Wireless networks are everywhere. Mobility … Wireless networks are everywhere. Mobility and flexibility, together with the elimination of wires derived from the nature of wireless communications, represent extremely useful advantages in recent past, present, and future of networked communications. However, the open and shared communication medium used by wireless networks is highly susceptible to interferences, which may induce the occurrence of temporary network partitioning (dubbed network inaccessibility), caused by disturbances in the medium access control (MAC) layer management operations. Existing analyzes of network operation in the time domain do not usually pay much attention to temporal issues caused by the occurrence of network inaccessibility, and therefore violation in timeliness and dependability properties may occur. In this paper we present our advances in the enhancement of the IEEE 802.15.4 NS-2 simulation module to measure and validate the occurrence of network inaccessibility in a IEEE 802.15.4 simulated network. Additionally, the correctness of a previous theoretical model designed to characterize network inaccessibility within IEEE 802.15.4 networks is also validated, improving the temporal modeling of IEEE 802.15.4 wireless communications. of IEEE 802.15.4 wireless communications.