IEEE 802.11 standards

Wireless LAN (WLAN) based on IEEE 802.11 standards uses different types of Service Sets to define how devices communicate within a wireless network. These service sets specify the architecture and functionality of the network. Below are the key types:

1. Basic Service Set (BSS)

• The fundamental building block of an 802.11 network.
• Consists of a single access point (AP) and multiple client devices (stations).
• Identified by a Basic Service Set Identifier (BSSID), which is typically the MAC address of the AP.
• Communication between clients must go through the AP.

2. Extended Service Set (ESS)

• A collection of multiple BSSs interconnected by a Distribution System (DS) (usually a wired network).
• Provides seamless roaming, allowing devices to move between APs without losing connectivity.
• Uses a common SSID (Service Set Identifier) to identify the network.

3. Independent Basic Service Set (IBSS) – Ad Hoc Mode

• A peer-to-peer wireless network without an access point.
• Devices communicate directly with each other.
• Used for temporary or small networks, such as file sharing between laptops.

4. Mesh Basic Service Set (MBSS)

• A wireless mesh network where APs (mesh nodes) communicate with each other to extend coverage.
• No centralized controller; devices dynamically route data through the network.
• Used in large-scale deployments like smart cities or campus-wide Wi-Fi.

5. Distribution System (DS)

• Connects multiple BSSs to form an ESS.
• Can be wired (Ethernet) or wireless (Mesh networks).