Wireless technologies are the building blocks used to create networks that provide devices with access to the internet and other network resources. The most common application of these technologies is for creating Wireless Local Area Networks (WLANs) and providing mobile internet access through cellular networks.

Wireless LAN access points and devices connecting to the internet Figure 1: Wireless Network Connectivity

Learning Objectives

By the end of this chapter, you will be able to:

  • Classify wireless networks by range: short-range, medium-range (WLAN), and wide-area.
  • Describe the components of a WLAN and the Wi-Fi standards.
  • Compare the WLAN security protocols WEP, WPA, WPA2, and WPA3.
  • Explain how cellular networks, hotspots, and tethering provide mobile Internet access.
  • Plan a simple, secure wireless network for a small business.

Types of Wireless Networks by Range

Range Typical technologies Distance Business example
Short-range (PAN) Bluetooth, NFC, ultra-wideband Centimetres to ~10 m Wireless card readers, tap-to-pay, headsets
Medium-range (WLAN) Wi-Fi, mobile hotspots (MiFi) Tens of metres Office, hotel, college, and café networks
Wide-area (WWAN) Cellular 4G/5G, fixed wireless broadband Kilometres Field sales staff, delivery riders, ATMs in remote areas
Satellite Geostationary and low-earth-orbit satellites Very wide areas Connectivity for remote sites, trekking lodges, disaster response

Wireless Local Area Networks (WLAN)

A WLAN is a network that allows devices to connect and communicate wirelessly within a limited area, such as a home, school, or office building. The most common technology used for WLANs is Wi-Fi.

flowchart TB
    INTERNET(("🌐 Internet"))
    MODEM["📟 Modem"]
    AP["📡 Access Point\n(Wireless Router)\nBroadcasts SSID"]

    subgraph DEVICES["Connected Devices"]
        LAPTOP["💻 Laptop\nWireless NIC"]
        PHONE["📱 Smartphone"]
        TABLET["📱 Tablet"]
        TV["📺 Smart TV"]
    end

    INTERNET --> MODEM --> AP
    AP -.->|"📡 Wi-Fi Signal"| DEVICES

    style AP fill:#1565c0,color:#fff

Figure 2: Wireless Local Area Network (WLAN) Architecture

Key Components of a WLAN

  1. Access Point (AP): The central device that broadcasts the wireless signal. In most homes, this functionality is built into a wireless router. The AP connects to the wired network infrastructure (e.g., a cable or fiber modem) to gain access to the internet.

  2. Wireless Network Interface Card (NIC): A component inside a device (like a laptop, smartphone, or smart TV) that allows it to communicate with a wireless network. Every device on a WLAN needs a wireless NIC.

  3. SSID (Service Set Identifier): The public name of a wireless network. When you open your device and see a list of available Wi-Fi networks, you are seeing a list of SSIDs being broadcast by nearby access points.

Wi-Fi Standards

Wi-Fi is defined by the IEEE 802.11 family of standards. Newer generations are faster and handle more devices at once.

Name Standard Approximate year Notes
Wi-Fi 4 802.11n 2009 Still found in older and low-cost routers
Wi-Fi 5 802.11ac 2013 Common in homes and offices; uses the 5 GHz band
Wi-Fi 6 802.11ax 2019 Better performance in crowded places with many devices
Wi-Fi 7 802.11be 2024 Very high speeds; still being adopted

Real speeds are lower than the advertised maximums and fall with distance, walls, and the number of users.

WLAN Security

Because wireless signals are broadcast through the air, security is a major concern. Unauthorized users could potentially access the network or eavesdrop on data being transmitted. To prevent this, WLANs use security protocols that encrypt the data and require a password for access.

  • WEP (Wired Equivalent Privacy): An early and now obsolete protocol with major security flaws.
  • WPA (Wi-Fi Protected Access): An interim improvement over WEP.
  • WPA2: For many years, this was the standard for securing wireless networks.
  • WPA3: The current and most secure protocol, offering stronger encryption and better protection against attacks.

Mobile Internet Access

Wide-area wireless networks, primarily cellular networks, provide internet access to mobile devices like smartphones and tablets.

  • Cellular Data: When you are not connected to Wi-Fi, your smartphone uses the cellular network (e.g., 4G LTE or 5G) to connect to the internet. This allows for continuous connectivity while on the move.

