DigiMesh messages timing

I am (very very) newbie with digimesh. I am evaluating the use of this network for my new project.
My network must connect 19 battery powered devices that communicate with the coordinator.
The coordinator is always on and powered from main supply.
All the battery powered devices MUST send 20bytes to coordinator every second. (I can’t miss one). I think this is possible with digimesh but the question is: the network nodes will can go in sleep for saving power ? My power budget for the battery powered device is 1mA costant current
All devices are located in a short distance max 10/15 meters But some devices can’t be in line of sight with coordinator and I think they will use multihop paths

This can be done with DigiMesh network using it Synchronized Sleep feature.

Sleep Coordinator module (SM=0x07) will remain awake and send sync sleep parameters to rest all battery powered modules (with SM=0x08).

You can calculate battery life using this:

thanks for reply asgm but my problem is to know the messages timinig. I do not find any document on this.
How I must set the sleep/wake timings. All devices must be ON until coordinator read all of them ?
I think yes because coordinator could use multiple paths.
Where I can found infos about bit rate over the air. For Reading 20bytes I need microsec/millisec ?
Setting the wake time = 20ms for reading all 19 devices can be reasonable ?