Fundamentals of Communication and Networking

What Fundamentals of Communication and Networking covers

Serial and parallel transmission, networks and their topologies, wireless, the TCP/IP stack, application layer protocols, the client server model and thin-client computing. Examined on Paper 2.

The 4 subtopics

Each one has its own page. AQA AS Computer Science students sit this topic in the first year.

• Communication methodsRecall questions on serial against parallel transmission, why serial wins over distance, and synchronous against asynchronous transmission and their overheads.Open →
• Communication basicsRecall questions on baud rate, bit rate, bandwidth, latency and protocol, and on why the bit rate can exceed the baud rate.Open →
• Network Topology and Types of NetworkingRecall questions on physical star and logical bus topologies and their operation, and on peer-to-peer and client-server networking.Open →
• Wireless networkingRecall questions on the adapter and the access point, the SSID, why wireless needs encryption when wired does not, and how far hiding the SSID actually protects.Open →

What you need to know

Answer each one before you reveal it.

Take Fundamentals of Communication and Networking further

The same content, four other ways.

Commonly confused

Pairs that lose marks when they are blurred together.

• Serial transmission vs Parallel transmission

  Serial transmission: bits travel sequentially along one channel. Parallel transmission: several bits travel simultaneously along separate wires.

• Peer-to-peer network vs Client-server network

  Peer-to-peer network: hosts have equal status and share resources directly. Client-server network: designated hosts request services from dedicated providers.

• Public IP address vs Private IP address

  Public IP address: a globally unique address routable across the Internet. Private IP address: an address reserved for internal networks and not globally routable.

Questions from this topic

Each one with the model answer underneath.

1. 1

   Define serial transmission.

   Model answer

   Serial transmission sends data one bit at a time, in sequence, down a single wire or channel. The bits arrive one after another and are reassembled into bytes at the receiving end.

2. 2

   Define parallel transmission.

   Model answer

   Parallel transmission sends several bits at the same time, each bit travelling down its own separate wire in a multi-wire link. A group of bits (for example eight) is therefore transmitted simultaneously rather than one after another.

3. 3

   Why is serial transmission preferred over parallel for anything but very short distances?

   Model answer

   Three reasons. First, skew: the wires in a parallel link are never electrically identical, so bits sent together arrive at slightly different times, and over distance the skew grows until the bits of one group overlap those of the next. Second, crosstalk: current in one wire induces interference in its neighbours, and this worsens as the wires get longer and as the data rate rises. Third, cost and bulk: a single-conductor cable is cheaper, thinner and more flexible than a multi-wire ribbon. Serial links can therefore be clocked much faster over distance, which more than offsets sending only one bit at a time.

4. 4

   Parallel transmission sends eight bits at once and serial only one. So why is a serial link often faster in practice?

   Model answer

   Because the achievable clock rate matters more than the number of wires. A parallel link is limited by skew and crosstalk, so its clock must be kept low enough that all eight bits still arrive within the same window. A serial link has neither problem, so it can be clocked at a far higher frequency. A single wire running many times faster beats eight wires running slowly.

5. 5

   Where is parallel transmission still a sensible choice?

   Model answer

   Over very short distances inside a computer, where skew and crosstalk have too little cable length to build up — for example the internal buses of a processor, or the connections between a processor and memory on a motherboard.

6. 6

   Define synchronous data transmission.

   Model answer

   In synchronous transmission the sender and receiver are kept in step by a shared clock signal, usually carried on a separate line or recovered from the data stream itself. Data is sent as a continuous stream of bits timed against that clock, with no gaps between characters, and the receiver samples the line at each clock tick.

What is inside Levo

Six ways to work the same material.

Fundamentals of Communication and Networking revision questions

Is Fundamentals of Communication and Networking examined at AS in AQA Computer Science?

Yes. It sits in Paper 2, which you take in the first year, so it is on the AS paper as well as counting towards the full A level.

What does Fundamentals of Communication and Networking cover in AQA AS-Level Computer Science?

4 subtopics: communication methods, communication basics, network topology and types of networking and wireless networking. Each one has its own page with questions and model answers.

How is Fundamentals of Communication and Networking organised?

By the AQA 7517 specification, subtopic by subtopic, so it matches the order you are taught it in.