資料紹介
What is DSL?
I researched about DSL. DSL is a very high-speed connection for Internet.
There are several kinds of popular connections for Internet. One ways is modem, which we use telephone line. Second way is LAN (Local Area Network). This connection mostly used in school or company. Third way is using Cable Modem. Many people, who are watching Cable TV, can have this connection from your cable TV provider. And the fourth way, which I will talk about is DSL. DSL is the short word for Digital Subscriber Line.
DSL use the same connection that we use in telephone line. This connection can send and receive very high amount of data. So its makes much easier to access picture, music and movie and many other stuffs. I think DSL will create the new period of Information Technology.
History of DSL
First theoretical experiment for DSL was happened in 1978 at AT & T Bell Laboratory.
But a semiconductor technology wasn’t high enough to use effectively. So this experiment (DSL) stopped temporarily at that time.
After few years later, at 1988, new DSL technology called DWM (Duplex Wideband Modem) development project started at Bell Laboratory. This is the origin for xDSL technology.
Most important purpose was the Telephone Company want to provide more fast connection service called T1 (1.5Mbps personal connection).
And the first DSL developed in 1990. That is called ADSL (Asymmetric DSL). This purpose was for VOD (Video on Demand – Service that we can select which video channels we want to watch) so, downloading speed was fast and the uploading speed was slow (Asymmetry).
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What is DSL?
I researched about DSL. DSL is a very high-speed connection for Internet.
There are several kinds of popular connections for Internet. One ways is modem, which we use telephone line. Second way is LAN (Local Area Network). This connection mostly used in school or company. Third way is using Cable Modem. Many people, who are watching Cable TV, can have this connection from your cable TV provider. And the fourth way, which I will talk about is DSL. DSL is the short word for Digital S...
