Go wireless, or go home
More than a couple years ago, I was sitting in a sales call meeting with a civilian networking architect-type for the U.S. Navy. We were talking about terms like “unlimited bisection bandwidth,” “secure IP networking over software-defined radio,” and other at-the-time esoteric concepts before getting down to the agenda. We were going over the benefits of InfiniBand in high-throughput, low-latency networking applications and seeing how that might fit into his plans.
After discussing the higher-altitude stuff and listening patiently while we contrasted the finer points of InfiniBand versus Ethernet, he leaned back and said something that went more or less like this: “Do you remember Token Ring? How about FDDI? I heard the same things, that those networks had advantages in topology, throughput, latency, and the like. Know what? Ethernet beat them both. I have no doubt that there are advantages to InfiniBand in some applications. But Ethernet will improve, and will beat it, and will get faster again and beat the next thing that comes along. And Ethernet will connect to many, many more devices.”
That is a very smart man. He was right, without any offense to the InfiniBand folks and the many other networks I’m about to list. When it comes to having to connect to a lot of things easily, betting against the mainstream doesn’t pay off. However, there may be specific jobs with a limited number of dedicated connections where a unique technology with advantages makes sense.
Have you ever thought industrial networking was all about “fieldbuses?” I once did. If you are sitting in a plant right now, with a lot of wired connections, you probably share that view. You have machines running on a particular protocol that was adopted so your programmable logic controllers could talk openly to machines, and chances are there is now a your-favorite-fieldbus-to-Ethernet gateway somewhere in your equation. You might even have one of the various standards running over Ethernet itself, but offering better real-time assured packet delivery methods. There is definitely a place for wired fieldbus and similar network technology, and it will continue to be around for a long time. For instance, we have an interesting viewpoint from ON Semiconductor proposing CAN as the choice in “Robust communication systems migrate into building intelligence.”
The mainstream future is wireless, however, and our astute architect’s comment comes into the picture quickly. He saw the potential of widely adopted standards and wireless networking. But there’s a slightly different reality taking shape. With something like 15 billion devices in play and a range of wireless choices for different jobs, getting connected isn’t as simple as choosing one network.
A good example: I have a little machine right here on my desk, and it has four wireless connections including CDMA, Wi-Fi, Bluetooth, and GPS. This type of device with wireless networking, computing, and human interface technology, perhaps in a bit more rugged package, is the future of industrial computing.
3G cellular, including things like CDMA, gives you a built-out network for voice and data that’s pretty ubiquitous, except maybe on the Island of Misfit Toys (I still laugh at Verizon’s current commercial advertising the Motorola DROID, shown in Figure 1).
4G will soon provide more bandwidth and more coverage, especially in emerging markets that in many cases are jumping straight to 4G technologies instead of establishing a wired infrastructure. ADC explains more about the use of cellular networks as part of an automation application in “Cellular networks do more than voice.”
Wi-Fi – what our friend earlier would probably have called “wireless Ethernet” – presents more use cases. Unlike several years ago when wireless network carriers wanted to own all the traffic, they are now begging smart phone suppliers to include Wi-Fi so that tasks like browsing and e-mail can be offloaded from overtaxed 3G networks. Wi-Fi is in almost every house that has a computer, so it’s a natural choice to hook up gaming consoles, media players, major appliances, Web-enabled devices like thermostats, and more. Wi-Fi is in almost every business, too, and can provide facility coverage quickly and inexpensively. GainSpan and Our Home Spaces explain more about Wi-Fi and the jobs it’s doing in “Wi-Fi and U-SNAP: Advancing smart grid adoption in homes.”
The other two networks are for more specific jobs. Bluetooth, as we’ll learn in the December 2009 issue of Embedded Computing Design with interviews from the Bluetooth SIG and Continua Health Alliance, is doing more than just connecting to headsets and printers; it’s about to show up in a whole range of devices. GPS is also in the equation to make location-based information a reality.
There are also wireless networks almost too numerous to list – ZigBee, 900 MHz, WirelessHART, 6LoWPAN, Wireless USB, RFID, ISA 100, and others – that do many jobs well.
Here’s the reality. As wireless proliferates, what we are already seeing is:
· Very small devices at the “new edge” (where networks haven’t been so far) with one wireless technology
· More devices at the “near edge” (where people and devices meet, and the nodes are fairly countable in a home or office) with a combination of wireless technologies including the mainstream Wi-Fi connection
· All kinds of devices connecting with the cloud (where there are billions of nodes) and what’s coming in over the air in the form of 4G, GPS, and other global networks being built out today
Industrial apps definitely need to take full advantage of this trend. Device and equipment designers need to go wireless quickly, or get left home in this new wireless world.