Wireless Data Update – Beating the Technology Shell Game
Only now, with the carriers upgrading to “2.5G” (Second-and-a-half Generation) is wireless
data over a digital cellular network becoming an attractive option for enterprise applications
The technologies involved in 2.5G wireless data have exotic names like GPRS and 1xRTT and
they promise to deliver data rates faster than wireline dial-up. They are also packet-switched
data networks, not requiring a dedicated circuit to transmit data, meaning greater reliability.
Just about all of the major carriers have begun their build-out of 2.5G networks (Sprint PCS is
calling theirs “3G,” but it uses 2.5G technology. This could be a result of the wireless carrier’s
propensity to “round up.”). We will review 2.5G technologies in detail below.
While all this was happening several other technologies were also coming into their own for
wireless data (which we’ll cover below):
- Mobitex – The technology behind Cingular Interactive (originally the RAM Network).
Mobitex drives the Blackberry messaging terminals used by Wall Streeters, and those
with a low tolerance of email deprivation. Along with CDPD, Mobitex is another hero
of the early mobile data story.
- Satellite – Great coverage, as long as you’re outside. Generally more expensive than
terrestrial (earth-bound) technologies, satellite is the “go-to-guy” when you need
ubiquitous coverage.
- 802.11 – A short-range wireless data technology generally used for wireless networking
that can be a powerful complement to your wireless data application.
It’s also worth noting that there are a number of additional technologies that, in some cases, can
provide value to the enterprise user. However, for the sake of brevity we won’t be discussing
them here. These technologies include:
- Bluetooth – Named for the 10th century Danish king Harold Bluetooth, this technology
was developed to connect devices over short distances without cables. It is very
powerful and useful and can connect a mobile device to peripherals like printers, GPS
receivers, etc… without the cost or trouble of cabling.
- 3G – The “next big thing” in wireless or a “[fat] pipe dream?’ 3G is still too far out on
the radar screen to worry about now. In fact, there are those who believe 3rd Generation
wireless data will never make it in the US, because 2.5G will offer capabilities that will
be good enough for most applications.
- Circuit-switched cellular data – The need for a wireless “dialup” connection from a
phone and rates ranging from 9.6 Kbps to 14.4 Kbps won circuit-switched data its place
in this section.
- Paging – Savaged by cellular, paging is still hanging on in some quarters. The most
attractive technology being ReFlex?, a two-way paging technology developed by
Motorola, but the bandwidth is generally too low for serious enterprise applications.
- Motient – A combination of the American Mobile Satellite and ARDIS network.
ARDIS was originally created for field service workers, and Motient offers
functionality similar to Cingular Interactive’s Mobitex network.
Now that we’ve walked down memory lane, let’s examine some of the things you should
consider when reviewing your wireless technology options.
Wireless Application Considerations
There are a number of factors you should consider when reviewing your wireless technology
options. Here is a list of questions you should ask yourself:
What is my application supposed to do? This is the first question you should ask yourself. You
need to define each mobile user’s needs and create a clear set of objectives. Look at the
processes you will be mobilizing. Understand how they are done now so you can contrast your
new solution to determine the return on investment that mobility can provide. Some tasks are
better left manual, but many will benefit from being automated.
Do I really need wireless? – This may seem like an odd question in the “anytime, anywhere”
world we live in, but it is a significant one. There is a difference between mobile and wireless.
A mobile application is one that can be used away from the office or plant. Mobile applications
can bring huge improvements in productivity, with simple batch processing or synchronization
of data at the beginning and end of a shift. Where wireless makes a difference is where realtime
data is important. This can be in terms of messaging and work order delivery, access to
back-end databases and Geographic Information Systems (GIS), or for the tracking of workers
and vehicles in the field. You need to answer this question honestly, or you may end up with a
set of expensive complex features that are not used, or worse still, an application that doesn’t
deliver the tools and information your mobile worker needs.
Do I need coverage everywhere? – Or, maybe a better way to phrase this is, “Am I willing to
pay a premium to have coverage 100% of the time?” Reviewing the wireless data network
coverage maps for your area and understanding the objectives of your application can answer
this question. If you can live with units going out of coverage occasionally, you can use a
terrestrial wireless data technology. If you can’t afford to have a unit out of the coverage area
for even a moment, then you can’t afford not to use a celestial (satellite) network. These
questions will weigh heavily on the ultimate return on investment your application delivers, and
the cheapest solution often doesn’t return the greatest value to your business.
What kind of device does my field worker need? You need to consider the questions above and
then think about how the mobile device will be used in the field. If the devices going to be used
by sales personnel, you can often get away with consumer-grade hardware like Compaq iPAQs
for mobile wireless applications. If your application is going to be used outdoors by a field
worker like an inspector, lineman or meter reader you’ve got to go with ruggedized hardware.
Remember, when your guy drops a consumer-grade device out of the truck into a puddle, you
lose the device. Sometimes you also lose the data. But you always lose the productivity gains
that the device was supposed to give you until you can get a new device into that worker’s
hands. Ruggedized devices cost more, but they can do a lot to preserve your ROI and decrease
your total cost of ownership.
Wireless data Tecnologies
We’ve gone over more wireless history than you probably care to know. And we’ve briefly
delved into the thought process that goes into planning and implementing your wireless project.
Now we get to the fun stuff – technologies and hardware – but we’ll temper the excitement of
thinking about gadgets with some real considerations of coverage and cost.
CDPD
As noted, Cellular Digital Packet Data has been a workhorse of enterprise wireless data
applications. It wasn’t fast but coverage was pretty good. The ultimate fate of CDPD was
sealed recently when AT&T Wireless announced in October 2002 that it would not be issuing
any new CDPD IP addresses as of March 2003, and that the network would be decommissioned
in March of 2004. This means, if you use CDPD, you better start thinking about a migration
plan now. Verizon, the other major CDPD operator has not announced plans to take down their
network, but overall coverage will be highly diminished when AT&T sends this workhouse out
to pasture. For reference purposes, here are the key statistics on CDPD:
Peak Data Rate: 19.2 kbps
Coverage: Good in many urban and suburban areas, poor in rural areas.
Pros: A proven, if pokey, wireless data technology.
Cons: CDPD’s days seem numbered.
Costs: As of November 2002, Verizon sells CDPD service for $25 per month
for unlimited use with a two-year contract.
