Enhancing the IEEE 802.15.4 MAC with dynamic GTS allocation for medical applications

Wireless monitoring systems for biomedical measurements are becoming self-evident in future health care environments. The benefit of such systems lies in reduction of costs in health care equipment and also in more efficient treatment of patients resulting, e.g., in reduced waiting times in hospitals. Transmitting measured vital biomedical information over wireless channel requires effective and reliable solutions in the medium access control (MAC) layer, which is responsible for allocating the channel resources among different users in a conflict free manner. In this paper, we introduce a novel dynamic slot allocation scheme based on IEEE 802.15.4 MAC to be utilized in hospital environment. We make a comparative performance analysis between the original IEEE 802.15.4 and the developed DGTS (dynamic guaranteed time slot) allocation scheme and study the effective utilization of the GTS (guaranteed time slot) slots. Based on the analysis, it can be concluded that the GTS allocation scheme is essential if IEEE 802.15.4 MAC is utilized for transmitting vital biomedical information. Furthermore, it can be stated that the proposed DGTS allocation scheme significantly improves the performance of the protocol, since it is able to dynamically adapt to traffic changes, whereas the original GTS allocation is producing saturated or degraded throughput when the number of end devices is increased.