The IEEE 802.11s standard is an amendment to the IEEE 802.11 Wi-Fi standard, which specifically defines the architecture and protocols for mesh networking within a wireless LAN (WLAN). Mesh networks are decentralized networks where data can travel across multiple nodes (access points or APs) to reach its destination, without the need for each node to be wired to a central hub or router.
Here’s a deeper dive into the IEEE 802.11s:
Mesh Networking:
- The primary goal of the 802.11s standard is to establish a wireless mesh network. In this network, data packets are forwarded from one mesh station (mesh STA) to another until they reach their destination.
Mesh Peering:
- For two mesh STAs to communicate, they must first establish a peer link, achieved through a peer link establishment process. Once established, mesh STAs can forward data frames on behalf of other mesh STAs.
Path Selection:
- 802.11s introduces a method for path selection, determining the most efficient route for data to travel from its source to its destination within the mesh. The default protocol for this is called the “Hybrid Wireless Mesh Protocol” (HWMP).
Self-Healing:
- Mesh networks can adapt to changing conditions. If one node fails or becomes unreachable, the network can automatically find another path for data delivery.
Security:
- 802.11s uses the “Simultaneous Authentication of Equals” (SAE) method, which is a secure way of establishing peer links in a mesh network.
Interworking:
- The standard allows for interworking with traditional IEEE 802.11 networks. This means mesh networks can be integrated into existing WLANs.
Applications:
- Mesh networks are particularly useful in scenarios where it’s challenging or expensive to wire every access point. This includes large campuses, outdoor areas, event spaces, or regions hit by natural disasters where the wired infrastructure might be compromised.
Benefits:
- Scalability: Easily add more nodes to the network.
- Redundancy: Multiple possible paths offer a failover in case of node failures.
- Coverage: Mesh networks can cover large areas, especially where it’s impractical to deploy wired networks.
Considerations:
- Complexity: Managing and configuring a mesh network can be more complex than a traditional WLAN.
- Performance: Data packets might have to hop through multiple nodes to reach their destination, which could introduce latency and reduce bandwidth.
In summary, IEEE 802.11s offers a standardized approach to creating wireless mesh networks within the broader framework of the Wi-Fi standards. It enables robust and flexible networking in scenarios where a traditional WLAN might not be practical or efficient.