Traffic Priority Based Channel Assignment Technique for Critical Data Transmission in Wireless Body Area Network.

In recent days, intelligent biomedical sensors and wearable devices are changing the healthcare industry by providing various heterogeneous vital signs of patients to the hospitals, caregivers, and clinicals. This collective form of monitoring sensor devices forms a very short-range Wireless Body Area Network (WBAN) and plays a key role in the data gathering process. If any sensor node in the network detects abnormal values that should be transmitted promptly via wireless medium with less delay. A single medium allows one-way delivery of a data packet, and it may not be sufficient to satisfy the high volume of communication demand between the sensor nodes in the network. In the same way, the packet prioritization does not guarantee the packet will get there on time and sometime it may cause priority conflicts among the nodes. It is only mean that the flow of delivery service handles that critical data packet before handling other data packets. However, unexploited time slots and bandwidth wastage will occur due to inefficient backoff management and collisions. To minimize the aforementioned issues, various backoff procedures, adaptive slot allocation mechanisms, priority-based medium access control protocols have been developed but suffer limitations in the context of providing priority-based channel access with less backoff conflicts and dedicated allocation of time slots for critical nodes in all cases. Based on these deliberations, a more effective Traffic Priority-based Channel Access Technique (TP-CAT) is proposed using IEEE 802.15.6 in order to minimize the transmission delay of critical data packet and solve conflicts among other priority nodes during the backoff phases. Firstly, a Low Threshold Criticality-based Adaptive Time slot Allocation algorithm (LT-CATA) is presented to decrease the priority slot conflicts between the low threshold data traffic from the same and different type of user priority nodes. Secondly, a High Threshold Criticality-based Adaptive Time slot Allocation algorithm (HT-CATA) is developed to reduce the priority slot conflicts between the high threshold data traffic from the same and different types of user priority nodes. Additionally, a novel Random Overlapping Backoff value Avoidance (ROBA) technique is introduced to eliminate the overlapping issue during the selection of random backoff value among the sensor nodes. Since, the proposed technique greatly reduced the channel access delay and transmission delay of critical data packet as well as other types of priority data packet. The Simulation results are verified in the CASTALIA 3.2 framework using omnet++ network simulater to relatively evaluate the performance metrics of the TP-CAT technique with state-of-the-art protocols. From the analysis of the results, it is evident that the TP-CAT technique provides better performance in terms of delay, energy consumption, and throughput in healthcare monitoring environments.