6. Smart Radio Network Topologies

6. Smart Radio Network Topologies

Smart Radio Network Topologies

The Smart Radio supports several different network configurations. The Simple Config menu makes it easy to configure the radio. The Simple Config menu is accessed in the web GUI at network → simple config.

Basic Network Configurations

The Simple Configuration menu is shown in Fig. 11. It should be the starting point of any network design. From here, you should first choose the mode which you want to switch to, and a selection of the more common configuration options, and then click Apply.





























Fig. 11 Simple Configuration Menu

These are the support network configurations.

1.      Mesh

2.      Multi-hop relay for range extension

3.      Muti-hop relay for NLOS conditions

4.      WDS AP/Client

5.      Dynamic Mesh

The basic network configuration in any of these modes is designed so that the entire Smart Radio network acts like one big Ethernet switch. Any host machines plugged into this “Ethernet switch” will be able to communicate with one another as long as they are on the same IP subnet, regardless of the IP addresses of the Smart Radios. In order to access the Smart Radios themselves, however, it is necessary for the host machines to be on the same IP subnet as the Smart Radios.

Mesh

All Smart Radios are setup in Mesh mode by default. In mesh mode, all nodes are able to communicate directly with each other and data can even hop between nodes to reach a destination. This is illustrated in Fig. 12. Maintaining the mesh requires additional network overhead compared to WDS AP/Client mode. Some benefits of Mesh mode compared to other modes include

·       The network is homogenous and there is no need to configure each node differently

·       There is no single point of failure

·       The network can be extended beyond the line of sight through intelligent packet routing


Fig. 12 – Mesh mode

WDS AP/Client

WDS AP/Client mode is a star network configuration. All data must go through the AP. If meshing is not required, this is the preferred network mode as it is more responsive than Mesh mode. 


Fig. 13 – WDS AP/Client mode

Some benefits of WDS AP/Client mode compared to the others

·       It provides the highest throughput

·       It automatically searches for the best channel on start-up

·       Client devices automatically scan and reconnect to the AP if the AP switches channels 

Dynamic Mesh

Dynamic Mesh is a state-of-the-art network protocol based on establishing multiple redundant paths in a mesh network. Dynamic Mesh has ZERO packet re-routing or failover time. Dynamic Mesh also supports dual radio failover where two back-to-back radios on the same or different frequency bands route packets redundantly between nodes (Fig. 14). This makes Dynamic Mesh best-in-class in terms of latency and resiliency in highly dynamically changing environments.


Fig. 14 – Dual Radio Dynamic Mesh

Some benefits of Dynamic Mesh mode compared to other modes include

·       ZERO failover or packet re-routing time

·       No single point of failure

·       Can support very large number  of nodes in a single network

Extended Modes

Aside from the basic network configurations above, the Smart Radio also supports

1.      Gateway mode

2.      Multi-Radio Mesh mode

3.      Mesh + AP mode

4.      Wired Backbone

Gateway Mode

Gateway mode is supported in both WDS AP/Client and Mesh modes. In Gateway mode, one node is elected as a gateway to a wider network (the internet for example). The main data interface is connected to your modem, and performs NAT between the Smart Radio’s LAN and the wider network. Additionally, the gateway Smart Radio starts a DHCP server on the LAN on the 10.222.0.0/16 subnet and a gateway IP address of 10.222.1.1. From firmware version 2022-02 onwards, ETH1 runs the DHCP client which connects to your modem, and ETH0 is bridged to the local network. Fig. 15 illustrates gateway mode for a mesh configuration. 



Fig. 15 – Gateway mode

Multi-Radio Mesh mode

Multi-Radio Mesh mode is specifically designed to extend the range of a network without sacrificing throughput. Looking at the diagram below, if both sets of radios operated in the same band, then they would need to share airtime. In Multi-Radio Mesh mode, radios are connected to each other over wire using the ETH1 interface. 


Fig. 16 – Multi-Radio Mesh

Mesh + AP mode

Mesh + AP mode is illustrated in Fig. 17. Two or mode units form a mesh backbone and also run an AP which is bridged to the mesh. Of note is that this is standard AP mode and not WDS AP mode. The APs are interoperable with standard WiFi clients for 2.4-GHz models if the channel bandwidth is set to 20-MHz.  


Fig. 17 – Mesh + AP mode
Wired Backbone

Although not a selectable mode, the Smart Radio supports extension of the network with a wired backbone in all three basic modes. In Mesh mode, it is necessary to enable “Bridge Loop Avoidance” when using a wired backbone. In WDS AP/Mode, no additional configuration is required, and clients can roam between WDS APs even with the APs on different operating channels. Typical handover duration is 0.2 seconds for APs in the same channel and 0.6 seconds for APs in different channels. Dynamic Mesh also supports use of a wired backbone with zero failover time.

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Fig. 18 – Wired Backbone

Use Case Examples

As can be seen, the Smart Radio is very flexible and provides many software configurable operating modes. This allows it to be used in many different use cases. Please refer to the Technical Library section of the website for application notes on these use cases. 



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