Structured Data Cabling

 

 

 

 

 

 

 

 

 

CSCS Card

a cscs card is required before you are allowed to work on site this involves learning about health and safety and an addon module should be added (working at heights) also working with hazardous substances should be completed now or at a later time. the link bellow shows how to get the ball rolling.

http://www.ctcswl.co.uk/cscs

3667-02 Course Outline and details

http://www.cityandguilds.com/documents/ind_cleaning/Level_2_award_3667-02_Handbook_Final_v2.pdf

 

3667-02 Module one

Unit 101

Outcome 1

Principles of communications cabling

Identify safe working practices in Communication systems

Underpinning knowledge

The candidate will be able to

 

1 state the rules for safe working when undertaking installation eg

working in confined spaces

electrical safety including grounding/bonding

fire stopping

 

2 statutory requirements, Health and Safety at Work Act (HASAWA)/Control of Substances

Hazardous to Health (COSHH) or relevant national safety standards

asbestos awareness

state the rules for safe working when carrying out preparation in terms of safe handling and containment of cleaning materials

 

3. safe use of cutting and stripping tools

the disposal of waste material

state the rules for safe working and any special precautions when carrying out a

communications installation in terms of selection and use of tools and materials

 

4. identification of hazardous working conditions

hazardous environment

state the rules for safe working and any special precautions to be observed when

terminating cables in terms of

• identification of hazardous working conditions

• correct and safe use of tools and equipment

• correct waste disposal

• storage of tools

• safe working when handling cable

• care in using chemicals for cleaning

• care in use of resins and adhesives.

 

Unit 101

Outcome 2

Principles of communications cabling

Describe the basic principles of SI units and symbols

Underpinning Knowledge

 

The candidate will be able to:

Identify basic SI units

kilogram (kg) 1000 grams

second (s)

ampere (A)

metre (m)

Kelvin (K)

identify names and symbols for preferred SI prefixes

giga (G)

mega (M)

kilo (k)

milli (m)

micro (μ)

nano (n)

tera (T)

pico (p)

identify waves and wave motion , sound waves ,electromagnetic waves

define amplitude, wavelength (λ), frequency (f) and the unit of frequency (hertz)

state the relationship between velocity, frequency and wavelength (v = fλ)

 

Unit 101

Outcome 3

Principles of communications cabling

Describe the basic principles of communications

systems

Underpinning Knowledge

 

The candidate will be able to:

1 state the meaning of ‘telecommunications’

 

2 identify basic communication systems

• information source (transmitter)

• information destination (receiver)

• transmission/ transfer link (communications channel)

 

3 outline the basic principles of cable systems: eg the source is directly connected to the

receiver by means of cable links; attenuation is directly proportional to the distance travelled

 

4 state the sources of interference: eg electromagnetic radiation and unwanted signals

 

5 list sources of distortion: eg non-linearity, harmonics

 

6 identify the properties of differing types of transmission links (channels)

 

7. properties: typical attenuation in dB, normalised attenuation in dB/km, susceptibility to

interference, unwanted radiation of signals

fixed links: wired (shielded and unshielded copper multipairs, shielded and unshielded

copper twisted pairs, copper coaxial), optical fibre

identify various methods of communicating over a channel

• simplex (one-way communication)

• duplex (two-way communication)

• half/semi-duplex (two-way communication but only one-way at any one time)

• broadcast

• serial

• parallel

 

8 identify types of information carried by communication systems: eg sound, picture or data

 

9 state the systems available for communication eg internet, telephone, radio and television

 

10 categorise signals into audio, video and data types

 

11 state the difference between ac and dc signals

 

12 identify the following terms in relation to ac signals: frequency, amplitude, phase, wavelength, period, velocity, harmonics

 

13 state the differences between analogue and digital signals

 

14 state the meaning of bandwidth

 

15 state the meaning of the baseband of complex signals

 

16 distinguish between baseband and broadband

A Baseband network is one that provides a single channel for communications across the physical medium, so only one device can transmit at a time. Devices on a Baseband network are permitted to use all available bandwidth for transmission. –check —

 

17 recognise that analogue information may be converted to digital signals and vice versa

 

18 state that variation of the amplitude, frequency or phase of a carrier wave can be used to

convey information

 

19 state the meaning of ‘gain’ in communication systems

In electronics, gain is a measure of the ability of a circuit to increase the power or amplitude of a signal from the input to the output

 

20 state the meaning of ‘attenuation’ in communication systems

attenuation is the degration of a signal through a transmission medium in a communication system, and is directly proportional to the length of the transmission medium.

