Cables and its TypesEmirates Office Systems and Supplies

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Introduction

This presentation discusses 3 types of Cables:

Coaxial Cables

Twister Pair Cables

Fiber Optic Cables

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COAXIAL CABLE

Consists Of Five Parts:

A center conductor

Insulation covering the center conductor, called a "dielectric“

A braided shield surrounding the dielectric

An optional foil shield

An outer jacket

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Cross Section View

Figure 2.1

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Coaxial Cable with Foil Shield

Figure 2.2

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Coaxial Cable Connectors

1. RCA Connector

The same basic connector is still in wide use today in home theater cables

Easy to connect and disconnect

Each signal is sent on a different cable

Yellow – Video White – Audio Right Red – Audio Left

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Coaxial Cable Connectors

1. BNC Connector

The BNC (Bayonet Neill-Concelman) connector is a very common type of RF connector used for terminating coaxial cable

BNC connector has two bumps on the female side that slide into corresponding grooves on the male side

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Coaxial Cable Connectors

1. F-pin Connector

The F-pin connector is probably the most recognized of the coaxial connectors

Used with televisions and VCRs for decades

Easiest to attach to a coax cable as it does not require any soldering

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Cable Types

1. RG 58

Core diameter: 0.9mm

Impedance: 75 Ω

Largely used in the commercial security camera industry

Cable can also be found attached to testing equipment and 2-way radio systems.

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Cable Types

2. RG 59

Core diameter: 0.81mm

Impedance: 50 Ω

Once the standard for cable TV, RG59 cables are still found packaged with VCRs and TV’s

RG6 coaxial cable is becoming much more popular, making RG59 no longer the industry standard.

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Cable Types

3. RG 6

Core diameter: 1.0mm

Impedance: 75 Ω

RG6 cable is differentiated from RG59 cable by having a thicker copper center conductor

Used in professional video applications, carrying either baseband analog video signals or serial digital interface (SDI) signals

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Advantages Of Coaxial Cable

Signals entering the cable can cause unwanted noise making it useless.

A continuous current flow, even if small, along the imperfect shield of a coaxial cable can cause visible or audible interference.

More expensive than twisted pairs and is not supported for some network standards.

Bulky and also has high attenuation so would have the need to implement repeaters

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Disadvantages Of Coaxial Cable

Signals entering the cable can cause unwanted noise and picture ghosting. Excessive noise can overwhelm the signal, making it useless.

A continuous current flow, even if small, along the imperfect shield of a coaxial cable can cause visible or audible interference.

More expensive than twisted pairs and is not supported for some network standards.

It’s also very bulky and also has high attenuation so would have the need to implement repeaters

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TWISTED PAIR CABLE

• Twisted pair cable consists of a pair of insulated wires twisted together.

• It is a cable type used in telecommunication for very long time.

• Cable twisting helps to reduce noise pickup from outside sources and crosstalk on multi-pair cables.

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Individual color coded cables of UTP15

Classification of TP

Twisted Pair cables are classified into 2 main types:

1. Unshielded Twisted Pair2. Shielded Twisted pairTwisted Pairs are used to carry data speeds from

10 Mbps to 100 Mbps, but speed can be decreased by number of error characteristics

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Twisted Pair View

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Unshielded Twisted Pair

UTP are used for voice and low speed data communication since a long time.

• Unshielded Twisted Pair cables were first used in telephone systems by Alexander Graham Bell in 1881.

• Today, most of the millions of kilometres of twisted pairs in the world are outdoor landlines.

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UTP

• UTP cables are found in many Ethernet networks and telephone systems. For indoor telephone applications, UTP is often grouped into sets of 25 pairs according to a standard 25-pair color code.

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UTP – General Overview• Typical UTP cable has four pairs of wires in each

cable. Not all four pairs are used in actual applications.

• For most LANs, only two pairs are used, one in each direction to allow full duplex, simultaneous bidirectional communications.

• Due to the limitation on bandwidth and emission of radiation that could potentially affect other electronic devices, the higher speed networks are migrating toward using all four pairs.

