Wi-Fi Beats Beating the Bushes
Wi-fi and water pioneer Corpus Christi’s citywide network signals the future for two-way meter control.
As a job, it’s often nasty work: leaping fences, fighting off dogs, clambering over slopes, and dealing with the elements—all to read the water meter. High job turnover is endemic. At the City of Corpus Christi, TX, says Leonard Scott, business unit manager for the management information systems department, “It’s very difficult for us to keep these folks. The job’s just too dangerous.” Out of 47 current meter reader positions, several are vacant and most of the filled ones are from temp agencies. Meter staff members get hurt more often than those in the fire or police departments.
“The other thing we’ve found,” Scott adds wryly, “is that the readings we get aren’t very accurate.” Every day brings customer complaints for alleged over-billing.
And with manual readings there’s no easy access to water and gas usage histories.
So, in 2002, city managers in need of cutting budgets explored doing automated meter reading (AMR) for the area’s 146,000 water and gas meters. Besides wanting to cut overhead, they realized that revenue was being lost due to the current inventory of aged, under-reporting meters. Also, a wealth of data-driven benefits and improvements could be gained with AMR, ranging from greater accuracy in billing to better management of time, staff, and resources; leak detection; and robust analysis—just for starters.
 |
| Mike Carlisle ©Copyright 2005 |
Corpus Christi had already established itself as something of a “digital city”—one of only a dozen so designated by Intel—having installed a fiber-optic backbone to manage traffic control and enhance citywide data access. Citizens also can log on to www.cctexas.com to pay utility bills or parking and traffic tickets, apply for jobs, look up zoning records, and watch City Council meetings live. So, state-of-the-art AMR would dovetail well with other high-value city services.
AMR would also cost many millions of dollars but would pay back in time and yield savings for years to come.
The Council readily voted to proceed further.
A technology quest, by Public Technologies Inc. of Washington, DC, came up with several options, primarily comparing “mobile” or “drive by” AMR methods against a “fixed network” array. The latter requires more hardware and thus a higher first cost.
Initial expectations were that the bids for a mobile design would beat a fixed network easily. But, as Scott recounts, when a proposal came in from McLean, VA–based Northrop Grumman Information Technology, many in the procurement office were surprised to see that the “bigger” fixed network turned out to be, as Scott recalls, “not only the most complete and best bid for the city but also the most cost-effective.”
Northrop, an integrator, proposed using well-known AMR supplier Hexagram’s (Cleveland, OH) Star System array. This would carry a higher up-front price tag, but as the spreadsheets showed, over a 20-year life cycle it would likely come out cheaper, for several reasons.
Shhhh … Let Your MTUs Stay Asleep
First, Hexagram’s meter transmission units (MTUs) rely on a licensed wavelength of 450 megahertz. This yields a longer signal range (typically surpassing a mile, depending on topography) than competing systems using 900 megahertz. Hexagram’s Director of Marketing Todd Q. Adams notes, too, that this dedicated frequency is “solely for exchange of meter data on the network—there’s nothing competing and no compromising of readings.”
A stronger, clearer signal means that a network can be built with relatively fewer collection points: For Corpus Christi, the number worked out to about 180 towers to cover 147 square miles.
However, what turns out to be an even more critical advantage of the longer range and better accuracy is the resulting lengthened battery life. How does this occur?
Scott explains that “the basic infrastructures for mobile and fixed networks are virtually alike” in most respects—the key difference being that mobile requires an added degree of local two-way communication. As the mobile meter reader drives past them, the onboard receptor within each MTU must “wake up” its “sleeping” transmitter. Doing the wakeup requires MTUs to use a bit more standby power at all times so they can receive their “call.” This drains a bit of battery power, and thus mobile systems are at a disadvantage vis-à-vis a fixed network. The latter, being permanently nearby, can receive readings within a precise time frame rather than needing to “keep one eye open” all the time for the approaching mobile signal. The MTU gets to “sleep” nearly all the time, using almost no power.
Effectively, then, the difference translates into a need for new batteries “every five or six years” with a mobile design, says Scott. Replacements wind up being not just batteries but change-outs of the packaged radio too. “That’s kind of expensive at 30 or 40 bucks a pop,” he says. Over the system life cycle this works out to millions of dollars more.
