Exploiting Concurrency for Opportunistic Forwarding in Duty-Cycled IoT Networks
Exploiting Concurrency for Opportunistic Forwarding in Duty-Cycled IoT Networks
复制标题
利用并发性实现占空比物联网网络中的机会转发
DOI：
10.1145/3322496
复制
发表时间：
2019
影响因子：
4.1
通讯作者：
Jiang Hongbo
中科院分区：
文献类型：
--
作者：
Liu Daibo;Cao Zhichao;He Yuan;Ji Xiaoyu;Hou Mengshu;Jiang Hongbo
由于物联网（Zhao et al. 2018）（IoT）设备的能源供应有限，广泛采用异步占空比无线电管理来节省能源。由于节点的睡眠时间表不同步，发送方必须重复发送帧以与其接收方协调或保持睡眠，直到接收方的唤醒时间根据接收方的睡眠-唤醒时间表到来。在这种情况下，利用最早的转发机会而不是确定性转发器的机会转发在利用占空比物联网网络的信道资源方面显示出巨大的优势。具有时间和空间多样性的多种转发选择增加了机会转发中的冲突容忍机会，从而潜在地增强了占空比多跳网络的整体性能。然而，由于当前的通道竞争机制主要侧重于避免冲突，因此对于并发性的利用过于保守。为了解决这个问题，在本文中，我们建议 COF 充分利用占空比物联网网络中机会转发的潜在并发性。 COF 通过以下方式实现并发传输：(i) 测量正在进行的传输干扰下的条件链路质量，然后 (ii) 进一步对潜在并发机会的优势进行建模。 COF根据并发的预期收益来决定是否采用并发方式传输。 COF还采用并发标志和信号特性，避免并发传输无序造成的数据冲突，提高条件链路质量估计的准确性。 COF 可以轻松集成到传统的非同步和占空比协议中。我们已经实现了 COF 并在 40 节点测试台上评估了其性能。结果表明，COF 可以有效地利用机会转发中的潜在并发性，并且在不同的流量负载和网络密度下，COF 的性能优于最先进的协议。
Due to limited energy supply of Internet of Things (Zhao et al. 2018) (IoT) devices, asynchronous duty cycle radio management is widely adopted to save energy. Since the sleep schedules of nodes are unsynchronized, a sender has to repeatedly send frames to coordinate with its receiver or keep sleeping until the receiver’s wake-up time will come according to receiver’s sleep-wake schedule. In such contexts, opportunistic forwarding, which takes the earliest forwarding opportunity instead of a deterministic forwarder, shows great advantage in utilizing channel resource for duty-cycled IoT networks. The multiple forwarding choices with temporal and spatial diversity increase the chance of collision tolerance in opportunistic forwarding, potentially enhancing the overall performance of duty-cycled multi-hop networks. However, since the current channel contention mechanisms mainly focus on collision avoidance, it is too conservative to exploit concurrency. To address this problem, in this article, we propose COF to fully exploit the potential Concurrency for Opportunistic Forwarding in duty-cycled IoT networks. COF achieves concurrent transmission by: (i) measuring conditional link quality under the interference of on-going transmissions, and then (ii) further modeling the benefit of potential concurrency opportunities. According to the expected benefit of concurrency, COF decides whether or not to transmit in concurrent way. COF also adopts concurrency flag and signal features to avoid data collision caused by disordered concurrent transmissions and enhance the accuracy of conditional link quality estimation. COF can be easily integrated into the conventional unsynchronized and duty-cycled protocols. We have implemented COF and evaluated its performance on a 40-node testbed. The results show that COF can effectively exploit potential concurrency in opportunistic forwarding and COF outperforms the state-of-art protocols under diverse traffic load and network density.