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Placement and Layout Considerations
ZoneDirector 9.8 User Guide, 800-70599-001 Rev B
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the fact that not all users are using the network concurrently), if you use an
oversubscription ratio of 4:1, such a network could actually support 40 users at
1Mbps.
In a Smart Mesh network, the Root AP (RAP) has all its wireless bandwidth available
for downlink, because the uplink is wired. For Mesh APs (MAPs), the available
wireless bandwidth has to be shared between the uplink and the downlink. This
degrades performance of a Mesh AP as compared to a Root. This problem is
mitigated somewhat by dual radio APs when the uplink and downlink traffic can be
sent/received on two separate radios.
Placement and Layout Considerations
• Utilize two or more RAPs: To prevent having a single point-of-failure, it is always
best to have 2 or more RAPs so that there are alternate paths back to the wired
network.
• More roots are better: The more Root APs in the design, the higher the
performance. Therefore, as far as possible, try to wire as many APs as is
convenient.
• Design for max 3 hops: Avoid an excessive number of hops in your mesh
topology. In general, the goal should be to have the lowest number of hops,
provided other considerations (like Signal >= 25%) are met. Limiting the number
of hops to 3 or less is best practice.
• Place a Root towards the middle of a coverage area to minimize the # hops
required to reach some MAPs.
• If there are multiple Roots, ensure that the Roots are distributed evenly
throughout the coverage area (not clumped up close together in one area).
Shown in
Figure 220 is an ideal scenario, along with a not-so-ideal scenario. Of
course, the whole purpose of mesh is to provide coverage in areas that are hard
to wire, therefore the ideal may not be possible. But as far as possible, evenly
spaced Root APs are preferable.