It should be noted that AMR technology is constantly leapfrogging, and what may have been the case, as just described, pertaining to a few years ago may no longer be so, and this comparative assessment might be disputed by competing vendors.
At any rate, MTUs—being purchased in huge quantities—are by far the biggest cumulative expense in an AMR conversion. Hence, making intelligent technology evaluations and life cycle cost analyses is critical.
As just noted, Hexagram and several other makers encase their units to combine the battery, transmitter, and data encoder inside hard plastic, to which the meters are attached. In this respect, Scott notes that Hexagram’s MTU doubles its usability by enabling connection ports for both the gas and the electric in each device. In Corpus Christi, about 70% of the utility customers have both services (the balance having only water).
Installing new meters, along with MTUs, makes sense labor-wise, of course. Hexagram’s packaged pods were thus mated with meters from Neptune, the market leader. Offering what is a reportedly an exceptional capability, Neptune’s “smart” encoders can detect leaks, tampering, and reverse-flow conditions directly at the meter. Data emits from meters seamlessly into Hexagram’s transmission package, which is optimized for this advanced capability. (In fact, this past June, Hexagram formalized a distribution arrangement with Neptune, who will henceforth represent Hexagram exclusively, notes Adams.) Neptune data thus streams into Hexagram’s billing, customer service, and customizable data collection system. Neptune’s software can also reportedly integrate data from assorted MTUs and hybrid mobile or network systems.
Inventorying Your Meters
Step one in any automation project would typically consist of taking stock of the installed base of meter types. Scott comments: “We knew how many were out there, but we didn’t know what brand, what model, the year installed—and even, as it turned out in most cases, the size of the input pipe, whether five-eighths-inch, 0.75-inch, or 2-inch.”
This kind of hardware hodgepodge and potpourri, he adds, is not at all unusual. Meter vintages span several decades. Having inadequate records of “what’s where” is probably a norm. Older structures dating from obsolete building code eras and using non-standard pipe dimension may be unrecorded.
All of this poses a major challenge to doing the overall costing, planning, scheduling, and bulk ordering of the correct new replacement meters and of the right encoding interfaced to mesh with this mélange.
Hexagram’s Adams adds that hardware inventory taking and assessments of this sort are indeed routine. Automatic meter readers must somehow be custom rigged to achieve compatibility with older, discontinued, and unconventional meter types. Fortunately, he adds, Hexagram has now done 75 AMR implementations, including large arrays in Boston and Washington, DC, and thus the company “has seen just about everything.” On a parenthetical note he adds that last year his employer signed what will reportedly be the largest AMR contract to date with Pacific Gas and Electric—numbering at least 4.1 million MTU endpoints.
In any case, taking careful inventory will also help in doing “triage” on the matter of which meters should be scrapped outright and which rebuilt. Replacement of many or most—especially the older ones—is always advisable, as any vendor or water company will tell you. Start with the oldest first, of course, as these are likeliest to be under-recording and losing money daily.
Phasing In
For Corpus Christi, the anticipated huge cost, sheer magnitude, and logistical challenge of the automation necessitated dividing the project into digestible bites. Scott notes: “We’re replacing one-fifth at a time, as opposed to all at once. Any overage [in purchased hardware] that we end up with each year we will keep in inventory until the next year is authorized on the build-out.”
Also, to break in slowly, the department opted to do a formal pilot project first. This aimed at obtaining a better heads-up for the long range by sampling and moving cautiously in year one. “We knew the technology would work,” he says, “but the pilot was done to help us digest it all” in view of several unknowns, like the installed base of meters. “We had made projections on what the addition of AMR might involve, so the pilot validated that and helped us find any other missing variables in this process.”
This was concluded in the spring of 2005, after which the city reassessed. In order to economize on the thousands of MTU bundles, Corpus Christi decided to rebuild meters selectively and package them with the Hexagram components. A retrofit of this kind costs only $40; outright replacement with a new kit comes to around $90. So far, Scott says, rebuilding versus replacement has broken even at around half-and-half—i.e., 60% of the water meters are being replaced, and 40% of the gas. “Each year that we enter into the process,” he adds, “the more accurate our estimates will be in terms of numbers of meters of all sizes. And, obviously, when we reach year five we’re going to have to zero out.”