 

21 explain why gain and attenuation are usually measured in decibels (dBs)

A. http://en.wikipedia.org/wiki/Gain

 

22 state the relationship for the power ratio expressed in dBs for the following ratios and vice

versa:

A.

2 (3dB)

4 (6dB)

8 (9dB)

10 (10dB)

100 (20dB)

1000 (30dB)

1000000 (60dB)

1/2 (-3db)

1/4 (-6dB)

1/8 (-9dB)

1/10 (-10dB)

1/100 (-20dB) etc

 

23 calculate, in dBs, the overall gain and/or attenuation of simple systems given the

gain/attenuation of the individual stages

 

24 explain the meaning of multiplexing in communication systems

 

25 state the advantages and disadvantages of optical fibre compared to copper.

 

 

Unit 101

Outcome 4

Principles of communications cabling

Describe the basic principles of data

communication

Underpinning knowledge

The candidate will be able to:

1 state that data networks allow computers or other data terminals to exchange information

 

2 state the advantages and disadvantages of digital communication

 

3 state the advantages and disadvantages of analogue communications

 

4 identify analogue and digital signals eg

a analogue signal and the basic concepts of voice and video signals

b how digital signals are produced

c why digital signals are used rather than analogue

d the methods by which digital signals are transmitted

 

5 state that binary encoding is typically used on digital networks

 

6 distinguish between ‘bits’ (b) and ‘bytes’ (B)

bits are either 1′s or 0′s their are 8 bits (b) in a byte (B)

 

7 state the meaning of bit error rate (BER) and give typical figures for copper and optical fibre

systems

 

8 explain that there are two methods of transmitting data: serial using a single transmission

line and parallel using multiple lines

 

9 explain the advantages of transmitting data by these two methods:

• serial: can be used over longer distances

• parallel: can send higher data rates over shorter distances

 

10 identify applications for serial data communication and parallel data communication

 

11 explain why ‘modems’ are required for computer communication

 

12 state the main categories of computer networks:

metropolitan area networks (MAN)

wide area networks (WAN)

local area networks (LAN)

storage area network (SAN)

identify the basic topologies of computer networks: eg star, bus, ring.

 

3667-02 Module Four

Unit 104

Outcome 1

Copper cabling in an internal environment

Work safely with copper cabling in an internal

environment

Practical activities

The candidate will be able to:

1.conduct a risk assessment prior to installation of copper cables in an internal environment.

2.work safely when installing, terminating and testing copper cables in an internal environment.

 

Underpinning knowledge

 

The candidate will be able to state the rules for :

1.safe working with copper cabling when undertaking installation eg statuary requirements

HASAWA/COSHH or relevant national safety standards working in confined spaces.

 

2.safe working with copper cabling when carrying preparation in terms of use of tools and

equipment, personal safety requirements, identification of hazardous work conditions

 

3.safe working in terms of electrical safety eg compliance with BS7671 or relevant national

standard, use of earthing

 

4.the safe use of battery/electrically powered test equipment and power leads

Unit 104

Outcome 2

Copper cabling in an internal environment

Understand basic electrical theory and safety with

reference to data communications cabling

Practical activities

 

The candidate will be able to:

1.use a multi-meter to measure voltage and resistance

 

2.use Ohm’s law to solve simple electrical circuit problems

Underpinning knowledge

 

The candidate must be able to

1.distinguish between different electrical conductors and different insulators

 

2.state the materials that make up electrical conductors and insulators

Conductive

• silver
• copper
• gold
• aluminum
• iron
• steel
• brass
• bronze
• mercury
• graphite
• dirty water

• concrete

Non Conductive – Insulators

• glass
• rubber
• oil
• asphalt
• fiberglass
• porcelain
• ceramic
• quartz
• (dry) cotton
• (dry) paper
• (dry) wood
• plastic
• air
• diamond
• pure water

 

3.explain capacitance and inductance and their relationship to a copper cable

possible answer

 

4.recognise the international standard symbols for electrical components

possible answer

 

5.state the effects of an electric current

• heating

• chemical

• magnetic

 

6.state the SI units of current (ampere), potential difference (volt) and resistance (ohm)

 

7.state Ohm’s law and its use in solving simple electrical circuit problems

 

8.describe the relationship between MHz and Mbits

 

9.explain the following test parameters

 

return loss

Return loss is a measure of reflections caused by the impedance changes at all locations along the link and is measured in decibels (dB). Mismatches predominantly occur at locations where connectors are present, but they can also occur in cable where variations in characteristic impedance along the length of the cable are present.

