Path diversity for enhanced media streaming

TLDR

Media streaming over best‑effort networks is challenged by dynamic bandwidth, loss, and delay, so path diversity—using multiple paths such as CDN servers, Wi‑Fi access points, or relays—has emerged to mitigate these issues. This article reviews the benefits and applications of path diversity for media streaming. The paper surveys coding and streaming techniques over multiple paths, architectures for single or multiple senders to a single receiver, and the design, analysis, and performance modeling needed to choose optimal paths or servers.

Abstract

Media streaming over best effort packet networks such as the Internet is quite challenging because of the dynamic and unpredictable available bandwidth, loss rate, and delay. Recently, streaming over multiple paths to provide path diversity has emerged as an approach to help overcome these problems. This article provides an overview of the benefits and use of path diversity for media streaming. The different approaches to media coding and streaming over multiple paths are examined, together with architectures for achieving path diversity between single or multiple senders and a single receiver. Important examples include using the distributed servers in a content delivery network to provide path diversity to a requesting client, using multiple 802.11 wireless access points to provide path diversity to a mobile client, and using relays to provide low-latency media communication. The design, analysis, and operation of media streaming systems that use path diversity are considered, with emphasis on the accurate performance models needed to select the best paths or best servers.