The five-year phase-in also makes the workload more manageable and softens the impact on staff. Automation is now eliminating a fraction of the meter reader positions each year. Staff reductions will thus more likely occur by natural attrition rather than layoff. By the end of the process in around 2010, the original contingent of 47 readers will be whittled to just four “who’ll be assigned,” Scott says, “to maintenance and troubleshooting on the electronic portion of the system.” If others remain, they’ll be offered vacant city jobs and will keep their benefits.
Wi-Fi and Water: A Good Mix?
Backhauling data from these meters back to City Hall was, by far, the most novel and high-profile aspect of this project. Here, the “digital city” opted to go cutting-edge all the way—and now enjoys the distinction of being the first AMR fixed network anywhere with a wi-fi (“wireless fidelity”) net to carry two-way signals to the office.
Introduced only in 1999, wi-fi quickly roared to the lead as the technology of choice for networking. Typically, it outstrips high-speed fiber or cable, says Scott, “on a surprisingly low cost-per-byte basis,” with considerably less hardware than a hard-wired system. Wireless routers for a city can attach to traffic signal poles, streetlights, buildings, and water and radio towers for seamless coverage.
However, using wi-fi to carry meter data is probably a kind of “overkill,” in the sense that an ordinary cell phone dialup is well established and cost-effective, and a wi-fi net is capable of far, far more. Don Schlenger—a well-known AMR observer and partner of Cognyst Consulting in Kinnelon, NJ—notes, “The fact is, to carry data from the data collector back in the utility office costs almost nothing, anywhere”—as, again, data “can be transmitted for a few minutes each night” via cell phone. “It’s so cheap,” he says, “that you would never build an infrastructure to cover it.”
However, cities “want wi-fi for public communications and to provide a service to their citizens,” he adds. So, the AMR role rides along as one “client service” along many. “Corpus Christi,” he sums up, “is on the leading edge” in applying wi-fi as a pioneer.
Initially, the city had indeed embraced wi-fi largely to carry the home leg of its AMR. However, when the citizenry discovered the host of other “cool stuff” they’d be getting, the wi-fi aspect was fast-tracked and the priority. So, instead of building the wi-fi in five-year increments, it is now, as of September 2006, fully operational.
An early phase of this was launched about two years ago, covering an 18.5-square-mile test area. In the spring of 2005, AMR signals began rolling in smoothly. On this point, Scott recalls, “We were very nervous about what that was going to do, until we actually tested it as a pilot.” Fears were groundless: Everything worked almost flawlessly. “And now we’re very comfortable with it,” he says.
To provide complete coverage citywide, about 300 Tropos MetroMesh weather-protected routers were installed, all told.
Corpus Christi now boasts being “the only area in the world with 147 square miles of unbroken wi-fi coverage,” Scott told a local media outlet during the time of its commissioning. Users now enjoy “anywhere, anytime” access to resources such as the library, City Hall, and museums. Transmissions race at up to 2 megabits per second—faster than most cable and several dozen times better than dialup. There’s potential for 5.5 megabits per second, depending on traffic.
The Water Department’s AMR data share a small portion of bandwidth with police, fire, EMS, public works crews, and city offices. Even when the AMR system is fully built within five years, all of this city traffic will take only about 40% of the total capacity.
Data security is maintained by sub-dividing bandwidth portions for public safety, municipal systems, private subscribers, and visitors. Access security and SSL-encrypted registration and authentication are required.
Robust Data on the Move
As for the water meters and MTU endpoints, as of late summer 2006, about 20,000 meters—one-sixth of the eventual AMR conversions—are now completed.
To collect their signals, 25 tower sites (of the eventual 180) are perched on utility poles, etc., at about one per square mile. Power is supplied either by solar photovoltaics or the grid. Each collector takes hundreds of signals from surrounding meters. (Adams points out, too, that Hexagram collectors are handling as many as 20,000 or 30,000 each, elsewhere.)
At each tower a small onboard PC converts the analog radio frequency waves to digital packets, and then sends these in pre-defined transmission bursts over the Ethernet.
