Ethernet is the usual method for wired connections in a LAN. Devices plug into a switch or router using Ethernet cables.

Wi-Fi is a wireless connection method that uses radio waves to link devices to a LAN. Devices usually connect through a wireless access point or router.

Give two benefits of a wired connection compared with a wireless one.

A wired connection is usually faster and more reliable. A wired connection suffers less interference and is harder to intercept, because an attacker needs physical access to the cable.

Give two benefits of a wireless connection.

Users can move around freely and stay connected. New devices can join the network without any extra cables being installed.

Give two drawbacks of a wireless connection.

A wireless connection is usually slower and less reliable, especially through walls or far from the access point. Radio signals can be picked up by anyone in range.

OCR GCSE Computer Science J277

Systems Architecture

Topic overview CPU components and the fetch-execute cycle Factors affecting CPU performance Embedded systems

Memory and Storage

Topic overview RAM, ROM, cache and virtual memory Secondary storage: magnetic, optical and solid state Data units and storage capacity calculations Binary, denary and hexadecimal conversions Binary addition, overflow and binary shifts Character sets, ASCII and Unicode Bitmap images, colour depth and resolution Sound sampling, sample rate and bit depth Lossy and lossless compression

Computer Networks, Connections and Protocols

Topic overview LANs, WANs and network performance Client-server and peer-to-peer networks Network hardware, DNS, hosting and the cloud Star and mesh topologies Wired and wireless connections, IP and MAC addresses Protocols, standards and layers

Network Security

Topic overview Malware, social engineering and brute-force attacks Denial of service, data interception and SQL injection Identifying and preventing vulnerabilities

Systems Software

Topic overview User interfaces, memory management and multitasking Peripheral, user and file management Utility software

Ethical, Legal, Cultural and Environmental Impacts of Digital Technology

Topic overview Ethical and cultural issues in digital technology Environmental impact of digital technology Privacy and digital technology Computer Science legislation and software licences

Algorithms

Topic overview Abstraction, decomposition and algorithmic thinking Flowcharts, pseudocode and structure diagrams Trace tables and correcting algorithms Linear and binary search Bubble, merge and insertion sort

Programming Fundamentals

Topic overview Variables, constants, operators and assignment Sequence, selection and iteration Data types and casting String manipulation and file handling Arrays, records and SQL Functions, procedures and random numbers

Producing Robust Programs

Topic overview Defensive design, input validation and authentication Writing maintainable code Testing, errors and test data

Boolean Logic

Topic overview Logic gates and truth tables Combining gates in logic diagrams

Programming Languages and Integrated Development Environments

Topic overview High-level and low-level languages and translators The integrated development environment (IDE)

Computer Networks, Connections and Protocols

Wired and wireless connections, IP and MAC addresses

3 things to know
J277/01

Overview

Ethernet, Wi-Fi and Bluetooth, wired against wireless connections, encryption on wireless networks, IPv4 and IPv6 addresses, and how MAC addresses differ from IP addresses.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

What is Ethernet?

Key term

What is Wi-Fi?

Key term

What is Bluetooth mainly used for?

Questions from this subtopic

Each one with the model answer underneath.

1
What is Ethernet?
Model answer
Ethernet is the usual method for wired connections in a LAN. Devices plug into a switch or router using Ethernet cables.
2
What is Wi-Fi?
Model answer
Wi-Fi is a wireless connection method that uses radio waves to link devices to a LAN. Devices usually connect through a wireless access point or router.
3
What is Bluetooth mainly used for?
Model answer
Bluetooth connects devices wirelessly over a short range. Typical uses are linking headphones, speakers or a smartwatch to a phone.
4
Give two benefits of a wired connection compared with a wireless one.
Model answer
A wired connection is usually faster and more reliable. A wired connection suffers less interference and is harder to intercept, because an attacker needs physical access to the cable.
5
Give two benefits of a wireless connection.
Model answer
Users can move around freely and stay connected. New devices can join the network without any extra cables being installed.
6
Give two drawbacks of a wireless connection.
Model answer
A wireless connection is usually slower and less reliable, especially through walls or far from the access point. Radio signals can be picked up by anyone in range.

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Systems Architecture

Memory and Storage

Computer Networks, Connections and Protocols

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