1. Wired Transmission 24 Wired Transmission 24

2. Wired Transmission 24 This is about the method used to actually transmit or send data That means actual wires or cables You need to know three types And the advantages/disadvantages You might think wires are boring But imagine life without Sky TV, the web and computer networks…

3. Wired Transmission 24 UTP Cable Co-axial Fibre Optic

4. Wired Transmission 24 When it comes to cabling, you might think ‘who cares’ ? But networks are hugely important today So designers take care to pick the right cable to build networks Key issues are cost and speed, meaning how much data the cable can carry The goal is to reduce latency That’s the delay in between sending and receiving data

5. Wired Transmission 24 STP Cable Co-axial Fibre Optic Network Digital TV Backbone

6. Wired Transmission 24 Backgrounder – Cables & Digital Data Information such as computer data and telephone calls can be converted into electrical signals These can be carried through wires that conduct electricity, such as copper cables But the info can also be converted into light signals and transmitted by optical fibre Let’s have a quick look at how that works…

7. Wired Transmission 24 Backgrounder – Data Means Bits Binary Bit is a 0 or a 1 Byte is 8 bits 01100001 Remember that ‘digital’ data means 1s & 0s…

8. Wired Transmission 24 Backgrounder – Electric Signals 11000010 That digital data can be shown as a ‘square’ wave, like on & off… And those 1s and 0s could be high & low voltage on a wire… But electric signals must have no interference to get clean 1s & 0s

9. Wired Transmission 24 UTP UTP is the cable used for for most LANs, like our network in school It’s called Unshielded Twisted Pair Inside are several pairs of copper wire They’re twisted to stop electrical interference UTP cable is popular for LANs because it is cheap and can carry lots of data There’s also Shielded Twisted Pair (STP)…

10. Wired Transmission 24 UTP Unshielded STP Shielded

11. Wired Transmission 24 You’ll find ‘coax’ round the back of at your satellite TV box It has two copper conductors separated by an insulator That enables it to work at higher data rates than twisted pair It can be used for networks but costs more than UTP and is harder to install because it’s not as flexible Co-Axial

12. Wired Transmission 24 Strands of glass as thin as hair that carry data as light Lots of fibres are bundled together to form cables Cheaper than traditional copper telephone wire T1 lines give local connection T3 lines form Internet backbone Fibre Optic

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15. Wired Transmission 24 SUBMARINE CABLE MAP

16. Wired Transmission 24 Backgrounder – Electrical Interference Optical signals can be transmitted so far due to how light travels…

17. Wired Transmission 24 Backgrounder – Optical Data A laser at one end of the pipe switches on and off to send each bit. Modern fiber systems with a single laser can transmit billions of bits per second -- the laser can turn on and off several billions of times per second. The newest systems use multiple lasers with different colors to fit multiple signals into the same fiber.

18. Wired Transmission 24 STP Cable Co-axial Fibre Optic Network Digital TV Backbone

19. Wired Transmission 24 Wired Transmission 24

20. Wired Transmission 24 Wired Transmission 24