6.4 Extending skills
Paragraph 2 – Global and local networking infrastructure
• available bandwidth varies across world: domestic fibre = rapid growth, wireless broadband = limited growth
• international and internal connections dependent on size of cables or of radio signals
• fibre-optic cables most efficient transmission; in the sea connecting continents – continuing to create links between continents and countries
Paragraph 3 – Challenges in global networking
• 2010 onwards, huge growth in video content – ‘video on demand’ services – large amounts of data needs to be transferred
• 2020s rapid demand for synchronous communication: distance working + conference calls – connection quality a key issue – latency >300ms = problems for VoIP, e.g., overlapping voices, delay hearing voice, long echoes
• team-gaming emerging as growth area – data throughput – but low latency key
Paragraph 4 – CDNs as a solution for content
• content delivery network (CDN) – geographically-distributed servers – minimizing latency
• content on servers in different global regions (points of presence (PoPs)) – close to major markets – requests directed to region with lowest latency
• regularly requested content can be included in CDN with less regular content elsewhere
Paragraph 5 – Future developments
• continuing need for ‘always on’ networking – combines wired and wireless – need for increased bandwidth and lower latency
• 5G wireless networking: provides very flexible access for users, 10 times faster than existing 4G networks, great potential, content delivery, but also synchronous interaction
• 5G ideally linked by fibre-optic backbone, but some microwave connections if fibre too difficult or costly
3. Set for individual work or pairwork. Depending on the group and the amount of time available, you may want to allocate individual paragraphs. You could also ask students to complete the full text as a homework task.
6.4_B
Monitor and encourage. If appropriate, feed back visually using the model answer provided below and in the PDF.
Model answer Planning networks for the future
A number of things need to be considered when planning networks. One of the most important is the network throughput. This is the volume of data which is transferred from a network source to a network destination over a specific period of time.
Network throughput is affected by a number of factors. A key factor is the bandwidth of the network. This is often referred to as the width of the data pipe and it is measured in megabits per second (Mbps). A narrower pipe means that less data is transferred, while a wider pipe means more data is transferred. Another factor is network latency. This is the time that it takes for packets of data to move from the network origin to the network destination. If the network has low latency, then there are only small delays in transferring the data. If it has higher latency, then there will be longer delays.
The amount of available bandwidth varies considerably across the world. In countries where fibre-optic cable is available in people’s homes then there will be a rapid growth in the available bandwidth. However, where the population relies on wireless broadband, there is a much more limited growth of available bandwidth. The amount of available bandwidth in internet connections between countries depends on the size of the cables or the capacity of the radio signals which connect them. Fibre-optic cables are the most efficient methods of data transmission. They can be used in the sea to create links between continents. Cables continue to be laid, creating new links and increasing existing capacity between continents and countries.
The demand for network capacity continues to grow. From 2010 onwards, there was a huge growth in the amount of video content on the networks. ‘Video on demand’ services meant that large amounts of data needed to be transferred between suppliers and their customers. During the early 2020s, there was a rapid increase in the demand for synchronous communication. This was due to the growth in distance working and in the number of conference calls being made. Connection quality now became a key issue. When network latency was >300ms
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