 

explain the following test parameter

equal level far end cross talk (ELFEXT)

 

explain the following test parameter

powersum calculations

 

 

explain the following test parameter

delay skew

Delay Skew

Delay skew is calculated as the difference between the propagation delay for each of the four wire pairs. The fastest propagation delay among the four measurements is used as one extreme, and the slowest propagation delay measured is the other extreme. The difference between the two measurements becomes the delay skew. EIA/TIA-568-B permits no more than 44ns of delay skew between the fastest and slowest pairs in the cable for the Permanent Link configuration, and 50ns for the Channel Link. The high-throughput network applications such as 1000BASE-T and 10GBASE-T are most sensitive to delay skew; they also permit no more than 50ns of delay skew.

Some newer high-speed network implementations, such as 1000BASE-T, achieve very high data rates by simultaneously transmitting data on all the wire pairs of a four-pair cabling link. The encoded signal is sent simultaneously in four parts, one part on each wire pair, and all four parts must be received very close to the same time to be interpreted correctly.

One of the reasons delay skew was first included in several testing standards is because some Category 5 cables were constructed with different insulating materials around the copper conductors. This construction is referred to as heterogeneous. Homogeneous cable construction requires that all wire pairs be constructed with one and the same kind of insulating material. The insulating material has a significant influence on the NVP of the cable. There are two (then) relatively common instances of heterogeneous cables: the 2+2 cable and the 3+1 cable. In these cables the wires in two or three pairs are insulated using Teflon FEP, whereas the wires in the other pairs are insulated using a polyethylene compound. This heterogeneous construction method was used to meet the demand for category cable in view of a Teflon shortage that plagued the industry for a few years following a fire in a Teflon plant in 1995. The Teflon FEP insulated wire pairs exhibit the typical Category 5 NVP value of 69 percent, whereas the other pairs transmit the signals somewhat slower and have an NVP value that is several points lower (65 percent or 66 percent). Those 2+2 or 3+1 cables are unable to support technologies such as 1000BASE-T due to very poor delay skew performance.

Delay skew is a critical measure for 1000BASE-T, 10GBASE-T, and any other implementation where multiple pairs are used to transmit simultaneously in the same direction. The receiver PHY must realign the received bits so that despite receiving the first data from one data unit transmission on one wire pair several time-slots away from the last data from the same data transmission on another wire pair, the whole transmission is reassembled and delivered to the next higher layer as if it were received at the same time.

propagation delay

propagation delay is equivalent to the amount of time that passes between when a signal is transmitted and when it is received on the other end of a cabling channel

 

attenuation-to-crosstalk ratio (ACR)

 

length

 

 

attenuation

Attenuation is signal loss or the decrease in signal amplitude over the length of a link (see Figure 2-6). The longer the cable and the higher the signal’s frequency, the greater the attenuation or loss is. Therefore, be sure to measure attenuation using the highest frequencies that the cable is rated to support.

Attenuation needs to be measured only from one direction on the link (on all pairs) because attenuation of a specific wire pair is the same when measured in opposite directions.

In Figure 2-7, the signal amplitude decreases with distance to represent signal loss through attenuation and the related measurement of insertion loss.

Attenuation is caused by a loss of electrical energy due to the resistance of the wire (converting the energy to heat), and when energy leaks through the cable’s insulating material. This loss of energy (attenuation or insertion loss) is expressed in decibels (dB). Lower attenuation values are an indication of better link performance. For example, when comparing the performance of two links at a particular frequency, a link with an attenuation of 10dB (a factor of 3.16) performs better than a link with an attenuation of 20dB (a factor of 10). Link attenuation is determined by the cable’s construction, length, and the frequencies of the signals sent through the link. In the 1 to 100MHz frequency range, the attenuation is dominated by the skin effect and is proportional to the square root of frequency. That is, the higher the frequency, the greater the attenuation.

 

explain the following test parameter

near end cross talk (NEXT)

When it comes to overall twisted-pair link operation, crosstalk has the greatest effect on link performance. Crosstalk is the undesirable signal transmission from one wire pair to another nearby pair (see Figure 2-12). Unwanted crosstalk signals generally result from capacitive and inductive coupling between adjacent pairs. Crosstalk increases at higher frequencies and is very destructive to data signaling. Most low-speed LAN protocols need two pairs of twisted-pair cable, one pair for each direction of traffic. Higher-speed LAN protocols typically need multiple pairs, and typically operate simultaneously in both directions on each twisted pair.

