Advanced Hybrid Broadcast and Broadband System
for Enhanced Broadcasting Services

Digital TVs that connect to the Internet are becoming the rule rather than the exception and broadcasters are eager to make use of this expanded functionality to better serve their viewers. A paper, excerpted here, from the 2011 NAB Broadcast Engineering Conference (BEC, April 9-14, 2011, Las Vegas, Nev.) describes an effort underway by the Science and Technology Research Laboratories of the Japan Broadcasting Corporation (NHK) to develop an advanced hybrid broadcast and broadband system called "Hybridcast."

This paper, Advanced Hybrid Broadcast and Broadband System for Enhanced Broadcasting Services, was co-authored by Akitsugu Baba, Kinji Matsumura, Sigeaki Mitsuya, Masaru Takech, Yasuaki Kanatsugu, Hiroyuki Hamada, and Hisakazu Katoh, all with NHK. For their efforts, this group of co-authors was awarded the NAB Best Paper Award for "…a paper of exceptional merit published in the 2011 NAB BEC Proceedings." This award was presented at the NAB Technology Luncheon on Wednesday, April 13. Shown in the photo is Mr. Baba receiving the award from BEC Conference Committee Chairperson Dom Bordonaro of Cox Radio.

INTRODUCTION - NHK is developing an advanced hybrid broadcast and broadband system called Hybridcast to integrate broadband technology with broadcasting. Hybridcast provides many features, including precise synchronization of content from different delivery channels, support for third party applications and program presentation by seamless interaction among multiple device types, including mobile terminals. In addition, Hybridcast is designed to simplify the implementation of receivers by using server-side cloud computing technology. Compatibility with existing digital broadcasting systems is also provided.

NEW SERVICES AVAILABLE UNDER HYBRIDCAST - Broadcasting is the fundamental component of all the services described in this paper. Content elements and additional functionalities offered over broadband are for enhancement and enrichment of the existing broadcast services. One service is the multi-device linkage service, the purpose of which is to establish a convenient and personalized viewing environment by seamlessly working across multiple device types, including mobile terminals. To establish such an environment, an application on the terminal communicates and works synchronously with the application on a Hybridcast receiver. For example, a mobile terminal can be used as a remote control to manipulate Hybridcast content as shown in the figure at right. In addition, it can be used to access personalized services such as recommendations and bookmarking. In this case, a mobile terminal acts as a secondary display for watching TV.

BASIC ARCHITECTURE OF HYBRIDCAST - The Hybridcast system consists of three blocks: broadcaster servers, service-provider servers and receivers (see figure below). The broadcaster servers broadcast content and content-related information, which only the broadcasters hold, to the service provider servers. The service provider servers provide applications, content and the relevant information to the receivers or end users; the broadcasters can provide services in this block as well. Hybridcast receivers execute applications to realize various services. Such an application-centric service enables a rather simple receiver implementation.

Applications executed on a Hybridcast receiver, called "Hybridcast applications," handle the broadcast content as well as the content and relevant information obtained from the service provider servers. The applications can also utilize receiver functions such as the synchronization and the multi-device linkage. These applications are available from a known application repository, and can be created by third parties as well as by the broadcasters and service providers. The participation of third-party application developers is expected to spawn a legion of developers and thereby increase the number of Hybridcast users. However, the authenticity of such applications is an important issue. In the case of some applications, an application administrator may require to authenticate and authorize them.

CONCLUSION - We propose the Hybridcast system that will provide new services using a broadcast-broadband combination. In this paper, examples of services enabled by Hybridcast, basic system architecture, and the key technologies used in the Hybridcast system are described. The feasibility and usability of Hybridcast services and the flexibility of the Hybridcast system architecture are verified by means of prototypes.

This paper is included in its entirety in the 2011 NAB Broadcast Engineering Conference Proceedings, available on-line from the NAB Store. For additional conference information visit the NAB Show web page.