Wireless Local Area Network (WLAN) is a highly popular wireless networking system that provides high-speed data transmission over long distances without the need for cables or wires.
In this article, readers will become familiar with the basic WLAN devices. Basic WLAN devices include wireless network cards, wireless access points, and WBridge (wireless bridge).
Wireless Network Cards
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Wireless network cards are not significantly different from wired network cards used in LANs. Wireless network cards exchange information with the network operating system through a dedicated controller. Therefore, any application can utilize the wireless network for data transmission. However, unlike wired network cards, wireless network cards do not require any connecting cables. Wired network cards can use ISA slots (now rarely used) or PCI slots (commonly used) on desktop computers, or PCMCIA slots in laptops. Wireless network cards typically have an external antenna that can be mounted on a wall or another location in the room.
Wireless Access Points (AP)
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Wireless Access Points (AP) create coverage zones, linking mobile nodes to wired LAN infrastructures. Since access points allow for extended coverage, WLANs can be implemented throughout an entire building or university campus, creating a vast wireless access area. These access points not only facilitate information exchange with wired networks but also filter traffic and act as bridges to other standards. The filtering function helps preserve bandwidth on radio channels by eliminating excess traffic.
Due to the asymmetric duplex bandwidth between wireless and wired information, access points require appropriate buffering and memory resources. Buffers are primarily used to store data packets at the access point when a mobile node attempts to move out of the coverage area or when a mobile node operates in low power mode. Access points communicate with each other over wired networks to manage mobile nodes. An access point does not need to control access from multiple mobile nodes (meaning it can operate with a distributed random access protocol like CSMA). However, a centrally managed multiple access protocol controlled by an access point has several advantages. Common wired network interface options for access points include 10Base2, 10BaseT, ADSL modem, and ISDN.
WBridge – Wireless Bridge
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WBridge (Wireless Bridge) is similar to wireless access points, except that they are used for external channels. Depending on the distance and area that requires the external antenna, WBridge is designed to connect networks together, particularly in buildings with distances of up to 32 kilometers.
WBridge provides a fast and cost-effective alternative to using cables or leased telephone lines and is often used when traditional wired connections are impractical or difficult, such as across rivers, rugged terrain, private areas, highways, etc. Unlike cable links and dedicated telephone circuits, WBridge can filter traffic and ensure that wireless networks are well connected without losing necessary traffic.
