Telemetry Gets Smart

Maybe it was only a matter of time: Italian appliance-maker Ariston's margherita2000.com is a washing machine that uses short-message service (SMS) to communicate with its owners and service centers. Thanks to the Web-ready-appliances protocol, it also can work with other appliances to reduce energy use.

A far-fetched telemetry app? Maybe not. Granted, telemetry often is upstaged by flashier wireless-data applications such as portals, but it's changing, partly because the industries it serves are changing. Two examples are the gas and electric industries, among the earliest adopters of telemetry. Both are in the early stages of deregulation, which promises to increase competition and the pressure to cut costs and develop value-added services.

"One reason that they're putting in telemetry to their larger users is to help monitor the load," said Corey Tkachuk, Global Data Wireless vice president, marketing and sales. "That's a value-added service. They take the bill, do an analysis and say, 'If you didn't turn all four lines on at once, you wouldn't have this big spike, and we wouldn't have to charge you so much.'"

A similar application is interruptible-rate service: The customer gets a reduced rate in exchange for allowing the utility to turn off power to certain devices during peak periods. That approach is headed for the home, too.

"One of our customers is looking at putting smart thermostats in the home," said John Wambaugh, CellNet Data Systems CTO. "They give the customer a rebate and take control of that thermostat at specific peak-load times so that they don't have to go on the grid and buy expensive power. Instead, they can turn that thermostat up or down."

All those value-added services eventually could translate into a need for more bandwidth. In the process, telemetry no longer will be seen as just a narrowband application.

"Because data is priced per amount of bandwidth or time used, they treat it as narrowband applications," said Jeff Newman, Omnipoint Technologies director, wireless-solutions division. "Talking to a lot of utility companies, we've seen this desire to collect more data in terms of amount and frequency of reads. I think they've been limited in that in terms of the prices of devices and the prices of airtime. As we move toward more packet-based solutions, where components of that cost model begin to become cheaper, I think that a lot of the telemetry customers that we work with are going to substantially upgrade the amount of data they collect."

ROOM FOR MORE That trend toward collecting more data more often should dovetail nicely with the migration to 2.5G. For users, advantages include more bandwidth, more efficient throughput and a constant connection, but without per-minute charges.

"With GPRS and EDGE, you get true Internet connectivity," Newman said. "You can look like an IP device. You could have an Internet-based host solution: Give each meter a remote IP address. You've got tremendous amounts of data capability: 14.4kb/s through 56kb/s on the uplinks isn't going to be uncommon in the next couple of years."

Users already are exploring using that capability to deliver enhanced services such as tornado warnings and control smart household devices. For carriers, 2.5G technologies such as GPRS and 1XRTT are attractive for telemetry applications because data now ties up fewer network resources.

"From a circuit-switched side, (GPRS) will tie up fewer voice channels and make more efficient use of the time that they're on the air," said Chris Resavy, senior director, network engineering and operations, at Omnipoint Communications, currently in GPRS trials. "There's no set-up time. It's just: 'I'm on the air. Here's the data. I'm gone.' From an SMS perspective, it will free up additional bandwidth that we can use for information-based services."

Just because a 144kb/s pipe is available doesn't necessarily mean that telemetry applications will use all 144kb/s.

"I like to think that out of that 144kb/s channel, we could put 144 users at 1kb/s," said Scott McArthur, Telus Mobility director of technology-development strategy. "It isn't necessarily one user at 144kb/s. That's where we're going to see some of the advantages for telemetry in the future: The ability to have many users doing many things, all on a shared channel, which should bring down the effective cost."

It isn't so much that 2.5G suddenly makes high-bandwidth telemetry apps attractive. Rather, it's that many telemetry apps might continue to be mainly low bandwidth, but their business case becomes more compelling.

"The telemetry applications that I've seen people considering are typically much lower bandwidth and make use of the bandwidth as you move to a packet upgrade," said John Davison, an Ovum analyst who follows 2.5G. "You're able to support many more users cost-effectively compared with current technologies. It makes the simple applications over cellular viable. There are people looking at high-bandwidth applications, but I think the larger opportunity is in enabling the less-demanding applications but to a wider audience."

Despite 2.5G's advantages, CDPD and circuit-switched data will remain a good fit for many telemetry apps.

"If we look at a lot of those applications today, CDPD is overkill," said Greg Speakman, Sierra Wireless marketing director, vertical markets. "It's too much bandwidth, too expensive, too high speed for those applications, and we're seeing the control channel and similar things being used to address those needs. So if you look at those and ask, 'What's 2.5G going to bring?' It doesn't seem that it's going to bring a whole lot because the devices are potentially more expensive. The bandwidth isn't necessary because it's small amounts of data. The price of the airtime has yet to be determined and is expected to be higher."

Although CDPD's maximum throughput is 19.2kb/s, overhead such as error correction cuts that to roughly 11kb/s. With compression, that's fine for carrying retinal scans from an ATM.

"The only place where you need bigger pipes is in messaging," said Wambaugh of CellNet Data Systems, which uses a private network. "I might want to get a boatload of information from a device such as history for a month. (Or) reconfigure it (by) downloading a new set of firmware."

Although video would be more demanding, a remote camera that periodically sends only still frames wouldn't require as much bandwidth. In the end, the value depends more on the quality of the information and less on its sheer quantity.

"You can take an oil-well head that's 80km away from the closest town, and rather than sending somebody for a couple of hours to drive there and back, you could just look at a video connection and monitor what the current condition is around the well head: Are we going to have to send a snowplow crew before we send a field crew?" said Telus Mobility's McArthur. "That's one area where I see that we could enhance telemetry services by offering more information than we have in the past."