Using mobile computers when in transit implies mobile computing.
This is effectuated by using wireless technologies such as LAN, WAN,
Wi-Fi, GPRS, etc. LAN refers to Local Area Networking. This is not
a very mobile technology, as it restricts the area of its reach. LAN
refers to the connectivity of two or more fixed or mobile computing
devices within a particular area. This connection can be done physically
by cables (in which case it would not be an example of mobile
computing) or other connections such as infrared rays and wireless
connections. LAN enables computers within its reach to share and compute
data. It is primarily an intranet network.
WAN is Wide Area
Networking. It is wider in its outreach. WAN refers to the connection of
two locations. These locations may be connected internally through LAN
networks. WAN essentially uses wireless connections between its
locations.
MAN is another kind of network used in mobile
computing. It stands for Metropolitan Area Networking and it connects
mobile computing devices within a particular city or metropolitan area.
Devices such as mobile phones and car computers can be hooked up onto
MAN to keep them interconnected. MAN provides speeds of 128 kbps or 256
kbps. Cities such as New York, Philadelphia, Minnesota, Atlanta,
Baltimore, Dallas and about 15 major airports in America are currently
connected by MAN.
Cell phones are currently the most commonly used
mobile computing devices on the planet. They use wireless technologies
such as GSM, CDMA, WLL, GPRS, EDGE, 3G etc. for their connectivity.
Currently, GPRS or General Packet Radio Service is considered a
fast-growing technology. GPRS networks coupled with EDGE or Enhanced
Data Rates for Global Evolution provide fast Internet connection on cell
phones. They can provide data transfer speeds of about 384 kbps, which
are much higher than GSM and CDMA technologies.
Besides these
popular services, there are also some lesser-known networks that have
been introduced lately. One such network, the Metricom, was available in
12 cities and 15 airports. However, it is no longer available due to
the company's financial constraints. ArrayComm and SWIFTComm are
relatively new networks that promise speeds of up to 1 Mbps to the
mobile computer user.
