2.4 · Streaming, IoT & Cloud Services
Goal: describe streaming and modern Internet applications such as IoT and cloud computing.
What "streaming" means
Streaming delivers media to the user as it is being received, instead of waiting for the entire file to download.
- The player buffers a few seconds ahead.
- Stops working when the network drops below required bandwidth.
Common streaming applications
| Application | Example |
|---|---|
| Voice mail | iPhone Visual Voicemail |
| Videoconferencing | Zoom, Microsoft Teams |
| Web/live casting | YouTube Live, Twitch |
| Music streaming | Spotify, Apple Music |
| Video on demand | Netflix, Disney+ |
The C&A Guide highlights voice mail, videoconferencing, and webcasting by name.
Internet of Things (IoT)
The IoT is the network of physical devices embedded with sensors and software that exchange data over the Internet.
| Example | What it does |
|---|---|
| Smart thermostat | Adjusts temperature based on routine |
| Smart lock | Opens via smartphone |
| Wearable | Tracks steps, heart rate |
| Smart city sensors | Air quality, traffic, parking |
| Industrial IoT | Monitor factory machinery |
The HKEAA mentions IoT as part of "smart city" applications.
Cloud computing
Cloud computing delivers compute, storage, and software over the Internet, paid by usage.
| Layer | What it offers | Example |
|---|---|---|
| SaaS Software as a Service | Ready apps | Gmail, Google Docs, Salesforce |
| PaaS Platform as a Service | App-hosting platforms | Heroku, AWS Elastic Beanstalk |
| IaaS Infrastructure as a Service | Raw servers/storage | AWS EC2, Azure VMs |
Benefits
- No on-premises hardware.
- Scale up/down on demand.
- Pay-as-you-go.
- Disaster recovery built in.
Risks
- Vendor lock-in.
- Privacy (data leaves your premises).
- Outages (rare but cause widespread impact).
Smart city
A city using ICT to:
- Monitor and manage traffic, energy, public transport, environment.
- Engage citizens via mobile apps.
- Use data analytics to plan services.
Hong Kong examples: Smart Lampposts, MTR's IoT-based passenger flow monitoring.
Exam-style question
Q (4 marks): Explain how streaming differs from downloading, and give two examples of real-world streaming applications. Outline one benefit of cloud-based applications over installed software.
Sample answer:
- Streaming plays media as it arrives, without storing the complete file locally; downloading saves the entire file first before opening it.
- Examples: live streaming on YouTube Live or Twitch; video-on-demand on Netflix.
- Cloud benefit: cloud apps are accessible from any device with a browser, automatically updated, and back up data centrally, removing the need for local installation or manual updates.
Key takeaways
- Streaming = play as you receive.
- IoT = networked physical devices.
- Cloud = compute / storage / software over the Internet, on demand.
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