Implementation of the WirelessHART MAC layer in the OPNET simulator

WirelessHART standard is the first international standard for Industrial Wireless Sensor Networks (IWSN) approved by International Electrotechnical Commission (IEC), and, as such, it is worthwhile to implement on simulator platforms. Based on the study of WirelessHART standard, this paper is a primary implementation of the Medium Access Control layer of WirelessHART standard. To our best knowledge, this is the first comprehensive implementation of WirelessHART using the OPNET simulator. This paper also proposes the improvement of shared slot access method by using slotted Carrier Sense Multiple Access/Collision Avoidance (CSMA/CA), which outperforms the existing slotted ALOHA by increasing the throughput for 2% and reducing the packet loss. Flexible dedicated slot assignment has also been proposed to reduce the packet loss rate caused by influences of the physical channel.