How coverage distance and interference distance ar

Question

I need to know the difference between the maximum coverage distance of a RSU and the maximum interference distance and how they are affected by each other. I know the coverage distance is calculated from the path loss and similar models but don't know how message reception is affected by interference distance and how its value is calculated (in veins example, it is set to 2600m)

I am implementing a scenario including one rsu and one vehicle moves from far away towards the rsu. When i used the same values as the veins example, all messages are received even when the vehicle was far. Then i tried to change the value of maximum interference and set it to 260 instead of 2600, what happened is that when the vehicle is far away the rsu doesn't receive any messages and when it come closer to the rsu it receive the message. Does anyone have an interpretation for that case?

Answer 1

In Veins 4.6, wireless transmissions are modeled by having a transmitting radio module send an event to all radio modules that are in range. Those radio modules can then change their internal state to reflect the fact that interference on the channel has increased or (if the signal is sufficiently strong and the radio is ready to receive) that a new message is being received.

Always informing all radios in a simulation about each ongoing transmission might be a bit wasteful, though. After all, most radios are likely so far away that the impact of a single transmission is negligible. Veins 4.6 therefore uses MiXiM's ConnectionManager module to determine which radio should be getting events from which radio.

The distance up to which events are still being considered to impact other radios is set using ConnectionManager maxInterfDist parameter. In the Veins example simulation, this parameter is set to 2600m. In other words, in the example simulation it is assumed that any transmission sent from more than 2600m away will have been attenuated so much (mostly by buildings) that even the interference it causes is no longer worth considering.

Thus, setting this parameter to a larger value (say, 100km) should not change a simulation's results, only cause the simulation to run somewhat slower (as it is now considering many transmissions that are so weak they do not substantially alter the simulation's state).

Conversely, setting this parameter to a smaller value (say, 10m) will result in a simulation that gives wrong results (as it is no longer considering many transmissions, even those that cause substantial interference -- or those that could have been received successfully).