Network Types: PAN, LAN and WAN

A computer network is two or more devices (computers, printers, phones, servers) connected together so they can communicate and share resources such as files, printers, and internet connections.

Networks are classified primarily by their geographical scale — how large an area they span.

Network type	Full name	Typical scale	Example
PAN	Personal Area Network	A few metres	Bluetooth headphones connected to a phone
LAN	Local Area Network	A building or campus	School or office network
WAN	Wide Area Network	Cities, countries, or worldwide	The internet

A single organisation may use all three: an employee's phone forms a PAN with their smartwatch; their laptop connects to the office LAN; the office LAN connects to a head office via a WAN.

The internet is the largest example of a WAN — a global network of interconnected networks.

Connecting devices in a network creates both benefits and risks compared to using standalone computers.

Advantages:

• Resource sharing — printers, scanners, and storage can be shared among many users instead of every computer needing its own
• File sharing — files can be stored centrally on a server and accessed by any authorised user on the network
• Communication — email, messaging, and video conferencing all depend on network connectivity
• Centralised management — software can be installed, updated, and configured from one server rather than on every device individually
• Cost savings — sharing resources (printers, internet connections) reduces hardware costs per user

Disadvantages:

• Security risks — a connected device is reachable from across the network; malware can spread rapidly between networked devices
• Central point of failure — if the server or key network hardware fails, all users may lose access to files and resources
• Cost of setup — installing cables, switches, routers, and servers requires significant upfront investment
• Maintenance — networks require ongoing management: monitoring, troubleshooting, and updating
• Privacy — data passing over a network can potentially be intercepted if not encrypted

Exam tip: For six-mark "advantages and disadvantages" questions, give three of each with a brief explanation. Bullet points without explanation earn half marks at best.

A PAN is a network covering a very small area, typically within a few metres of a single person. It connects a person's own devices to each other.

Characteristics:

• Range: typically up to 10 m
• Ownership: a single individual
• Transmission: wireless (Bluetooth) — the AQA specification requires knowledge of Bluetooth for PANs

Common PAN examples:

Device	Connection
Smartphone ↔ wireless headphones	Bluetooth PAN
Laptop ↔ wireless mouse/keyboard	Bluetooth PAN
Smartwatch ↔ smartphone	Bluetooth PAN
Phone ↔ laptop (tethering)	Bluetooth PAN

PANs are typically set up automatically when devices are paired and require no infrastructure (no router, no cables, no internet connection).

Limitations: Very short range; designed for one person's devices only; lower data rates than Wi-Fi; not suitable for multi-user resource sharing.

A LAN covers a single building, campus, or site — a school, office, hospital, or home.

Characteristics:

• Range: typically up to a few kilometres across a site
• Ownership: usually owned and managed by a single organisation or household
• Transmission: mix of wired (Ethernet/copper or fibre) and wireless (Wi-Fi)
• High data transfer speeds (typically 1 Gbps on wired connections)

Typical LAN infrastructure:

• Switch — connects devices within the LAN; forwards data only to the intended recipient
• Router — connects the LAN to the internet (or another network)
• Wireless access point (WAP) — allows wireless devices to connect to the LAN
• Server — central machine storing files, managing user accounts, running applications

Worked example — A school has 600 student laptops, 30 printers, and a file server. Switches in each corridor connect devices to a central switch; the central switch connects to the router; the router connects to the internet. Students access files on the server over the LAN and reach the internet through the router.

Because the organisation owns the LAN, it has full control over security, configuration, and maintenance.

A WAN connects networks over large geographical areas — across cities, countries, or continents. An organisation uses a WAN to link its separate LANs together.

Characteristics:

• Range: national or global
• Ownership: shared infrastructure — organisations lease connections from telecommunications companies rather than owning the physical cables
• Transmission: typically fibre optic for the backbone, but the final connection to premises may use copper or wireless
• Speeds: generally lower than LAN speeds across long distances; high variability depending on link type

Comparing LANs and WANs:

Feature	LAN	WAN
Geographical area	Building or campus	Cities, countries, global
Ownership	Single organisation	Shared / leased infrastructure
Speed	High (1 Gbps typical)	Lower and more variable
Security	Easier to control	Harder to control (shared medium)
Cost to set up	Moderate	High (leased lines, international cables)

The internet is the most significant WAN — a global system of interconnected networks using standardised protocols (TCP/IP) to allow any device to communicate with any other.

Feature	PAN	LAN	WAN
Typical range	~10 m	Building/campus	Countries/global
Typical owner	Individual	Organisation	Shared (telecoms providers)
Common media	Bluetooth	Copper, fibre, Wi-Fi	Fibre (backbone), copper, wireless
Example	Smartwatch + phone	School network	The internet
Speed	Low	High	Variable (often lower than LAN)
Security control	Full (personal)	Full (organisation)	Partial (shared infrastructure)

Worked exam question — "A company has offices in London and Tokyo. Each office has a local network of 200 computers. Describe the most appropriate network type for each: (a) connecting computers within the London office, (b) connecting the London and Tokyo offices."

(a) LAN — the computers are in one building; a LAN provides high-speed, secure, organisation-controlled connectivity.

(b) WAN — the offices are in different countries; a WAN (using leased fibre links from a telecoms provider) connects the two LANs across the global distance.

1. Describing the internet as a LAN

The internet is the world's largest WAN. A LAN is confined to a single site. Students sometimes write "the internet is a LAN" or confuse the office network (LAN) with the internet connection it uses.

2. Stating that LANs are always faster than WANs

LANs typically have faster speeds within the site, but a WAN backbone fibre link between two cities can be very fast. The distinction is about geographical scale and ownership, not just speed.

3. Forgetting to name the network type when asked to identify it

A question asking "what type of network is used in a school?" requires the answer "LAN" — not a description like "a network in a building". Naming the type correctly is required for the mark.

4. Confusing disadvantages of networking with disadvantages of a specific network type

General networking disadvantages (security risk, cost, single point of failure) apply to all network types. Exam answers should address what is specific to the network type asked about where possible.

5. Omitting explanation when listing advantages or disadvantages

"Sharing resources" alone scores one mark at most. "Sharing resources — for example, a single printer can be used by all 30 computers in the office, reducing hardware costs" scores higher because the example and the benefit are both stated.