A WLAN is a wireless computer network that links two or more devices using wireless communication to form a LAN within a limited area such as a home, school, campus, or office building. A WLAN is a network system wherein Wi-Fi is one of the most common technologies in this system. Therefore, WLAN includes Wi-Fi.
Benefits of WLAN
WLAN technology first appeared in the United States. It was primarily used as a wireless extension of the last-mile network and was mainly applied in households. At that time, the American people had a strong demand for wireless Internet access due to the cabling difficulties (most Americans living in villas with courtyards) and the popularity of laptops and tablets. This in turn accelerated the proliferation of WLANs.
Compared with wired networks, WLANs have the following benefits:
High mobility: It is easy to connect to WLANs that are free from cable and port location constraints. This makes WLANs ideal for scenarios where users are often moving, such as in office buildings, airport halls, resorts, hotels, stadiums, and cafes.
Flexible deployment: WLANs provide wireless network coverage in places with difficult cabling, such as subways and roadways. Wireless network coverage eliminates or reduces complex cabling, thereby simplifying deployment, reducing costs, and facilitating scalability.
Is WLAN and Wi-Fi the Same Thing?
Wi-Fi is a trademark of the WFA, and is also a wireless network communication technology based on IEEE 802.11. The WFA has announced the use of Wi-Fi to improve the interoperability of products in compliance with IEEE 802.11 standards.
WLAN is short for wireless local area network. Quite simply, WLANs provide network communication using radio waves such as lasers and infrared signals, instead of physical connections. They provide wireless network communication using high-frequency radio waves (such as those on the 2.4 GHz and 5 GHz frequency bands) and comply with IEEE 802.11 standards. WLAN in our daily life refers to that implemented based on IEEE 802.11 standards. During the evolution and development of WLAN, various technical standards have emerged, such as Bluetooth, Wi-Fi, and HyperLAN2. Among them, Wi-Fi is now most commonly used due to its advantages such as simple implementation, reliable communication, high flexibility, and low implementation costs. Gradually, Wi-Fi becomes a synonym of WLAN.
Simply put, WLAN is a network system, while Wi-Fi is a technology in this network system. Therefore, WLAN includes Wi-Fi.
Are WLANs Secure?
WLANs are easy to deploy and expand, flexible, and cost-effective. On WLANs, service data is transmitted through radio signals. As such, service data can easily be intercepted or tampered with by attackers when being transmitted on open wireless channels.
Common WLAN security threats are as follows:
No Wi-Fi authentication: Attackers can easily connect to WLANs and then attack the entire network.
Unencrypted wireless data: Attackers can intercept and tamper with service data transmitted on wireless channels by obtaining packets over the air interface.
Perimeter threats: Rogue APs advertise the same SSIDs as authorized APs. As a result, STAs connect to rogue APs, resulting in data interception by attackers.
To cope with the preceding security threats, differentiated security protection measures are required to protect against network attacks, for example:
Link authentication and user access authentication are used to prevent unauthorized use of network services. To this end, an enterprise-class user authentication solution is deployed to authenticate and manage user identities in a centralized manner.
Data encryption is used to improve data security. As such, WPA3 — featuring stronger encryption — is available to protect user data transmitted over the air interface from being cracked. WPA3 has a 256-bit key and is currently the most powerful encryption algorithm.
Rogue APs can be detected and contained using wireless attack detection technology. For this reason, Wireless Intrusion Detection System (WIDS) and Wireless Intrusion Prevention System (WIPS) can be deployed to detect air interface threats and phishing APs in real time and take containment measures to protect networks against intrusions.
WLAN Roaming
On a WLAN, users require mobile communication. The signal coverage of a single AP, however, is limited. As such, users often move from the coverage area of an AP to that of another AP. To prevent network interruptions while users move between different APs, the concept of WLAN roaming is introduced.
WLAN roaming is a process wherein a station (STA) — when moving to the boundaries between two APs — associates with the new AP and disconnects from the original AP, during which connections are not interrupted. Simply put, WLAN roaming is similar to cell handover for a mobile phone. When a mobile phone moves from the coverage area of a base station to that of another base station, the mobile phone still enjoys uninterrupted and seamless call experiences.
Common WLAN roaming technologies include traditional roaming, fast roaming, smart roaming, and lossless roaming.
Basic Elements of WLAN
STA: a terminal that complies with 802.11 standards. Examples include a PC that has a wireless network interface card (NIC) or a mobile phone that supports WLAN.
AP: a device that provides 802.11-compliant wireless access services for STAs. APs function as a bridge between wired and wireless networks.
STA and AP
For more information, see WLAN