Inside each collector, configurable slots can be tweaked to interact with whatever backhaul communications channel(s) a city may wish to use—i.e., cell phones, wi-fi, fiber-optic, Ethernet, or other. “It’s very flexible and not technology dependent,” notes Adams.
Upon reaching the Water Department, data flows into software for billing, resource management, leak reporting, consumption profiling, and a range of new functions. Scott observes, “Ownership of a system allows you to do all kinds of things that are great for economic development and customer service.”
A few more examples:
One immediate practical gain has been the discovery that the replacing of older meters netted an increase in water consumption measurements averaging, says Scott, “slightly less than 12%. For us, that’s a recapture of a loss.” Another big change:
“We’re not estimating anymore,” he says, and bills are more accurate. “Revenues are enhanced.” (And, perhaps predictably, now some citizens call to complain about that!)
Thanks to automated meter reading and data collection, customers can check their own meter data online. Gas and water consumption history, at any given location, will be available.
Rather than doing single monthly readings, automated meters can report valuable data every day—or, as might be useful for a high-volume customer, even more frequently. Northrop Grumman’s Jeffrey King, director of sales and marketing for the Information Technology group, adds that a fixed network enables a city to “grab information throughout the day, in multiple cycles … every five minutes … or twice a day. [As a manager, he adds] … I’ve got information that I can do something with. I can come to work every morning and have the network tell me which 40 meters had a plus or minus 10% spike in usage, day over day, or week over week, month over month … I can have it printed out and I can have my customer support branch call those houses and ask if they’ve got a toilet running or leak in the backyard or basement filling up with water … That’s the usage of this technology.”
Twice-daily readings provide redundancy, and the appearance of major discrepancy flags a problem to troubleshoot.
Fine-tuned water measurements will improve flow controls and reduce system breaks.
Water conservation programs during drought can be implemented and monitored.
Change- or stop-service processing is automatic. If a customer wants to close an account, no meter reading field trip is needed.
Lastly, as for the gas management side: Tight monitoring of usage will enable Corpus Christi to dovetail community consumption volumes with market price fluctuations, to gain purchasing efficiency.
Most of these gains and others lie just over the horizon, as Corpus Christi is only into year two; but all have been proven elsewhere.
Looming a bit farther ahead will be expanded two-way traffic, with the ability to turn water service on and off from one central control panel, and “WiMax” for AMR is reportedly just a few years away.
Still another significant innovation in play is what Scott calls “leap-frog reading,” in which MTUs communicate not upward to towers but laterally. “Basically,” he explains, “they ‘wake up’ and pass their readings on to the next meters that are in proximity … and meters are continuously reporting” this way. This method, he says, “circumvents the need for data collection units” (i.e., antenna towers). Especially for electric utility meters that don’t rely on batteries, he adds, “It makes a lot of sense.”
Future Utilities: Water-Gas-Electric and Wi-Fi?
The total cost here—for the full AMR deployment, for perhaps 60,000 or more new meters, and for citywide wi-fi—is currently projected to total around $25.6 million. Wi-fi takes $7.1 million, and the balance covers AMR, spread over five years. “This is obviously a big whack,” Scott observes. But amortization makes it manageable.
What About Payback?
Accurate projections are a crapshoot, but in July an independent consultant calculated that the nearly $27 million outlay will be recouped in about 14 years. Thereafter, Corpus Christi should save $1.6 million over the remaining six years of the 20-year life. Even higher savings, at $8 million, are envisioned by a city study.
What’s most intriguing (and also, at the moment, highly controversial) is the prospect that not only will a water department gain a technology, but lucrative revenue from selling the excess bandwidth could pay for the AMR and an entire network, handily. As of September 2006 the city is reportedly offering broadband Internet access for about $20 per month; a large subscription would net a huge windfall. The city has begun looking for commercial partners to manage the enterprise and retail bandwidth. “We look at this operation as a 60-40 split,” Scott comments—i.e., the lion’s share “is available for wholesale … And we’ll allow ISPs to resell that.”
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The government will be charged for its use on a co-op basis. “The cost of each byte of throughput is charged out accordingly and is extremely low,” he adds.
“Moving forward,” he sums up, “there’s tremendous potential for this.”
Author's Bio: Writer David Engle specializes in construction-related topics.
