Aiming at the problem that the data traffic rises with the increase of data visitors in large-scale Wireless Sensor Networks (WSN), a data traffic optimization WSN system framework was designed and implemented to build large-scale WSN and reduce the network data traffic. The IPv6 and IPv6 over Low Power Wireless Personal Area Network (6LoWPAN) technology were adopted to build large-scale WSN. To integrate the WSN and traditional Internet, the Message Queuing Telemetry Transport (MQTT) and Message Queuing Telemetry Transport for Sensor Network (MQTT-SN) protocols were deployed in application layer to build system publish/subscribe model. The experimental results show that, when system has 5 sensor nodes, compared with the Constrained Application Protocol (CoAP) based WSN system, the data traffic of the proposed system is 18% of the former. It proves that the proposed system framework can effectively control the impact caused by increasing visitors to WSN data traffic.

This article focused on the mobile sink scheduling problem in Wireless Sensor Networks (WSN). A mobile single-sink scheduling algorithm in wireless sensor networks was proposed based on Linear Programming (LP). Firstly, the problem was mathematically modeled and formulated in time domain, and the problem was re-formulated from time to space domain to reduce the complexity. Then a polynomial-time optimal algorithm was proposed based on linear programming. The simulations confirm the efficiency of the algorithm and the results show that the algorithm can significantly improve the network lifetime of wireless sensor networks.