Cutting the cable
- By John K. Waters
Skyline chili is famous for its three-ways (chili served on a bed of
spaghetti and topped with grated American cheese), its chilidogs (known as
''Coney Islands'') and its lightning-fast service (customers are served within
about two minutes of being seated). For most of its history, waitstaff at the
52-year-old Midwestern restaurant chain actually shouted their orders to the
''That was our first wireless network,'' said franchisee Pete Perdikakis, who
owns three of the restaurants in Cincinnati. ''It was very low-tech and sometimes
pretty chaotic, but it was fast.''
Perdikakis, who has been in the business for nearly 30 years, believed that
he would eventually need to implement an integrated point-of-sale (POS) system
to compete with other fast-food restaurants. But he could not afford to
compromise Skyline's famous service levels.
''All the POS systems I'd seen in other restaurants would have slowed things
down in mine,'' Perdikakis said. ''I wasn't interested in having my waitresses
running back to re-enter their orders in a centralized terminal. I kept asking
about wireless, but no one seemed to get how that technology would work in a
A year ago, Perdikakis was finally able to implement the POS he wanted
without sacrificing Skyline's vaunted service. He did it by utilizing a wireless
local-area network (WLAN) that connects the kitchen directly to Hitachi
handhelds carried by his waitstaff.
In the health-care industry, the orders are not for chilidogs, and mistakes
cannot be sent back to the kitchen, but the same technology used at Skyline
Chili is helping hospitals to save money and lives.
''One of the greatest problems in American health care is medication error,''
said Dr. John Halamka, CIO at CareGroup Healthcare System, Boston, and associate
dean of the Harvard Medical School. ''Typically, physicians either write a
prescription by hand or call it in by phone. Both scenarios leave openings for
Halamka cited a report, To err is human: Building a
safer health system ,
published by the Institute of Medicine of the National Academies of Science,
that states that more people die each year as a result of medical errors than
from motor vehicle accidents, breast cancer or AIDS. And every medication error
costs about $5,000 in increased hospital stays or complications.
''As we saw it, the way to solve the problem was to implement an IT system
that would ensure that every medication went from the doctor's brain to the
patient's vein with no handoffs and great enforcement of all rules about dosages
and interactions and allergies,'' Halamka said.
Last year, CareGroup launched a system the company believes will do just
that. The Physician's Order Entry (POE) system, first implemented at Beth Israel
Deaconess Medical Center in Boston, puts the entire process of medication
delivery, from ordering, to pharmacy fulfillment to patient delivery, on the
Web. And a key enabling technology of the new system is a hospital-wide wireless
LAN connecting laptops in the hands of physicians.
These two widely disparate examples illustrate the remarkable range of WLAN
implementations in the enterprise class. The current generation of tetherless
networks that transmit data over unlicensed radio frequencies has already
demonstrated its effectiveness in a host of vertical markets, including health
care, retail, manufacturing, warehousing and academia. Now, as it finds its way
into more general business settings and, increasingly, into publicly accessible
implementations, it is clear that WLAN is poised for a boom.
According to a recently published report from the Yankee Group, Boston, more
than half of all large U.S. businesses plan to roll out wireless systems during
the next two years. Analysts at Stamford, Conn.-based Gartner Dataquest expect
global WLAN equipment shipments to grow 73% this year alone, constituting a 26%
increase in revenue. Gartner also expects shipments to increase in 2003 to 26.5
million units, up from 15.5 million units this year, with revenue approaching
$2.8 billion, up from $2.1 billion in 2002. The analysts expect unit sales in
this sector to continue to climb through 2007.
For IT managers, implementing a wireless LAN involves a few technical
challenges, offers some important opportunities for cost savings and improved
efficiencies, and presents some fairly substantial security risks. And according
to most industry watchers, the question is not whether your organization will
implement a WLAN, but when and, perhaps more importantly, how.
Planning is the key
Wireless local-area networks are extremely
flexible systems typically implemented as extensions to, or alternatives for,
their wired counterparts. As anyone who has looked at this technology knows,
WLANs transmit packets of data via radio waves from access points (also called
base stations) that are installed in the physical environment and wired to
Ethernet hubs or servers. The access points typically transmit a radio frequency
over areas between several hundred and several thousand feet. WLANs do not
require line-of-sight to establish connections, and the transmissions can
penetrate walls and other non-metal barriers. They work a lot like cell phone
systems, handing off roaming users from one base station to another within the
One logical starting point for those testing the WLAN waters might simply be
to set up a network to serve a small segment of the larger organization -- sort
of a wireless pilot program. This approach allows IT managers to measure the
gains and recognize the advantages of the system without a major commitment.
