IEEE 802.11s

IEEE 802.11s is Wireless LAN standard and an IEEE 802.11 amendment for mesh networking, defining how wireless devices can interconnect to create a WLAN mesh network, which may be used for relatively fixed (not mobile) topologies and wireless ad hoc networks. The IEEE 802.11s working group draws upon volunteers from university and industry to provide specifications and possible design solutions for wireless mesh networking. As a standard, the document was iterated and revised many times prior to finalization. IEEE 802.11s is Wireless LAN standard and an IEEE 802.11 amendment for mesh networking, defining how wireless devices can interconnect to create a WLAN mesh network, which may be used for relatively fixed (not mobile) topologies and wireless ad hoc networks. The IEEE 802.11s working group draws upon volunteers from university and industry to provide specifications and possible design solutions for wireless mesh networking. As a standard, the document was iterated and revised many times prior to finalization. 802.11 is a set of IEEE standards that govern wireless networking transmission methods. They are commonly used today in their 802.11a, 802.11b, 802.11g, 802.11n and 802.11ac versions to provide wireless connectivity in the home, office and some commercial establishments. 802.11s extends the IEEE 802.11 MAC standard by defining an architecture and protocol that supports both broadcast/multicast and unicast delivery using 'radio-aware metrics over self-configuring multi-hop topologies.' 802.11s inherently depends on one of 802.11a, 802.11b, 802.11g, 802.11n or 802.11ac carrying the actual traffic. One or more routing protocols suitable to the actual network physical topology are required. 802.11s requires Hybrid Wireless Mesh Protocol, or HWMP, be supported as a default. However, other mesh, ad hoc (Associativity-Based Routing, Zone Routing Protocol, and location based routing) or dynamically link-state routed (OLSR, B.A.T.M.A.N.) may be supported or even static routing (WDS, OSPF). See the more detailed description below comparing these routing protocols. A mesh often consists of many small nodes. When mobile users or heavy loads are concerned, there will often be a handoff from one base station to another, and not only from 802.11 but from other (GSM, Bluetooth, PCS and other cordless phone) networks. Accordingly, IEEE 802.21, which specifies this handoff between nodes both obeying 802.11s and otherwise, may be required. This is especially likely if a longer-range lower-bandwidth service is deployed to minimize mesh dead zones, e.g. GSM routing based on OpenBTS. Mesh networking often involves network access by previously unknown parties, especially when a transient visitor population is being served. Thus the accompanying IEEE 802.11u standard will be required by most mesh networks to authenticate these users without pre-registration or any prior offline communication. Pre-standard captive portal approaches are also common. See the more detailed description below of mesh security.