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UTP

• The cable has four pairs of wires inside the jacket.

• Each pair is twisted with a different number of twists per inch to help eliminate interference from adjacent pairs and other electrical devices.

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Classification of UTP

• The tighter the twisting of the UTP, the higher the supported transmission rate and the greater the cost per foot.

• The EIA/TIA (Electronic Industry Association/Telecommunication Industry Association) has established standards of UTP and rated six categories of wire (additional categories are emerging).

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Categories of UTPCategory Speed Use

1 1 Mbps Voice Only (Telephone Wire)

2 4 Mbps Local talk & Telephone (Rarely used)

3 16 Mbps 10BaseT Ethernet

4 20 Mbps Token Ring (Rarely used)

5 100 Mbps (2 pair)1000 Mbps (4 pair)

100BaseT EthernetGigabit Ethernet

5e 1,000 Mbps Gigabit Ethernet

6 10,000 Mbps Gigabit Ethernet

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• Category 1There are no performance criteria for this cable. Functional it is equivalent to UL level 1. The cable usage is for basic communications and power-limited circuits.

• Category 2Usage up to 2 MHz, not EIA/TIA specified for data use. Functional equivalent to UL level 2 or IBM Type 3. The usage is voice and low-speed data.

• Category 3Usage up to 16 MHz, EIA/TIA 568 Commercial Building Telecommunications Wiring Standard for Horizontal UTP Cable (TSB PN-2841) for both UTP and STP. Functional equivalent to UL level 3. Usage e.g. 4 Mbps Tokenring 10 Mbps ethernet.1.25"-2.50"/twist4.8"-9.6"/foot

• Category 4Usage up to 20 MHz, EIA/TIA 568 TSB PN-2841 for both UTP and STP. Functional equivalent to UL level 4. Usage e.g. 16 Mbps Tokenring 10 Mbps ethernet.0.60"-1.00"/twist ..12"-20"/foot 24

Widely Used Categories of Cables

• The three most popular and widely used cables are Cat 5, Cat 5e, and Cat 6.

• It is important to pick the right category cable for the project that you are doing.

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Cat 5

Cat 5• Category 5 cable can be used to carry Ethernet traffic of up to 100Mbit/s

and ATM of up to 155Mbit/s. • The standard cable of an Ethernet 100Base-TX is Cat 5. Cat 5 is a twisted

pair cable created for high signal integrity. • Some are unshielded while others are shielded. Applications of Cat 5• Cat 5 is used in structured cabling for computer networks, token ring,

basic voice services, and ATM. • The Category 5 cable has four twisted pairs in a single cable jacket. • Cat 5 generally has three twists per inch of each individual twisted pair of

24 gauge wires inside of the cable.

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Cat 5e

• Category 5e is an upgraded version of the Cat 5 standard and is capable of carrying data up to 1000Mbit/s.

• Cat 5e is the standard cable for use in Ethernet 1000Base-T. • Cat 5e is able to carry data longer distances than Cat 5. Cat 5e can be used

confidently for 350 meters. Cat 5e has better performance measures.• Stranded is much more flexible and is used for military applications. • Cat 5e is terminated in two different schemes, but there is no difference in

the scheme used.

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Cat 6

• Cat 6 is similar to Cat 5e but is designed with even stricter standards. • Cat 6 is backward compatible with Cat 5/Cat 5e. • Cat 6 has a standard performance of 250 MHz and works with both

1000BASE-T and 10BASE-T / 100BASE-TX• It also works with 10GBASE-T standard, but there are limits if Cat 6

unshielded cable is used. • Like earlier Cat 5e/ Cat 5, Cat 6 contains four twisted copper wire pairs.

The cable is made usually with 22 to 24 AWG gauge wire.• The cable is made usually with 22 to 24 AWG gauge wire. Cat 6, when

used in a patch cable function, is often terminated with a RJ-45 connection.

