  Unmanned Aerial Vehicle (UAV) ad hoc network has achieved significant growth
for its flexibility, extensibility, and high deployability in recent years. The
application of clustering scheme for UAV ad hoc network is imperative to
enhance the performance of throughput and energy efficiency. In conventional
clustering scheme, a single cluster head (CH) is always assigned in each
cluster. However, this method has some weaknesses such as overload and
premature death of CH when the number of UAVs increased. In order to solve this
problem, we propose a dual-cluster-head based medium access control (DCHMAC)
scheme for large-scale UAV networks. In DCHMAC, two CHs are elected to manage
resource allocation and data forwarding cooperatively. Specifically, two CHs
work on different channels. One of CH is used for intra-cluster communication
and the other one is for inter-cluster communication. A Markov chain model is
developed to analyse the throughput of the network. Simulation result shows
that compared with FM-MAC (flying ad hoc networks multi-channel MAC,FM-MAC),
DCHMAC improves the throughput by approximately 20%-50% and prolongs the
network lifetime by approximately 40%.
