The Social Benefits of S-TDMA DSB Networks

Osamu Ichiyoshi

2007/1/5

1. Social benefits of Synchronous TDMA Direct Satellite Broadcasting Network

A new direct satellite broadcasting network is proposed. The system solves the basic problems of conventional DSB networks as follows.

For details, please see .New Systems and Applications for DSB Networks.htm

<Problems with conventional DSB>

The transmit stations exist only in a limited area. Therefore direct broadcasting from remote sites is impossible. To do that, access links to the transmit stations from the remote sites need to be established, which is lousy and expensive. This centralized transmission side structure tends to bring about impoverishment of the broadcast contents and decline of the market.

<Solution by the proposed system>

Multiple stations located anywhere in the coverage area can directly transmit signals to a shared transponder and the combined signal from the satellite can be received with existing DSB receivers. Normally up to 10 stations can share a transponder for standard TV broadcasting. The transmit station can be VSAT with antenna diameter 1.2-2.4m. Direct live reporting from the event sites with SNG vehicles will be also possible. Thus the proposed system provides a truly direct satellite broadcasting for the transmit side as well as the receive side. The wide area, single hop and direct access features of satellite communications can be fully utilized.

<Social benefits by the proposed system>

The direct transmission capability of the proposed system will open a vast information dissemination means for a great many people who had formerly no access for national broadcasting network. A true public access network will be realized. The transmitters are no more limited to news media but will be open for the general public. The immediate social benefit is direct transmission of far greater ranges of information for the people, by the people and of the people. A similar effect brought by the Internet in the field of communication will occur in broadcasting as the entrance for the national networks become open to the general public. And such evils of the Internet as spam mails and harmful websites can be avoided in the proposed system because the number of the transmit stations will be at most thousands instead of billions and the transmitters can be readily identified and must pay for the usage of the system. Thus the general public will obtain a reliable broadcasting network through which direct information will be conveyed form far greater ranges of information sources.

2. Social Benefits S-TDMA Integrated Networks

As there will be many transmit stations in the proposed system, it will be easy to integrate the local broadcasting and communication networks to a unified nationwide network.

The local broadcasters can immediately expand their broadcasting areas to nationwide scales. It will open new business opportunities not only for the broadcasters but also for the local industries and governments. The local industries can now promote their products through their local broadcasting stations for the national market. The local governments, NPOs NGOs, Special Interest Groups or even individuals will be provided with a means of access to the nationwide broadcasting networks.

The public access will be realized to its full potentials.

For the communication the long distance trunk lines can be provided by the S-TDMA DSB networks. The natural integration of communication and broadcasting is a great feature of the S-TDMA which was applied to a remote islands network in Japan about twenty years ago. A few of the telephony channels can be used for radio broadcasting as well. The image of the system is depicted in the following figure. The system will be especially useful for countries with many remote islands and mountainous areas.

3. Social Benefits of S-TDMA DSB & LAN

As there will be a few DSB stations in their neighborhoods, the ISP, ASP can set various Internet servers at the local broadcast stations and combine the Internet and the DSB networks. The users can utilize a router with a satellite link interface cheaply available off the shelf to form a combined Internet and DSB networks. The network concept is depicted in the following figure.

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System Configuration of Direct Satellite Inter-Net

Features

（１） Existing Direct Satellite Broadcasting（DSB）receivers can be re-used.

（２） The return links (terrestrial or satellite) can readily realize an evolution of DSB network to Broadband Internet anywhere in the coverage areas of DSB.

（３） The Direct-satellite-inter-Network (DSxN) servers set at the Earth Station and made accessible from the Internet can provide users with such new applications;

- Broadband access to the Internet for users in remote areas,

- Nationwide Internet broadcasting or multicasting

- Teleconferences; nationwide and quite many participants,

- Contents Delivery Network; a large quantity of contents to a great many users,

- Distance learning to a great many people distributed nationwide,

and many other Group communications

（４） Multiple Earth Stations can share the same satellite channel in TDMA modes. This gives the service providers the flexibility in using the channel capacity as much as required for the applications. Thus an effective usage of the channel and economic operation for the service providers will become possible.

In short the system realizes the Internet equipped with full broadcast (unlimited number of receivers) and multicast (a large number of participants) capability. In another words, the system provides a two way nationwide broadcasting network accessible even from homes.

The social benefits of the network will be enormous and fundamental. For example, the town meetings can be expanded to regional or national meetings, thus can promote direct participation of the people into the regional or national operations, which will strengthen the democracy and widen the scope of views exchanged nationwide. Other applications of the system to universal broadband Internet access, emergency communications, contents delivery and distance learning will be beneficial for the well balanced local and national development.

About the author

Mr. Osamu Ichiyoshi joined NEC Corporation in 1973. He has worked in development of satellite communications throughout his career. He was responsible for development of Clock Synchronous TDMA systems for Nippon Telephony and Telegraph Public Corporation in the early 80’s. The satellite loop clock synchronization technology established for those systems gives the technical background for the present proposal. The proposed system is based on a unique but field-proven technology.

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