## 1 Introduction
In Reference [4], the authors presented that typical clustering schemes of MANETs were classified into six categories such as dominating-set-based (DS-based) clustering, low-maintenance clustering, mobility-aware clustering, energy-efficient clustering, load-balancing clustering and combined-metrics-based clustering. Particularly, the idea of DS-based clustering is to find a connected set of dominating nodes (CDS) with a minimum size. The obtained CDS is used as a routing space for routing process. In low-maintenance clustering approach, the main goal of clustering is to provide a stable cluster architecture by minimizing re-clustering situations. This issue helps to save the cost of clustering process. The main task of mobility-aware clustering is also to construct a stable cluster structure. The main idea of this clustering approach is that mobile nodes are classified into groups based on the movement of node. In energy-efficient clustering scheme, a MANET should try to save its energy consumption in order to prolong the network lifespan. Because a cluster head has to handle more tasks than a member, its energy is easily exhausted and network communication may be interrupted. There are some approaches to solve this problem such as limiting the time that a mobile node can serve as a cluster head continuously, guaranteeing the CDS connected and removing unnecessary mobile nodes with low energy level from the CDS and serving slave nodes as many as possible and minimizing the total energy consumption between all communicating master-slave pairs, where a master is a cluster head and a slave is a member. Load-balancing clustering algorithms provides an optimum number of clusters to improve the system performances. The number of mobile nodes in each cluster is set by an upper and a lower limit. When a cluster size exceeds its limit, the number of mobile nodes is adjusted by re-clustering. The main idea of combined-metrics-based clustering is to produce a weighted function which is a combination of parameters such as node degree, residual energy capacity, moving speed. This weighted function is used for the cluster heads selection process to obtain a cluster structure, which improves the system performances. In Reference [5], the authors proposed a probabilistic clustering algorithm. In this algorithm, a node with more vacant channels has a higher probability to become a cluster head. Next, each CH broadcasts their list of vacant channels. If a node has one or more common channels with a CH, it sends a join request message including its vacant channels' list and ID to the cluster head. Finally, each cluster head decides a final communication channel based on the received channel lists from non-cluster head nodes. In Reference [6], a weighted function was proposed by combining the degree of connectivity, mobility, time of a cluster head (CH) and sum of distances to neighbors to elect cluster heads in MANETs. A distributed weighted clustering algorithm (DWCA) was presented in Reference [7] to optimize the configuration and power for the cluster heads in MANETs. In Reference [8], a weighted clustering algorithm was studied, called enhancement on weighted clustering algorithm (EWCA). In EWCA, transmission power, transmission range, mobility and battery energy parameters were used to elect CHs and achieve the load balancing to enhance the stability of clusters in MANETs. A mobility based clustering approach was proposed in Reference [9] to support mobility management and multicast routing in MANETs. Topology control is a challenging problem because there is no fixed infrastructure in MANETs, the connected dominating set (CDS) has been considered as an effective approach to design clusters and virtual backbones in MANETs [10]. In Reference [11], a CDS based distributed algorithm was proposed based on node IDs to reduce the size of CDS. A reduction-based methods were presented in References [12;13] to find a CDS from one node with maximum vertex degree and some rules were also introduced to reduce the size of CDS.