Test devices measure crosstalk by applying a test signal to one wire pair and measuring the amplitude of the crosstalk signals received by other wire pairs. Near-end crosstalk (NEXT) is computed as the ratio in amplitude (in volts) between the test signal transmitted and the crosstalk signal received when measured from the same end of the link. This ratio is generally expressed in decibels (dB). Higher NEXT values (smaller received crosstalk signals) correspond to less crosstalk and better link performance. The NEXT test is also the most common method used to infer the presence of split pairs in twisted-pair links.

Although crosstalk is a critical performance factor for twisted-pair links, it is also difficult to measure accurately, especially at lower frequencies where many of the common LAN protocols operate. TIA/EIA-568-B specifies that NEXT must be measured at increments or intervals not greater than the maximum frequency step size increments shown in Table 2-5. For improved accuracy, a smaller step size is better, although this may take longer to measure. A Category 3 link needs to be tested to 16 MHz and a Category 5e link to 100MHz, because those are their maximum frequency ratings.

Table 2-5. Maximum frequency step sizes allowed for compliance with TIA/EIA-568-B

Frequency Range	Maximum Allowed Step Size
1 to 31.25MHz	150kHz (or 0.15MHz)
31.25 to 100MHz	250kHz (or 0.25MHz)
100 to 250MHz	500kHz (or 0.5MHz)
250 to 500MHz	1MHz

NEXT loss must be measured from every pair to every other pair in a twisted-pair link, and from both ends of the link. This equates to 12 pair combinations for the typical four-pair cabling link. To shorten test times, some older field testers allowed the user to test the NEXT performance of a link by using larger frequency step sizes. The resulting distance between measurements does not comply with TIA/EIA-568-B, and may overlook link crosstalk faults.

All signals transmitted through a link are affected by attenuation. The farther the signal travels, the smaller it becomes. Because of attenuation, crosstalk occurring farther down the link contributes less to NEXT than crosstalk occurring at the near end of the link (refer to Figure 2-12). If the signal that is crossing to another pair is smaller, the amount that is available to cross is correspondingly smaller too. Furthermore, the coupled signal still has to travel back to the source end and is further attenuated as it returns. Thus, near-end crosstalk is worse closest to a transmission source where the signal is the largest (greatest amplitude) and the attenuation in the return path is the shortest. To verify proper link performance, you should measure NEXT from both ends of the link; this is also a requirement for complete compliance with all the high-speed cable specifications.

Crosstalk can be minimized by twisting wire pairs more, so that the signal coupling is “evened out.” Twisted-pair wiring for LANs have more twists per unit length than telephone wiring. LANs use TIA/EIA Category 3 or better cable. Telephone wiring is typically comparable to the old UL Level 1 (see Table 2-1), and might not seem to be twisted at all. The higher the category, the more twists per unit length in the cable are necessary, and the higher the frequency rating will be. To ensure reliable LAN communications, cable pairs must not be left untwisted even for short distances. For this same reason, cables with parallel conductors (ribbon type or “silver satin” type cables) should never be used in LAN applications.

Signals from twisted-pair wiring may “leak” to the outside world and to other adjacent cables. The principle behind balanced twisted-pair cables is that, at every location along the cable, the voltage in one wire of a wire pair is equal in amplitude but opposite in phase to the voltage in the other wire of the wire pair. In addition to some other undesirable side effects, imbalance creates the effect of an antenna and receives external signals—thereby disrupting data with electromagnetic interference (EMI) and radio frequency interference (RFI). Substantial improvements have recently been made to cabling components—connectors in particular—which has had a positive impact because the majority of link problems occur at connectors, and the new connectors reduce these effects. To minimize the antenna effect, shielding the cable is a possible solution. When shielded cabling is used, however, a new set of potential problems is introduced, such as ground loops due to differences in the ground (earth) potential at opposite ends of the link. The ground-loop problem is often more serious than the EMI/RFI problem.

Generally, the problem of NEXT is worse in shielded cabling. The reason for this is that crimping the plugs to the shield of the cable enhances capacitive imbalance, one of the sources of NEXT. Also, shielded twisted-pair wiring is harder to install correctly, making it more prone to this sort of problem. Shielded twisted-pair cable comes in two basic types: 1) shielded twisted pair (STP), which has a foil shield around each individual pair and another shield around the four pairs, and 2) foil-screened twisted pair (FTP) or screened twisted pair (ScTP), which has a shield around the outside of the group of four pairs only, and is usually 100 ohm cabling. Some legacy cables could be either 120 ohm or 150 ohm cabling. With the advent of the 10GBASE-T application and the concerns over alien crosstalk, many manufacturers are promoting shielded or screened cable types. New terminology has been introduced to emphasize the cabling construction. The name F/UTP has been introduced to designate the foil around the four unshielded wire pairs. Proper grounding procedures must be followed when using these cable types. Screened cable types have been widely used in Europe because of strict laws intended to limit EMI/RFI emissions. As a side effect, they reduce external noise from interfering with the signals on the link. If proper balance is maintained, however, UTP cabling can provide EMI/RFI performance levels that also satisfy the European requirements.

