ABB Wireless

Tuesday, November 25, 2008

A multi-use network that defies labels

As an engineer, it's my job to figure out ways to make our networks faster, more reliable, and easier to use. When a customer gives us the opportunity to log into their network, I like to take advantage of the chance to understand how it's working and what could be improved.

This morning, I logged into the Tropos Control web-based management console of what I thought was a city-wide meter reading network. The dashboard showed me a map of the routers (definitely city-wide), a histogram of throughputs (looked good -- 99% of routers were getting more than 1 Mbps), and a plot of usage. It didn't look right -- why was there almost 5 GB per hour of upstream traffic on the network? Utility meters couldn't possibly use that much bandwidth. I clicked through to generate a list of the top client devices on the network. Aha! The MAC addresses matched Axis Communications, a solution partner that makes IP video cameras. It makes sense -- the city has a high-capacity IP infrastructure, so why not use it for video surveillance, too? There was another unexpected graph on the Tropos Control dashboard. The number of connected client devices was not flat, but varied significantly throughout the day. This is characteristic of public access networks, where people come and go with their iPhones and laptops, but not of a meter-reading or video surveillance network, with devices connected 24/7. Sure enough, I saw iPhones and Centrino laptops in the client list, and a quick trip to the city's website confirmed that the network had been opened up to residents for free Internet access.

This is a great example of the value of a standards-based IP wireless network. Since so many devices are compatible, it's easy to just connect them up and add new applications. More and more cities are getting hard to label, with their meter-reading-public-safety-intelligent-transportation-system-video-surveillance-smart-grid-IP-wireless networks!

Cyrus Behroozi
Chief Scientist