基于6LoWPAN的嵌入式多网关系统设计与实现

6LoWPAN是一种在IEEE802.15.4标准基础上IP化实现无线传感器网络的技术。在现有单目的导向的有向无环图（DODAG）环路由协议标准下，存在围绕单边界路由器的网络拥塞和能耗问题。设计了一种嵌入式6LoWPAN多网关协议和系统，嵌入式网关节点具备双模通信功能，可实现无线传感网（WSN）和固定IPv6网络的物理连接，双模网关通过固网建立与6LoWPAN根边界路由器之间的IP隧道来实现上下行路由。通过对现有6LoWPAN协议标准的补充和优化，使双模节点具有网内和网际路由能力，从而实现多网关架构和多径路由功能。优化的多点互通拓扑位置和流量分担算法实现上下行链路的有效负载平衡，也减小了节点多跳路由能耗。通过对多网关平台进行实验测试，并与单网关系统对比测试，结果表明该方案不仅实现了6LoWPAN在以太网的多点接入，降低了网络内数据传输时延和丢包率，并且提升了网络整体吞吐量。

Design and implementation of embedded multi-gateway system based on 6LoWPAN

6LoWPAN (IPv6 over Low power Wireless Personal Area Network) is a technology to realize the IP connection of wireless sensor network based on IEEE802.15.4 standard. The network congestion and energy consumption problem exists around the single bounder router under the existing single DODAG (Destination Oriented Directed Acyclic Graph) protocol. An embedded 6LoWPAN multi-gateway protocol and system was designed. The embedded gateway node has dual-mode communication function, which can realize the physical connection between WSN (Wireless Sensor Network) and fixed IPv6 network. The dual-mode gateway implements uplink and downlink routes by establishing an IP tunnel between the 6LoWPAN root border router and it. By supplementing and optimizing the existing 6LoWPAN protocol standard, the dual-mode node has intra-network and inter-network routing capabilities, so as to achieve multi-gateway architecture and multi-path routing function. The optimized multi-point interworking topology and traffic sharing algorithm was used to realize the effective load balance between uplink and downlink links, and also to reduce the energy consumption of multi-hop routing of nodes. Experiments were carried out on multi-gateway platforms and single gateway systems. The results show that the proposed scheme can achieve 6LoWPAN multi-gateway Ethernet access, reduce network node transmission delay and packet loss rate, and improve the overall network throughput.