Biomedical Engineering Reference
In-Depth Information
Geographical Scope
The geographical extent of a network is significant because it affects bandwidth, security, response
time, and the type of computing possible. For example, it is only because of the high-speed Internet
backbone that real-time teleconferencing and model sharing are possible on a worldwide basis.
Although the geographical boundaries are somewhat arbitrary the networks are commonly referred to
as personal area networks (PANs), LANs, metropolitan area networks (MANs), or wide area networks
(WANs), as depicted in
Figure 3-3
. Although many networks are interconnected, they can also
function alone.
Figure 3-3. Network Geographical Scope. Bioinformatics R&D incorporates
network resources on worldwide (WAN), institution-wide (MAN), and
laboratory-wide (LAN and PAN) levels.
PANs, which are limited to the immediate proximity of the user, or about a 10-meter radius, are
typically constructed using wireless technology. LANs extend to about 100-meters from a central
server, or a single floor in a typical research building. MANs take over where LANs leave off, covering
entire buildings and extending tens of kilometers. MANs are typically implemented with digital
subscriber line (DSL), cable modem, and fixed wireless technologies. WANs extend across the
continent and around the globe, and are typically composed of a combination of terrestrial fixed
satellite systems, coaxial cable, and fiber optical cable. The public switched telephone network and
the Internet are examples of WANs.
Grid computing, in which multiple PCs are interconnected to form a distributed supercomputer, can
take advantage of LAN, MAN, and WAN technology, as a function of computer processing speed,
network connection bandwidth, and the effectiveness of the software that coordinates activities
