Internet of things (IoT) is a network of different interconnected objects that are capable to collect and exchange data without human interaction. IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) is the common IoT routing protocol. One of the main drawbacks of the RPL protocol is lack of support of load balancing leads to unfair distribution of traffic load in the network which may decrease network efficiency. In this paper for load balancing, we proposed a new method called C-Balance based on cluster ranking to increase the network lifetime. In this method, two ranks are calculated for each node. The first rank is used to identify clusters and cluster heads and the second rank is used to select parents of each cluster head to forward packets towards the destination. To calculate these ranks, several metrics are used including Expected Transmission Count, hop count, residual energy and number of children. To investigate the performance of the proposed method, it has been simulated with Cooja simulator in the form of nodes with mobility and non-mobility scenarios plus using a random topology network with 20, 40 and 60 nodes experiments. The results are compared with OF0 and MRHOF standard objective functions as well as the QU-RPL method. The final results in both scenarios show that the proposed method in the field of energy consumption, network lifetime and load balancing has improved compared to the other methods. In terms of end-to-end delay, the proposed method has more delay compared to the standard objective functions and QU-RPL method. The calculation of the mean packet delivery ratio (PDR) of these four methods also shows that the proposed method has an acceptable performance. Final results indicate that on average, there is a 30–45% improvement in energy consumption, 15–23% reduction in average number of children and 22–48% improvement in network lifetime are obtained compared to the other methods. Finally, there is about 12% progress for PDR compared to the OF0.

物联网（IoT）是由不同的互连对象组成的网络，这些对象无需人工即可收集和交换数据。低功耗有损网络（RPL）的IPv6路由协议是常见的IoT路由协议。RPL协议的主要缺点之一是缺乏对负载平衡的支持，导致网络中流量负载的分配不公平，这可能会降低网络效率。在本文中，为实现负载平衡，我们提出了一种基于群集排序的称为C-Balance的新方法，以延长网络寿命。在这种方法中，为每个节点计算两个等级。第一级用于标识群集和群集头，第二级用于选择每个群集头的父级以将数据包转发到目的地。要计算这些排名，使用了多个指标，包括预期传输计数，跳数，剩余能量和子代数。为了研究该方法的性能，已使用Cooja模拟器以具有移动性和非移动性场景的节点的形式以及使用具有20、40和60个节点实验的随机拓扑网络对它进行了仿真。将结果与OF0和MRHOF标准目标函数以及QU-RPL方法进行比较。两种情况下的最终结果表明，与其他方法相比，该方法在能耗，网络寿命和负载平衡方面均得到了改善。在端到端延迟方面，与标准目标函数和QU-RPL方法相比，该方法具有更大的延迟。这四种方法的平均分组传送率（PDR）的计算也表明，所提出的方法具有可接受的性能。最终结果表明，与其他方法相比，平均而言，能耗降低了30–45％，平均儿童数量减少了15–23％，网络寿命提高了22–48％。最后，与OF0相比，PDR的进度约为12％。