Understand how the characteristics of wired and wireless connectivity…

The idea

Wired and wireless connections differ in how they carry data, and this affects performance. Wired links, such as Ethernet, use a physical cable, which usually gives higher speed, greater bandwidth and lower latency, but the device is limited by the cable length and must be plugged in. Wireless links, such as Wi-Fi, carry data through the air, so devices can move within range, but speed and bandwidth generally fall as distance increases or as walls and interference weaken the signal. Latency is the delay before data starts to arrive; wired links often have lower latency, while wireless links can suffer more delay and variation. Bandwidth is the amount of data that can be transferred per unit time, so a higher-bandwidth link can carry more data at once. Range is how far a signal can travel while remaining usable.

What earns the marks

• Wired connections use a physical cable and typically offer higher speed, greater bandwidth and lower latency than wireless.
• Wireless connections allow mobility within range but speed and bandwidth usually decrease as distance increases or interference grows.
• Latency is the delay before data transfer begins, and it affects how responsive a connection feels.
• Bandwidth is the amount of data that can be transferred per unit time, so higher bandwidth supports more simultaneous data.
• Range is the distance over which a connection remains usable, and it limits where wireless devices can operate.

Common mistakes and how to put them right

• Treating bandwidth and speed as identical.

  Put it right: Bandwidth is the capacity per unit time, while speed is how quickly data travels.

• Assuming wireless is always slower.

  Put it right: Wireless can be fast at close range, but it is more affected by distance and interference.

• Confusing latency with bandwidth.

  Put it right: Latency is delay, while bandwidth is the amount of data carried per unit time.

• Ignoring range: a wireless connection outside its usable range will drop or slow down, regardless of its rated speed.

Exam tips

• Match each option to the correct characteristic, such as speed, range, latency or bandwidth, before choosing.
• Use the scenario in the question, such as a device that must move around, to decide whether wired or wireless is more suitable.
• Eliminate options that confuse delay with capacity, since latency and bandwidth are different measures.