Today XDSL, cable modem and wireless network solutions are used to connect the high speed networks without the much cost that is associated with the dedicated circuits and frame relay network technologies. XDSL collectively refers to all DSL (digital subscriber’s lines). DSL or XDSL is a technology that allows the data transmission over the regular telephone lines. XDSL is a coding technique that allows digital signals up to 50 Mbps over the copper pair cables. The XDSL technology assumes that digital data does not require to be changed into analog and vice versa. Instead digital data is transmitted to the computers directly as digital data. XDSL technology uses more bandwidth on the regular phone lines.
In order to utilize more frequencies and bandwidth XDSL equipment must be installed at both ends and the copper wire between the two devices. Video on demand is a relatively new service that can be offered on the XDSL cable. The “X” in the XDSL signifies that there are different flavors in the DSL technology. XDSL provides the direct link and network communication between the customer and the career.
DSL is widely used in the telecommunication networks and in the broadband services to the corporate offices and the home users. DSL technology uses different modulation techniques such as two binary one quaternary, discrete multi tone, quadrature amplitude modulation, career less amplitude and phase modulation. These modulation techniques are standardized by the international standardized organizations.
The associated flavors and the common types of the DSL are HDSL, XDSL, VODSL, ADSL, VDSL and SDSL (Single pair digital subscriber lines). DSL technologies also known as last mile technologies because they are used for the data transmissions from the DSL stations to the subscriber’s home or office.
XDSL with the lower data transmission rate like 1.5 Mbps is being used in the residences. The high data transmission XDSL provides transmission rate up to 50 Mbps and is being used in the business sector and the VDSL.
In operations XDSL is similar to the ISDN lines because both operate over the copper telephone lines (POTS). XDSL provides high speed for the data/signal transmissions i.e. up to 32 Mbps for the upstream and the 32 Kbps to 1 Mbps for the downstream speed.
XDSL is a high speed connection but on the downside it has some distance limitations. Among the other limitations include bundling of wire, line impairment and only a small number of people can be benefited from the XDSL over the existing copper base.
There are some other types of the XDSL, which includes VODSL (Voice DSL) and VDSL. Voice traffic has high priority over the data traffic to ensure the quality of service and the data transmission rate up to 1.5 Mbps. Other the other hand VDSL (Very High Bit Rate DSL) supports 13 Mbps to 55 Mbps over the twisted pair cable.