January-February 2007
Wi-Fi Beats Beating the Bushes
Wi-fi and water pioneer Corpus Christi’s citywide network signals the future for two-way meter control.
As a job, it’s often nasty work: leaping fences, fighting off dogs, clambering over slopes, and dealing with the elements—all to read the water meter. High job turnover is endemic. At the City of Corpus Christi, TX, says Leonard Scott, business unit manager for the management information systems department, “It’s very difficult for us to keep these folks. The job’s just too dangerous.” Out of 47 current meter reader positions, several are vacant and most of the filled ones are from temp agencies. Meter staff members get hurt more often than those in the fire or police departments.
“The other thing we’ve found,” Scott adds wryly, “is that the readings we get aren’t very accurate.” Every day brings customer complaints for alleged over-billing.
And with manual readings there’s no easy access to water and gas usage histories.
So, in 2002, city managers in need of cutting budgets explored doing automated meter reading (AMR) for the area’s 146,000 water and gas meters. Besides wanting to cut overhead, they realized that revenue was being lost due to the current inventory of aged, under-reporting meters. Also, a wealth of data-driven benefits and improvements could be gained with AMR, ranging from greater accuracy in billing to better management of time, staff, and resources; leak detection; and robust analysis—just for starters.
|
| Mike Carlisle ©Copyright 2005 |
Corpus Christi had already established itself as something of a “digital city”—one of only a dozen so designated by Intel—having installed a fiber-optic backbone to manage traffic control and enhance citywide data access. Citizens also can log on to www.cctexas.com to pay utility bills or parking and traffic tickets, apply for jobs, look up zoning records, and watch City Council meetings live. So, state-of-the-art AMR would dovetail well with other high-value city services.
AMR would also cost many millions of dollars but would pay back in time and yield savings for years to come.
The Council readily voted to proceed further.
A technology quest, by Public Technologies Inc. of Washington, DC, came up with several options, primarily comparing “mobile” or “drive by” AMR methods against a “fixed network” array. The latter requires more hardware and thus a higher first cost.
Initial expectations were that the bids for a mobile design would beat a fixed network easily. But, as Scott recounts, when a proposal came in from McLean, VA–based Northrop Grumman Information Technology, many in the procurement office were surprised to see that the “bigger” fixed network turned out to be, as Scott recalls, “not only the most complete and best bid for the city but also the most cost-effective.”
Northrop, an integrator, proposed using well-known AMR supplier Hexagram’s (Cleveland, OH) Star System array. This would carry a higher up-front price tag, but as the spreadsheets showed, over a 20-year life cycle it would likely come out cheaper, for several reasons.
Shhhh … Let Your MTUs Stay Asleep
First, Hexagram’s meter transmission units (MTUs) rely on a licensed wavelength of 450 megahertz. This yields a longer signal range (typically surpassing a mile, depending on topography) than competing systems using 900 megahertz. Hexagram’s Director of Marketing Todd Q. Adams notes, too, that this dedicated frequency is “solely for exchange of meter data on the network—there’s nothing competing and no compromising of readings.”
A stronger, clearer signal means that a network can be built with relatively fewer collection points: For Corpus Christi, the number worked out to about 180 towers to cover 147 square miles.
However, what turns out to be an even more critical advantage of the longer range and better accuracy is the resulting lengthened battery life. How does this occur?
Scott explains that “the basic infrastructures for mobile and fixed networks are virtually alike” in most respects—the key difference being that mobile requires an added degree of local two-way communication. As the mobile meter reader drives past them, the onboard receptor within each MTU must “wake up” its “sleeping” transmitter. Doing the wakeup requires MTUs to use a bit more standby power at all times so they can receive their “call.” This drains a bit of battery power, and thus mobile systems are at a disadvantage vis-à-vis a fixed network. The latter, being permanently nearby, can receive readings within a precise time frame rather than needing to “keep one eye open” all the time for the approaching mobile signal. The MTU gets to “sleep” nearly all the time, using almost no power.
Effectively, then, the difference translates into a need for new batteries “every five or six years” with a mobile design, says Scott. Replacements wind up being not just batteries but change-outs of the packaged radio too. “That’s kind of expensive at 30 or 40 bucks a pop,” he says. Over the system life cycle this works out to millions of dollars more.
