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What is the desired height of a node location? The higher the better?

Huub Schuurmans's picture
The short answer is: five to ten stories is nice. The long answer:

The optimum height depends on both the desired coverage and capacity and the local density (number of nodes in a certain area).

If a node (accesspoint) is put on a high roof, it covers a large area. The coverage is good. This kind of nodes are preferrably in the starting phase of a network: large number of potential users, sufficient capacity (not many users yet). However, every accesspoint can only serve a limited number of users, otherwise the bandwidth is reduced. If the number of users in a certain area increases you have to do something about this. If there are still frequencies (channels) available you could add accesspoints at this same location, using the free channels. But the number of channels that can be used per node is limited to 3 or 4 (and some maybe used for interlinks with other nodes).

The only way out is to 're-use' the same channels by adding new nodes at a different location. Wehave to take care, however, that these additional nodes are at a relatively low location, to avoid interference.

When the network grows and the number of users increases, we need more and more nodes at ever lower locations. Ultimately this could mean that at some point in the development of the network we have to take down a node at a high location. We therefore use the high locations preferrably NOT as a public accesspoint but only for interconnections. A good example is Node SOM on the Escher tower, the highest building in Leiden.