Early attempts at data transmission used either an analog
modem or CDPD, but these never really proved financially
rewarding to the carriers. The analog modems are very slow and
do not warrant further discussion. CDPD transmitted packet
data over an analog network. It was a niche market rather than
a mass market: Data rates were moderate (19.2 Kbps), phones
and modems were expensive, applications were very limited,
and most people never even knew that it existed. CDPD is still
in use as a slow-speed (by today’s standards), Wireless Internet
connection on analog and dual-mode phones.
Newer equipment and protocols have resulted in many
wireless transmission schemes, some competitive (directly or
indirectly) and some complementary to the others. For limited
mobility applications, we have wireless local and personal area
networks (WLANs and PANs) with standards such as Home
RF, IEEE 802.11, or Bluetooth. Mobile data networks such as
Mobitex and Ardis, for public or private wide area networks are
used mostly for dispatch and service industries. Wireless PDAs
(Palm, Handspring, etc.) and Pocket PCs (Compaq, HP, etc.)
have their own data networks such as OmniSky or they use a
cellular phone with a modem. In the cellular networks themselves,
SMS, WAP, I-Mode, and J2ME compete as data application
platforms. GPRS competes with CDPD or other modem
technology on cellular phones. Yet, all of these technologies are
needed to make wireless mobility truly ubiquitous. (A more indepth
description of the technical characteristics of these significant
technologies follows in Chapter 2.)
With the proliferation of so many standards as shown in
Figure 1-10, there is an increasing need for convergence. Users
will demand that their Wireless Internet service be simple, fast
and uninterrupted. Many locations such as inside buildings are
very difficult for wireless carriers to provide adequate coverage.
One possible solution maybe the construction of public
WLANs. Wireless LANs are currently being built because the
technology is fast, proven, inexpensive and available. Wireless
Internet users who operate within a WLAN environment can
get better coverage than that promised by 3G. The bandwidth available is up to 11 Mbps with 802.11b. Other technologies
could result in even higher bandwidths. Solutions will be created
that make the experience as simple as possible for both
the users and the wireless providers. If billing is handled by the
wireless provider on the users existing account, incremental
income is realized and the carriers like that rather than viewing
the WLAN as a competitor.