广播是无线传感器网络一项重要的操作，而网络中节点能量通常受限且通信链路不稳定。针对低占空比传感器网络中引入机器人作为可移动汇点的场景，设计了考虑延迟和能耗的高效广播策略。首先采用最小覆盖圆算法，寻找最优广播位置。然后提出了一种延迟约束的高能效广播树算法（DCEBT）。DCEBT在构造广播树时，使用新的量度来充分利用无线广播特性减小能耗，同时基于地理位置对节点进行延迟约束。结果表明，利用机器人的移动性优化广播位置可改善广播性能。而和目前常用的方法相比，DCEBT在保持延迟性能相当的条件下，能大幅提高能量效率。
Flooding is an important operation in wireless sensor networks (WSNs), but the energy of sensor nodes is usually limited and the communication links are unreliable in WSNs. An efficient flooding strategy is designed for low-duty-cycle WSNs where mobile robots act as data sinks with considering both delay performance and energy efficiency. The smallest enclosing circle algorithm is used to search the optimal flooding position. And then, a delay-constrained energy-efficient broadcasting algorithm (DCEBT) is presented. DCEBT adopts a novel metric for energy optimization, and restricts the delay of nodes based on their locations. The results show that exploiting the mobility of robots to optimize the flooding position could improve the flooding performance. And compared with common flooding schemes, DCEBT increases the energy efficiency greatly while achieving comparable delay performance.
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