Wireless' Byte-Size Bandwidth

Despite recent advancements, bandwidth remains a rare commodity for users of wireless data applications.

by / November 30, 1999 0
In the world of wireless technologies, bandwidth is more precious than gold. It's so scarce and valuable that when you examine the few government applications using wireless, data-transfer rates are measured a few hundred bits at a time.

Without speed or capacity, wireless data networks have remained the poor cousins of information technology. Outside of public safety, only a small number of government agencies have shown any interest in working with wireless data. Those that have admit their functionality is extremely limited.

But the world of 9.6Kbps transfer rates may be over soon. Wireless carriers on several fronts are pushing new standards that could boost capacity well beyond what's available today. For the next several years, digital wireless bandwidth is expected to grow anywhere from 20 to 40 times that of standard analog transmissions. In the near future, wireless users could be running applications with data rates ranging from 344Kbps to 1.25Mbps, according to research firms that follow the technology.

But with every bit of good news about technology, there's some bad news too. Different carriers are pushing different standards to speed wireless along. Tens of millions of dollars will have to be spent on software and hardware to upgrade cellular base stations across the country before this bandwidth is available outside a handful of metro areas. Few businesses and consumers have shown much interest in high-capacity wireless solutions. Without the demand, only a handful of carriers are willing to gamble the kind of money needed to build out a national wireless data network. It's the old "chicken and egg" thing in technology again, observed one analyst. Which comes first: the technology or the demand? No one knows for sure.





At a Snail's Pace

Five years ago, two wireless data companies dominated the market. ARDIS and RAM Mobile Data provided analog wireless services that covered the largest metropolitan areas in the United States. Data-transfer rates for these networks ranged from 4.8Kbps to 8Kbps.

Today, wireless data networks can reach speeds of 19.2Kbps thanks, in large part, to CDPD (cellular digital packet data). However, few wireless users ever experience CDPD's top-rated speed because of a phenomenon known as overhead, which cuts throughput. Overhead can occur from a variety of technical factors, or something external, such as car speed as the user tries to download a file while driving. The result can be data-transfer rates as much as 50 percent below the maximum advertised by carriers.

For the uninitiated, the bandwidth gap between wireless and wired connections can appear tremendous. Today's wireless has roughly 500 times less bandwidth than standard local area networks, according to Mike Bauer, director of product management at Cerulean Technology, Inc. Even when compared to dial-up connections, wireless is still about three times slower.

The result, said Bauer, is that the public and private sectors have been forced to build wireless applications within the confines of the bandwidth limitations. That has meant using compression software to reduce the size of the data and adopting communication techniques that reduce the possibility of transmission slowdowns.

Government agencies have also had to carefully parse their workers' information requirements before building a wireless application. "You need to know what information is needed by the field worker and what information is needed in realtime from the field worker," said Bauer. In addition, agencies need to know what systems contain the information that must be sent and received by field workers.

Another major consideration is usability. If the client interface for the wireless application isn't easy to navigate in the field, workers will become frustrated. In other words, explained Bauer, "don't give the field worker a Web browser when all he needs is to click on a few boxes and icons."

Given the bandwidth limitations, the trick to making wireless more palatable for customers is to add value in other areas, according to Ralph Fuller, business-development manager for IBM. "We know our government customers want to avoid proprietary protocols and private infrastructure," he said, "so we've focused on offering them solutions using TCP/IP and Java applications, which can run on any operating system."

By crafting flexible solutions, government agencies can change components without having to change the rest of the system. For example, field workers can start with PalmPilots and change to notebooks or another kind of hand-held device down the line.

The ultimate goal, Fuller said, is to tap into the benefits of wireless data solutions. These include improved productivity for field workers -- as much as 300 percent, according to some figures -- greater data access and increased accuracy of data as it moves between the field and headquarters. For law enforcement applications, safety is considered a prime benefit of wireless because it allows officers in the field to identify drivers and their criminal records by tapping into national crime databases.



Impact on Government

In today's harsh and often violent environment, it's no surprise that public safety officials place a high premium on safety in their jobs. Because of wireless technology's ability to reduce the safety-risk factor, public safety agencies in general, and law enforcement agencies in particular, are the biggest users of wireless data networks.

Beyond public safety, the most likely places you are going to find wireless solutions are in public utilities, inspections, probation, lotteries and a few IT departments. Within public safety, both fire and emergency medical services are beginning to deploy wireless applications.

Wireless LAN
How do you wire your government's departments together when the threat of natural disaster forces them out of their central location? If you're like the city of Berkeley, Calif., you turn to wireless networking.

In 1998, engineers found Berkeley's City Hall seismically unsafe to withstand a possible earthquake from the Hayward fault, just a few miles away. With little time to spare, the city quickly moved into seven different buildings.

