Cisco CISCO1005-CH Deployment Guide - Page 22

Determining Deployment Requirements Deployment Building Type Identifying the building type and its RF characteristics is critical in determining how many Cisco Radios will be needed. The following table shows three basic building types that are common in the enterprise market. If the building does not fall into one of these categories then some amount of professional service may be needed. Table 2 Building Type Building Type Description Typical Office Space This is the most common enterprise building. This type of building consists of large open cubicle areas with walled offices and conference rooms. Drywall Office Space This type of building consists of mostly offices with dry wall characteristics. Brick/Concrete Walled Office Space This type of building consists of concrete or brick walls for both exterior and for interior office space. Old buildings found on college campuses are good examples of this type of building. Other There are some buildings such as sports arenas and stock exchanges that do not fit into one of the typical categories. These buildings typically require some special consideration or professional service. Building Homogeneity If the building does not have similar RF characteristics throughout the coverage area, the coverage area needs to be divided into areas with similar characteristics and the design process repeated for each area. Average Client Throughput The desired average user throughput is 1 Mbps to 18 Mbps. Average client throughput is related to 802.11 protocol and signal strength, and thus Cisco 1000 series lightweight access point density. In terms of protocol, 802.11b can support an average user throughput of up to 6 Mbps and 802.11a and 802.11g can support a typical average user throughput of up to 20 Mbps with reasonable Cisco 1000 series lightweight access point densities. Generally, the stronger the signal, the higher the client throughput. However, as shown in the figure below, there is a point above which a stronger signal does not increase client throughput. For 802.11b networks, this point is typically -75 dBm, above which average client throughput is 5 to 6.5 Mbps regardless of increase in signal strength. For 802.11a networks, this point is typically between -50 dBm and -60 dBm, above which average client throughput is 24 to 30 Mbps regardless of increase in signal strength. Note that for 802.11a, the range over which the average client throughput improves is between -80 dBm and -50 dBm. Deployment Guide: Cisco Aironet 1000 Series Lightweight Access Points 4 78-17279-01