter of adding APs; it can require an additional site survey and the possible relocation of
existing APs.
simply a matter of adding APs; it can require an additional site survey and the possible relocation of
existing APs.
Data-Only Deployment
Data-only deployments do not require a large amount of overlap. This is because 802.11 clients respond
to a lower signal from a nearby AP by stepping down their rate and taking a longer time to transmit. The
required overlap is determined by the WLAN data rate requirement described in
to a lower signal from a nearby AP by stepping down their rate and taking a longer time to transmit. The
required overlap is determined by the WLAN data rate requirement described in
. For data-only networks, the rule of thumb for separation of APs is typically
120–130 feet, but, when making your estimation for AP separation, remember to factor in objects that
affect RF coverage, such as wall densities, machinery, elevators, or even wide-open space with steel
cages, because your results can vary depending on the RF environment. RRM has been developed for
this type of deployment and it is very useful for controlling the RF coverage.
affect RF coverage, such as wall densities, machinery, elevators, or even wide-open space with steel
cages, because your results can vary depending on the RF environment. RRM has been developed for
this type of deployment and it is very useful for controlling the RF coverage.