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.