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Low Carbon Economy considerations in designing and operating Content Delivery Networks for VoD services

IP.com Disclosure Number: IPCOM000199040D
Original Publication Date: 2010-Oct-01
Included in the Prior Art Database: 2010-Nov-23

Publishing Venue

Motorola

Related People

Boscovic, Dragan: AUTHOR [+4]

Abstract

CDN is a distributed content management and delivery system overlaid on the data network. It is based on a system of servers with massive storage that places copies from the content library closer to the end user so as to maximize the available bandwidth, and consequently reduces the data access times. A farm of servers provides computations, storage, applications and data transfer and as such is central to the CDN architecture, from which all content is sourced or passed through. For the case of a video CDN, as the popularity and penetration of video and time shifted TV viewing increases so does the need for additional clusters of video servers. Centralized hosting model offers easier resource optimization and management by the virtue of virtualization technologies. However, the centralization trend brings some unfavorable conditions in terms of energy usage as data centers are normally over provisioned to for peak demand and require a dedicated temperature management system. Worldwide, data centers consume around 40,000,000,000kW/hr of electricity per year that amounts to 18% of the total energy consumed by ICT industry. Big portion of energy consumption, roughly 52% is wasted due to equipment inefficiencies, non-ideal design and poorly implemented algorithms and management schemes. The need for better energy efficiency of data centers is clear and would significantly cut the CO2 emission from ICT operations projected to be around 1.5 billion of tons in 2020. The task of improving CDNs efficiency is complex and can only be achieved through better operational exploitation of individual parts and by simpler architectures and intelligent content management algorithms that will bring the energy cost into the overall performance optimization function. In this article, we are to shed additional light onto the technical challenges and recommend possible improvements as related to the energy consumption within a given CDN topology. The issues such as datacenter cooling, power conversion or proportional computing are generic to the topic of Green Data Centers and as such not discussed here, instead this paper focuses on the topology of CDN overlay networks and related caching and replication algorithms as main domains to pay attention to when designing next generation of green CDNs.

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Low Carbon Economy considerations in designing and 

op  

erating Content Delivery Networks for VoD services

Dr Dragan Boscovic1, Mike Needham1, Dr Faramak Vakil1, Dr Jin Yang2 

The advances in information, computer technology and broadband connectivity have eased the way to reach desired content. TV service is not immune to these changes and watching television is today increasingly switching to an on-demand type of experience. This is especially true for the Internet TV (IPTV) services, requiring numerous precisely orchestrated technologies to deliver a quality viewing experience and services such as Video-on-Demand (VoD), live TV, private video recording (PVR) capabilities, time-shifted television (TSTV), Near VoD, Subscription VoD services, etc. This transition to the time shifted viewing has also brought forth many technical challenges regarding the distribution of electronic content, such as how to send large video files, how to deal with the stream load when all users are ordering the same or different films, how to transmit the video stream to a global network over a long distance. It is where a Content Delivery Network (CDN) comes into the overall VoD system design in order to resolve these issues.

CDN is a distributed content management and delivery system overlaid on the data network. It is based on a system of servers with massive storage that places copies from the content library closer to the end user so as to maximize the available bandwidth, and consequently reduces the data access times. A farm of servers provides computations, storage, applications and data transfer and as such is central to the CDN architecture, from which all content is sourced or passed through. For the case of a video CDN, as the popularity and penetration of video and time shifted TV viewing increases so does the need for additional clusters of video servers.

Centralized hosting model offers easier resource optimization and management by the virtue of virtualization technologies. However, the centralization trend brings some unfavorable conditions in terms of energy usage as data centers are normally over provisioned to for peak demand and require a dedicated temperature management system. Worldwide, data centers consume around 40,000,000,000kW/hr of electricity per year that amounts to 18% of the total energy consumed by ICT industry. Big portion of energy consumption, roughly 52% is wasted due to equipment inefficiencies, non-ideal design and poorly implemented algorithms and management schemes. The need for better energy efficiency of data centers is clear and would significantly cut the CO2 emission from ICT operations projected to be around 1.5 billion of tons in 2020. The task of improving CDNs efficiency is complex and can only be achieved through better operational exploitation of individual parts and by simpler architectures and intelligent content management algorithms that will bring the energy cost into...