It should be noted that AMR technology is constantly leapfrogging, and what may have been the case, as just described, pertaining to a few years ago may no longer be so, and this comparative assessment might be disputed by competing vendors.
At any rate, MTUs—being purchased in huge quantities—are by far the biggest cumulative expense in an AMR conversion. Hence, making intelligent technology evaluations and life cycle cost analyses is critical.
As just noted, Hexagram and several other makers encase their units to combine the battery, transmitter, and data encoder inside hard plastic, to which the meters are attached. In this respect, Scott notes that Hexagram’s MTU doubles its usability by enabling connection ports for both the gas and the electric in each device. In Corpus Christi, about 70% of the utility customers have both services (the balance having only water).
Installing new meters, along with MTUs, makes sense labor-wise, of course. Hexagram’s packaged pods were thus mated with meters from Neptune, the market leader. Offering what is a reportedly an exceptional capability, Neptune’s “smart” encoders can detect leaks, tampering, and reverse-flow conditions directly at the meter. Data emits from meters seamlessly into Hexagram’s transmission package, which is optimized for this advanced capability. (In fact, this past June, Hexagram formalized a distribution arrangement with Neptune, who will henceforth represent Hexagram exclusively, notes Adams.) Neptune data thus streams into Hexagram’s billing, customer service, and customizable data collection system. Neptune’s software can also reportedly integrate data from assorted MTUs and hybrid mobile or network systems.
Inventorying Your Meters
Step one in any automation project would typically consist of taking stock of the installed base of meter types. Scott comments: “We knew how many were out there, but we didn’t know what brand, what model, the year installed—and even, as it turned out in most cases, the size of the input pipe, whether five-eighths-inch, 0.75-inch, or 2-inch.”
This kind of hardware hodgepodge and potpourri, he adds, is not at all unusual. Meter vintages span several decades. Having inadequate records of “what’s where” is probably a norm. Older structures dating from obsolete building code eras and using non-standard pipe dimension may be unrecorded.
All of this poses a major challenge to doing the overall costing, planning, scheduling, and bulk ordering of the correct new replacement meters and of the right encoding interfaced to mesh with this mélange.
Hexagram’s Adams adds that hardware inventory taking and assessments of this sort are indeed routine. Automatic meter readers must somehow be custom rigged to achieve compatibility with older, discontinued, and unconventional meter types. Fortunately, he adds, Hexagram has now done 75 AMR implementations, including large arrays in Boston and Washington, DC, and thus the company “has seen just about everything.” On a parenthetical note he adds that last year his employer signed what will reportedly be the largest AMR contract to date with Pacific Gas and Electric—numbering at least 4.1 million MTU endpoints.
In any case, taking careful inventory will also help in doing “triage” on the matter of which meters should be scrapped outright and which rebuilt. Replacement of many or most—especially the older ones—is always advisable, as any vendor or water company will tell you. Start with the oldest first, of course, as these are likeliest to be under-recording and losing money daily.
Phasing In
For Corpus Christi, the anticipated huge cost, sheer magnitude, and logistical challenge of the automation necessitated dividing the project into digestible bites. Scott notes: “We’re replacing one-fifth at a time, as opposed to all at once. Any overage [in purchased hardware] that we end up with each year we will keep in inventory until the next year is authorized on the build-out.”
Also, to break in slowly, the department opted to do a formal pilot project first. This aimed at obtaining a better heads-up for the long range by sampling and moving cautiously in year one. “We knew the technology would work,” he says, “but the pilot was done to help us digest it all” in view of several unknowns, like the installed base of meters. “We had made projections on what the addition of AMR might involve, so the pilot validated that and helped us find any other missing variables in this process.”
This was concluded in the spring of 2005, after which the city reassessed. In order to economize on the thousands of MTU bundles, Corpus Christi decided to rebuild meters selectively and package them with the Hexagram components. A retrofit of this kind costs only $40; outright replacement with a new kit comes to around $90. So far, Scott says, rebuilding versus replacement has broken even at around half-and-half—i.e., 60% of the water meters are being replaced, and 40% of the gas. “Each year that we enter into the process,” he adds, “the more accurate our estimates will be in terms of numbers of meters of all sizes. And, obviously, when we reach year five we’re going to have to zero out.”
