Quality of Service Monitoring for Video Streaming in Mobile Ad-hoc Networks

Abstract

This thesis work is done in the context of a recently launched research project on delay-tolerant streaming, where the vision is to provide a video streaming solution capable of performing in a dynamic, wireless, mobile environment without the presence of a fixed infrastructure.

There are situations where regular wireless communication networks are not accessible or the connectivity is limited. Examples of such situations are emergency and rescue operations, where communications infrastructure may be non-existent or destroyed. The use of mobile devices connected using mobile ad-hoc network (MANET) technology and operating independently of any existing infrastructure, can help overcome these difficulties and provide connectivity despite large-scale disasters. Also, a lot of information cannot be communicated through conventional systems, such as phones or radio. The ability to transmit streaming multimedia data could potentially save lives in an emergency situation.

Multimedia streaming is a topic that has not received much attention in MANET research. Furthermore, most of the research and experiences with MANETs in general are based on work done in simulated environments. However, in contrast to most prior MANET research, this thesis uses a practical approach. We present a working solution for serving and consuming streaming video using the Nokia 770 Internet Tablet that can serve as a starting point for future work on video streaming in mobile ad-hoc networks. The solution is based entirely on open-source software, and can thus be freely used and modified for future research.

We also demonstrate how we were able to perform cross-layer monitoring of the video streaming solution through a strategy of combining hardware resource monitoring and different network measurement methods. In addition, we show how to set up a small-scale, real-world testbed for mobile ad-hoc networks to perform such monitoring.

Using this testbed, we the evaluated the performance of video streaming on the Nokia 770 in a mobile ad-hoc network environment. Our main finding is that to avoid degrading the normal operation of the devices or the network during streaming, conservation of CPU resources must be a priority when designing a video streaming solution for mobile ad-hoc networks.

We also investigated the wireless link data reported by the Nokia 770 wireless interface drivers, and found that the reported values have serious limitations compared to the values reported by other wireless devices.