Coding has traditionally aimed to securely and efficiently convey specific information messages, for example speech in a phone call, to one or more receivers. Today?s communication networks, however, increasingly deliver content rather than a specific message. Popular networks that serve content-type traffic include advertising networks, news aggregators, and social media. This proposal formulates a novel theoretical framework aiming to determine the fundamental performance limits and design principles for content-type networks. This new research direction promotes the progress of science and has the potential to transform the way content-type traffic is encoded and transmitted in networks. As a result, this research is expected to benefit society at large by laying the foundation for a more efficient design of network services, and to be of immediate and far-reaching use for both private and public sectors. This proposal integrates discovery research and education: it develops a rich learning experience for students through an integrated inter-university program and curricular development. The investigators will keep serving as a role model for minority students, especially young women, by active engagement at their institutions and within their peer societies.
The research work in this proposal is fundamentally motivated by current trends in the Internet traffic: today society increasingly relies on content-type services for educational, professional and social purposes. This proposal explores coding specifically targeted to content-type communication; it can therefore form a solid theoretical foundation for the design and optimization of future network services. This proposal formulates new research directions not explored before by addressing the following main technical objectives: (1) Develop an information theoretical framework by proposing a novel model for classical message-specific index coding and extending it to content-type pliable index coding, deriving inner and outer bounds, and efficient numerical algorithms for their evaluation. (2) Derive fundamental bounds and practical coding strategies for content-type coding, where clients are interested in multiple, as opposed to a single content, identify order approximations and study extensions to noisy network versions of the problem. (3) Develop oblivious strategies for servers with limited knowledge about the clients' side-information (for instance, the server knows the number of downloads of the clients but not necessarily which ones); quantify the amount and quality of the side-information necessary for optimal performance. (4) Investigate the case where all content is not "equal" (for instance, because of personalized recommendations based on the client's past behavior); connect with recommendation systems, and understand how preferences affect the content-type algorithms and bounds.
For each technical objective, the investigators will develop tools from information theory, network coding, and algorithms to address the novel questions posed in this research. The new framework is expected to significantly advance the state-of-the-art and fundamental understanding of content-type coding from both a theoretical (information theory) and a more practical (code and algorithm design) perspective. The results of this research will be timely presented at major national and international professional venues in the information theory, network coding, and networking communities. The proposal has also a strong educational and outreach component. In order to reach the general public the investigators will leverage the departmental media tools to demonstrate the developed technology and its practical impact. Students will receive a solid foundation in communications, coding and networking thus acquiring the fundamental skills to be successful in the competitive, diverse, and global workforce market. It is the investigators? goal to serve as a role model for minority students, especially women.
