Know and understand the uses of wi-fi and Bluetooth

4 Networks and the Effects of Using Them

Objective

Know and understand the uses of Wi‑Fi and Bluetooth, the network hardware they work with, the types and topologies of networks they create, related security, health and e‑safety considerations, and how they support cloud services and e‑conferencing.

1. Network Environments

• Internet – The global public network that connects millions of private, public, academic, business, and government networks.
• Intranet – A private network that uses Internet protocols (TCP/IP) but is restricted to an organisation’s internal users.
• Extranet – An extension of an intranet that provides controlled access to external partners, suppliers or customers.

Diagram idea: A cloud labelled “Internet” connected to an organisation’s “Intranet” (router‑protected). A separate “Extranet” link shows a secure VPN connection to a partner’s network.

2. Network Hardware that Supports Wireless Connections

• Router – Connects a LAN to the Internet, performs NAT, assigns IP addresses via DHCP and often includes a built‑in wireless access point (AP).
• Wireless Access Point (AP) – Provides Wi‑Fi coverage for devices; can be standalone or integrated in a router.
• Network Interface Card (NIC) – Internal or external card that gives a device wired (Ethernet) or wireless (Wi‑Fi/Bluetooth) connectivity.
• Switch – Connects multiple devices in a LAN; learns MAC addresses and forwards frames only to the correct port.
• Bridge – Links two network segments (e.g., wired LAN ↔ wireless LAN) and forwards traffic based on MAC addresses.
• Hub – Simple repeater that sends incoming signals to all ports; largely obsolete for modern wireless networks.

3. Common Network Topologies (Syllabus 4.1)

4. Types of Networks (Syllabus 4.1)

5. IP Fundamentals (Syllabus 4.2)

• IPv4 vs IPv6 – IPv4 uses 32‑bit addresses (e.g., 192.168.1.1); IPv6 uses 128‑bit addresses (e.g., 2001:0db8::1) and provides a vastly larger address space.
• Static vs Dynamic addressing – Static IPs are manually set and never change; dynamic IPs are assigned automatically by a DHCP server.
• DHCP (Dynamic Host Configuration Protocol) – Provides devices with an IP address, subnet mask, gateway and DNS information.
• NAT (Network Address Translation) – Allows many private IP addresses to share a single public IP address, improving security and conserving address space.
• Subnetting (basic) – Divides a larger network into smaller logical segments (e.g., 255.255.255.0 mask for a /24 network).

6. What is Wi‑Fi?

Wi‑Fi (Wireless Fidelity) is a family of IEEE 802.11 standards that enable devices to join a LAN and access the Internet without cables.

• Frequency bands: 2.4 GHz, 5 GHz, 6 GHz (Wi‑Fi 6E).
• Typical range: 10–30 m indoors, up to 100 m outdoors (depends on standard, antenna, obstacles).
• Key standards: 802.11b/g/n/ac/ax (Wi‑Fi 4‑6).
• Data‑transfer rates: 11 Mbps (802.11b) → >9 Gbps (802.11ax with 8 × 8 MU‑MIMO).
• Network topology: Infrastructure (router/AP) or ad‑hoc.
• Typical devices: Laptops, smartphones, tablets, smart TVs, printers, IoT hubs.

7. What is Bluetooth?

Bluetooth is a short‑range, low‑power wireless technology (IEEE 802.15.1) designed for point‑to‑point or point‑to‑multipoint communication.

• Frequency band: 2.4 GHz ISM band.
• Typical range: Class 2 – up to 10 m; Class 1 – up to 100 m.
• Versions: 1.0 → 5.4, each improving speed, range and power consumption.
• Data‑transfer rates: 1 Mbps (Bluetooth 1.2) → 2 Mbps (classic 5.0) ; up to 50 Mbps in Bluetooth 5.2 LE high‑speed mode.
• Network topology: Piconet (max 8 active devices) and scatternet (multiple linked piconets).
• Typical devices: Headsets, keyboards, mice, fitness trackers, smart watches, car audio systems.

8. Comparison of Wi‑Fi and Bluetooth

9. Advantages and Disadvantages

Wi‑Fi

• Advantages: high speed, supports many users, covers whole homes/offices, enables Internet and cloud access.
• Disadvantages: higher power use, can suffer interference from other 2.4 GHz devices, requires an AP/router.

Bluetooth

• Advantages: low power, simple pairing, ideal for peripherals, inexpensive hardware.
• Disadvantages: limited range and speed, few simultaneous connections, not suitable for large data transfers.