The five-year phase-in also makes the workload more manageable and softens the impact on staff. Automation is now eliminating a fraction of the meter reader positions each year. Staff reductions will thus more likely occur by natural attrition rather than layoff. By the end of the process in around 2010, the original contingent of 47 readers will be whittled to just four “who’ll be assigned,” Scott says, “to maintenance and troubleshooting on the electronic portion of the system.” If others remain, they’ll be offered vacant city jobs and will keep their benefits.
Wi-Fi and Water: A Good Mix?
Backhauling data from these meters back to City Hall was, by far, the most novel and high-profile aspect of this project. Here, the “digital city” opted to go cutting-edge all the way—and now enjoys the distinction of being the first AMR fixed network anywhere with a wi-fi (“wireless fidelity”) net to carry two-way signals to the office.
Introduced only in 1999, wi-fi quickly roared to the lead as the technology of choice for networking. Typically, it outstrips high-speed fiber or cable, says Scott, “on a surprisingly low cost-per-byte basis,” with considerably less hardware than a hard-wired system. Wireless routers for a city can attach to traffic signal poles, streetlights, buildings, and water and radio towers for seamless coverage.
However, using wi-fi to carry meter data is probably a kind of “overkill,” in the sense that an ordinary cell phone dialup is well established and cost-effective, and a wi-fi net is capable of far, far more. Don Schlenger—a well-known AMR observer and partner of Cognyst Consulting in Kinnelon, NJ—notes, “The fact is, to carry data from the data collector back in the utility office costs almost nothing, anywhere”—as, again, data “can be transmitted for a few minutes each night” via cell phone. “It’s so cheap,” he says, “that you would never build an infrastructure to cover it.”
However, cities “want wi-fi for public communications and to provide a service to their citizens,” he adds. So, the AMR role rides along as one “client service” along many. “Corpus Christi,” he sums up, “is on the leading edge” in applying wi-fi as a pioneer.
Initially, the city had indeed embraced wi-fi largely to carry the home leg of its AMR. However, when the citizenry discovered the host of other “cool stuff” they’d be getting, the wi-fi aspect was fast-tracked and the priority. So, instead of building the wi-fi in five-year increments, it is now, as of September 2006, fully operational.
An early phase of this was launched about two years ago, covering an 18.5-square-mile test area. In the spring of 2005, AMR signals began rolling in smoothly. On this point, Scott recalls, “We were very nervous about what that was going to do, until we actually tested it as a pilot.” Fears were groundless: Everything worked almost flawlessly. “And now we’re very comfortable with it,” he says.
To provide complete coverage citywide, about 300 Tropos MetroMesh weather-protected routers were installed, all told.
Corpus Christi now boasts being “the only area in the world with 147 square miles of unbroken wi-fi coverage,” Scott told a local media outlet during the time of its commissioning. Users now enjoy “anywhere, anytime” access to resources such as the library, City Hall, and museums. Transmissions race at up to 2 megabits per second—faster than most cable and several dozen times better than dialup. There’s potential for 5.5 megabits per second, depending on traffic.
The Water Department’s AMR data share a small portion of bandwidth with police, fire, EMS, public works crews, and city offices. Even when the AMR system is fully built within five years, all of this city traffic will take only about 40% of the total capacity.
Data security is maintained by sub-dividing bandwidth portions for public safety, municipal systems, private subscribers, and visitors. Access security and SSL-encrypted registration and authentication are required.
Robust Data on the Move
As for the water meters and MTU endpoints, as of late summer 2006, about 20,000 meters—one-sixth of the eventual AMR conversions—are now completed.
To collect their signals, 25 tower sites (of the eventual 180) are perched on utility poles, etc., at about one per square mile. Power is supplied either by solar photovoltaics or the grid. Each collector takes hundreds of signals from surrounding meters. (Adams points out, too, that Hexagram collectors are handling as many as 20,000 or 30,000 each, elsewhere.)
At each tower a small onboard PC converts the analog radio frequency waves to digital packets, and then sends these in pre-defined transmission bursts over the Ethernet.
