Users Guide

Dell PowerConnect ArubaOS 5.0 | User Guide RF Plan | 79
Overlap Factor
The Overlap Factor is the amount of signal area overlap when the APs are operating. Overlap is important if an
AP fails as it allows the network to self-heal with adjacent APs powering up to assume some of the load from the
failed device. Although there may be no holes in coverage in this scenario, there is likely to be a loss of
throughput. Increasing the overlap allows for higher throughputs when an AP has failed and allows for future
capacity as the number of users increases.
You can select a pre-determined value from the drop-down overlap menu or specify a value in the text box to the
left of the drop-down. The following table describes the available options.
Users/AP
Enter the number of users you expect to have on your WLAN in the Users text box. Enter the number of users
per AP you expect in the Users/AP text box.
The numbers entered in the these two text boxes must be non-zero integers between 1-255 inclusive.
Table 13 Design Model Radio Buttons
Radio
Button
Description
Coverage Use this option to let RF Plan automatically determine the number of APs based on desired data
rates and the configuration of your building.
The higher the data rate, the smaller the coverage area, and the more APs that are required.
Coverage is the most common type of installation.
Capacity Use this option to let RF Plan determine the number of APs based on the total number of users,
ratio of users to APs, and desired data rates.
Capacity-based coverage is useful for high capacity conference or training rooms, where the APs
could have a high volume of users.
Custom Use this option to specify a fixed number of APs.
Custom coverage is useful for deployments with a known number of APs or if you have a fixed
project budget.
Table 14 Overlap Factor Values
Overlap
Factor
Description
100% Low Use this option for buildings that contain open spaces such as warehouses.
150% Medium Use this option for most typical office environments with cubicles and sheetrock walls that have higher
WLAN user density than warehouses.
200% High Use this option for dense deployments such as buildings with poor RF coverage characteristics including
buildings with thick brick or concrete walls, lots of metal, or excess RF noise (for example, data centers).
Custom Use this option to enter a custom rate. For most office spaces, 120% works well.
When specifying the custom rate, the valid range is 1% to 1000%.
Note: The Users text boxes are active only when the Capacity model is selected.