Grown up WiFi for grown up applications

ABB's Tropos redefines industrial wireless.

From lily-pad connections to mesh networks – ABB WiFi comes of age with Tropos technologies.

WiFi is 16 years old, and has slowly grown from a beloved, if disruptive, child into a productive adult. But with age comes responsibility, and industrial companies around the world want WiFi systems that are as dependable, reliable, and robust as their operational systems. This is where ABB’s Tropos technology can step up to the plate.

Shoehorning the venerable Ethernet wired networking standard into a radio signal was awkward, to say the least, and while the standard has evolved, most WiFi deployments remain attached to the original hub-and-spoke architecture which ABB’s Tropos eschews for the sake of building a better wireless network.

Hub and spoke is fine for updating Facebook, “lily-pad” WiFi can cover most of an area most of the time, with each pad of coverage plugged into a wired connection to provide wireless access to the Internet at its center.

Most wi-fi deployments resemble the floating leaves of the water lily; pretty to look at but lacking the blanket coverage needed for running a power grid or an industrial production system.

In this configuration access points sit at the middle of the leaf, and the stem bridges the gap between cable and radio networks using the internationally-available frequency bands at 2.4GHz and/or 5GHz.

These bands are free to use just about everywhere, but they are becoming crowded. Not many routers are as clever as ABB’s Tropos, which scans to find the cleanest band, and as few users bother to change frequencies the defaults are often congested, despite neighboring bands being empty.

Channel 1, the frequency where all the cool routers like to hang out.

But it’s not only other WiFi users who clutter up the bands, microwave ovens also run at 2.4GHz and the 5GHz band fills up with baby monitors and CCTV systems, all wanting to use the license-free radio spectrum. That slows the connection to the lily pad, and that’s before we even think about that single cable running down the stem.

Just as every lily pad needs its own stem, every access point in these networks needs a wire connecting it to the internet. Walk 100 yards from an access point and the signal disappears, unlike more-advanced cellular systems which perform such “hand-offs” automatically. A moving Tropos router can provide such a hand-off, or a client device can be caught as it drops from the edge of a cell.

Rather than each access point having its own wire (stem) the Tropos routers connect to each other, with every node acting as a relay for the others. As long as one router in the mesh has a wired connection the network remains live, but additional wires can be added to increase capacity and provide redundancy, while the network constantly optimizes itself to provide the fastest routing.

With these techniques Tropos creates seamlessly-meshed networks, providing connectivity across 400 square kilometers of potash mine (in White Springs, Florida) or the city of Venice (in Veneto, Italy) with equal fidelity.

Self-forming mesh networks are inherently robust.

Self-forming mesh networks are inherently robust: knock out a single router and the mesh reforms around it within seconds, though with each router being waterproof to a depth of a meter and (optionally) equipped with a battery, there’s little reason to expect failure.

Fitting an additional router is also trivial: just bolt onto an outside wall and plug in the power, then watch while the router finds a suitably-empty frequency and the Tropos operating system reconfigures the network to take advantage of the new hopping point.

If more capacity is needed then one simply runs a cable to any of the nodes and the network will start pulling data down it, the multiplicity of connections not only provides redundancy (should one connection fail) but also balances the load to provide the best end user experience without the end user noticing.

Not that the end user needs to be a person – with the cost of WiFi falling, it’s rapidly becoming the connectivity of choice for embedded sensors, activators and other automation devices. WiFi can be added to any device for very cheaply these days and manufacturers are falling over themselves to internet-enable all kinds of machinery, which will become reliant on robust wireless coverage.

Those devices, and users, might be connected direct to a fixed router, or via a mobile mesh router such as the Tropos 4310, which provides coverage on board the Venice water taxis. The Tropos 4310 hops between fixed mesh routers, making each connection before the previous one drops, in much the same manner as a mobile phone. That means the user is never for a moment without connectivity, and never has to worry where their connection is coming from.

Tropos technology isn’t limited to slow-moving water taxis.

Tropos technology isn’t limited to slow-moving water taxis, it can equally provide connectivity to a fast-moving train or vehicles making their way around a site, and with the latest XA models happy to operate anywhere between -40 and +70°C, and in salt-fog environments, there aren’t many places on earth that this grown-up WiFi cannot cope with.

So that’s what Tropos mesh networks are: WiFi all grown up and ready for use across industrial sites and utility campuses. These environments are a far cry from Starbucks or the office LAN, but with Tropos, ABB can bring wireless connectivity out of the white-collar environment and into the real world where it can connect users, and their machines, reliably, dependably and robustly, no matter where the connection is needed.


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About the author

Bill Ray

Bill Ray is an engineer turned scribe, now working for ABB as a Technical Writer. He previously worked for the scurrilous internet rag The Register, prior to which he made phones, at O2, and set-top boxes, at Cable & Wireless. He's authored two technical books on Java and now spends most of his time trying to understand the power business.
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