Although wireless networking and mobile computing are often related, they are not identical. Portable computers are sometimes wired. For example, if a traveler plugs a portable computer into the telephone jack in a hotel, we have mobility without a wireless network. Another example is someone carrying a portable computer along as he inspects a train for technical problems. Here a long cord can trail along behind (vacuum cleaner model).
On the other hand, some wireless computers are not portable. An important example here is a company that owns an older building that does not have network cabling installed and wants to connect its computers. Installing a wireless LAN may require little more than buying a small box with some electronics and setting up some antennas. This solution may be cheaper than wiring the building.
Although wireless LANs are easy to install, they also have some disadvantages. The error rates are often much higher, too, and the transmissions from different computers can interfere with one another.Typically they have a capacity of 11 Mbps (IEEE 802.11b), which is much slower than wired LANs.
Wireless networks come in many forms. Some universities are already installing antennas all over campus to allow students to sit under the trees and consult the library's card catalog. Here the computers communicate directly with the wireless LAN in digital form. Another possibility is using a cellular (i.e., portable) telephone with a traditional analog modem. Direct digital cellular service, such as CDPD (Cellular Digital Packet Data), GPRS(General Packet Radio Service), SMS(Short Message System) and MMS(Media Message System) is becoming available in many cities.
As laptops become smaller, mobile phones become more versatile, and both become more affordable, the future progression of wireless networking and mobile computing seems to be certain. Furthermore, many people are becoming more accustomed to computing from anywhere and on the go. Checking bank transactions, restaurant suggestions, taking courses at online universities, and up to date traffic and directions are just a few conveniences people enjoy. Does this assure the future of these technologies, though?
While many people believe that wireless portable computers are the wave of the future, at least one dissenting voice has been heard. Bob Metcalfe, the inventor of Ethernet, has written: "Mobile wireless computers are like mobile pipeless bathrooms--portapotties. They will be common on vehicles, and at construction sites, and rock concerts. My advice is to wire up your home and stay there" (Metcalfe, 1995). Will most people follow Metcalfe's advice? Time will tell.