Wired vs wireless networks
OCR J277 Paper 1 sets 4–8 mark questions on networking hardware and the trade-offs between wired and wireless connections. You need to know the role of each piece of hardware and be able to compare wired and wireless on speed, range and security.
Network hardware
| Device | Role |
|---|---|
| NIC (Network Interface Card / Controller) | Hardware that lets a device connect to a network. Has a unique MAC address. Wired NIC has an Ethernet socket; wireless NIC has an antenna. |
| Switch | Connects devices on a wired LAN. Receives a frame, reads the destination MAC address, and forwards it only out of the port the destination is on. |
| Router | Connects different networks together (e.g. a home LAN to the internet). Routes packets using IP addresses; performs NAT in a home router. |
| Wireless Access Point (WAP) | Allows wireless devices to join a wired LAN. Often built into the same box as the home router. |
| Transmission media | Copper cable (cheap, slower), fibre-optic cable (fast, long-range, immune to electromagnetic interference), radio waves (Wi-Fi, no cabling). |
Wired vs wireless — comparison
| Property | Wired (Ethernet / fibre) | Wireless (Wi-Fi) |
|---|---|---|
| Speed | Generally faster and more consistent (Gigabit / 10 Gigabit Ethernet, fibre 100 Gbps+) | Slower, varies with distance and interference (Wi-Fi 6 ~1 Gbps in ideal conditions) |
| Range | Limited by cable length; needs cable everywhere | Limited by signal strength — typically 10–50 m indoors; weak through walls |
| Security | More secure — must physically connect to the cable to intercept | Less secure — radio signals broadcast; need encryption (WPA2/WPA3) |
| Setup cost | Higher — cabling and ducting | Lower — no cabling required |
| Mobility | Tethered to cable | Free to move within signal range |
| Reliability | Fewer errors; not affected by other Wi-Fi networks | More errors from interference, walls, distance |
How a switch differs from a hub
A hub is older — it broadcasts every frame to every port, wasting bandwidth and exposing data. A switch reads the destination MAC and forwards only to that port — faster, more secure, and now standard.
Common OCR exam mistakes
- Saying a switch routes between networks — that is a router. A switch only operates within a single LAN.
- Saying a router uses MAC addresses — routers use IP addresses; switches use MAC.
- Forgetting that wireless requires encryption to be reasonably secure.
- Listing devices without explaining what each does — OCR mark schemes want the role.
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