Figure 2-13 shows typical NEXT test results. In both figures, the bottom curve is the TSB67 limit for NEXT and the top lines are the results for this test. When a reported margin is positive, this indicates that the worst-case NEXT is better than the limit, whereas a negative margin indicates that the results are worse than the limit. The cursor is positioned at the frequency where the worst-case margin was detected. The irregular shape of the top curve demonstrates that unless NEXT is measured at many points along the frequency range, low points (points of worse NEXT loss) could easily go undetected. Therefore, TIA/EIA-568-B defines a maximum frequency step size for NEXT measurements, as shown in Table 2-5.

If a NEXT failure is detected, it is possible to use other tests to pinpoint where along the length of the link the failure is occurring. One such test is called Time Domain Crosstalk (TDX), which is displayed in the same graphic format as a Time-Domain Reflectometry (TDR) test. The difference between TDR and TDX is that, in the case of a TDR, the signal is applied at one wire pair and the reflections are measured on the same wire pair. TDR reflections occur because of impedance anomalies. TDX applies a signal to one wire pair and measures the coupled signal on an adjacent wire pair.

Figure 2-14 shows two typical high-definition TDX test results. The vertical measurement spikes represent sources and magnitude of crosstalk. The vertical red lines are positioned at locations where the tester has determined the cable-under-test ends to be, and distance is shown at the bottom of the graph accordingly. The black vertical line is the user moveable cursor used to determine distance from the local tester end. The left graphic shows the point-source impact of a bad connection, either due to poor workmanship or poor connecting hardware. The right graphic shows crosstalk all along the cable-under test, which indicates that the cable itself is not good quality.

 

explain the following test parameter

Wire map

A wiremap test begins with a simple continuity test to ensure that each connector pin from one end of the link is connected to the corresponding pin at the far end, and is not connected to any other conductor or the shield. If the test signal does not reach the other end, the wire is open. If the DC voltage test signal crosses onto another wire because they are touching, it is shorted. Although this is enough for telephone and other low-frequency applications, simple continuity between pins from one end of the link to the other is not sufficient for typical networking applications.

 

explain the following test parameter

dc loop resistance

All metallic cables insert a certain amount of DC resistance into a circuit, this is measured in Ohms. DC resistance increases proportionately with the length of cable being tested.

 

explain the following test parameter

nominal velocity of propagation (NVP) – nominal velocity of propagation

 

explain the following test parameter

bandwidth

 

13. state the effect of signalling when using copper communications cables with respect to

a. basic concept of characteristic impedance (Zo)

b. The reason for maintaining the twist in copper pairs and their effect on the cable’scharacteristic impedance

c. the cable’s characteristic impedance of not complying with the minimum bend radius

d. applying excessive pull tension

 

18.state the rules for copper cable installation and management in terms of compliance with

European and International standards

 

19 .interpret cable wiring diagrams.

Level 2 Award in Communications Cabling (3667-02)

Unit 104

Outcome 3

Copper cabling in an internal environment

Install copper communication cabling, following

recommended installation procedures in

accordance with current applicable standards

Practical activities

The candidate will be able to:

1.check cable and components before installation

 

2.undertake a site survey prior to commencing work

 

3.check that correct cable laying procedures are followed.

Underpinning knowledge

 

The candidate must be able to

1. describe the various cable topologies available for the installation of copper cables eg

point to point

star

branching tree

bus

ring

grid

mesh

 

2. state the different cable types available for use in copper networks eg

coaxial cables

multi-core cables

unshielded twisted pair (UTP)

shielded twisted pair (STP)

foil screen twisted pair (FTP)

supplementary/secondary shielded TP cable types

 

3. state the relevant classes, standards and categories of cabling including categories 5e and 6

and classes D and E

 

4 .state requirements for

a. interpreting wiring diagrams and drawings

b. fixing cabling communication racks

c. providing cable supports and wall fixing

d. fixing horizontal and vertical cables

e. interpreting cable labelling and colour codes

f. compliance with appropriate building regulations

 

5. state the rules and any special precautions to be observed when carrying out installation

 

6. state the rules and any special precautions to be observed when carrying out a site survey

 

 

Level 2 Award in Communications Cabling (3667-02)

Unit 104

Outcome 4

Copper cabling in an internal environment

Terminate copper communication cabling

Practical activities

The candidate will be able to:

1. Terminate hardware in accordance with manufacturer’s recommendations and correctly

mount into communications panels/wall/floor boxes/cabinets and frames, etc.

