What Is WLAN (Wireless Local Area Network)?

A WLAN, or Wireless Local Area Network, is a type of local area network (LAN) that uses high-frequency radio waves rather than wires to communicate and transmit data over short distances. It enables devices to connect and communicate wirelessly within a limited area, such as a home, school, computer laboratory, office building, or campus. This technology provides users the mobility to move around within a local coverage area and still be connected to the network.

WLAN vs. Wi-Fi

WLAN and Wi-Fi are terms often used interchangeably, but they refer to different aspects of wireless networking.

A WLAN is a broader concept that encompasses any type of wireless network within a localized area. It can be based on various wireless communication standards, including but not limited to Wi-Fi. The technology behind WLANs allows devices within the coverage area to communicate with each other and access shared resources (like the internet and printers) without the need for physical cables.

Wi-Fi, on the other hand, specifically refers to a set of wireless network protocols based on the IEEE 802.11 family of standards, which is the most widely used technology for creating WLANs. Wi-Fi is a specific method of achieving wireless connectivity standardized and certified by the Wi-Fi Alliance, an organization that ensures interoperability between different wireless devices. Wi-Fi technology enables devices such as smartphones, laptops, tablets, and other smart devices to connect to the internet or each other wirelessly within the range of a Wi-Fi network. The term "Wi-Fi" doesn't stand for anything but is a trademarked phrase representing the IEEE 802.11 standards.

In summary, while all Wi-Fi networks are WLANs, not all WLANs are Wi-Fi networks, as WLANs can utilize other wireless technologies for connectivity.

A Short History of WLAN

The journey of WLANs traces its origins to the 1970s with the pioneering ALOHAnet project, marking the initial steps towards localized wireless communication. During the 1980s, the landscape was characterized by diverse, proprietary wireless solutions tailored for specific applications, hindered by the lack of standardization. The 1990s heralded a turning point with the IEEE's development of the 802.11 standards, establishing a foundation for interoperable wireless networks. By 1997, the release of the original IEEE 802.11 standard introduced a modest speed of 2 Mbps, setting the stage for future enhancements.

The late 1990s saw a critical advancement with IEEE 802.11b, boosting speeds to 11 Mbps and significantly enhancing WLAN usability and appeal. This era also witnessed the formation of the Wi-Fi Alliance, promoting Wi-Fi as a brand for IEEE 802.11 standard-based WLANs, a move that would drive Wi-Fi to become synonymous with wireless networking.

As the new millennium unfolded, WLAN technology rapidly advanced with the introduction of 802.11a and 802.11g standards, offering increased speeds and reliability. This period marked the widespread embrace of Wi-Fi, extending its reach into homes, businesses, and public spaces. The 2010s further accelerated this momentum, with new standards like 802.11n and 802.11ac introducing Multiple Input Multiple Output (MIMO) technology and achieving gigabit speed levels, integrating Wi-Fi into an ever-expanding array of devices, and becoming a staple of daily life.

Entering the 2020s, the latest advancements with 802.11ax (Wi-Fi 6) and Wi-Fi 6E promise to revolutionize WLANs by delivering unparalleled speed, efficiency, and capacity. This ongoing evolution underscores the relentless drive towards meeting the escalating demand for wireless connectivity in our increasingly interconnected world.

What Is WLAN Used For?

WLAN technology is used extensively across various sectors and for multiple purposes thanks to its flexibility, mobility, and ease of setup. Here are some common uses of WLAN:

Home networking. One of the most widespread uses of WLAN is in home networking, allowing family members to connect smartphones, laptops, tablets, smart TVs, and IoT devices like smart thermostats and security cameras to the internet and each other without the clutter of cables.
Businesses and offices. In the business environment, WLANs enable employees to remain connected to the network from anywhere in the office, facilitating mobility and flexible workspace arrangements. They support the use of laptops, smartphones, and tablets for meetings, presentations, and general work, enhancing productivity and collaboration.
Education. Schools, colleges, and universities use WLANs to provide students and faculty with access to educational resources, online libraries, and learning management systems from anywhere on campus.
Public hotspots. WLAN technology is behind the Wi-Fi hotspots in cafes, hotels, airports, and public libraries, offering internet access to the public.
Healthcare. Hospitals and clinics use WLANs to connect medical devices, access patient records, and enable telemedicine services. Wireless connectivity supports mobile health carts, patient monitoring devices, and handheld devices for staff, improving efficiency and patient care.
Industrial and warehouse applications. WLANs facilitate the use of handheld scanners, wearable devices, and automated robots in warehouses and manufacturing plants, enabling efficient inventory management, tracking, and automation processes.
Transportation and logistics. In transportation, WLANs allow for the tracking and management of vehicles and cargo, improving logistics operations and real-time information flow.
Smart cities and IoT. WLANs play a crucial role in smart city initiatives, connecting various sensors and devices used in traffic management, public safety, environmental monitoring, and utility services, facilitating the collection and analysis of data for better city management.