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UTP Uses• UTP cabling, because of its 100-year history of use by telephone systems,

both indoors and out, is also the most common cable used in computer networking. It is a variant of twisted pair cabling.

• UTP cables are often called Ethernet cables after Ethernet, the most common data networking standard that utilizes UTP cables, although not the most reliable.

• UTP is the most common type of media used for communications systems and in structured cabling systems.

• UTP cable is used extensively due to its flexibility. • UTP can be used for voice, low-speed data, high-speed data, audio and

paging systems, and building automation and control systems.• UTP cable can be used in both the horizontal and backbone cabling

subsystems.• For horizontal cables, the number of pairs recommended by industry

standards is a four-pair cable29

Shielded Twisted Pair:

• Although UTP cable is the least expensive cable, it may be susceptible to radio and electrical frequency interference.

• If you must place cable in environments with lots of potential interference, or if you must place cable in extremely sensitive environments that may be susceptible to the electrical current in the UTP, shielded twisted pair may be the solution.

• Shielded cables can also help to extend the maximum distance of the cables.• Twisted pair cables are often shielded in attempt to prevent electromagnetic

interference. • Because the shielding is made of metal, it may also serve as a ground. • However, usually a shielded or a screened twisted pair cable has a special

grounding wire added called a drain wire. This shielding can be applied to individual pairs, or to the collection of pairs. When shielding is applied to the collection of pairs, this is referred to as screening.

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STP

• STP cabling includes metal shielding over each individual pair of copper wires.

• This type of shielding protects cable from external EMI (electromagnetic interferences). e.g. the 150 ohm shielded twisted pair cables defined by the IBM Cabling System specifications and used with token ring networks.

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Screened Shielded Twisted Pair

• ScSTP cabling, also known as Screened Fully shielded Twisted Pair (ScFTP) is both individually shielded (like STP cabling) and also has an outer metal shielding covering the entire group of shielded copper pairs (like ScUTP). This type of cabling offers the best protection from interference from external sources.

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Parameters that Effect Performance of TP

The different kinds of error characteristics are:1. Attenuation2. Near-End Cross Talk3. Return Loss4. Attenuation to Cross Talk Ratio5. Impedance6. Propagation Delay

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FIBER OPTICS• Cable consisting of one or more optical fibers.

• An optical fiber is made up of the core, cladding and the buffer coating.

• Fiber elements are coated with plastic layers for protection.

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Cross Sectional View

1. Core: 8 µm diameter2. Cladding: 125 µm dia.3. Buffer: 250 µm dia.4. Jacket: 400 µm dia.

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Characteristics

Fibre optical cables are widely used in communication over long distances.

The fibre is immune to electromagnetic interference resulting in very low loss.

There is no crosstalk.

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Total Internal Reflection

• The fibre optic works on the principle of Total Internal Reflection.

• The light ray is guided along the cable without escaping.

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Refraction through Fiber

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Types Of Fibers

• Single Mode Fiber

• Multimode Fiber

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Single Mode Fiber

• Small core of diameter 8-10 um.

• Can be used over a range of 2 Km.

• Used for telecommunication in wide area networking.

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Fiber Coating

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Multi Mode Fiber

• Much larger core than single mode.

• Core diameter of 62.5 to 125 um.

• Allows hundreds of ray to pass simultaneously.

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Multi Mode Characteristics

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Manufacturing

• Glass Optical Fibres are made of mainly silica and have a refractive index of 1.5.

• Some other materials like flourozirconate and flouroaluminate are also used.

• Plastic Optical Fibres have a refractive index of 0.5.

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Silica & Phosphate Structure

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Splicing

• Optical Fibres may be joined together by the process of splicing.

• Fusion Splicing is done using a specialised equipment called spilicing machine.

• It is done when two fibres are to be joined together.

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Splicing Machine

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References

1. physics.princeton.edu2. www.lanshack.com3. www.doityourself.com4. www.books.googles.com5. www.whatis.techtarget.com6. www.merriam-webster.com7. www.engineeringtoolbox.com

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