 

2. Terminate registered jack (RJ) 45 connectors from at least three vendors on to UTP and FTP

cabling

Underpinning knowledge

 

The candidate must be able to

1.explain how to use cable preparation and termination tools

 

2.state how to terminate Cat.5e patch leads

 

3.state insulation displacement contact (IDC) methods of terminating multi-core copper cables

within wiring systems and 110 block wiring systems

 

4.state the method of terminating line jack units (LJUs) to telephone cable

 

5.state the rules and any special precautions for termination in terms of

a.problems with incorrect cable termination

b.selection and use of tools and connectors

 

6.identify in which situations/environments you would use stranded and solid core cables

Level 2 Award in Communications Cabling (3667-02)

Unit 104

Outcome 5

Copper cabling in an internal environment

Test FTP, UTP and multicore copper links

Practical activities

The candidate will be able to:

1.use a range of commercially available cable testing equipment that will test

a. FTP and UTP copper cable permanent links

b. a multi-core cable installation

c. installations to relevant performance standards ie categories 5e and 6, and classes D

d. a telephone cabling system

Underpinning knowledge

 

 

The candidate must be able to

1.explain the importance of testing cabling plant installations

 

2.state the applications of national and international testing standards

 

3.explain the application and use of continuity and loop testing equipment

 

4.explain the terms

a.split pairs

b.transposed/crossed pairs

c.reversed pairs

d.mixed pairs

 

5.state the correct methods of measuring the following

a. NEXT from both ends of the cable

b. ACR

c. Return loss (dB)

d. Cable length

e. (dc) resistance (Ohms)

f.  Propagation as a delay in units of ns

g. Cable attenuation (dB)

h. Delay skew

i. Wire maps

j. FEXT and ELFEXT

k. Powersum calculations

 

6.state the methods for testing telephone cabling.

==================

THE END

==================

 

AS THIS COURSE IS SPLIT INTO 2 PARTS, THE THEORY AND THE PRACTICAL I WILL  LIST BOTH PARTS INDIVIDUALLY.

 

 

THEORY

 

 

PRACTICAL

Data Communication Principles

The Sine Wave

The sine wave is an important fundamental in electronics and data communication.

 

 

Frequency is the number of cycles per second and is measured in Hertz (Hz)

Wavelength is inversely proportional to frequency

i.e. Wavelength varies as 1/frequency    (See example)

Analog signals

Analog means analogous to, or a representation of.

 

Here the time of day could be represented by the amplitude of a sine wave.

Digital signals

Digital signals are discrete square steps (pulses) that represent the binary digit ’1′ or ’0′

 

The time of day could be represented by a digital signal by a series of ’1′s or ’0′s

9 in binary = 1×2³ + 0×2²+ 0×2¹+ 1×2⁰ = 8 + 0 + 0 + 1

 

24 in binary = 1×2⁴ + 1×2³ + 0×2² + 0×2¹ + 0×2⁰ = 16 + 8 + 0 + 0 + 0

Here is a simple description of binary arithmetic.

Digital signals are composite signals made up of many sinusoidal frequencies

 

A 200Hz digital signal may be a composite of 200, 600, 1000, 1400, 1800, 2200, 2600, 3000, 3400 and 3800 sinusoidal signals.

The higher the frequency components you include, the better your representation of the original signal. This spreadsheet demonstrates that 9 components give a more accurate representation of a square wave than 5 components.

Bandwidth

Bandwidth is an important consideration in the design of electronic communication equipment. It is a range of frequencies that the equipment or channel is capable of processing. Unnecessary bandwidth costs money.

There is little point in connecting equipment designed to handle a range of frequencies say, 400MHz to a transmission system designed for a range of 400Hz.

A good practical example of this principle is the public telephone system. Human hearing has a frequency response range of 20 – 20000Hz and the human voice a range of 100 – 10000Hz. There is little point in designing a telephone system with a bandwidth greater than 20 – 20000 Hz. In fact most telephone systems are designed with a bandwidth of 300 – 3400Hz. The composite higher and lower frequencies of speech are not needed to hear and understand a conversation.

Capacity

The capacity of a channel carrying binary digital signals is twice the bandwidth.

For example a channel having a bandwidth of 1000Hz can carry 1000 x 2bits of data equal to 2000bits per second.

 

 

Media

The Electromagnetic Spectrum

All electronic communication operates within the electromagnetic spectrum travelling, theoretically, at the speed of light.