How Does a WLAN Work?

A Wireless Local Area Network operates by connecting devices to the internet or each other without the need for physical wires, using radio frequency (RF) technology. The process involves several key components and steps, which work together to enable wireless communication:

Access Points (APs). The heart of a WLAN is the access point (AP), a device that broadcasts and receives wireless signals to and from connected devices. APs are typically connected to a wired router, switch, or modem, and act as a bridge between the wireless and wired networks. They convert the data received from wireless devices into wired signals and vice versa.
Wireless network adapters. Devices like laptops, smartphones, and tablets have wireless network adapters built into them. These adapters enable the devices to communicate with the wireless network. When a device wants to join a WLAN, its adapter sends a signal to the nearest AP.
Radio frequencies. WLANs use radio waves to transmit data. The most common frequencies used are the 2.4 GHz and 5 GHz bands, each offering different channels to minimize interference and optimize performance. The 6 GHz band is also being introduced with newer standards like Wi-Fi 6E.
SSID (Service Set Identifier). Each wireless network is identified by a unique name known as an SSID. When a device searches for wireless networks, it lists the SSIDs of all available networks. Users select the desired network (SSID) and, if required, provide a password to connect.
Data transmission. Once a device is connected to an AP, data can be transmitted wirelessly between the device and the network. Information sent through the network is divided into small packets, which are encoded as radio waves and transmitted over the selected frequency. The AP receives these waves, decodes them back into data, and sends the data through the wired network to the internet or other network resources.
Encryption and security. Encryption protocols such as WPA2 (Wi-Fi Protected Access 2) or WPA3 are used to secure data transmission over a WLAN. These protocols encrypt data sent over the air, making it difficult for unauthorized users to intercept or understand the information.
Management and control. WLANs are managed and controlled through software that allows network administrators to configure settings, monitor network performance, and manage access. This includes setting up guest networks, restricting access to certain websites, and prioritizing traffic for certain applications.

WLAN Architecture

WLAN architecture is designed to facilitate wireless communication within a specified area, such as a home, office, or campus. The architecture of WLAN is primarily defined by the IEEE 802.11 series of standards, which outline the methods and protocols for ensuring secure, reliable wireless networking. There are several types of WLAN architectures, each serving different needs and scenarios. Here's an overview of the most common architectures:

1. Basic Service Set (BSS)

The basic service set is the simplest form of a WLAN architecture, consisting of a single access point and multiple wireless clients connected to it. This setup forms a single cell in a WLAN network. The AP serves as the gateway to other network resources or the internet. A BSS operating independently without a connection to a wired network is called an Independent Basic Service Set (IBSS) or ad-hoc network, where devices communicate directly with each other.

2. Extended Service Set (ESS)

An extended service net expands upon the BSS concept, linking multiple access points together to create a larger coverage area. Each AP in an ESS is connected to a wired network, allowing seamless communication between different BSSs. This setup enables devices to roam freely within the coverage area, automatically switching to the best available signal without losing connection. ESS is commonly used in office buildings, campuses, and other large environments.

3. Distribution System (DS)

The distribution system connects multiple access points in an ESS to a wired network, facilitating communication between different BSSs and routing data to the correct destination. The DS can use various physical media for connectivity, including Ethernet cables, fiber optics, or even wireless links. It is an integral part of the ESS architecture, ensuring that data can flow smoothly across the network and reach external networks like the internet.

4. Mesh Network

Mesh WLAN architecture is designed for high reliability and a large coverage area without needing a wired backbone. In a mesh network, each AP communicates directly with multiple other nodes, dynamically determining the best path for data to travel through the network. This self-forming, self-healing architecture is highly resilient, as data can be rerouted if a node goes down, making it ideal for outdoor or challenging environments.

Types of WLAN

WLANs come in various types, tailored to meet different requirements and scenarios. These types are categorized based on network configuration, deployment style, and the specific technologies or protocols they employ.

1. Infrastructure WLANs

This is the most common type of WLAN, where devices connect to the network through at least one fixed access point connected to the wired network infrastructure. This setup provides a stable and extended coverage area and allows for easy management of network security and connectivity. WLANs are used in homes, offices, schools, and public Wi-Fi hotspots, supporting a wide range of devices and applications, from simple internet browsing to complex enterprise applications.

