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Wireless LAN Design Guide for High Density
Client Environments in Higher Education
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802.11 and Scalability: How much bandwidth will a cell provide?
To scale 802.11 networks to reliably deliver consistent bandwidth to a large number of users in close proximity, it is important to
examine certain WLAN fundamentals under reasonably ideal conditions. Once the rules are understood, the ways to manipulate
them to maximum advantage will be presented.
examine certain WLAN fundamentals under reasonably ideal conditions. Once the rules are understood, the ways to manipulate
them to maximum advantage will be presented.
In real WLANs, the actual application throughput is what matters to the end user, and this differs from the signaling speed. Data
rates represent the rate at which data packets will be carried over the medium. Packets contain a certain amount of overhead
that is required to address and control the packets. The application throughput is carried as payload data within that overhead.
Table 2 shows average application throughput by protocol under good RF conditions.
rates represent the rate at which data packets will be carried over the medium. Packets contain a certain amount of overhead
that is required to address and control the packets. The application throughput is carried as payload data within that overhead.
Table 2 shows average application throughput by protocol under good RF conditions.
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Are 802.11n Data Rates Dependable?
Today, many clients are 802.11n ready and this can provide throughput and efficiency increases in a high-density deployment.
Most WLANs, however, will support a mix of client protocols. Evaluating the historic average client mix in a WLAN is possible by
either looking at the WLAN controller graphical user interface (GUI) or at Cisco Wireless Control System reports and using this
historic mix of information for planning purposes. Unless the WLAN is very unique, most environments will likely be dealing with
a diverse mix of clients and protocols for the near future. Consider that other factors, such as the number of connections, can
also be expected to vary over time and for these reasons it is often a best practice to build in some buffer to smooth the long
term results. The raw speed advantage of 802.11n high throughput (HT) rates is impressive and boosts the overall efficiency and
capacity of the design by permitting more users or higher speeds to be realized on the same channel. Figure 4 shows mixed
client protocol capacities for a given cell.
Most WLANs, however, will support a mix of client protocols. Evaluating the historic average client mix in a WLAN is possible by
either looking at the WLAN controller graphical user interface (GUI) or at Cisco Wireless Control System reports and using this
historic mix of information for planning purposes. Unless the WLAN is very unique, most environments will likely be dealing with
a diverse mix of clients and protocols for the near future. Consider that other factors, such as the number of connections, can
also be expected to vary over time and for these reasons it is often a best practice to build in some buffer to smooth the long
term results. The raw speed advantage of 802.11n high throughput (HT) rates is impressive and boosts the overall efficiency and
capacity of the design by permitting more users or higher speeds to be realized on the same channel. Figure 4 shows mixed
client protocol capacities for a given cell.