Mobile streaming media CDN enabled by dynamic SMIL
Takeshi Yoshimura, Yoshifumi Yonemoto, Tomoyuki Ohya, Minoru Etoh, Susie J. Wee · 2002
In this paper, we present a mobile streaming media CDN (Content Delivery Network) architecture in which content segmentation, request routing, pre-fetch scheduling, and session handoff are controlled by SMIL (Synchronized Multimedia Integrated Language) modification. In this architecture, mobile clients simply follow modified SMIL files downloaded from a streaming portal server; these modifications enable multimedia content to be delivered to the mobile clients from the best surrogates in the CDN. The key components of this architecture are 1) content segmentation with SMIL modification, 2) on-demand rewriting of URLs in SMIL, 3) pre-fetch scheduling based on timing information derived from SMIL, 4) SMIL updates by SOAP (Simple Object Access Protocol) messaging for session handoffs due to clients mobility. We also introduce QoS control with a network called an RTP monitoring agent to enable appropriate control of media quality based on both network congestion and radio link conditions. The current status of our prototyping on a mobile QoS testbed MOBIQ is reported in this paper. We are currently designing the SOAP-based APIs (Application Programmable Interfaces) needed for the mobile streaming media CDN and building the CDN over the current testbed.