Karalis Apostolos, Zorbas Dimitrios, Douligeris Christos
Department of Informatics, University of Piraeus, 18534 Piraeus, Greece.
Tyndall National Institute, University College Cork, T12R5CP Cork, Ireland.
Sensors (Basel). 2019 Apr 14;19(8):1789. doi: 10.3390/s19081789.
IEEE802.15.4-time slotted channel hopping (TSCH) is a medium access control (MAC) protocol designed to support wireless device networking, offering high reliability and low power consumption, two features that are desirable in the industrial internet of things (IIoT). The formation of an IEEE802.15.4-TSCH network relies on the periodic transmissions of network advertising frames called enhanced beacons (EB). The scheduling of EB transmissions plays a crucial role both in the joining time and in the power consumption of the nodes. The existence of collisions between EB is an important factor that negatively affects the performance. In the worst case, all the neighboring EB transmissions of a node may collide, a phenomenon which we call a full collision. Most of the EB scheduling methods that have been proposed in the literature are fully or partially based on randomness in order to create the EB transmission schedule. In this paper, we initially show that the randomness can lead to a considerable probability of collisions, and, especially, of full collisions. Subsequently, we propose a novel autonomous EB scheduling method that eliminates collisions using a simple technique that does not increase the power consumption. To the best of our knowledge, our proposed method is the first non-centralized EB scheduling method that fully eliminates collisions, and this is guaranteed even if there are mobile nodes. To evaluate our method, we compare our proposal with recent and state-of-the-art non-centralized network-advertisement scheduling methods. Our evaluation does not consider only fixed topology networks, but also networks with mobile nodes, a scenario which has not been examined before. The results of our simulations demonstrate the superiority of our method in terms of joining time and energy consumption.
IEEE802.15.4 时隙信道跳频（TSCH）是一种旨在支持无线设备联网的介质访问控制（MAC）协议，具有高可靠性和低功耗这两个工业物联网（IIoT）中所需的特性。IEEE802.15.4 - TSCH 网络的形成依赖于称为增强信标（EB）的网络广告帧的周期性传输。EB 传输的调度在节点的加入时间和功耗方面都起着关键作用。EB 之间的冲突存在是对性能产生负面影响的一个重要因素。在最坏的情况下，节点的所有相邻 EB 传输可能会发生冲突，我们将这种现象称为完全冲突。文献中提出的大多数 EB 调度方法全部或部分基于随机性来创建 EB 传输调度。在本文中，我们首先表明随机性会导致相当大的冲突概率，尤其是完全冲突的概率。随后，我们提出了一种新颖的自主 EB 调度方法，该方法使用一种不增加功耗的简单技术来消除冲突。据我们所知，我们提出的方法是第一种完全消除冲突的非集中式 EB 调度方法，即使存在移动节点也能保证这一点。为了评估我们的方法，我们将我们的方案与近期的和最先进的非集中式网络广告调度方法进行比较。我们的评估不仅考虑固定拓扑网络，还考虑具有移动节点的网络，这是之前尚未研究过的场景。我们的模拟结果证明了我们的方法在加入时间和能耗方面的优越性。