But whether you dip in a toe or jump in with both feet, CareGroup's Halamka
advises IT managers to plan their WLAN installations carefully, beginning, he
said, with requirements. ''You can't really design your system until you have at
least a basic idea of what you want it to do and who you want it to support,''
Halamka knows whereof he speaks; CareGroup designed and built its massive POE
system in-house for what is considered to be the second largest integrated
health-care delivery system in the Northeastern United States. CareGroup
comprises six hospitals, including Beth Israel Deaconess Medical Center, Mount
Auburn Hospital, New England Baptist Hospital, Deaconess-Waltham Hospital,
Deaconess-Glover Hospital and Deaconess-Nashoba Hospital.
It took Halamka and company two years to develop the system, which represents
the continuing efforts of 35 doctors, who developed business rules for the
system; 23 programmers, who created applications; and 20 trainers, who adjusted
hospital business processes and made sure hospital personnel knew how to operate
in the new POE environment. The Cache data repository on which the system runs
includes 21 Terabytes of data.
IT managers planning an enterprise-class WLAN installation should review
customer requirements, Halamka said, as well as business requirements, such as
how many users the network will need to support; how many devices, like
printers, will be accessed via the network; how many of the mobile devices
(laptops, PDAs) currently in use in the organization are already wirelessly
enabled; how many access points will be needed to cover the facility; how many
ports in the Ethernet network (if the organization has one) are available for
access points; and, of course, which standard will be employed.
Besides radio NIC cards for the mobile devices, the basic hardware component
of the WLAN is the access point. Access points link the untethered devices to
the wired network. Because of their limited range, multiple access points are
necessary to cover most facilities. Halamka recommends performing an RF site
survey to determine the number of access points you will need. You can hire
consultants to do it, or you can do it yourself. Walk the facility, review the
building's blueprints and look for potential problem areas, such as elevator
shafts, central air ducts and cafeterias.
Assume about one access point per 70,000 square feet of coverage area. This
assumes a range of about 150 feet, but forms of attenuation and specific
performance requirements may affect this number, Halamka said.
Also give some early consideration to system demand. Do you expect the load
on the system to be fairly stable, or are you likely to see frequent increases
in demand? Most access points deployed in enterprise settings readily
accommodate 10 to 25 users. High-density usage areas in your facility may
require additional access points to support the transmission of large data
Keep in mind, too, that your WLAN installation may require additional
electrical wiring and outlets to power the access points.
And think carefully about the end-user devices. Do you go with a PDA or a
laptop? What are the pros and cons? CareGroup experimented with equipping its
doctors with iPaq handhelds, but the company soon settled on Dell laptops.
''The problem with using handhelds is that the screen real estate is pretty
small,'' Halamka explained, ''and working with a stylus is an added complication
-- you've probably heard about doctors' handwriting. And a foldable keyboard
wasn't the answer; by the time you have your keyboard, your iPaq, your wireless
network connection and your extra battery, you're lugging around as much weight
as a laptop.''
Screen size was also a consideration at Skyline Chili. After experimenting
with Palm devices, Skyline's Perdikakis settled on Hitachi HPW600 handheld PCs,
which provide a screen nearly the size of a piece of notebook paper.
''The Palm was too small at that time,'' said Perdikakis. ''We wanted something
that would fit every item on two pages with no scrolling.''
The Skyline system, which utilizes PixelPoint's wireless POS application
running on the Hitachi handhelds, is based on mobile database technology from
iAnywhere Solutions, and installed by solution provider Ideal Inventory Systems.
The application allows waitstaff to enter orders -- which are instantly sent via
Proxim's 802.11b-based WLAN directly to the kitchen -- into their handhelds.
With the RF survey completed, requirements in
place, and some consideration given to hardware, it is time to think about
standards. To many organizations, WLAN standards constitute a confusing
alphanumeric soup. Without a doubt, 802.11b is currently the most widely
implemented WLAN specification in the enterprise class. It was the first to
follow 802.11, and it is affordable, fast and interoperable. But with the
certification of the faster 802.11 standard, and the 802.11g standard nearly
approved, exactly which one to implement is no longer clear, nor is the
migration path to the newer, emerging technologies.
In fact, there are also 802.11c, f, h, and i
specifications. The specifications most IT managers will need to understand are
a, b and g. (See the related story ''Alphabet soup,''
which has a complete list of 802.11 specs.)
In 1997, the Institute of Electrical and Electronics Engineers (IEEE)
developed the 802.11x specifications for WLANs. Today, it is by far the most
prominent and successful in enterprise-class implementations throughout the U.S.
