The overall process of data exchange is explained using
Fig. 6. Sensors S1, S2, and S4 all have packets to transmit
to sensor S3 at the start (indicated by the arrow on the time
axis). They each sense the channel for DIFSdata. Intuitively
from (9), sensor S2 with the residual energy of 3.0 V, should
experience the shortest backup duration, as opposed to S1 and
S4. However, this does not imply that the nodes with higher
residual energy will always have a shorter back off duration,
as the random selection of the backoff slots within the window
does contribute to the overall backoff time. This selection of the
window [CWmin, CWcurrent] is independent of node’s residual
energy.