MeshDynamics 4455 and 4325 mobility nodes are employed both by US military and US allies. They have validated that the MD4000 provides superior connectivity even at high speeds. Applications include video surveillance with cameras mounted on vehicles and connecting with nodes along the road. Both static and mobile units have been in operation along the Arizona Mexico border since 2005. Mobile units have also been employed in armored vehicle convoy applications in Iraq. 
 
The MD4455 is essentially the "mobile" version of the three radio MD4350 - there are two 5GHz 802.11a backhaul radios, and a 2.4GHz 802.11b/g AP radio.  The fourth radio slot on the MD4455-AAIA motherboard houses a scanning radio. The scanning radio listens to the RF environment and helps the node make judicious parent node selections in a high speed mobility environment. 
    
A cluster of mobile MD4455 will automatically form a network with each other. If the cluster physically separates into two smaller clusters, each will then become its own independent network.  If two separate clusters/networks physically come together, one single network will form and all nodes + associated clients will then be able to share data.
 

Bridging across frequency bands: MeshDynamics mesh networks incorporate both mobile and stationary nodes. The underlying framework supports complete interoperability, regardless of node configuration. Additionally extending the mesh across frequency bands is also supported. In the figure above, a 4325 mobile node is connected with a 4455 mobile node. The 4455 is part of a 5.8GHz backhaul. Note that the 4325 uplink is connected via the 2.4GHz so-called service radio of the 4455.
 
Choice of Backhaul: When deciding whether to use 2.4GHz based products (4220,4325) RF pollution must be considered. The clients are 2.4GHz and will interfere with a 2.4GHz node-to-node (backhaul) link. In addition, 802.11b clients - if attached to the 2.4GHz backhaul (e.g. 4220, 4325) slows the performance of of the node-to-node link. 4220 and 4325 mesh nodes thus should be limited in servicing few child nodes. On the positive side, 2.4 GHZ has about twice the range at 5GHz, so 4325, 4220 are preferable where range supersedes backhaul capacity. 4325, 4220 are also used when the nodes are edge based - that is no child nodes connected to them.
   
In all other situations, 5GHz mesh nodes (4455, 4350) are suggested. 
 
1. Military Mesh Networks  Overview document on why Military Mesh Networks require third generation mesh. 
2. Army Science Board Presentation  Invited Presentation made to the Army Sciences Board,  April 2007. 
3. Border Security Applications and Solutions: Mobile and static mesh network deployments along Mexico-Arizona border
4. High Speed Mobility Test -1  Video tapes of glitch free video transmission over 4 hops, traveling at 50+ mph.
5. High Speed Mobility Test -2  Video feed from one vehicle to another, both connected to the mesh network.