Inside each collector, configurable slots can be tweaked to interact with whatever backhaul communications channel(s) a city may wish to use—i.e., cell phones, wi-fi, fiber-optic, Ethernet, or other. “It’s very flexible and not technology dependent,” notes Adams.
Upon reaching the Water Department, data flows into software for billing, resource management, leak reporting, consumption profiling, and a range of new functions. Scott observes, “Ownership of a system allows you to do all kinds of things that are great for economic development and customer service.”
A few more examples:
One immediate practical gain has been the discovery that the replacing of older meters netted an increase in water consumption measurements averaging, says Scott, “slightly less than 12%. For us, that’s a recapture of a loss.” Another big change:
“We’re not estimating anymore,” he says, and bills are more accurate. “Revenues are enhanced.” (And, perhaps predictably, now some citizens call to complain about that!)
Thanks to automated meter reading and data collection, customers can check their own meter data online. Gas and water consumption history, at any given location, will be available.
Rather than doing single monthly readings, automated meters can report valuable data every day—or, as might be useful for a high-volume customer, even more frequently. Northrop Grumman’s Jeffrey King, director of sales and marketing for the Information Technology group, adds that a fixed network enables a city to “grab information throughout the day, in multiple cycles … every five minutes … or twice a day. [As a manager, he adds] … I’ve got information that I can do something with. I can come to work every morning and have the network tell me which 40 meters had a plus or minus 10% spike in usage, day over day, or week over week, month over month … I can have it printed out and I can have my customer support branch call those houses and ask if they’ve got a toilet running or leak in the backyard or basement filling up with water … That’s the usage of this technology.”
Twice-daily readings provide redundancy, and the appearance of major discrepancy flags a problem to troubleshoot.
Fine-tuned water measurements will improve flow controls and reduce system breaks.
Water conservation programs during drought can be implemented and monitored.
Change- or stop-service processing is automatic. If a customer wants to close an account, no meter reading field trip is needed.
Lastly, as for the gas management side: Tight monitoring of usage will enable Corpus Christi to dovetail community consumption volumes with market price fluctuations, to gain purchasing efficiency.
Most of these gains and others lie just over the horizon, as Corpus Christi is only into year two; but all have been proven elsewhere.
Looming a bit farther ahead will be expanded two-way traffic, with the ability to turn water service on and off from one central control panel, and “WiMax” for AMR is reportedly just a few years away.
Still another significant innovation in play is what Scott calls “leap-frog reading,” in which MTUs communicate not upward to towers but laterally. “Basically,” he explains, “they ‘wake up’ and pass their readings on to the next meters that are in proximity … and meters are continuously reporting” this way. This method, he says, “circumvents the need for data collection units” (i.e., antenna towers). Especially for electric utility meters that don’t rely on batteries, he adds, “It makes a lot of sense.”
Future Utilities: Water-Gas-Electric and Wi-Fi?
The total cost here—for the full AMR deployment, for perhaps 60,000 or more new meters, and for citywide wi-fi—is currently projected to total around $25.6 million. Wi-fi takes $7.1 million, and the balance covers AMR, spread over five years. “This is obviously a big whack,” Scott observes. But amortization makes it manageable.
What About Payback?
Accurate projections are a crapshoot, but in July an independent consultant calculated that the nearly $27 million outlay will be recouped in about 14 years. Thereafter, Corpus Christi should save $1.6 million over the remaining six years of the 20-year life. Even higher savings, at $8 million, are envisioned by a city study.
What’s most intriguing (and also, at the moment, highly controversial) is the prospect that not only will a water department gain a technology, but lucrative revenue from selling the excess bandwidth could pay for the AMR and an entire network, handily. As of September 2006 the city is reportedly offering broadband Internet access for about $20 per month; a large subscription would net a huge windfall. The city has begun looking for commercial partners to manage the enterprise and retail bandwidth. “We look at this operation as a 60-40 split,” Scott comments—i.e., the lion’s share “is available for wholesale … And we’ll allow ISPs to resell that.”
The government will be charged for its use on a co-op basis. “The cost of each byte of throughput is charged out accordingly and is extremely low,” he adds.
“Moving forward,” he sums up, “there’s tremendous potential for this.”