2. Ad-hoc WLANs (or Independent Basic Service Set, IBSS)

In an ad-hoc WLAN, wireless devices communicate directly with each other without the need for a central AP. This peer-to-peer network is formed spontaneously and is ideal for temporary networking needs. Ad-hoc WLANs are suitable for small, temporary setups such as meetings, file-sharing sessions among devices in proximity, or in situations where infrastructure is not available or practical.

3. Mesh WLANs

Mesh WLANs consist of nodes (routers, switches, or other devices) that connect directly, dynamically, and non-hierarchically to as many other nodes as possible. This self-healing, scalable network improves coverage and reliability. Mesh WLANs are ideal for covering large areas like campuses, cities, or industrial environments where laying cables is impractical. They are also used in smart home configurations for seamless device connectivity.

4. Enterprise WLANs

Designed for the needs of businesses and large organizations, enterprise WLANs incorporate advanced security, management, and scalability features. They typically involve multiple APs managed by a central controller and support sophisticated user authentication and network policy enforcement. It is deployed in corporate offices, hospitals, universities, and large retail spaces, where managing a large number of users, devices, and traffic securely is essential.

5. Wi-Fi Direct

Wi-Fi Direct allows Wi-Fi devices to connect to each other without a wireless access point. This technology facilitates direct peer-to-peer communication, simplifying the process of connecting devices directly. They are used for direct file transfers, printing, and streaming between devices like smartphones, printers, cameras, and computers without the need for an internet connection or a central network.

Advantages and Disadvantages of WLAN

WLANs have some advantages and disadvantages users should consider.

Advantages

Here are some key benefits of WLAN:

Mobility and flexibility. WLANs allow users to access network resources from any location within the wireless network's coverage area. This mobility supports productivity and convenience, as users are not tethered to a specific location.
Ease of installation. Installing a WLAN typically requires less time and effort compared to traditional wired networks. There's no need to run cables through walls or ceilings, making WLANs ideal for buildings where physical cabling is difficult or impossible.
Cost-effectiveness. Although the initial setup cost of a WLAN might be comparable to that of a wired network, the overall expense is lower over time. This is due to reduced wiring costs, the ease of adding new users, and the mobility benefits that reduce or eliminate the need for additional cabling as organizational layouts change.
Scalability. WLANs can be easily scaled to accommodate more users and services. Adding new users to the network typically involves little more than providing them with network access credentials and ensuring adequate wireless coverage.
Guest access. WLANs make it easier to provide network access to visitors, clients, and contractors without compromising the security of the primary network. This can be especially beneficial in corporate, educational, and retail environments.
Support for BYOD (Bring Your Own Device). Many organizations support a BYOD policy, where employees use their personal devices for work purposes. WLANs facilitate this by allowing easy connectivity for a wide range of devices.
Reduces cable clutter. By eliminating the need for extensive cabling, WLANs help maintain a cleaner, more organized work or living space.
Enhanced collaboration. The ease of connecting to a WLAN supports greater collaboration among users, who can work together, regardless of their physical location within the network's coverage area.
Rapid deployment. For businesses that need to set up, relocate, or tear down operations quickly (such as in the construction, event management, or consulting sectors), WLANs offer a rapid deployment option.

Disadvantages

On the other hand, WLANs have some disadvantages, such as:

Security risks. WLANs are inherently more vulnerable to security breaches compared to wired networks. The wireless nature of communication makes it easier for unauthorized users to intercept the wireless signal and gain access to the network if proper security measures are not in place.
Interference. WLAN performance can be negatively affected by interference from other wireless devices and electromagnetic sources. Common household devices like microwaves, cordless phones, and Bluetooth devices operate in the same frequency range as most WLANs and can cause signal disruption.
Range limitations. The effective range of a WLAN is limited. Physical obstacles, such as walls and floors, and distance from the access point can significantly degrade signal strength. Extending coverage often requires additional hardware such as repeaters or additional access points.
Lower speed. Compared to wired networks, WLANs generally offer lower data transmission speeds. While the latest WLAN standards support higher speeds, actual performance can be much lower due to factors like distance from the AP, physical obstructions, and interference from other devices.
Bandwidth limitations. In environments with a high number of users, the available bandwidth for each device decreases, potentially leading to slower internet speeds and reduced network performance.
Reliability issues. WLAN connections can be less stable and more prone to dropping out than wired connections, especially in areas with high interference or poor signal strength.
Setup and management complexity. While setting up a basic WLAN can be straightforward, configuring a network for optimal performance and security, especially in an enterprise environment, can be complex and require specialized knowledge.
Power consumption. Wireless devices, especially those that are battery-operated, consume more power when connected to a WLAN due to the continuous communication between the device and the access point.