4.1.4 Wired and wireless connectivity
Wired vs Wireless Connectivity
Devices connect to a network either via a physical cable (wired) or through radio waves (wireless). The choice of connection type affects four key performance characteristics: speed, range, latency and bandwidth.
Performance Characteristics
Speed is how quickly data is transferred, measured in bits per second (Mbps or Gbps). It is the rate at which data flows once the connection is established.
| Connection type | Typical speed |
|---|---|
| Ethernet (wired, Cat 6) | 1–10 Gbps |
| Wi-Fi (wireless, 802.11ac/Wi-Fi 5) | Up to ~1 Gbps (variable) |
| Wi-Fi (wireless, 802.11n/Wi-Fi 4) | Up to ~300 Mbps (variable) |
Wired connections are generally faster and more consistent. Wireless speed is affected by distance, interference and the number of connected devices sharing the access point.
Range is the maximum distance over which a connection can function. Beyond this range, the signal degrades to the point where the connection becomes unusable.
- Wired: limited by cable length — Ethernet (Cat 5e/6) is rated to approximately 100 metres per segment. Longer distances require switches or repeaters. The connection is entirely reliable within that distance.
- Wireless: typical indoor Wi-Fi range is 20–50 metres, reduced by walls, floors and interference. Range can be extended with additional access points. The connection degrades gradually with distance.
For large buildings or outdoor areas, wired infrastructure (or multiple wireless access points) is needed to maintain coverage.
Latency is the time delay between a signal being sent and received, measured in milliseconds (ms). It is the responsiveness of the connection rather than its raw throughput.
- Wired: very low latency — a direct physical connection with no contention or interference. Typical wired LAN latency: 1–5 ms.
- Wireless: higher latency than wired — radio signals introduce processing overhead; interference and contention between devices sharing the same frequency add variable delay. Typical Wi-Fi latency: 10–50 ms.
Latency matters most for real-time applications: online gaming, video calls and financial trading systems where even 50 ms of extra delay is noticeable or costly.
Bandwidth is the maximum amount of data that can be transmitted over a connection per unit of time — analogous to the width of a pipe rather than the speed of flow. Measured in Mbps or Gbps.
- Wired: dedicated bandwidth — a wired connection provides its full rated bandwidth to the connected device. On a switched network, each port gets its own full-bandwidth connection.
- Wireless: shared bandwidth — all devices connected to the same wireless access point share the total available bandwidth. The more devices, the less each gets.
Note: speed and bandwidth are related but distinct. Bandwidth is the theoretical maximum capacity; speed is the actual rate achieved in practice, which is always less than or equal to bandwidth.
Wired vs Wireless — Summary
| Characteristic | Wired (Ethernet) | Wireless (Wi-Fi) |
|---|---|---|
| Speed | Fast, consistent | Variable, affected by distance and interference |
| Range | ~100 m per cable segment | ~20–50 m indoors (walls reduce this) |
| Latency | Very low (1–5 ms) | Higher (10–50 ms), variable |
| Bandwidth | Dedicated per port | Shared among all connected devices |
| Mobility | None — device must be cabled | Full — device can move within range |
| Security | More secure — physical access required | Less secure — signal can be intercepted |
| Installation | Requires cabling infrastructure | Easier — no cables to lay |
Key Takeaways
- Speed: how fast data transfers — wired is faster and more consistent.
- Range: maximum effective distance — wired is ~100 m; wireless ~20–50 m.
- Latency: delay between send and receive — wired is lower and more predictable.
- Bandwidth: maximum capacity — wired is dedicated; wireless is shared.
- Wireless provides mobility and easier installation; wired provides reliability and security.