2) Multi-frequency hierarchical structure. Multifrequency
hierarchical network is the lower node and small
communication range, and advanced node communication
range, such as the two level network, a frequency
communication with the cluster member nodes and cluster
member, a frequency of communication with the cluster
head nodes, keep the communication between cluster heads
with another frequency.Because a single node distance is
limited, and communication within each cluster can be a
single jump. It can also be multi-hop communication, and
the information will be transmitted to the superior network
once the information to cluster head. The network can use
higher transmission bandwidth, or it can be superior to the
network and it directly connect to a wired network.