HTML and CSS Reference
In-Depth Information
14.1.2.1. Low speed
Often known as first- or second-generation data access, low-speed cel-
lular access operates at rates similar to that of a 56-kilobaud dial-up
modem. Providers typically charge by the byte (!), with packages offer-
ing blocks of bytes on a monthly basis. Because of its speed and rel-
atively high cost, low-speed access is intended for intermittent, sparse
use for specific small-volume tasks. Continuous access using these plans
is not feasible, both from the cost perspective and from its arduously
slow data rate. This kind of low-speed access is available exclusively
on mobile phones and some convergence devices from many different
vendors.
14.1.2.2. High-speed cellular access
Recent advances in cellular technology have enabled carriers to offer
high-speed cellular access with speeds ranging up to 1.5 megabits per
second. At these speeds, users can enjoy a high-quality web experience
that includes video and audio content. Recognizing the market potential,
most carriers offer high-speed access in a single-price, unlimited-usage
plan. Marketed under a variety of monikers (such as EDGE and EVDO,
among others), this kind of connectivity was originally deployed in mo-
bile phones, but is fast showing up in PDAs, convergence devices, and
some laptop computers.
14.1.2.3. WiFi
Many web-enabled PDAs and some convergence devices include 802.11
wireless networking and, consequently, can connect with compatible
wireless LAN access points that have become ubiquitous in the last few
years. Whole cities and campuses now provide pervasive wireless and
consequent mobile access to the Internet. While most devices offer the
"b" version of the technology (802.11b), which operates at a maximum
of 11 megabits per second, some newer devices include the "g" version,
which provides for rates up to 54 megabits per second. Access costs
