Deparment of ECE, CEG Campus, Anna University, Chennai, India.
J Med Syst. 2018 Sep 20;42(11):206. doi: 10.1007/s10916-018-1054-y.
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.
近年来，智能生物医学传感器和可穿戴设备通过向医院、护理人员和临床医生提供各种患者的异构生命体征，正在改变医疗保健行业。这种集体形式的监测传感器设备形成了一个非常短程的无线体域网（WBAN），并在数据采集过程中发挥着关键作用。如果网络中的任何传感器节点检测到异常值，应通过无线介质尽快传输，延迟尽量小。单个介质允许单向传输数据包，并且对于网络中传感器节点之间的高通信量需求，它可能不足以满足。同样，数据包优先级并不能保证数据包按时到达，有时它可能会导致节点之间的优先级冲突。这只是意味着在处理其他数据包之前，传输服务的流程会处理该关键数据包。然而，由于低效的退避管理和冲突，未充分利用的时隙和带宽浪费将发生。为了最小化上述问题，已经开发了各种退避程序、自适应时隙分配机制、基于优先级的介质访问控制协议，但在提供基于优先级的信道访问、减少退避冲突和为所有情况下的关键节点分配专用时隙方面存在局限性。基于这些考虑，提出了一种基于流量优先级的信道访问技术（TP-CAT），该技术使用 IEEE 802.15.6 来最小化关键数据分组的传输延迟，并解决退避阶段中其他优先级节点之间的冲突。首先，提出了一种基于低阈值关键的自适应时隙分配算法（LT-CATA），以减少来自同一和不同类型用户优先级节点的低阈值数据流量之间的优先级时隙冲突。其次，开发了一种基于高阈值关键的自适应时隙分配算法（HT-CATA），以减少来自同一和不同类型用户优先级节点的高阈值数据流量之间的优先级时隙冲突。此外，引入了一种新颖的随机重叠退避值避免（ROBA）技术，以消除传感器节点在选择随机退避值期间的重叠问题。由于该技术大大减少了关键数据分组和其他类型优先级数据分组的信道访问延迟和传输延迟。使用 omnet++网络模拟器在 CASTALIA 3.2 框架中进行了仿真验证，以相对评估与最先进协议的 TP-CAT 技术的性能指标。从结果分析可以看出，在医疗保健监测环境中，TP-CAT 技术在延迟、能耗和吞吐量方面提供了更好的性能。