The 802.11b spec -- better known as Wireless Fidelity or Wi-Fi -- was the
first to be implemented. It provides speeds approaching those of wired LANs (11
Mbps) in the unlicensed 2.4 GHz band, which is the same radio frequency band on
the wireless spectrum as cordless phones and microwave ovens. But concerns about
interference from these devices were outweighed by the advantages of the
Wi-Fi covers about 400 feet per access point in a typical office
implementation. Its ability to handle most enterprise-class networking needs --
things like e-mail messaging, database access, Internet access and traditional
office networking -- drove widespread early adoption of the spec. According to a
report from Cahners In-Stat, by 1999, more than 50% of the WLANs being deployed
were for traditional office applications.
Although 802.11a was ratified by the IEEE at about the same time as 802.11b,
the simplicity of Wi-Fi made it a favorite among developers, who were able to
get products to market based on that spec very quickly.
But demand for higher bandwidth capabilities to support things like streaming
video and multimedia has begun driving the development of 802.11a-based
products. This spec offers data transfer speeds approaching 54 Mbps, operating
in the 5 GHz band. The bad news is that it is a completely different area of the
wireless spectrum from 802.11b, which makes it incompatible with Wi-Fi. 802.11b
uses Direct Sequence Spread Spectrum (DSSS), while the 802.11a utilizes
Orthogonal Frequency Division Multiplexing (OFDM).
The good news is that OFDM can carry up to five times the amount of data over
the air as DSSS. And the 5 GHz band is not nearly as crowded. In fact, it is
virtually free from interference -- no worries about intruding microwaves from
the break room. Within that band, 300 MHz has been allocated for 802.11a-based
products, making room for 12 clear channels for data transmissions.
However, as Tiberio Massaro points out in his paper, Understanding WLAN
standards, the 5 GHz band is divided into lower, middle and upper bands, which
means that ''... the 802.11a standard does not have the entire band available for
transmission.'' And ''... output power is not consistent throughout the band. This
ultimately indicates that range and bandwidth performance will vary drastically
from client to client,'' he writes.
The range at which users of an 802.11a-based system will actually get the 54
Mbps transmission speeds is about 20 meters. Implementers of an 802.11a system
will have to consider providing more access points. Still, organizations with no
current WLAN installations that can standardize and control the nomadic devices
will want to seriously consider implementing an 802.11a-based network.
Finally, with its ratification pending in 2002, many eyes are turned to the
802.11g specification. 802.11g is designed to serve as an intermediate product
between Wi-Fi and 802.11a. It will operate in the 2.4 GHz band, but will utilize
OFDM as its modulation scheme. It is expected to deliver the same bandwidth
performance as 802.11a products. Also, 802.11g is planned to be completely
backward-compatible with Wi-Fi.
Whatever the specification, WLANs have the ability to operate in two modes:
''ad-hoc mode'' and ''infrastructure mode.'' Ad-hoc, or peer-to-peer mode, allows
users to share files directly between end-user machines while operating in
workgroups, without the need to connect to an access point. Infrastructure mode
allows mobile clients equipped with network interface cards to connect to a
network via the access points.
Security without wires
Wireless networks are inherently more
difficult to protect than wired systems, so special care must be taken to
consider security when planning a WLAN implementation. According to Rob Veitch,
director of business development at iAnywhere Solutions, a Dublin, Calif.,
subsidiary of Sybase Inc. that focuses on mobile, embedded and workgroup
database solutions, keeping hackers out of your wireless system will require
some extra effort.
''It's computing outside the firewall,'' Veitch said. ''WLAN is never actually
inside the firewall. Once you understand that, it's not hard to deal with it.
Just think of it as the equivalent of someone dialing up from outside.''
One of the biggest security problems with enterprise WLANs may simply be an
organization's tendency to view them as secondary to their wired LANs. IT
managers should keep in mind that the signals transported via WLANs pass through
facility walls and are transmitted into garages and parking lots, as well as out
into the streets. Another problem: Data on most handheld devices is not
encrypted, and information can be stolen during the transmission process. This
is a network that needs stronger security.
The IEEE has defined an encryption mechanism called Wired Equivalent Privacy
(WEP) for 802.11b-enabled WLANs. WEP encrypts the body of each 802.11 data frame
to thwart packet analyzers. WEP should dissuade the casual snooper, but it has
its drawbacks, primarily stemming from the fact that the secret key used for
encrypting the session can be easily retrieved by sniffing a number of encrypted
packets sent over the air. Nick Hunn, manager director of TDK Systems Europe in
London, believes that enterprises should not rely solely on the current standard
WEP encryption technology. (The IEEE has said that it plans to solve the flaws
of WEP through more advanced encryption methods.)
''WEP certainly has its problems,'' Hunn said, ''but it's better than nothing.
