Link for Transmission media cable
https://www.technologyuk.net/telecommunications/networks/transmission-media.shtml
Network Transmission Media
Various physical media can be used to transport a stream of bits from one device to another. Each has its own characteristics in terms of bandwidth, propagation delay, cost, and ease of installation and maintenance. Media can be generally classified as guided (e.g. copper and fibre cable) and unguided (wireless) media. The main categories of transmission media used in data communications networks are listed below (please note that wireless transmission media will be dealt with elsewhere).
Twisted pair copper cable
Coaxial copper cable
Optical fibre
Wireless transmission
Twisted pair cable
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Twisted pair copper cable is still widely used, due to its low cost and ease of installation. A twisted pair consists of two insulated copper cables, twisted together to reduce electrical interference between adjacent pairs of wires. This type of cable is still used in the subscriber loop of the public telephone system (the connection between a customer and the local telephone exchange), which can extend for several kilometres without amplification. The subscriber loop is essentially an analogue transmission line, although twisted pair cables are also be used in computer networks to carry digital signals over short distances.
The bandwidth of twisted pair cable depends on the diameter of wire used, and the length of the transmission line. The type of cable currently used in local area networks has four pairs of wires. Until recently, category 5 or category 5E cable has been used, but category 6 is now used for most new installations. The main difference between the various categories is in the data rate supported - category 6 cable will support gigabit Ethernet. The main disadvantage of UTP cables in networks is that, due to the relatively high degree of attenuation and a susceptibility to electromagnetic interference, high speed digital signals can only be reliably transmitted over cable runs of 100 metres or less.
Unshielded twisted pair cable
Shielded Twisted Pair (STP) cable was introduced in the 1980s by IBM as the recommended cable for their Token Ring network technology. It is similar to unshielded twisted pair cable except that each pair is individually foil shielded, and the cable has a braided drain wire that is earthed at one end during installation. The popularity of STP has declined for the following reasons:
High cost of cable and connectors
More difficult to install than UTP
Ground loops can occur if incorrectly installed
There is still a cable length limitation of 100 metres
Shielded twisted pair cable
Coaxial cable
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A coaxial cable has a central copper wire core, surrounded by an insulating (dielectric) material. Braided metal shielding surrounds the dielectric and helps to absorb unwanted external signals (noise), preventing it from interfering with the data signal travelling along the core. A plastic sheath protects the cable from damage. A terminating resistor is used at each end of the cable to prevent transmitted signals from being reflected back down the cable. The following diagram illustrates the basic construction of a coaxial cable.
Construction of coaxial cable
Coaxial cable has a fairly high degree of immunity to noise, and can be used over longer distances (up to 500 metres) than twisted pair cable. Coaxial cable has, in the past, been used to provide network backbone cable segments. Coaxial cable has largely been replaced in computer networks by optical fibre and twisted pair cable, with fibre used in the network backbone, and twisted pair used to connect workstations to network hubs and switches.
Thicknet cable (also known as 10Base5) is a fairly thick cable (0.5 inches in diameter). The 10Base5 designation refers to the 10 Mbps maximum data rate , baseband signalling and 500 metre maximum segment length . Thicknet was the original transmission medium used in Ethernet networks, and supported up to 100 nodes per network
https://www.technologyuk.net/telecommunications/networks/transmission-media.shtml
Network Transmission Media
Various physical media can be used to transport a stream of bits from one device to another. Each has its own characteristics in terms of bandwidth, propagation delay, cost, and ease of installation and maintenance. Media can be generally classified as guided (e.g. copper and fibre cable) and unguided (wireless) media. The main categories of transmission media used in data communications networks are listed below (please note that wireless transmission media will be dealt with elsewhere).
Twisted pair copper cable
Coaxial copper cable
Optical fibre
Wireless transmission
Twisted pair cable
[Return to top of page]
Twisted pair copper cable is still widely used, due to its low cost and ease of installation. A twisted pair consists of two insulated copper cables, twisted together to reduce electrical interference between adjacent pairs of wires. This type of cable is still used in the subscriber loop of the public telephone system (the connection between a customer and the local telephone exchange), which can extend for several kilometres without amplification. The subscriber loop is essentially an analogue transmission line, although twisted pair cables are also be used in computer networks to carry digital signals over short distances.
The bandwidth of twisted pair cable depends on the diameter of wire used, and the length of the transmission line. The type of cable currently used in local area networks has four pairs of wires. Until recently, category 5 or category 5E cable has been used, but category 6 is now used for most new installations. The main difference between the various categories is in the data rate supported - category 6 cable will support gigabit Ethernet. The main disadvantage of UTP cables in networks is that, due to the relatively high degree of attenuation and a susceptibility to electromagnetic interference, high speed digital signals can only be reliably transmitted over cable runs of 100 metres or less.
Unshielded twisted pair cable
Shielded Twisted Pair (STP) cable was introduced in the 1980s by IBM as the recommended cable for their Token Ring network technology. It is similar to unshielded twisted pair cable except that each pair is individually foil shielded, and the cable has a braided drain wire that is earthed at one end during installation. The popularity of STP has declined for the following reasons:
High cost of cable and connectors
More difficult to install than UTP
Ground loops can occur if incorrectly installed
There is still a cable length limitation of 100 metres
Shielded twisted pair cable
Coaxial cable
[Return to top of page]
A coaxial cable has a central copper wire core, surrounded by an insulating (dielectric) material. Braided metal shielding surrounds the dielectric and helps to absorb unwanted external signals (noise), preventing it from interfering with the data signal travelling along the core. A plastic sheath protects the cable from damage. A terminating resistor is used at each end of the cable to prevent transmitted signals from being reflected back down the cable. The following diagram illustrates the basic construction of a coaxial cable.
Construction of coaxial cable
Coaxial cable has a fairly high degree of immunity to noise, and can be used over longer distances (up to 500 metres) than twisted pair cable. Coaxial cable has, in the past, been used to provide network backbone cable segments. Coaxial cable has largely been replaced in computer networks by optical fibre and twisted pair cable, with fibre used in the network backbone, and twisted pair used to connect workstations to network hubs and switches.
Thicknet cable (also known as 10Base5) is a fairly thick cable (0.5 inches in diameter). The 10Base5 designation refers to the 10 Mbps maximum data rate , baseband signalling and 500 metre maximum segment length . Thicknet was the original transmission medium used in Ethernet networks, and supported up to 100 nodes per network
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