A peer-assisted server-based error recovery approach for IPTV networks

To achieve the desired service quality in IPTV networks, we need effective and resource-efficient error recovery techniques to overcome the problems encountered during the delivery of the IPTV content to the end-users. To enable quick recovery from packet losses, one idea is to utilize an error recovery server (ERServ) that is placed in-between the end-users and the content delivery server. Within this framework, error recovery process is initiated once an end-user sends a repair packet request to the ERServ, and the process is finalized when the repair packet transmitted by the ERServ in response is successfully delivered to the end-user. Even though the use of an ERServ presents an effective solution to improve the perceived quality at the end-users, as the number of users connected to the ERServ increases, we may observe scalability related problems (e.g., dropped requests or increased response times). Consequently, during such overloaded periods, we cannot guarantee the timely delivery of the repair packets, which may lead to significant performance degradations at the end-users. To prevent this from happening, we propose to utilize peer-based error recovery in addition to server-based recovery, for which the main objective is to prevent the ERServ from entering a non-responsive state. We achieve this objective by redirecting the error recovery load towards the end-users during times when the ERServ reaches a critical server-load level.