  • Mobile Hotspot (Tethering): Most smartphones have a feature that allows them to act as a portable wireless router. The phone uses its cellular data connection to access the internet and then shares that connection with other nearby devices (like a laptop) by creating its own small Wi-Fi network.

Public Wireless Hotspots

A hotspot is a physical location that offers internet access over a WLAN. These are commonly found in public places like cafes, airports, hotels, and libraries. While they offer great convenience, they also come with security risks.

  • Open Networks: Many public hotspots are “open,” meaning they do not require a password and do not use encryption. When you use an open network, any data you send or receive could potentially be intercepted by a malicious actor on the same network (a “man-in-the-middle” attack).
  • Best Practices: When using public Wi-Fi, it is crucial to avoid sending sensitive information (like passwords or financial details) and to use a Virtual Private Network (VPN). A VPN encrypts all of your internet traffic, creating a secure tunnel that protects your data even on an open network.

Worked Example: Wi-Fi for a 30-Room Hotel in Pokhara

The owner of a lakeside hotel wants reliable Wi-Fi for guests and a secure network for the reception and accounts computers.

  1. Internet connection: A fibre connection from a local ISP, with a mobile 4G router as a backup for outages.
  2. Bandwidth estimate: At the evening peak, perhaps 40 devices are active at once, using on average 2 Mbps each for browsing and video calls: 40 × 2 = 80 Mbps. A 100 Mbps plan leaves a small margin; 150 Mbps is safer in the tourist season.
  3. Coverage: One router cannot cover three floors through concrete walls. The hotel installs one access point per floor plus one for the restaurant and garden, all managed together so guests roam without reconnecting.
  4. Separate networks: A guest SSID with its own password (changed regularly) and a separate staff SSID for reception, billing, and CCTV. Guests cannot see or reach staff computers.
  5. Security: WPA3 (or WPA2 where old devices need it) with strong passwords; the router’s admin password changed from the default; firmware kept up to date.
  6. Fair use: A per-device speed limit on the guest network so one guest streaming video does not slow everyone else.

The main business lessons: plan for peak use, separate guest and business traffic, and treat Wi-Fi as part of the guest experience that appears in online reviews.

Wireless Networks in Nepal

Most Nepalis connect to the Internet through mobile phones on 4G networks operated by Nepal Telecom and Ncell, with 5G under trial and gradual rollout. Fibre-to-the-home with Wi-Fi routers is common in cities and growing in towns. Public Wi-Fi is offered by many cafés, hotels, and some public places, often without encryption. In remote hill and mountain areas, coverage gaps remain, and some trekking lodges and remote offices rely on satellite or long-distance wireless links. For businesses, this means designing services that still work on slow or interrupted mobile connections.

Summary

Wireless networks are classified by range: short-range networks such as Bluetooth and NFC, medium-range WLANs based on Wi-Fi, wide-area cellular networks, and satellite. A WLAN uses access points, wireless network interface cards, and SSIDs; newer Wi-Fi generations offer more speed and capacity. Because wireless signals travel through the air, WLANs must be protected with WPA2 or WPA3, never the obsolete WEP. Cellular data, tethering, and hotspots give mobile Internet access, but open public hotspots are risky without a VPN. A good business network plans for peak demand, separates guest and staff traffic, and is configured securely.

Key Takeaways

  • Wireless networks are short-range (PAN), medium-range (WLAN), wide-area (cellular), or satellite.
  • A WLAN needs an access point, wireless NICs in devices, and an SSID.
  • WEP is obsolete; use WPA3 or at least WPA2.
  • Open public Wi-Fi is unencrypted; use HTTPS and a VPN for sensitive work.
  • Separate guest and business networks, and size bandwidth for peak use.

Discussion Questions

  1. Why should a business never use the same Wi-Fi network for guests and its accounting computers?
  2. What are the risks of logging in to a bank or wallet app on a café’s open Wi-Fi?
  3. How should an app designed for users in rural Nepal handle slow or interrupted mobile connections?

Exam-Style Questions

Short answer

  1. What is a WLAN? Name its main components.
  2. What is an SSID?
  3. Distinguish between WPA2 and WEP.
  4. What is tethering (a mobile hotspot)?
  5. Why are open public hotspots risky?

Long answer

  1. Classify wireless networks by range and explain the business uses of each type.
  2. Explain the components and security of a wireless LAN, and design a secure Wi-Fi network for a small business in Nepal.