Not surprisingly, this sudden move imposed some thorny technological challenges, not the least of which was how to network what had been 840 desktop PCs, more than 40 servers and an IBM AS/400. Pulling T1 lines under the streets to connect some buildings up to a half-mile away was out of the question, according to Chris Mead, the city's information systems manager.

Instead, Berkeley turned to a radio-based solution from RadioLAN. Using antennas the size of a hand, the city has linked several buildings using RadioLAN's BridgeLINK units, which are capable of transmitting at speeds of up to 10Mbps.

So far, 300 city workers are able to use the wireless bridges to support a variety of office applications. "We like the technology because it's quick and easy to install, and it's faster than T1," said Mead. The solution is also cost-effective, only about $5,000 per link. The only limitation is that the buildings must be within line of sight and the range is currently limited to a half-mile.

The RadioLAN solution is also a big step up from earlier versions of wireless links, according to Mead, who has experimented with infrared technology to transmit wireless data between buildings. Whenever it rained or when the sun set, the system stopped transmitting.

For example, American Medical Response, a private firm hired by cities and counties in 38 states to provide emergency medical services, has launched a mobile data-collection application using PalmPilots.

Initially, 300 of the company's field staff will use the Palms in San Mateo County, Calif., to capture information ranging from details about their dispatch to the patient's vital signs. The data is required under a new state law, according to Eric Gee, an operation analyst specialist with the company. ore palatable for customers is to add value in other areas, according to Ralph Fuller, business-development manager for IBM. "We know our government customers want to avoid proprietary protocols and private infrastructure," he said, "so we've focused on offering them solutions using TCP/IP and Java applications, which can run on any operating system."

By crafting flexible solutions, government agencies can change components without having to change the rest of the system. For example, field workers can start with PalmPilots and change to notebooks or another kind of hand-held device down the line.

The ultimate goal, Fuller said, is to tap into the benefits of wireless data solutions. These include improved productivity for field workers -- as much as 300 percent, according to some figures -- greater data access and increased accuracy of data as it moves between the field and headquarters. For law enforcement applications, safety is considered a prime benefit of wireless because it allows officers in the field to identify drivers and their criminal records by tapping into national crime databases.



Impact on Government

In today's harsh and often violent environment, it's no surprise that public safety officials place a high premium on safety in their jobs. Because of wireless technology's ability to reduce the safety-risk factor, public safety agencies in general, and law enforcement agencies in particular, are the biggest users of wireless data networks.

Beyond public safety, the most likely places you are going to find wireless solutions are in public utilities, inspections, probation, lotteries and a few IT departments. Within public safety, both fire and emergency medical services are beginning to deploy wireless applications.

Wireless LAN
How do you wire your government's departments together when the threat of natural disaster forces them out of their central location? If you're like the city of Berkeley, Calif., you turn to wireless networking.

In 1998, engineers found Berkeley's City Hall seismically unsafe to withstand a possible earthquake from the Hayward fault, just a few miles away. With little time to spare, the city quickly moved into seven different buildings.

Not surprisingly, this sudden move imposed some thorny technological challenges, not the least of which was how to network what had been 840 desktop PCs, more than 40 servers and an IBM AS/400. Pulling T1 lines under the streets to connect some buildings up to a half-mile away was out of the question, according to Chris Mead, the city's information systems manager.

Instead, Berkeley turned to a radio-based solution from RadioLAN. Using antennas the size of a hand, the city has linked several buildings using RadioLAN's BridgeLINK units, which are capable of transmitting at speeds of up to 10Mbps.

So far, 300 city workers are able to use the wireless bridges to support a variety of office applications. "We like the technology because it's quick and easy to install, and it's faster than T1," said Mead. The solution is also cost-effective, only about $5,000 per link. The only limitation is that the buildings must be within line of sight and the range is currently limited to a half-mile.

The RadioLAN solution is also a big step up from earlier versions of wireless links, according to Mead, who has experimented with infrared technology to transmit wireless data between buildings. Whenever it rained or when the sun set, the system stopped transmitting.

For example, American Medical Response, a private firm hired by cities and counties in 38 states to provide emergency medical services, has launched a mobile data-collection application using PalmPilots.

Initially, 300 of the company's field staff will use the Palms in San Mateo County, Calif., to capture information ranging from details about their dispatch to the patient's vital signs. The data is required under a new state law, according to Eric Gee, an operation analyst specialist with the company.

Eventually, the company plans to deploy several thousand PalmPilots nationwide. These handhelds will be equipped with wireless modems, so that personnel can forward vital information about the patient while en route to the hospital. American Medical Response paramedics will also be able to use the Palms to tap into a patient database to find out if they have any allergies to medications. Wireless technology will also enable the company's dispatch centers to automatically reroute ambulances away from overcrowded hospitals.

This kind of wireless application is still in its formative stage, according to Gee. "There are federal requirements about transmitting medical records across wireless networks based on open protocols," he said. "We may have to wait for the issue to be addressed by digital certificates. Some kind of encryption is going to be required."

