Learning Objectives

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

  • Define wireless networking and classify wireless networks by range.
  • Describe the key components of a Wireless LAN (WLAN) and the main Wi-Fi standards.
  • Identify other wireless technologies such as Bluetooth, NFC, and cellular networks.
  • Compare wired and wireless networks.
  • Understand the importance of wireless security and how to secure a Wi-Fi network.

Wireless Networking

Wireless networking allows devices to connect to a network and communicate without the use of physical cables. The most common technology for wireless networking is Wi-Fi.

flowchart TB
    subgraph WIRED["Wired Network"]
        WC[Cable/Fiber] --> WS[Stable, High Speed]
        WC --> WL[Fixed Location]
    end
    subgraph WIRELESS["Wireless Network"]
        WR[Radio Waves] --> WM[Mobile, Flexible]
        WR --> WI[Interference Risk]
    end

Figure 1: Wired vs Wireless Network Comparison

Wireless networks carry data using radio waves, microwaves, or infrared signals instead of copper or fiber cables.

Types of wireless networks by range

Type Full form Range Example technology
WPAN Wireless Personal Area Network A few meters Bluetooth, NFC
WLAN Wireless Local Area Network A home, office, or campus Wi-Fi
WMAN Wireless Metropolitan Area Network A city WiMAX, city-wide wireless
WWAN Wireless Wide Area Network A country or wider Cellular (4G/5G), satellite

Wireless Local Area Network (WLAN)

A WLAN is a LAN that is created using wireless technology. The key components are:

  1. Access Point (AP): A device that broadcasts the wireless signal. In a home network, this is usually a wireless router.

  2. Wireless Network Interface Card (NIC): A component in each device (computer, smartphone, etc.) that allows it to connect to the wireless network.

Other terms you should know:

  • SSID — the network name you see when searching for Wi-Fi.
  • Hotspot — a public place or a phone that shares an internet connection over Wi-Fi.
  • Mesh Wi-Fi — several access points working together to cover a large house or office without dead zones.

Wi-Fi standards

Wi-Fi is based on the IEEE 802.11 family of standards:

Standard Popular name Notes
802.11n Wi-Fi 4 Widely used older standard; 2.4 and 5 GHz
802.11ac Wi-Fi 5 Faster; uses the 5 GHz band
802.11ax Wi-Fi 6/6E Faster and better in crowded places with many devices

The 2.4 GHz band reaches farther and passes through walls better; the 5 GHz band is faster but has shorter range.

Other Wireless Technologies

  • Bluetooth — short-range connection for headphones, keyboards, speakers, and file sharing.
  • NFC (Near Field Communication) — works within a few centimeters; used for tap-to-pay cards and phones.
  • Infrared — line-of-sight communication, used in TV remote controls.
  • Cellular networks — 4G and 5G mobile data provided by telecom operators.
  • Satellite — internet and communication for remote areas, ships, and aircraft.
  • Microwave links — point-to-point transmission between towers, often used by ISPs and telecom operators in hilly terrain.

Wired vs Wireless Networks

Aspect Wired network Wireless network
Mobility Devices fixed to cable points Users can move freely
Installation Cabling takes time and effort Quick and easy to set up
Speed Generally faster and more stable Can slow down with distance and interference
Security Harder to tap without physical access Signals travel through the air; must be encrypted
Cost Cable and labour costs Cheaper to extend to new devices
Reliability Less affected by walls and interference Affected by walls, distance, and other devices

Wireless Security

Because wireless signals are broadcast through the air, security is a major concern. It is essential to secure a wireless network to prevent unauthorized access. This is done using security protocols that encrypt the data and require a password.

  • WEP (Wired Equivalent Privacy): An old and insecure protocol that should never be used.
  • WPA (Wi-Fi Protected Access): An improvement over WEP.
  • WPA2: Was the standard for many years and is still widely used.
  • WPA3: The current and most secure standard, offering stronger encryption.

How to secure a Wi-Fi network

  1. Change the router’s default admin password.
  2. Use WPA3 (or WPA2 if WPA3 is not available) with a strong Wi-Fi password.
  3. Keep the router’s firmware updated.
  4. Create a separate guest network for visitors.
  5. Turn off WPS if it is not needed.

Risks of public Wi-Fi

Open Wi-Fi in cafés, hotels, and bus parks may be monitored by attackers, or may even be a fake hotspot with a trusted-sounding name. Avoid logging in to banking apps on public Wi-Fi, prefer websites with HTTPS, and use mobile data or a VPN for sensitive tasks.

Business Scenario

A café in Lakeside, Pokhara, offers free Wi-Fi to customers. Initially, staff laptops and the billing computer share the same network as customers, which is risky. The owner sets up a guest network for customers with a separate password and bandwidth limit, keeps staff devices on a WPA3-protected network, and adds a second access point to remove dead zones on the rooftop seating area.

Summary

Wireless networking, most commonly implemented with Wi-Fi, allows devices to connect to a network without cables. Wireless networks range from personal (Bluetooth) to wide-area (cellular) networks. A wireless LAN is created using an access point (router) that broadcasts a signal to devices with wireless NICs, following IEEE 802.11 standards such as Wi-Fi 5 and Wi-Fi 6. Wireless offers mobility and easy installation but can be slower and less secure than wired networks. Because these signals are broadcast through the air, security is critical: networks should be protected with WPA3 or WPA2, strong passwords, updated firmware, and separate guest access.

Key Takeaways

  • Wireless networking uses radio waves instead of cables.
  • Wireless networks are classified as WPAN, WLAN, WMAN, and WWAN by range.
  • Wi-Fi is the most common WLAN technology and follows IEEE 802.11 standards.
  • A wireless network requires an access point and wireless NICs.
  • Wireless offers mobility and easy setup; wired offers speed, stability, and security.
  • WPA3 is the current standard for securing wireless networks.

Discussion Questions

  1. What are the main advantages of a wireless network over a wired network?
  2. What are the risks of connecting to an unsecured public Wi-Fi network?
  3. How do you check what type of security your home Wi-Fi network is using?

Exam-Style Questions

Short answer

  1. What is wireless networking? List four wireless technologies.
  2. Differentiate between WPAN, WLAN, and WWAN with examples.
  3. What is an access point?

Long answer

  1. Compare wired and wireless networks. Which would you recommend for a small office, and why?
  2. Explain the importance of wireless security and the steps to secure a Wi-Fi network.