Besides functioning as an WAP (Wireless Access Point) that just provides wireless access to client devices, APs are able to have different types of functions in addition to this. These are:
- Workgroup Bridge (WGB)
- Outdoor Bridge
- Repeater Mode
- Mesh Basic Service Set (MBSS)
WGB- WGB (Workgroup Bridge) is a wireless configuration in which an AP becomes a wireless client to connect a group of wired devices such as PCs, printers, and legacy equipment to a wireless network. Unlike a standard AP operational mode, the AP operating in WGB mode connects wirelessly to a root AP and forwards traffic between the wired devices and the wireless network. This allows multiple non-WiFi devices to communicate over the WLAN without built-in wireless capabilities. This allows a company or environment to support legacy equipment while migrating to wireless solutions. In WGB mode, the AP associates with the root AP, like a laptop would associate with a WAP.
Definition: A root AP is the primary AP in the network that directly connects to the DS (Distribution System) and serves as the main gateway between the wireless network and the wired network. In wireless network architecture such as mesh, repeater, and WGB deployments, the root AP provides network connectivity to the wired infrastructure (switches and routers) and forwards traffic between the APs, wireless clients, and the wired network. A root AP essentially acts as the entry and exit point for traffic between the wireless network and the wired network.
Traffic Flow:
Legacy Printer > WGB > Root AP > DS > AP > Client
Outdoor Bridge Mode- An outdoor bridge mode is a configuration that connects two or more separate networks over long distances using wireless links instead of physical cables. In this mode, two or more APs are configured to form a point-to-point or point-to-multipoint connection, where traffic flows wirelessly from one bridge AP to another bridge AP. Unlike a standard AP mode, that provides wireless access to client devices such as laptops or smartphones, an outdoor bridge uses high-gain, directional antennas to establish a dedicated, high-speed wireless link that functions like a virtual Ethernet cable between networks. The reason its described as a virtual ethernet cable is because the communication is layer 2 communication, so traffic is traversing a large geographic distance but the frame is treated like an extended broadcast domain.
Repeater Mode- Repeater mode in an AP is a configuration in which an AP connects wirelessly to an existing root AP to extend the coverage area of a wireless network. Unlike a standard AP mode, an AP operating in repeater mode does not have a wired connection to the DS. Instead it maintains a wireless connection to the root AP while simultaneously rebroadcasting the same signal to client devices farther away. So it takes a signal then rebroadcasts the same signal extending coverage. Although this may seem helpful, the overall bandwidth and throughput goes down by 50 percent or more. This is because the same radio interface being used to receive data from the root AP is the same radio interface used to rebroadcast the signal, effectively using the wireless medium twice for the same traffic.
MBSS – A MBSS (Mesh Basic Service Set) is another AP configuration in which multiple mesh APs work together to form a self-organizing (mesh APs automatically find mesh APs to connect to) and self-healing (mesh APs can recover automatically from AP failures) wireless network. Unlike a typical BSS, where each AP requires a direct connection to the wired network, mesh nodes can communicate wirelessly with one another and dynamically forward traffic across multiple hops until it reaches a mesh portal or its destination. A mesh portal provides access to the wired network. This means that a client can potentially talk to another client without touching the DS if an optimal mesh path exists.
Traffic Flow (Optimal mesh path):
Client > Mesh AP > Mesh AP > Client
Traffic Flow Wired Network:
Client > Mesh AP > Mesh AP > Mesh Portal or Root AP > Wired Network
A MBSS allows the wireless coverage to be extended without requiring every mesh AP to have a wired network connection.
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