Network Card User Manual

1-9
Cisco Aironet Wireless LAN Adapters Installation and Configuration Guide for MS-DOS
OL-1744-02
Chapter 1 Overview
Coverage Options
Coverage Options
The system architecture options of the wireless station and access points provide for a variety of
coverage alternatives and flexibility. The system can be designed to provide a wide coverage area with
minimal overlap (Figure 1-5) or coverage with heavy overlap (Figure 1-6). The latter improves system
performance and protection against downtime in the event of a component failure.
Minimal Overlap Coverage
By arranging the access points so that the overlap in coverage area is minimized, a large area can be
covered with minimal system cost (Figure 1-5). The total bandwidth available to each mobile station
depends on the amount of data each mobile station needs to transfer and the number of stations located
in each cell. Seamless roaming is supported as a mobile station moves in and out of range of each access
point, thereby maintaining a constant connection to the wired LAN. Each access point (and adapter) must
be configured with the same SSID to provide the roaming capability.
Figure 1-5 Minimal Overlap Coverage Option
Heavy Overlap Coverage
By arranging the access points so that the overlap in coverage area is nearly maximized, a large number
of mobile stations can be supported in the same wireless infrastructure (Figure 1-6). However, units in
overlapping coverage areas on the same frequency will detect adjacent cell traffic and delay
transmissions that would cause collisions. This reduces the aggregate radio system throughput. Heavy
cell overlap is not recommended for maximum system throughput. Due to the redundancy in coverage
overlap, system access is not lost if an access point fails. If the access point fails, the station
automatically roams to an operational access point. With this system architecture, all access points and
PC Card units must be configured with the same SSID.
Wired LAN
65521