Utilities are also growing users of wireless data networks. Since the 1970s, energy companies have been using wireless technology to monitor gas and oil pipelines, control electric dispatch and transmission systems and read energy meters, the most common use of wireless.

Automated meter reading (AMR) was originally developed by electric utilities to reduce the number of human meter readers they had to dispatch. First generation AMR started when utilities equipped readers with hand-held devices to capture meter data. Later, drive-by systems were developed. Today, the emphasis is on network-based wireless systems. But this version of AMR is just beginning. Less than 1 percent of the 200 million meters in the United States are automated, according to The Yankee Group, a Boston-based research firm.

Despite the lack of acceptance, wireless AMR is starting to spread. Last year, the Pittsburgh Water and Sewer Authority (PWSA) announced it was providing AMR services to its 83,000 residential, commercial and industrial customers using wireless technology. The reason for the switch was a change in the public authority's billing cycle from quarterly to monthly. "We're billing our customers every month, but only reading their meter four times a year," said Greg Tutsock, PWSA's deputy executive director. "That's not good service for our customers."

PWSA is using a fixed wireless radio network system, developed by CellNet Data Systems Inc., and operated by Schlumberger Resource Management Services. Small radio transmitters are attached to water meters that send out data to a series of microcell controllers located about every half-mile. The controllers, in turn, transmit the data to a network of base stations.

When the $9 million network is completed, PWSA will be able to customize how it bills customers. "We can bill at the first of the month or the last, which can be helpful for people living on fixed incomes, such as pensioners or welfare recipients," Tutsock said. "For large customers, we can generate a summary bill for all their accounts instead of numerous individual bills."

The technology will also allow the authority to monitor usage patterns as often as every 15 minutes. By enhancing its operational response, PWSA will be able to detect leaks as well as acts of water theft or fraud. More importantly, PWSA will generate actual readings every month. "That's going to impact our cash flow," explained Tutsock. "In the past, we have underestimated readings in certain months. Now, we will get actual revenue from actual readings."



Future Boom

While the application that runs PWSA's automated meter-reading service is large and complex, the actual amount of data sent out by the radio transmitters is minute because of the narrow bandwidth used by the network. That's typical of most government wireless applications.

Starting next year, however, government agencies won't have to be so stingy when it comes to transmitting data over a wireless network. A number of wireless carriers are beginning to invest in second- and third-generation wireless networks. These networks are expected to dramatically increase the amount of data that can be transmitted via radio frequencies.

The most widely anticipated of the third-generation wireless standards is CDMA (code division multiple access), which uses spread-spectrum technology to spread a signal over greater bandwidth. Instead of transmitting at molasses-like data rates of 9.6Kbps or 14.4Kbps, users will be able to send and receive data at rates that could reach 1Mbps by 2003, according to estimates.

At that rate, field workers will not only be able to download e-mail messages with spreadsheet attachments, for example, they will also be able to navigate the Internet, access digital maps or provide staff with realtime video from the field.

So far, CDMA has caught on in Asia and is being backed by some big vendors in the wireless voice market, including Ericsson and Qualcomm. Research firms, consultants and the trade press are all praising the strengths of CDMA. Rosy forecasts make CDMA seem all but inevitable as the next standard for broadband wireless services.

Not so fast, say backers of other wireless standards. They point to the fact that CDMA is practically nonexistent in the United States as an operating network, and that Europe, the leading market for wireless voice communications, has already adopted another standard for data, known as GSM (Global System for Mobile communications).

These CDMA naysayers point to another wireless standard that has been around a bit longer. TDMA (time division multiple access) uses a different form of digital technology, which divides radio channels into time slots, providing a significant increase in capacity over the current analog cellular system. While TDMA is not quite as fast as CDMA, technological upgrades are expected to improve its speed. A TDMA base station also costs far less to build than a CDMA base station.

Currently, neither CDMA nor TDMA offer much in the way of coverage in the United States, and that's what matters to state and local governments right now, said Cerulean's Bauer. Wireless users would rather put up with the slower speeds than suffer through spotty coverage or no coverage at all. Others, such as IBM's Fuller and David Kerr, an analyst with Strategy Analytics, point to the fact that value-added features drive the wireless market, not capacity.

The question, with any new breakthrough in technology, is whether broadband wireless is a solution for a problem that already exists or just another solution in search of a problem. That's what carriers are asking themselves as they decide whether to invest millions of dollars in a wireless data infrastructure that can deliver a million bits per second over the airwaves to customers that may or may not need such throughput.

Optimists argue that it's best to give the public the megabits of wireless speed, then sit back and watch the fun begin. But if the costs for the service are too high and the coverage spotty outside of the big cities, then it may be many years before broadband wireless ever catches on.
Tod Newcombe Features Editor