Products designed for municipal mesh networks have gone through a number of design iterations as systems engineers have attempted to increase their performance and scalability. It's important to recognize the considerable limitations of existing systems in order to fully appreciate the capability that Wave Relay has to offer.

First Generation Mesh:

When municipal mesh networks were first deployed they utilized products which were based on a single radio architecture. The single radio was used both for linking the device in with the rest of the mesh network and as an access point to allow client connections over 802.11. This meant that not only did the mesh devices have to compete with each other for access to a single shared channel, but they had to share the channel with client devices as well. This resulted in extremely poor performance and poor scalability properties.

Second Generation Mesh:

In second generation mesh networks, the mesh routers were equipped with two wireless radios. One radio operated in the 5 GHz band for the mesh forwarding and the other radio was a standard 2.4 GHz radio acting as an access point. Since the 2.4 GHz radio was not being used for mesh routing, it could be configured to operate on any frequency, which again helps performance. The two radio design essentially doubled the system capacity since the clients did not have to contend with the mesh for access to the medium. However, this resulted in the mesh forwarding running on a single 5 GHz radio. Due to the increased path-loss experienced by the higher frequency, the mesh devices would have to be located significantly closer together. This required an increase in node density which created a massive increase in system cost. In addition, since the device only had a single 5 GHz radio, directional antennas can not be used to increase its range. A directional antenna can only be pointed in a single direction, which means you can not build an interconnected mesh using directional antennas if you only have a single radio. This was a big draw back in the design of second generation systems.

Third Generation Mesh:

The third generation designs consisted of devices with 3 radios. This allowed two 5 GHz radios to be used to create a high speed multi-hop meshed backhaul network and a single 2.4 GHz radio could be used for client access. Since the 2.4 GHz radio was not being used for mesh routing, it could be configured to operate on any frequency, which helps performance. Since there was now more then one 5 GHz radio, directional antennas could be used. These approaches generally had data coming in from one radio and going out the other radio. Since the 5 GHz radios were not operating on the same channel, they no longer lost bandwidth due to the hopping. This increased the system capacity and made the design significantly more scalable. However, the use of directional antennas combined with the fact that all the radios were operating on different channels, made the system significantly less fault tolerant. If one radio is going towards the internet connection and the other radio moves data away from the internet connection, then if a single radio fails, all of the down stream routers will become instantly disconnected. In this type of architecture you can not really build redundancy with extremely directional antennas, and there are no additional radios to allow for increased interconnectivity. While third generation designs definitely increased capacity and scalability, they became significantly more fragile and vulnerable to failure.

Wave Relay Mobile Ad hoc Networking - Beyond Mesh:

The Wave Relay system takes wireless multi-hop communication a step further. A Wave Relay router is a quad radio device. This provides multiple 5 GHz channels to build a 5 GHz backhaul, and enough radios to provide increased interconnectivity for fault tolerance. In addition, the Wave Relay router also runs its mesh routing protocol on the 2.4 GHz radio. This means that even if all of the backhaul links failed, the device can still remain connected to the rest of the network. Furthermore, multiple Wave Relay routers can be co-located and wired directly together to provide an even greater numbers of radios for extreme performance and redundancy. Wave Relay also provides peer-to-peer routing, which efficiently moves traffic from any source in the network to any destination. Previous generation systems were only designed to provide routing to the Internet gateway. This peer-to-peer capability opens up a whole new range of application possibilities and also makes Wave Relay ideally suited for first responder systems (which are fundamentally peer-to-peer in nature).