  This paper Various studies cited in the literature deal with the classic
problem of obstacle coverage, where the deployment environment, sensor nodes,
and base stations have characteristics that are considered perfect but suffer
from various flaws in the real world. This paper presents other barrier
coverage types ranked in a new classification based on linear and nonlinear
barrier coverage according to deterministic and insecure environments, and
enumerates some of the different current and future challenges of these
coverage types and connectivity in WSNs.