The thing to keep in mind is that it's not difficult to tap into something once
it's outside the four walls of the office. It doesn't really matter whether it's
wireless, modem or ISDN. You've got to say that security should be at a higher
level, peer-to-peer behind a VPN. Wireless is not alone in being vulnerable to
A Virtual Private Network (VPN) application can help to secure a wireless
network by creating an encrypted tunnel over the WLAN, which protects the
traffic from eavesdroppers, Hunn explained. But many handheld devices with
wireless access to the network cannot function as VPN clients. Another real
downside of VPNs is that they may lower the performance of the network. Plus,
users face the cumbersome process of manually re-authenticating and setting up a
new VPN tunnel every time they roam between access points. Often, users simply
end up ignoring the VPN policies.
Concerns about security should not keep IT managers from beginning to
considering WLAN installations, Hunn said, because whether they like it or not,
wireless is coming.
''The problem we have is that IT managers are utterly paranoid that if
anything goes wrong, they'll be out of a job,'' Hunn said. ''The result is,
they're saying, 'I wouldn't put wireless LAN in because it's not secure. Let's
wait for 802.11xyz.' What they're really doing is putting the problem off until
it's someone else's problem. That's why I think public access will drive way
ahead of corporate access. Next year, you'll begin seeing chief executives who
logged onto a public network when they were on the road, hitting up their IT
managers, saying 'I really liked this when I was at the hotel. Why can't I have
it here in my office?'''
A growing number of organizations are extending
their wireless networks into the great outdoors, circumventing the cost of
leased lines and the expense and hassle of running underground fiber optics.
802.11b has been widely adopted in point-to-point or point-to-multipoint
bridging in outdoor environments.
As you plan your WLAN, iAnywhere's Veitch suggests IT managers consider the
implications of wireless networks in outdoor environments. WLANs in outdoor
settings typically transmit between 180 meters and 385 meters at various rates.
The variability of the transmission rates is affected by the degree of
attenuation radio waves encounter with environmental obstructions, such as trees
or multiple towers.
Another type of outdoor WLAN, so-called wireless bridges, are capable of
spanning distances of 40 miles while supporting transmission speeds of 11 Mbps.
Universities have been the first organizations to adopt this application of
802.11b technology, using it to connect remote buildings and main facilities
throughout the campus.
Installations of publicly accessible WLANs, known as ''hotspots'' are, of
course, generating the greatest buzz right now. The idea of establishing WLANs
in public access areas, such as hotels, train stations, airports and even small
municipal areas, to create wireless ''hotspots'' is gaining considerable
traction. Researchers at Analysis Consulting expect the number of wireless
hotspots in public venues to grow to 41,000 and reach 21 million users worldwide
Public WLAN services are now becoming available at airports, hotels and cafes
in countries such as Austria, Germany, Norway and Sweden, according to a study
from market researchers at Cambridge, U.K.-based Analysys. The same analysts
forecast that there will be more than 20 million users of public WLAN services
in Europe by 2006.
''For most users, their first experience of WLAN isn't going to be in the
office, but via hotspots or other people's wireless networks,'' said TDK Systems'
Hunn. ''In most of Central London, I can open up my laptops and I have a network
connection. Some of them are nice, altruistic public ones, some are commercial
hotspots, and quite a number are companies who have forgotten that they need
In the U.S., hotspot activity is, well, hot. Hewlett-Packard (HP) recently
launched a global initiative designed to deploy hotspot infrastructure in public
sites. That same month, Toshiba announced that it would deliver new technologies
and services to support its effort to make WLAN access in public spaces
ubiquitous through hotspot access points. In October, Cisco Systems announced a
new wireless infrastructure product, the Aironet 1100 Series Access Point, an
802.11b device that features an integrated omnidirectional antenna and secure
mounting system, which allows it to be installed on ceilings, cubicle walls and
desktops. Starting December 1, 2002, Verizon says it will offer a suite of
802.11b wireless network packages with its home DSL service.
And as everyone who has not been living in a cave knows, Starbucks Coffee,
the Seattle-based mega-chain, along with T-Mobile International, the wireless
subsidiary of Deutsche Telekom AG, and HP launched the T-Mobile HotSpot service.
The WLAN implementation allows Starbucks customers to use their own notebooks
and handhelds to log on and check e-mail, surf the Web, watch streaming video or
download multimedia presentations.
''As these hotspots become more numerous,'' Hunn said, ''they will further
reinforce the wireless access model, persuading many laptop users to experiment
with wireless. By 2006 we predict that almost half the users of 802.11b will be
connecting to hotspots while they travel.''
According to Gartner Inc., there are currently 3.9 million global users of
hotspots, with about 2.7 million regular users in North America. By 2007,
Gartner projects there will be 63.8 million global users, with about 24.5
million of those in North America.