That is 2.997925 x 10⁸ metres per second. We have already seen that the velocity and strength over distance of electronic signals is affected by the transmission media and as such this media has to be selected carefully.

Media used for communication can be classified as guided or unguided.

Guided Media

Two wires

Used inside computers or for the transmission of data over short distances i.e. ribbon cables.

Limited to 50 metres and 19.2 Kbps.

Twisted pair

Least expensive and most widely used media for data transmission. Hundreds of twisted pairs are bundled together to make a cable.

Used for analog and digital communication within the telephone network and for computer networks within buildings.

Typically, capable of transmitting bandwidths up to 3 MHz over distances of 2 to 3 kilometres for digital transmissions, twice as much for analog.

Susceptible to all types of interference but easy to work with and interface.

Shielded twisted pair.

The twisted pair can be encased in a metal braid to reduce the effects of interference but is more expensive and difficult to interface.

Often chosen for better performance when the environment is noisy, for example in proximity to power cables.

Coaxial cable.

More expensive than twisted pair and laid as a single core cable. Used for analog and digital transmission over longer distances, for example joining LANs between buildings , and used for backbone networks within buildings. Also used for television distribution and long distance telephone transmission.

Typically capable of transmitting bandwidths up to 350MHz for distances up to 10 kilometres.

Can be used for broadband transmission.

Robust and fairly easy to work with but needs relatively expensive connectors.

Optical fibre

Still expensive compared to the other media but the price is dropping steadily. Used extensively for long distance transmission such as high capacity long distance telephone systems, cable television and backbone networks in MANS.

Typically capable of transmitting bandwidths up to 2000 MHz over distances of 100Km.

Not affected by electromagnetic interference and has low attenuation characteristics.

Signals are transmitted using LEDs (light emitting diodes) or lasers.

Can be difficult to work with and even dangerous. Requires precise interfacing and difficult to repair, join or tap into. Interfacing to electronic equipment requires transducers e.g. LED or lasers to electronic signal conversion. Much smaller in size and weight for the equivalent data capacity of other guided media.

Unguided media – wireless transmission

Wireless transmission radiates electromagnetic energy from antennae.

This can be directional – in a beam – or omnidirectional i.e. all around radiation.

Terrestrial Microwave

Communication is accomplished through line of sight parabolic dish antenna located on elevated sites.

Long distance communication is possible by using a series of relay stations. The distance between the stations is dependent on the height above the ground and is governed by the formula d = 7.14 x sqrt (K factor x height above ground).

Used for voice and television transmission and private communications and telephone networks e.g. emergency services, utilities etc.

Utilises a wide frequency band, 2 to 40 GHz but is susceptible to attenuation and interference. Attenuation can rise markedly in poor atmospheric conditions e.g. rain, but adversely affects the higher end of the frequency band which is only used for short distance transmission. Natural noise severely affects transmission frequencies below 2GHz.

Quick to install and overcomes the problems of laying cables in congested locations or over difficult terrain.

Satellite Microwave

Overcomes the line of sight problems of terrestrial microwave and can be used for point to point or broadcast transmission. Uses an uplink and downlink frequency, a common frequency set is referred to as the 4/6 range which uses a downlink frequency of 4GHz and an uplink frequency of 6GHz.

Typical uses of satellite microwave – television distribution, long distance telephone transmission, private business networks for global organisations.

Suffers the same attenuation problems as terrestrial microwave.

Broadcast radio transmission

Broadcast radio is omnidirectional and does not require complex dish antenna but allows a great deal of flexibility and is tolerant of alignment needs.

Covers the frequency range 3KHz to 1GHz. The concepts of broadcast radio are well known to the general public. Lower frequency signals are reflected off the ionosphere and this helps bounce signals between the atmosphere and the earth for wide reception coverage. Frequencies above 30MHz are not reflected from the atmosphere and rely on line of sight transmission.

Low frequencies are less susceptible to attenuation from atmospheric conditions but are affected by ionospheric changes.

Higher frequencies can be affected by reflection of signals.

Infrared transmission

Infrared communication is now common as a means of wireless communication between devices. It will not penetrate buildings and therefore is secure.

Used for very short line of sight transmission, remote car locking systems, wireless security alarms, remote TV channel changes etc.

 

Characteristics of different types of networks

A. Using conventional networking

LANs – Local Area Networks

LANs are in common use throughout major companies and organisations to allow users to share data and facilities such as printers and Internet links. They can be large – like UWE’s LANs – or small, like the one connecting the computers in my house.

