Research Of Routing Protocols Based On Improved Ant Colony Algorithm For Wireless Sensor Networks

In the application of WSN, regardless of hardware designing or software level, how tosave energy is always the first work of the research. Routing mechanism as the keytechnology of the WSN, how to reduce the energy consumption of the node and prolong thenetwork’s life is the top work while designing. This paper selects PEGASIS as the basicresearch object to put forward a WSN routing protocol named PBIACR which based on theimproved ant colony algorithm. The main works are as follows:1. In PEGASIS, it uses greedy algorithm, which can lead to long sub-chains between ofneighbor nodes easily, to construct a chain. To deal with the problem, it proposes PBACRbased on basic ant colony algorithm. In PBACR, it uses basic ant colony algorithm toconstruct a communication chain to avoid long sub-chains. From the simulation test whichused by Matlab, it firstly obtained the best value of the optimization parameters in thePBACR, and then it compared the length of the chain of the two algorithms. The result showsthat the length of the chain formed in the PBACR is shorter.2. On account of the problems such as premature stagnation, local optimization and so on,which exist in the chain construction mechanism of PBACR, it further proposes PBIACRprotocol. The main views of the protocol are as follows: Take the energy factor into thecalculation of the probability function to achieve the purpose that balances energyconsumption in the whole network. In order to reduce the ants over reliance on pheromone inthe process of searching path, it improves the probability function further to increase the ants’capability of random searching and avoid the "hot spots" which caused by prematurestagnation. Take the energy factor into the update mechanism and limit the pheromonebetweenτminandτmaxto avoid the non-global optimal solution caused by the excessive pheromone on a path.3. It is easy to produce the following problems while the node acts as the chain head inturn: the energy consumption of some node, which is far away from the Sink, is too fast orsome node leads to the communication failure due to the remained energy is too low. To solvethe problems, PBIACR improves the strategy of the chain head elected. It choose the maxvalue as the head through calculate the residual energy of the node and the distance that theone from the Sink node. If the value calculated is the same, it chooses the node that closerfrom the Sink node.4. It designs and implements the PBIACR and then simulates the protocol in the NS2 plat.It focuses on comparing the performance of the PBIACR and the PEGASIS. Theexperimental results are as follows: In terms of the whole energy consumption, the PBIACRprotocol is lower than the PEGASIS protocol. In terms of the life cycle, the PBIACR protocolis about more than 1.03 times than the PEGASIS protocol. In terms of the quantity of the datapacket that the Sink received, the PBIACR protocol is more than the PEGASIS protocol. Interms of the delay, the PBIACR protocol is shorter slightly.