Multimedia Cloud Computing
Internet is having a significant impact on the media-related industries which are using it as a medium to enable delivery of their content to end-users. Rich web pages, software downloads, interactive communications, and ever-expanding universe of digital media require a new approach to content delivery. Size and volume of multimedia content is growing exponentially. For example, more than 30 billion pieces of content such as web links, news stories, blog posts, notes, and photo albums are shared each month on Facebook. On the other hand, Twitter users are tweeting an average 55 million tweets a day that includes web links and photo albums. Web pages and other multimedia content are being delivered through content delivery networks (CDN) technologies. These technologies optimize network usage through dedicated network links, caching servers and by increasingly using peer-to-peer technologies. The concept of a CDN was conceived in the early days of Internet but it took until the end of 1990’s before CDNs from Akamai and other commercial providers managed to deliver Web content (i.e., web pages, text, graphics, URLs and scripts) anywhere in the world and at the same time meet the high availability and quality expected by their end users. For example, Akamai delivers between fifteen to thirty percent of all Web traffic, reaching more than 4 Terabits per second. Commercial CDNs achieved this by deploying a private collection of servers and by using distributed CDN software system in multiple data centres around the world.
A different variant of CDN technology appeared in the mid 2000’s to support the streaming of hundreds of high definition channels to paid customers. These CDNs had to deal with more stringent Quality of Service (QoS) requirements to support users’ experience pertaining to high definition video. This required active management of the underlying network resources and the use of specialized set-top boxes that included video recorders (providing stop/resume and record/playback functionality) and hardware decoders (e.g., providing MPEG 4 video compression/decompression). Major video CDNs where developed by telecommunications companies that owned the required network and had Operation Support Systems (OSSs) to manage the network QoS as required by the CDN to preserve the integrity of high definition video content. Just like the original CDNs, video CDN also utilize a private collection of servers distributed around the network of video service provider. The first notable CDNs in this category include Verizon’s FiOS and AT&T’s U-verse. Some CDN providers such as Limelight Networks invested billions of dollars in building dedicated network links (media-grade fiber-optic backbone) for delivering and moving content from servers to end-users.
A more recent variant of video CDNs involves the caching video content in cloud storage and the distribution of such content using third-party network services that are designed to meet QoS requirements of caching and streaming high definition video. For example, Netflix’s video CDN has been developed on top of Amazon AWS. CloudFront is Amazon’s own CDN that uses Amazon AWS and provides streaming video services using Microsoft Xboxes. While Cloud-based CDNs have made a remarkable progress in the past five years, they are still limited in the following aspects:
- CDN service providers either own all the services they use to run their CDN services or they outsource this to a single cloud provider. A specialized legal and technical relationship is required to make the CDN work in the latter case.
- Video CDNs are not designed to manage content (e.g., find and play high definition movies). This is typically done by CDN applications. For example, CDNs do not provide services that allow an individual to create a streaming music video service combining music videos from an existing content source on the Internet (e.g., YouTube), his/her personal collection, and from live performances he/she attends using his/her smart phone to capture such content. This can only be done by an application managing where and when the CDN will deliver the video component of his/her music program.
- CDNs are designed for streaming staged content but do not perform well in situations where content is produced dynamically. This is typically the case when content is produced, managed and consumed in collaborative activities. For example, an art teacher may find and discuss movies from different film archives, the selected movies may then be edited by students. Parts of them may be used in producing new movies that can be sent to the students’ friends for comments and suggestions. Current CDNs do not support such collaborative activities that involve dynamic content creation.
Major Research Issues in Multimedia Cloud Computing
- Collaborative content management workflows
- Ubiquitous content delivery
- Flexible content storage, compression, & indexing
- Content personalisation and contextualisation
- Community building
- Quality of service optimisation
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1. R. Ranjan, K. Mitra, and D. Georgakopoulos, “MediaWise Cloud Content Orchestrator”, Journal of Internet Services and Applications, Special Issue on Data Intensive Computing, Volume 4, Issue 2, January 2013, Springer. [ERA Nominated Journal – Included in 2012]
2. C. Wang, R. Ranjan, X. Zhou, K. Mitra, S. Saha, M. Meng, D. Georgakopoulos, L. Wang, and P. Thew, “A Cloud-based Collaborative Video Story Authoring and Sharing Platform”, CSI Journal of Computing, Volume 1, Issue 3, pages 8:66-8:76, November 2012, Computer Society of India Press. [Invited Paper – not ranked]
3. C. Wang, M. Meng, E. Zhou, and R. Ranjan, “A Social Network based Collaborative Video Story Composition Platform”, The Tenth International Conference on Service Oriented Computing (ICSOC 2012), November, 2012, Sanghai, China, LNCS. [ERA A Ranking]
4. R. Ranjan, K. Mitra, S. Saha, D. Georgakopoulos, A. Zaslavsky, “Do-It-Yourself Content Delivery Network Orchestrator”, International Conference on Web Information Systems Engineering (WISE’12), Pages 789-791, LNCS, Paphos, Cyprus, November 2012. [ERA A Ranking]
5. D. Georgakopoulos, R. Ranjan, K. Mitra, X. Zhou, “MediaWise – Designing Smart Media Cloud”, International Conference on Advnaces in Cloud Computing (ACC’12), Bangalore, India, July 2012, Universities Press. [Invited Paper – not ranked]