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.