How can I increase throughput on my wireless mesh network?
We have installed a wireless mesh network that connects two access points (APs) to mesh nodes that are mounted at 25 meters high on 23 light poles. Poles are distributed around a container yard that measures 650 meters by 1,000 meters. There are six rows of containers, varying in height depending upon container movement, stacked to a maximum of 6 containers high. Walkways and vehicle lanes are located in between container stacks. We had expected to achieve 10 Mbps throughput on the ground but do not. Please recommend a solution.
Assuming that your light poles are spaced at regular intervals, it sounds like your nodes are probably separated by 100-150 meters. That would be fairly far apart, even in open air with clear line-of-sight between all nodes. In your case, it seems likely that line-of-sight is heavily impeded by dense, reflective shipping containers, at least part of the time.
I recommend taking on-location measurements to determine how far the signal is currently propagating at strength sufficient to maintain 10 Mbps throughput, under representative container configurations, measured at regular intervals throughout the yard. You may need to add more wireless mesh nodes -– but more likely, you may want to use directional antennas to better focus transmissions between mesh nodes into walkways and vehicle lanes that provide clear line-of-sight. But don't just add mesh nodes; a thorough site survey is definitely the place to start.
This was first published in December 2009