10. Practical Applications in Everyday Life

1. Connecting a laptop to a wireless router for Internet access (Wi‑Fi – WLAN).
2. Streaming music from a smartphone to a Bluetooth speaker.
3. Using a Bluetooth keyboard and mouse with a tablet or mini‑PC.
4. Pairing wireless headphones to a laptop for video‑conferencing.
5. Transferring photos between smartphones via Bluetooth.
6. Setting up a home‑automation hub that talks to sensors and smart locks using Bluetooth Low Energy (PAN).
7. Accessing cloud‑based file‑sync services (e.g., Google Drive, OneDrive) over Wi‑Fi.
8. Joining an online class or meeting (Zoom, Teams) through a Wi‑Fi connection while using a Bluetooth headset for audio.

11. Security Considerations (Syllabus 4.2)

Wi‑Fi Security

• Use WPA3 encryption; if unavailable, use WPA2‑AES.
• Change the default router admin password and SSID.
• Enable a guest network to isolate visitors from the main LAN.
• Disable WPS unless required.
• Keep router firmware up‑to‑date.
• Implement a firewall (router‑built‑in or software) to filter inbound/outbound traffic.

Bluetooth Security

• Keep device visibility “hidden” when not pairing.
• Prefer “Just Works” only in trusted environments; use PIN/Passkey or Numeric Comparison for higher security.
• Apply firmware updates to headphones, wearables, and other Bluetooth devices.
• Avoid pairing in public places where “Man‑in‑the‑Middle” attacks are possible.

Authentication & Access Controls

• Enforce strong password policies (minimum 12 characters, mix of upper/lower case, numbers, symbols).
• Enable two‑factor authentication (2FA) for cloud accounts and critical services.
• Consider biometric authentication (fingerprint, facial recognition) where supported.

Anti‑Malware & General Safeguards

• Install reputable anti‑malware/antivirus software on all devices.
• Use a VPN on public or unsecured Wi‑Fi when accessing sensitive information.
• Regularly back up important data to a cloud service or external drive.

12. Electronic Conferencing (Syllabus 4.2)

• Hardware requirements: reliable Wi‑Fi or wired Ethernet, webcam (720p +), microphone or headset (preferably Bluetooth for mobility).
• Software platforms: Zoom, Microsoft Teams, Google Meet, Cisco Webex – all require a stable internet connection and up‑to‑date client.
• Etiquette:

  • Join meetings a few minutes early to test audio/video.
  • Mute microphone when not speaking to avoid background noise.
  • Use a virtual background or ensure a tidy real‑world background.
  • Respect privacy – do not record without permission.

• Security for meetings: set meeting passwords, enable waiting rooms, lock the meeting after all participants have joined.

13. Health, Safety and E‑Safety (Syllabus 5)

• Radio‑frequency (RF) exposure

  • Wi‑Fi (2.4 GHz/5 GHz) and Bluetooth (2.4 GHz) operate well below international safety limits (ICNIRP, IEEE).
  • Maintain a reasonable distance from routers (≈30 cm) when possible, especially for children.

• Electrical safety

  • Use the correct voltage charger for wireless devices; avoid charging near water.
  • Do not place Wi‑Fi routers on top of heat‑producing appliances.

• E‑safety and responsible use

  • Never share Wi‑Fi passwords with unknown persons.
  • Turn off Bluetooth when not in use to prevent “blue‑jacking” and to save battery.
  • Be alert to phishing attempts that may arrive via email or instant‑messaging on a Wi‑Fi network.

14. Cloud Computing and Wireless Networks (Syllabus 4.2 – Cloud Computing Sub‑point)

Wireless networks provide the high‑bandwidth link that makes cloud services practical in homes, schools and businesses.

• File‑sync & backup – Dropbox, OneDrive, Google Drive upload/download data over Wi‑Fi.
• Software‑as‑a‑Service (SaaS) – Online word processors, spreadsheets, learning platforms (Google Workspace, Microsoft 365) are accessed via Wi‑Fi.
• Streaming & media – Netflix, YouTube, Spotify rely on Wi‑Fi for smooth playback.
• IoT & smart‑home clouds – Sensors communicate via Bluetooth to a hub, which then uses Wi‑Fi to send data to cloud dashboards.
• Collaboration tools – Real‑time document editing, virtual classrooms and e‑conferencing depend on a stable Wi‑Fi connection.

15. Summary Diagram (Suggested)