ADSL Vs DSL Modem

Well most of you who have browsed through the Internet and reached this article are basically trying to find out the difference between ADSL and DSL modem. However, the answer can be a straight forward yes or no to whether there is any any ADSL and DSL difference or not. But, the solution to ADSL vs DSL modem query is not something that can be understood very easily. We need to understand some basic aspects before going into the details of the ADSL vs DSL modem comparison (if there is any).

What is a DSL Modem?

A modem as most of us know is a device that is used for modulation and demodulation of the data that is transmitted or received, respectively. Now, what does a voiceband modem do, when used for connecting to a network, such as the Internet. Well, it converts the digital data of the computer into sound signals and transmits it through the telephone channel. Similarly, it converts the voice signals that it receives to the digital data. This is how a simple voiceband modem works. The problem that the voiceband modems faced was their slow speed. A voiceband modem when connected to an ordinary copper telephone cable could only use a frequency range of 3400 Hz from the available bandwidth. But 56,000 bits per second, is the bandwidth allowed for communication through the lines. High speed Internet access or LAN access, video catalogs, electronic library viewing, etc. was not possible while using a voiceband modem. Besides, when the voiceband modem is connected to the telephone line for data transfer from the different terminals in a network, it was not possible to use the telephone at the same time. This gave rise to the need of a different modem, to access the network at a high speed and at the same time use the telephone lines too. Read more on what is the function of a modem.

Thus, the DSL (Digital Subscriber Line) came into existence. This technology allowed the use of the same telephone lines, made of copper to carry data using a very high bandwidth. This not only increased the speed but also allowed the use of the telephone line at the same time, when digital data was transferred using the same cable. The DSL modem allowed data to be transmitted and received a higher speed. All that is required is a DSL modem connected to the user's terminal and a similar DSL modem connected at the service provider's terminal. The basic features of a DSL modem which helped it gain an edge over the voiceband modems can be listed as under:

• Digital signals uses a technology to encode and decode data at a single carrier frequency.
• DSL modems can very effectively separate voice data used for the telephone connections and digital data, very effectively in the same communication channel.
• These modems also provide very effective channel separation.
• DSL modem uses the DSL protocol for transmission and reception of data.

Read more on DSL vs cable modem.

What is an ADSL Modem?

An ADSL (Asynchronous Digital Subscriber Line) is one of the types of DSL broadband communication technology. Hence, need less to say, an ADSL modem is a type of DSL modem. A downstream speed of 1.5 to 9 MBPS is possible and an upstream speed of 16 to 640 KBPS is possible, when using the ADSL modem. Now, the question that must be hitting your mind is that, then what is the difference between ADSL and DSL. Well, DSL modems can be of two types, SDSL (Synchronous Digital Subscriber Line) and ADSL. The difference comes when we use the word ADSL, we mean that data is sent and received at different speeds. It means that your modem sends data to your service provider at one speed and the downstream data, the data that you receive from the service provider is at a different speed. Hence, the word asynchronous has its significance in ADSL. The service in general is tiered, hence you pay different rates for different speeds.

ADSL Vs DSL Modem

I hope the answer must have already been clear. But still, let me give you a proper conclusion to the same discussion that we had above. DSL modem can have two types, SDSL and ADSL. Though, most of the times when we use the word DSL, we generally refer to the ADSL modem, but in certain cases, it can even be the SDSL modem. Hence, this is the difference. An ADSL modem can send and receive data at different speeds while SDSL modem can send data at only one speed.

That was all about ADSL and DSL difference. One is just the subset of the other. Hope this article on ADSL vs DSL modem proves to be of some help in getting your doubts cleared regarding these two terms.