Digital Signal 3 (DS3 or T3 line) is a digital signal level 3

T-carrier The T-carrier is a member of the series of carrier systems developed by AT&T Bell Laboratories for digital transmission of multiplexed telephone calls. The first version, the Transmission System 1 (T1), was introduced in 1962 in the Bell Syst ...

. The data rate for this type of signal is 44.736 Mbit/s (45 Mb). It can transport 28 DS1 level signals within its payload. It can transport 672 DS0 level channels within its payload. Such circuits are the usual kind between telephony carriers, both wired and

wireless Wireless communication (or just wireless, when the context allows) is the transfer of information (''telecommunication'') between two or more points without the use of an electrical conductor, optical fiber or other continuous guided transm ...

, and typically by OC1 optical connections.

Cabling

DS3 interconnect cables must be made with true 75-ohm

coaxial cable Coaxial cable, or coax (pronounced ), is a type of electrical cable consisting of an inner Electrical conductor, conductor surrounded by a concentric conducting Electromagnetic shielding, shield, with the two separated by a dielectric (Insulat ...

and connectors. Cables or connectors which are 50 ohms or which significantly deviate from 75 ohms will result in

signal reflection In telecommunications, signal reflection happens when a signal is transmitted along a transmission medium (such as a copper cable or an optical fiber) and part of it is reflected back toward the source instead of reaching the end. This reflection ...

s which will lower the performance of the connection, possibly to the point of not working
GR-139-CORE
''Generic Requirements for Central Office Coaxial Cable'', defines type 734 and 735 cables for this application. Due to losses, there are differing distance limitations for each type of cable. Type 734 has a larger center conductor and insulator for lower losses for a given distance. The

BNC connector The BNC connector is a miniature quick-connect/disconnect RF connector, radio-frequency connector for coaxial cable. It was introduced on military radio equipment in the 1940s, and has since become widely used in radio systems and as a common t ...

s are also very important as are the crimping and cable stripping tools used to install them. Trompeter, Cannon, Amphenol, Kings, and Canare make some of the most reliable 75 ohm connectors known.

RG-6 RG-6/U is a common type of coaxial cable used in a wide variety of residential and commercial applications. An RG-6/U coaxial cable has a characteristic impedance of 75 ohms. The term, ''RG-6'', is generic and is applied to a wide variety of c ...

or even inexpensive

RG-59 RG-59/U is a specific type of coaxial cable, often used for low-power video and Radio frequency, RF signal connections. The cable has a characteristic impedance of 75 Ohm (unit), ohms, and a capacitance of around 20pF/ft (60pF/m). The 75 oh ...

cable may work temporarily when properly terminated, though it does not meet telephony technical standards. Type 735 26 AWG is used for interconnects up to 225 feet, and Type 734 20 AWG is used for interconnects up to 450 feet.

Pricing

DS3 service is provided to businesses in the United States through

incumbent local exchange carrier An incumbent local exchange carrier (ILEC) is a local telephone company which held the regional monopoly on landline service before the market was opened to competitive local exchange carriers, or the corporate successor of such a firm, in the Un ...

and

competitive local exchange carrier A competitive local exchange carrier (CLEC) is a North American telecommunications provider classification that emerged based on the competition model of the Telecommunications Act of 1996 in the United States. The act required the previously esta ...

communication providers. The price, much like a T1 (or DS1) line, has two primary components: the loop (which is distance-sensitive) and the port (or the price the carrier charges to access the internet through their proprietary network).

References

External links

Detailed/Technical DS3-T3 Definition

The Fundamentals of DS3, Technical Note, Acterna, TB-FUNDS3-B-2/01
Telecommunications standards {{telecomm-stub

Cabling

Pricing

See also

References

External links