Time Slot Transmission Scheme with Packet Prioritization for Bluetooth Low Energy Devices used in Real-Time Applications
Time Slot Transmission Scheme with Packet Prioritization for Bluetooth Low Energy Devices used in Real-Time Applications
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DOI：
10.1007/s10776-020-00494-4
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发表时间：
2020-09-26
影响因子：
2.5
通讯作者：
de Freitas, Edison Pignaton
中科院分区：
文献类型：
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作者：
Agnoletto, Daniel;Jonsson, Magnus;de Freitas, Edison Pignaton
蓝牙低能量(BLE)是物联网和无线传感器网络领域日益发展的重要技术之一。由于其灵活性和独特的低功耗，越来越多的工业设备、家用电器和可穿戴设备正在使用它进行设计。然而，协议本身并没有完全覆盖这些网络的实时需求，如定时和服务质量。为了帮助改善和控制这些特性，本文提出了一种具有分组优先级的时隙传输方案。它基于将连接间隔划分和分配给两种类型的消息：实时消息和普通消息。其目标是为实时消息提供最低的丢包率和时间保证，同时为普通消息提供可接受的吞吐量。由于BLE连接关闭的概率随着通过其发送的数据包数的增加而增加，因此发送实时数据包的位置以及连接中普通消息的数量是关键因素。对于普通流被限制在它们之间的空间的实时分组，使用第一个和最后一个时隙减少了传输延迟的不确定性，并允许基于普通消息的数量进行概率调整。使用所提出的方案进行了仿真，观察到实时传输的时延方差降低了100倍以上。在可靠性方面，在误码率为10(-3)的情况下，大约5%的分组丢失。
Bluetooth Low Energy (BLE) is one of the most important technologies that feed the growing field of Internet of Things and Wireless Sensor Networks. Due to its flexibility and unique low power-consumption, an increasing number of industrial devices, household appliances and wearables are being designed using it. However, the real-time demands of these networks such as timing and Quality of Service are not fully covered by the protocol itself. To help improve and offer some control over these characteristics, this paper presents a time slot transmission scheme with packet prioritization. It is based on the division and allocation of the connection interval to two types of messages: real-time and ordinary. The goal is to offer the lowest packet loss and time guarantees for real-time messages, while providing acceptable throughput for ordinary ones. Since the probability of a BLE connection to close increases with the number of packets sent through it, the position where a real-time packet is being sent as well as the number of ordinary messages in a connection represent key factors. The use of the first and last slot for real-time packets with ordinary flow restricted to the space between them decreases the transmission delay uncertainty and allows probability tuning based on the number of ordinary messages. Simulations were performed using the proposed scheme and a reduction of more than 100 times in the delay variance was observed for real-time transmissions. Regarding reliability, around 5% of the packets were lost for a bit error rate of 10(-3).