Modular Mesh^TM Configurations. MeshDynamics MD4000 nodes support up to 4 radios in a single enclosure. Slots 0, 1 is generally used for the 5.8GHz or 4.9GHz backhaul uplink and downlink radios. The backhaul radios operate on non-interfering channels in the same  frequency band. This forms the Structured Mesh Backhaul. Slot 2 is generally used for a 2.4G or 4.9G AP radio. Slot 3 may be used for a 2nd downlink, 2nd AP radio or scanning radio intended to rapid hand off in high speed mobility applications.

Note: All models are software configurable. Models may be field upgraded by updating software and inserting additional radio cards. 

Explanation to Legend (numbers after black boxes refer to number markers above (1,2,3 ..)

  1 MD for Mesh Nodes or ME for Mesh Engines (OEM customers only, housing computer board in their own enclosures).
  2 Number of available radio slots. Standard board has 4. [Image]
  3 The number of radios used in this configuration- could be 2,3 or 4.
  4 Frequency band of the Uplink backhaul radio (in slot 0) : 5 for 5.8GHz, 2 for 2.4GHz, 4 for 4.9GHz Public Safely. 
  5 Model Configuration. Each of the four radio slots may be configured to be uplinks, downlinks, service radio or scanners.

Meaningful configurations center around the base model 4350: one uplink in slot 0, one downlink in slot 1 and service radio in slot 2. Variations around this base configuration depend on how slot 3 is configured. Slot 3 is reserved for the scanning radio needed in high mobility situations. If it is not a mobility situation, then slot 3 may house an additional downlink (4452) or an additional service radio (4458). If the mesh node has a permanent Ethernet link, then the uplink is not needed: Models 4454 and 4424 support a root node all downlink configuration. Supported configurations are:  {0,2,4} denote the number of backhaul downlinks present. Since there is generally always at least one downlink backhaul present, 0 is misleading. For legacy reasons, 0 denotes the common case of one backhaul, as in 4350. The most common configuration, Model 4350, has one 2.4GHz service radio in slot 2 and 5.8 GHz uplink and downlink in slots 0,1.  Additional downlinks on root nodes enables more bandwidth dispersion from a central Ethernet link. Models 4452 and 4454 support two and four backhaul downlinks respectively.    {5 } denotes a mobility Scanner (the "S" resembles a "5"). A passive listening radio housed in slot 3 provides information needed for the backhaul uplink to switch over to the next best candidate parent mesh node's downlink. Models 4455  and 4325 are four and three radio systems respectively with a scanning radio in slot 3 to ensure the rapid switch over from node to node in high speed mobile scenarios [More]     {8 } Model 4458 supports up to three 2.4GHz or 4.9GHx Access Points (AP) radios service clients with sectored antennas. Two variations are possible, one with one uplink and one downlink and two service radios: Model 4458-AAII. The second variation is where the downlink is not needed- as in edge nodes. In that case three slots are available for sectored antenna access. That configuration is Model 4458-AIII.

  6 Frequency band for the uplink radio, in slot 0. Typically A (802.11a) B (802.11b), G (802.11g) or P (Public Safety)
  7 Frequency band for the downlink radio, in slot 1. Usually matches uplink but bridging across freq. bands is permitted. 
  8 Frequency band for the service radio, in slot 2. Generally B (.11b), G (.11g) or I (both b and g). 

      Note: These are simply  default factory settings. The B, G, I settings may be user modified via the NMS.

  9 Frequency band for the service radio, in slot 3. Depends on the radio functionality. If none present, marked with "x". 
 
Note: Please use the MD4000 numbering scheme to discuss your custom configuration with our application engineers. Also note that other options (e.g. GPS, 3.3VDC boards) are not part of the configuration scheme. They are ordered as separate items.
 
Common configurations, 5.8GHz Backhaul
 

 
Click on an image above to access application notes on that configuration.
 
4250-AAxx: 2 radios, 11a uplink, downlink, slots 0,1. Intended as static backhaul, no AP for clients. Example   
4350-AAIx: 3 radios, 11a uplink, downlink, slots 0,1. Both 11b and 11g service available on slot 2 Slot 3 empty..   
4452-AAIA: 4 radios, 11a uplink, downlink, slots 0,1. Both 11b and 11g service available on slot 2. Second downlink in 3.
4454-AAAA: 4 radios, All 11a downlinks, slots 0,1,2,3. Intended as a root node, with four sectored antennas. .  
4458-AAII: 4 radios, 11a uplink, downlink, slots 0,1. Both 11b and 11g service available on sectored antennas, slots 2, 3
4458-AIII: 4 radios, 11a uplink in slot 0, no downlink. Slots 1,2,3 are sectored service radios for client access.   
4455-AAIA: 4 radios, 11a uplink, downlink, slots 0,1. Both 11b and 11g service in slot 2. 11a scanning radio in slot 3.  
4355-AAxA: 3 radios, 11a uplink, downlink, slots 0,1, No client AP, wireless backhaul only. 11a scanning radio in slot 3. 
 
Common configurations, 2.4GHz Backhaul
 
4220-BBxx: 2 radios, 11g uplink, downlink, slots 0,1. Used as 11b long range backhaul, sectored links, rural areas. 
4424-III: 4 radios, ALL downlinks, slots 0,1,2,3. Supports 11b and 11g. Intended as root, with four sectored services.   
4325-BBxB: 3 radios, 11b uplink, downlink, slots 0,1. 11b scanning radio in slot 3. Longer range at cost of throughput.

Choice of Backhaul: 5.8GHz vs 2.4GHz.  4220 and 4325 are the rough 2.4GHz equivalent of the 4250 and 4455 5.8GHz backhaul products. 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. [Image]. In all other situations, 5GHz mesh nodes (4455, 4458, 4452, 4454, 4350) are suggested.