• Share resources
• Private networks
• Maintained by user organisations
• Fast data transmission
• Short distances
• Use a variety of media but twisted pair and coax more common

MANs – Metropolitan Area Networks

This is a larger type of network interconnecting different LANs. Some organisations do not use the term MAN and call them a small WAN instead.

• Interconnected LANS over a wider area
• Connected buildings within a city
• Uses fast connection technology e.g. FDDI (Fibre Distributed Data Interface)
• Backbone networks
• Fast transmission of data

WANs – Wide Area Networks

• Heterogeneous in nature
• Some partial connections
• Mixed topologies
• Carry redundant circuits for heavy traffic
• A mixture of transmission media
• Uses routers and other devices
• International standards TCP/IP, X25 etc

Here is how LANs, MANs and WANs fit together:

(Source: University of Aberdeen)

VANS – Value Added Networks

Private networks joining a consortium of organisations

• Used by a group of organisations
• Maintained by the network provider
• Provide added services, e.g. email, EDI, databases
• Provide more efficient transactions between companies
• International standards for some services

B. Using web technologies

Intranets

Intranets use web technologies within an organisation to share information.

• Use web technologies – TCP/IP , web browsers, web servers etc
• Use proven technology
• Inexpensive to set up
• Compatible with future and present web technologies
• Have a reasonable security level

Extranets

Extranets bridge between different parts of the same organisation by communicating through the Internet.

• Use web technologies
• Connect the Intranets of different organisations together
• Use the Internet as a connecting media network
• Encourage business to business communications
• There are security issues for sensitive information

Virtual Private Networks – VPNs

These connect private networks via the Internet or leased lines but with extra security.

• Connects Intranets through leased lines
• Connects Intranets through the Internet but uses encryption and higher levels of security

Provides a more secure network for commercially sensitive information

LInk

http://www.cems.uwe.ac.uk/~phulbert/iticstart.htm

CSCS card expiration: November 2012

Todo

Working in confined space.

Working has hazardous substances.

Enhanced CRB check.

1. City & Guilds 3667-02 101 Compulsory

1. City & Guilds 3667-02 104 Copper

2. City & Guilds 3667-02 102 Internal Fibre

2. City & Guilds 3667-02 103 External Fibre

3. Crone course 1 day

 

Suppliers

Crone

Brand Rex

Panduit

 

 

Brand Rex Videos

brand rex

Termination of 10GPlus / Cat6Plus Shielded Tool-Free Snap-In Jack to an F-UTP Cable.

GigaPlus 24 Port Shielded Patch Panel Installation.

Cat6Plus 24 Port Half U Shielded Patch Panel Installation.

Termination of 10GPlus / Cat6Plus Shielded Tool-Free Snap-In Jack to an F/FTP Cable.

Termination of 10GPlus / Cat6Plus Shielded Tool-Free Snap-In Jack to an S/FTP Cable.

Cat6Plus 24 Port Half U UTP Patch Panel Installation.

Cat6Plus 24 Port UTP Patch Panel Installation.

Termination of 10GPlus / Cat6Plus Shielded Tool-Free Snap-In Jack to an U/FTP Cable.

Termination of 10GPlus / Cat6Plus Shielded Tool-Free Snap-In Jack to a Zone Cable (U/FTP).

GigaPlus 24 Port UTP Patch Panel Installation.

Cat6Plus 24 Port Shielded Patch Panel Installation.

Termination of 10GPlus / Cat6Plus Shielded Tool-Free Snap-In Jack to a U-UTP Cable.

 

Structured Cabling Video’s

 

Structured Cabling basics part 1

Structured Cabling basics part 2

Structured Cabling basics part 3

Structured Cabling basics part 4

Structured Cabling basics part 5

Cisco Structured Cabling

 

Funny Video

2 techs 1 closet

 

SHOPPING LIST

1 X small cutters 20mm

1 pair of Toner’s

Knee Pads

12v Drill

Hammer

Tape measure

Fishrods

Pulley

 

 

Standards

The standards for structured wiring specify that the horizontal link from end-to-end shall not exceed 100 meters or 328 feet. This end-to-end link is the link that is defined as the Channel in the TIA TSB-67 document. When measuring a channel, the end-user patch and equipment cords are to be used rather than the tester patch cords; the end connectors of the link are to be plugged directly into the field tester. As mentioned earlier, the TIA TSB-67 document also defines a link model called the Basic Link. The maximum length of a Basic Link is 90 meters (295 feet), plus 4 meters for the test equipment patch cords for a total of 94 meters (308 feet).

I this has a South Asian or Hindu look to it. i bet someone gonna tell me there a copy write for images made with circles. (lmao)

This project will use the tasker app to update your location on google latitude. Based oh cell tower location