Research On Key Technologies Of Heterogeneous Wireless Network Interconnection Based On Software Defined Radio

In recent years,wireless communication technologies such as ZigBee and WiFi have developed rapidly,and heterogeneous wireless networks have coexisted and deployed together.The ZigBee Alliance proposes the ZigBee-WiFi network concept,which combines the unique advantages of ZigBee and WiFi.Through the interconnection of heterogeneous wireless network ZigBee and WiFi,the advantages of both sides are played and the shortcomings of the other are made up.However,the traditional method uses dedicated integrated hardware to interconnect the heterogeneous wireless network ZigBee and WiFi to build a ZigBee-WiFi network,which has the disadvantages of poor scalability and flexibility,and cannot support new physical layers and signal processing algorithms.This paper proposes to use the emerging software radio technology to build a ZigBee-WiFi network.The ZigBee-WiFi network has excessive energy consumption of ZigBee nodes,so this paper improves the traditional ZBR routing algorithm to prolongs the network lifetime.The research work of this paper mainly has the following two aspects.In view of the shortcomings of traditional methods to build ZigBee-WiFi network with dedicated integrated hardware,this paper proposes to build ZigBee-WiFi gateway by using open source software radio platform GNU Radio and universal software radio peripheral.The gateway interconnects heterogeneous wireless networks ZigBee and WiFi to build a ZigBee-WiFi network.Software defined radio implements signal processing components through software programming to build a flexible and universal ZigBee-WiFi gateway.By testing the ZigBee-WiFi gateway in a real scenario,the results show that the gateway has a good ZigBee packet reception rate and real-time signal processing capabilities,can receive and demodulate ZigBee packets and extract the payload,and then encapsulate the WiFi data frame according to the payload,and ZigBee-WiFi gateway has strong anti-interference ability when transmitting WiFi data frames.At the same time,due to the excessive energy consumption of ZigBee nodes in the ZigBee-WiFi network,the traditional ZigBee routing algorithm needs to be improved.This paper proposes a ZigBee routing algorithm based on energy optimization.The algorithm improves the Cluster-Tree algorithm and AODVjr algorithm in the ZigBee routing algorithm by introducing node energy levels,routing cost,and redesigned neighbor tables.And it restricts the propagation direction of route request packets.In addition,the algorithm introduces the idea of clustering to divide the network into several logical clusters,adopts an improved Cluster-Tree algorithm within the cluster,and executes the improved AODVjr algorithm between clusters.And the energy level of the node dynamically changes following the energy threshold,and then different routing strategies are adopted according to the energy level.Through the ZigBee network simulation platform based on NS2,the improved ZigBee routing algorithm is tested.The experimental results show that the improved routing algorithm has great improvements in the remaining energy of the network,the number of dead node,the average end-to-end delay,and the packet delivery rate.The improved algorithm extends the life cycle of the network,thus improving the stability of the interconnection between ZigBee and WiFi.