Impedance and delay distortion
The transmission lines will have some portion of background noise, generated by external sources, the transmitter or adjacent lines. This noise is combined with the transmitted signal. The resulting distortion may be less, but the attenuation can cause the digital signal to drop to the level of the noise signal. The level of the digital signal is greater than the level of the noise signal, but approaches the level of the noise signal as it approaches the receiver. A signal made up of multiple frequencies is prone to delay distortion caused by impedance, which is the resistance to change of different frequencies. This can cause the different frequency components contained in the signals to arrive at the receiver out of time. If the frequency is increased, the effect worsens and the receiver will be unable to interpret the signals correctly. This problem can be solved by decreasing the length of the cable. Note that measuring impedance helps us detect cable breaks or missing connections. The cable must have an impedance of 100 ohms at the frequency used to transmit data. It is important to maintain a signal level above the noise level. The biggest source of noise in a multi-wire twisted pair cable is interference. Interference is a breakage of adjacent cables and is not a typical cable problem. Ambient noise in digital circuits is caused by fluorescent lamps, motors, microwave ovens, and office equipment such as computers, fax machines, telephones, and copiers. To measure interference, a signal of known value is injected at one end and the interference in neighboring cables is measured.
• - TIA-526-7 “Measurement of Optical Power Loss of Installed Single-Mode Fiber Cable Plant” – OFSTP-7 - (February 2002).
• - TIA-526-14-A “Optical Power Loss Measurements of Installed Multimode Fiber Cable Plant” – OFSTP-14 - (August 1998).
• - ANSI/TIA/EIA-568-B.1 Telecommunications Wiring for Commercial Buildings, Part 1: General Requirements, May 2001.
• - Addendum ANSI/TIA/EIA-568-B.1-1-2001, Addendum 1, Minimum Bend Radius for 4-Pair UTP and STP Cables, July 2001.
• - TIA/EIA-568-B.1-2 “Commercial Building Telecommunications Cabling Standard Part 1: General Requirements Addendum 2 – Grounding and Bonding Requirements for Screened Balanced Twisted-Pair Horizontal Cabling” - (February 2003).
• - TIA/EIA-568-B.1-3 “Commercial Building Telecommunications Cabling Standard Part 1: General Requirements Addendum 3 – Supportable Distances and Channel Attenuation for Optical Fiber Applications by Fiber Type” - (February 2003).
• - TIA/EIA-568-B.1-4 “Commercial Building Telecommunications Cabling Standard Part 1: General Requirements Addendum 4 – Recognition of Category 6 and 850 nm Laser Optimized 50/125 μm Multimode Optical Fiber Cabling” - (February 2003).
• - TIA/EIA-568-B.1-5 “Commercial Building Telecommunications Cabling Standard Part 1: General Requirements Addendum 5 – Telecommunications Cabling for Telecommunications Enclosures” – (March 2004).
• - TIA/EIA-568-B.1-7 “Commercial Building Telecommunications Cabling Standard Part 1: General Requirements Addendum 7 - Guidelines for Maintaining Polarity Using Array Connectors” – (January 2006).
• - TIA/EIA-568-B.2 “Commercial Building Telecommunications Cabling Standard Part 2: Balanced Twisted-Pair Cabling Components” - (December 2003).
• - TIA/EIA-568-B.2-1 “Commercial Building Telecommunications Cabling Standard Part 2: Balanced Twisted-Pair Cabling Components – Addendum 1 – Transmission Performance Specifications for 4-Pair 100 ohm Category 6 Cabling” - (June 2002).
• - TIA/EIA-568-B.2-2 “Commercial Building Telecommunications Cabling Standard Part 2: Balanced Twisted-Pair Cabling Components – Addendum 2 – Revision of Sub-clauses” - (December 2001).
• - TIA/EIA-568-B.2-3 “”Commercial Building Telecommunications Cabling Standard Part 2: Balanced Twisted-Pair Cabling Components – Addendum 3 – Additional Considerations for Insertion Loss & Return Loss Pass/Fail Determination” - (March 2002).
• - TIA/EIA-568-B.2-4 “Commercial Building Telecommunications Cabling Standard Part 2: Balanced Twisted-Pair Cabling Components – Addendum 4 – Solderless Connection Reliability Requirements for Copper Connecting Hardware” - (June 2002).
• - TIA/EIA-568-B.2-5 “Commercial Building Telecommunications Cabling Standard Part 2: Balanced Twisted-Pair Cabling Components – Addendum 5 – Corrections to TIA/EIA-568-B.2” – (January 2003).
• - TIA/EIA-568-B.2-6 “Commercial Building Telecommunications Cabling Standard Part 2: Balanced Twisted-Pair Cabling Components – Addendum 6 – Category 6 Related Component Test Procedures” – (December 2003).
• - TIA/EIA-568-B.2-11 “Commercial Building Telecommunications Cabling Standard Part 2: Balanced Twisted-Pair Cabling Components – Addendum 11 - Specification of 4-Pair UTP and SCTP Cabling” – (December 2005).
• - TIA/EIA-568-3 “Optical Fiber Cabling Components Standard” - (April 2002).
• - TIA/EIA-568-3.1 “Optical Fiber Cabling Components Standard – Addendum 1 – Additional Transmission Performance Specifications for 50/125 μm Optical Fiber Cables” – (April 2002).
• - TIA-569-B “Commercial Building Standard for Telecommunications Pathways and Spaces” - (October 2004).
• - TIA-598-C “Optical Fiber Cable Color Coding” - (January 2005).
• - TIA/EIA-606-A “Administration Standard for Commercial Telecommunications Infrastructure” - (May 2002).
• - J-STD-607-A “Commercial Building Grounding (Earthing) and Bonding Requirements for Telecommunications” - (October 2002).
• - Electronic Industries Alliance (EIA).
• - Telecommunications Industry Association (TIA).
• - Local area network, Local Area Network (LAN).
• - Wireless local area network, Wireless Local Area Network (WLAN).
• - Metropolitan Area Network, Metropolitan Area Network (MAN).
• - Wide area network, Wide Area Network (WAN).