Relay Chain Planning
Relay stations extend the effective coverage of a radio network. Each station consists of two radios operating on separate networks and connected by cable. A signal received by either radio is retransmitted by the other, enabling bidirectional communication between the two networks.
A relay chain forms one logical network from several physical radio networks. The figure illustrates a chain with four relay stations spanning five physical networks. To keep the diagram clear, it shows only the coverage areas of radios R2-2 and R3-1 in Net3.
A radio connected to a physical network in the relay chain must be able to reach both relay radios on that network. In the example, a radio in Net3 must establish connection to both R2-2 and R3-1 to communicate across the entire relay chain. Therefore, the useful coverage area for end-to-end communication in the relay chain is the area where the coverage of R2-2 and R3-1 overlaps.
Tools for Relay Chain Planning
Begin by planning the relay station locations. In the Radioplan API, use Connectivity Lines or Signal Level plots, with thresholds based on the selected radio type plus a planning margin—for example, 7 dB.
To identify the overlapping coverage of two radios in the same physical radio network in a relay chain, use PlotType.LeastSignalLevelDbm and select radios within the network.
To get a combined view of the relay chain coverage, i.e. the predicted areas where a user radio can communicate to the full relay chain, use these settings:
- Select plot type "Lowest Signal Level"
- Set IRadioCoverage.PlotGroupMethod to PlotGroupMethod.ByRadioNet
- Select the all radios in the RadioNets in the relay chain for show coverage
