Know and understand similarities and differences between Bluetooth and wi-fi

4 Networks and the Effects of Using Them

Objective (AO1)

Know and understand the similarities and differences between Bluetooth and Wi‑Fi, and be able to evaluate which technology is most appropriate for a given situation.

1 Core Network Components (Section 4.1)

• Router – connects a LAN to other networks (e.g., the Internet). Performs NAT, assigns IP addresses via DHCP, and can provide wireless access (Wi‑Fi). Typical home/school router also includes a built‑in firewall.
• Network Interface Card (NIC) – hardware in each device that provides a physical link to a network. Types: Ethernet NIC (wired), Wi‑Fi NIC (802.11), Bluetooth NIC (802.15.1/LE).
• Hub – a simple multi‑port device that repeats incoming Ethernet frames to all other ports. Creates a single collision domain; no MAC‑address learning.
• Switch – learns MAC addresses and forwards frames only to the intended port, creating separate collision domains and improving performance.
• Bridge – connects two separate LAN segments and filters traffic based on MAC addresses. Modern switches usually contain bridge functions.

Diagram (placeholder): labelled diagram showing a router, switch, hub and NICs (wired and wireless) linked together.

2 Wireless Technologies – Bluetooth vs Wi‑Fi (Section 4.1)

Both are IEEE‑defined radio standards, but they are optimised for very different tasks.

Wi‑Fi Standards Evolution (quick reference)

3 Cloud Computing & Wireless Gateways (Section 4.1)

Cloud computing provides on‑demand storage, processing and services over the Internet. In a school setting the typical flow is:

1. Device (laptop, tablet, sensor) connects to the local network – usually via Wi‑Fi.
2. The Wi‑Fi router forwards traffic to the school’s Internet gateway.
3. Data is sent to a cloud platform (e.g., Google Drive, Microsoft OneDrive, a school‑run AWS‑based dashboard).

Bluetooth‑LE Mesh devices (e.g., temperature or occupancy sensors) cannot reach the Internet directly. They forward their data hop‑by‑hop to a gateway hub** that is Wi‑Fi‑connected. The hub then pushes the aggregated data to the cloud for storage and analysis.

Example: A science lab installs 20 Bluetooth‑LE temperature sensors. Each sensor sends a reading every minute to a Raspberry‑Pi gateway. The Pi is linked to the school Wi‑Fi and uploads the data to a Google Cloud Firestore database, where teachers can view live temperature graphs on a tablet.

4 Network Issues & Communication (Section 4.2)

4.1 Security, Passwords, Anti‑malware, e‑Safety (AO2 & AO3)

• Typical threats

  • Eavesdropping – intercepting unencrypted traffic (more likely on open Wi‑Fi or Bluetooth “bluejacking”).
  • Man‑in‑the‑Middle (MitM) – rogue AP or Bluetooth device that pretends to be legitimate.
  • Rogue Access Point – unauthorised AP that mimics the school network.
  • Malware propagation via file sharing over Wi‑Fi.

• Counter‑measures (AO3)

  • Use strong, unique passwords (minimum 12 characters, mix of upper/lower case, numbers, symbols).
  • Enable WPA3‑Personal (or at least WPA2‑AES) on all school Wi‑Fi networks.
  • Activate MAC‑address filtering for critical devices (e.g., servers, admin laptops).
  • Keep firmware of routers, switches, NICs and Bluetooth devices up‑to‑date.
  • Disable “auto‑connect” for Bluetooth in public places; pair only with known devices.
  • Install reputable anti‑malware software on all laptops, tablets and shared PCs.

• e‑Safety checklist for students (AO2)

  • Never accept pairing requests from strangers.
  • Only connect to the school’s SSID – verify the exact network name.
  • Log out of cloud services when finished and lock the device.
  • Report any suspicious “free Wi‑Fi” hotspots to a teacher immediately.
  • Do not share passwords with classmates; use a password manager if allowed.

4.2 Video/Audio/Web‑Conferencing (AO2)

Typical bandwidth requirements (compressed streams):

• Voice‑only: 0.1 – 0.2 Mbps per participant.
• Standard‑definition video (480p): 0.5 – 1 Mbps.
• High‑definition video (720p/1080p): 3 – 5 Mbps per stream.
• Group call with screen‑share: 5 – 10 Mbps total.

Wi‑Fi 6/6E can comfortably support multiple simultaneous HD streams in a classroom. Bluetooth’s maximum of 2 Mbps is only sufficient for low‑quality audio or very small file transfers; it is unsuitable for video‑conferencing.

4.3 LAN, WLAN, WAN, Intranet, Extranet, Internet (AO1)

• LAN (Local Area Network) – covers a single building or campus; uses Ethernet cables and/or Wi‑Fi. Example: the school’s computer lab network.
• WLAN (Wireless LAN) – the wireless part of a LAN, implemented with Wi‑Fi access points. Example: the auditorium’s Wi‑Fi covering 200 seats.
• WAN (Wide Area Network) – connects multiple LANs over larger distances (e.g., the school district network or the Internet). Example: the link between the school and the central education authority’s data centre.
• Intranet – a private network using Internet protocols, accessible only to members of an organisation. Example: the staff portal where teachers upload lesson resources.
• Extranet – a restricted part of an intranet that external partners can access. Example: a parent‑teacher communication portal.
• Internet – the global public network that interconnects millions of WANs. Provides access to cloud services, web‑based learning platforms, etc.

Diagram (placeholder): simple topology showing a LAN (wired switches), WLAN (APs), connection to a WAN router, and the Internet cloud.

5 Practical Classroom Activities (AO2 – Skills)

1. Configure a secure Wi‑Fi network

   • Log into the school router’s admin interface (usually via 192.168.1.1).
   • Create a new SSID called ICT‑Class‑WiFi.
   • Set security to WPA3‑Personal (SAE) with a password of at least 12 characters.
   • Enable a “Guest Network” for visitors and disable “WPS”.
   • Take screenshots of the SSID settings and security options; save them in a folder named WiFi‑Config‑Evidence.

2. Pair a Bluetooth‑LE device

   • Turn on Bluetooth on a laptop (Windows 10/11 Settings → Bluetooth & devices) and on a Bluetooth‑LE speaker.
   • Select “Add a device”, choose the speaker, and complete the pairing (use PIN if prompted).
   • Capture a screenshot of the “Paired devices” list and note the device’s MAC address.
   • Play a 10‑second audio clip; use a stopwatch to record the time from “Play” to audible sound.

3. Compare data‑transfer performance

   • Transfer a 10 MB file from Laptop A to Laptop B via Bluetooth‑LE (use the “Send or receive files via Bluetooth” wizard). Record the transfer time.
   • Upload the same file to the school’s Google Drive over Wi‑Fi; record the upload time.
   • Enter the two times in a table, calculate the percentage speed difference, and comment on the result.

6 Analysis & Evaluation (AO3)

7 Assessment Objective Mapping (quick reference)

8 Key Points to Remember (Revision)

• Bluetooth → short‑range, very low power, ideal for peripherals, wearables and IoT sensors.
• Wi‑Fi → high‑speed, larger coverage, essential for Internet access, video‑conferencing and cloud services.
• Both standards continue to evolve: Bluetooth 5.2 adds multi‑stream audio; Wi‑Fi 6E/7 adds 6 GHz spectrum and multi‑gigabit throughput.
• Security is critical – use WPA3 for Wi‑Fi, enable Bluetooth LE Secure Connections, keep passwords strong and firmware up‑to‑date.
• Understanding the strengths and limits of each technology helps you design efficient, safe and future‑proof school networks.