Mesh networking refers to the architecture behind wireless local area networks (or WLANs). These self-healing wireless networks are comprised of multiple nodes (routing or access points) that distribute and share data and voice between one another. A mesh network can reconfigure itself automatically to make up for a downed node or pathway, for example.
The first iteration of mesh networks dates back to the late 1990s during the rise of WiFi, the wireless protocol that web-enabled Internet cafes with wireless connections.
Mesh networking is gaining momentum because it is more flexible, cost-effective and reliable than traditional LAN or T1 services. However, the main problem with mesh today is in the area of interoperability. Today a business essentially must commit to a single product vendor for its routers, radios, etc. if it wants the different access points to operate together. Because no standard mesh protocol exists today, one vendor’s products cannot interoperate with another vendor’s products. This limits the choices for the user and the overall capabilities of mesh networks.
To address this issue and further the ability and ubiquity of mesh networking, the IEEE formed the ESS Mesh Networking Task Group. Their goal was to design a standard mesh protocol, allowing vendors to certify their equipment as “802.11s Certified” equipment. Today businesses the world over are eagerly awaiting the ratification of the new 802.11s standard.
Here is a quick look back at how mesh has evolved from its inception:
First Generation Mesh – Mobile ad-hoc networks (MANet) with sing-radio mesh at each access point. These were first designed by universities for the military. Their goal was to use mesh networking on the battlefield. While the first iteration of the mesh network did in fact work, it came with significant congestion of data/voice traffic. This was mainly due to the fact that each access point had only a single radio for all traffic. The first product offered was designed by Mesh Networks Inc. Data Mesh This product offering was very expensive and worked at a much lower power output than mesh networks use today. Similar products followed using Ad-Hoc On Demand Vector routing (AODV) developed jointly by Ultramesh Inc, and Locustworld Inc.
Second Generation Mesh – New protocols emerged, in fact there are more than 70 competing schemes for routing packets across mesh networks. Some of these include:
AODV (Ad-hoc On Demand Distance Vector) B.A.T.M.A.N. (Better Approach To Mobile Adhoc Networking) PWRP (Predictive Wireless Routing Protocol) DSR (Dynamic Source Routing) OLSR (Optimized Link State Routing protocol) TORA (Temporally-Ordered Routing Algorithm) HSLS (Hazy-Sighted Link State)
This morass of protocols and products has fractured the industry and caused a weakening of the value of mesh as a valued infrastructure option.
Forthcoming 802.11S Mesh – 802.11s defines a default mandatory routing protocol (Hybrid Wireless Mesh Protocol, or HWMP), yet allows vendors to operate using alternate protocols, one of which is described in the draft (Radio Aware Optimized Link State Routing). HWMP is inspired by a combination of AODV (RFC 3561 ) and tree-based routing, while RA-OLSR is based on OLSR (RFC 3626). Once this standard is ratified, certifications of interoperability will allow a vendor to stamp their products as 802.11s. The Future – Mesh as a whole will still suffer from the restrictions of WiFi and even the nearly ratified WiMax protocols. Wireless data radios are still in their infancy, and new breakthroughs happen nearly every week. One of these innovations, Software Defined Radio (SDR), will allow an unprecedented ability to transmit and receive signals. Custom waveforms, clear channel send and receive, and other benefits of SDR will break wireless networks free from their current restrictive bonds.