Digital Subscriber Line (DSL)
Digital Subscriber Line (DSL) is a method of internet connection which gives the user the ability to connect to the internet at an very high rate of speed over their regular phone lines by using special hardware attached to both the user and switch ends of line.
DSL service attaches to your existing phone line, giving you a constant connection to the internet without trying up the phone line.
It is similar to the service provided by some cable companies. DSL gives you great data transmission speed, but distance limitations and line quality conditions can reduce what will actually be achievable.
This technology is still in the early stages. These digital services will ultimately be used to deliver bandwidth- intensive applications like video on demand and distance learning.
The advantage of DSL is that it is circuit oriented so that each connection is independent of all others, while cable networks are broadcast oriented, with each subscriber in an area receiving the same signals as all others in that area.
Cable networks are inherently hierarchical in nature and thus require two paths, one for downstream and one for upstream.
This requires either a second cable plant for upstream or a second frequency band allocated onto the existing system.