Heuristic-based Topology Path Optimization Strategy For Internet Of Things

In the Internet of Things,a large number of sensor nodes are deployed in the area to monitor the environment and collect information.However,in a large-scale network,it is usually necessary to send a message collected by a sensor node to a Sink node after multiple hops,so that some messages cannot arrive in time and the node consumes a large amount of energy,thereby shortening the life cycle of the network.In this case,how to build an efficient network topology has become a critical issue.The small world network model has proven to be a viable way to build a network topology.Adding a small number of shortcuts to the Internet of Things to build a small world model can not only reduce network latency,but also improve network reliability.In this paper,a heterogeneous network with common nodes and super nodes is designed to implement a topology with small world characteristics.We divide the network into a single Sink network and a multi-Sink network according to the number of Sink nodes existing in the network.The shortcut adding strategy(TOSG)of single-Sink network based on ant colony algorithm and the shortcut adding strategy(SAPS)of multi-Sink network based on particle swarm optimization algorithm are proposed respectively.In TOSG,according to the number of occurrences of all nodes in the shortest path obtained by ant colony algorithm,important nodes in network topology are found.Then we create some shortcuts based on the importance of the nodes to build a small world model.In SAPS,we create a fitness function by combining the average path length of the network and the load of the Sink node to evaluate the quality of the particles.Then use crossover and mutation to update the particles to find the solution for shortcut addition.A lot of simulation experiments have been done in this paper.Compared with existing algorithms,TOSG model has smaller average shortest path length.And it has a high aggregation coefficient.At the same time,compared with GMSW and LM-GAS,SAPS can significantly reduce the average path length of the network with a small number of shortcuts.And SAPS can also balance the load of Sink node well.