Abstract:  Efficient and reliable communication is critical for multimedia sensor networks such as real-time video surveillance. It is very challenging to attain such communication, as the sensors may not have the stable connection paths to their corresponding servers/sink nodes due to bandwidth constraints. On the other hand, the instability of the wireless paths may cause temporarily unreachability between the servers and the sensor nodes. As a consequence, users may suffer from the losing of their data or having the bad usage experiences. To overcome this problem, this paper designs and implements a novel multi-homed connection system for wireless multimedia sensors from the following aspects: (1) A system architecture enables the multimedia sensor to connect to multiple servers at the same time. (2) A novel multi-homed transmission protocol runs for the sensors to adapt to various Wi-Fi environments and application usages. (3) Extensive experiment results show that the system and protocol can improve the reliability of the multimedia data transmission. Compared with the traditional single-homed connection scheme, the system can always maintain the stable connection with nearly the same bandwidth, memory and CPU resource utilization.

Key words: multi-homed, multi-connection, reliability, wireless multimedia sensor

摘要： 对多媒体传感器网络中的实时视频传输来说，高效而可靠的通信是十分重要的。但是在实际条件下，当传感器向汇聚节点传输数据时，由于带宽的限制及传输链路不稳定等原因，传感器与汇聚节点之间的链接通常会变得不稳定。不稳定数据传输会影响传感器节点的正常数据传输，甚至会导致传感器节点无法与汇聚节点通信。这些问题让使用多媒体传感器网络的用户产生了较差的用户体验。为了解决这些问题，为无线多媒体传感器设计了一个全新的多宿主（multi-homed）多连接系统，并实现了原型系统。该系统的优势主要体现在以下三方面：（1）能够让多媒体传感器同时与多个汇聚节点（服务器）进行通信的系统架构；（2）能够适应多样的Wi-Fi环境和应用场景的多宿主传感器传输协议；（3）后续的实验结果也证明了该系统和协议可以提高多媒体数据传输的可靠性。与传统的单宿主（single-homed）连接模式相比，该系统能够在相同的带宽、内存和CPU资源限制下保持更加稳定的连接。

关键词: 多宿主, 多连接, 可靠性, 无线多媒体传感器