[TINYMESH] “We have a doubt about the connections dynamic and network architecture. Consider the image below: 1 – Gateway, Router and End device ar configured with the same RF Power 2 – Gateway signal can reach directly to End Device 3 – Router can reach to Gateway and End Device 4 – The End Device only can reach the Router when transmitting, but receive the signal from Gateway directly Although the end device can receive the signal from the Gateway (above RSSI acceptance level), once the End Device can’t reach the Gateway directly, the connection is never established and the second way through Router is never choosed. The tiny mesh algorithm favors the shortly way to gateway if the rssi level is above acceptance level. If the end device receive the signal from Gateway above acceptance level, but is not able to reach the gateway directly, even if we have a router between Gateway and End Device the connection is never establish. Do you have any explanation to this behavior and a way to improve and avoid this kind of scenario? “

“Up- and downstream transmission in the network follows two different principles:
1. On transmitting from a Gateway, the receiving device is allowed to receive and act on a packet that is received with valid CRC regardless of whether the packet is received from the Gateway device directly, or if received from the router device that is the normal transmission path.
2. On transmitting to the Gateway, the path is determined and may not be circumvented.

As a consequence of above, you may sometimes observe the below pattern. The Gateway is able to communicate directly to an end device / router, whereas the communication in the opposite direction always goes through an intermediate router.

The RSSI acceptance level controls the minimum signal strength required to create a link in the network. By increasing this level, you will increase the likelihood that a Router will connect on fewer hops / connect directly to the Gateway. On the negative side, this will tend to reduce network stability.

By setting the End device to transmit in ‘walk by’ mode, the End Device will not utilize the normal hop path, as it will not be expecting an ack from the receiving node. In this mode, you will probably experience that in most cases, the End Device packets will directly reach the Gateway device in both communication directions ( up- and downstream)

Last Update: November 9, 2017  

November 9, 2017   1051    Tinymesh Q&A