Slot 0, &  Slot 1 uplink and downlink form backhaul, operating on 5.8GHz, 4.9GHz or 2.4Ghz bands..
Slot 2 is generally used for a 2.4G or 4.9G AP (client access) radio.
Slot 3 may house another AP radio, another downlink or a dedicated scanning radio (mobile nodes) .
Slot 4+ may house other radios, specific to customer interests e.g. LTE, BLE etc. (MD6000 only) 

MD4250 is used for remote video surveillance and perimeter security.
MD4350 is a popular configuration with one 2.4GHz Access Point radio for client service.
MD4452 and MD4454 support two and four backhaul downlinks respectively.
MD4458 support multiple service radios supports 2 or 3 client AP  radios.  
MD4455 , MD4355 and MD4325 use a scanning radio in slot 3 for mobile infrastructure networks. More . 

Please click an image or link above for application notes on that model configuration

 Firmware Details for OEMs and System Integrators

1. Reference Software Code Base

Our radio abstracted software is OpenWRT and MAC80211 based.  It supports 1-6 radios.
We have successfully ported it to OEM boards  e.g.  Cavium, Intel IMX6 X86**
Radio abstractions and integration for Ath5k, Ath9k and Ath10k chipsets are available.
** the simulation framework uses an X86 Target for nodes living in the virtual network.. 

2. Reference Board Configurations: Three popular board configurations are:

Ventana 5520  - (MD2000). - a two slot board replacement for the one radio MD1000 series 
Ventana 5530  - (MD4000) - a four slot board replacement for the Legacy MD4000.   
Ventana 5400  - (MD6000) - Version of MD4000  with two available slots for application extensions.

3. Reference Radio Cards: Compex 900VX  802.11ac 3X3 has been field tested. See MeshSuite for more 

4. White Box Options for OEM Development and Field tests.

White Box for 04 antenna for either 4 radios 1X1 MIMO or 2 radios (4250 in 2 X 2) configurations.
White Box for 15 antenna customizable prototypes for OEM software licensees and integrators.   
     
Related Links  OEM Model Configuration Options  and  Options for Antennas, Power Supplies etc

  
Bridging Across Multiple Networks.  

Meshdynamics mesh nodes can bridge a 2.4 GHz sub tree with the 5.8GHz mesh network tree. This figure shows how this level of flexibility is supported. There are 4 mini-PCI slots on the board, two on the bottom and two on top. Each of the four slots can house a different frequency radio. This opens up some interesting possibilities including 2.4 GHz backhaul systems being part of a mesh with 5.8 GHz backhauls. Since the service and backhaul radios are distinct, it is possible to use a service radio to bridge over from a 5.8 GHz backhaul to 2.4 GHz backhaul. The 4325 Mobility Relay node on the bottom left has joined the mesh – even though the upper links are 5.8 GHz (blue) – through the service radio (pink). See also MeshControl 
 
Man-wearable Single Radio Modules.

Meshdynamics Interoperable framework supports both multi-radio and single radio modules (shown above). The compact multi-radio units form the core Mobile Mesh Backhaul. Communications at the edge of the network are supported by single radio mesh capable portable units to provide communication and connectivity at the network edge.

GPS Position Location Option. 

See GPS Options. The GPS location information is transmitted periodically with the mesh node heart beat. The mesh node location is automatically updated on the NMS. The NMS uses imported maps and dynamically manages the background image movement to ensure that the current location is correctly depicted.  

P3M^TM Persistent Mobile Mesh.

A cluster of mobile nodes 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. In a deployed combat environment in Iraq, vehicle-mounted nodes demonstrated reliable connectivity between convoy vehicles in simultaneous motion. Networks split and reformed dynamically and in real time. Applications supported by Meshdynamics systems operated flawlessly as vehicles moved through rugged terrain. Illustration  Press Release  Application Notes  Patent

Persistent Base Voice^TM (PBV).

VOIP phones function even when the SIP gateway is not reachable: the mesh nodes act as a temporary proxy SIP server till nodes rejoin the main mesh.  Illustration  Press Release  Application Notes Patent 
 
Network Aware Application Controller Framework

Machine controller applications, running on the mesh nodes, monitor and control enterprise assets at the network edge. More Meshdynamics works closely with our source code licensees to simulate and prototype OEM product offerings and solutions. The Abstracted Network for Enterprises and the Internet Of Things
  
Related Links

MD4000 Layout Design. Placements, modeling uplink and downlink spreads, antenna selection etc. 
MD4000 Installation Guide. Antenna selection, mounting, model configuration, trouble shooting.
MD4000 NMS Software Download For configuring nodes. NMS is not needed for the mesh network to run. 
MD4000 NMS Configuration Guide Detailed instructions on setting SSID, Encryption, QoS, VLANs etc.