How to find the single strength or metric of the link which doesn't have a direct connection with the source node. I have also attached the pictorial representation of my question it would help you to understand the question better.
thanks in advance.
signal strength is a layer 2 ( arguably L1 ) property
while you can generate all sorts of metrics to extrapolate a quasi-strength value... without upperlevel protocols that disseminate exact L2 attributes it cannot be done.
say for example, that the number 6 in your picture is an AP with overlapping channels... the b <> c links signal strength is affected. hence, node a would need to share node b or node c's L2 attributes via upper level protocol.
this concept is the fundamental benefit of wireless "controller" systems.
You can query a non-local OpenWrt device through RPC or SSH and command-line utilities. The signal-strength metrics should be available either way, but perhaps more robustly parsed from the ubus data.
