October 25, 2006
- Enabling Viewing of Digital Terrestrial Broadcasting and Making Use of Broadband Communications in Areas Where Optical Fiber Installation is Difficult -
NTT Infranet Corporation (hereinafter called NTT Infranet), KYOCERA COMMUNICATION SYSTEMS Co., Ltd. (hereinafter called KCCS) and The Furukawa Electric Co., Ltd. (hereinafter called Furukawa Electric) have succeeded in a demonstration experiment on a relay and distribution system in which digital terrestrial broadcasting signals are seamlessly transmitted using optical fiber and wireless relay system.
The experiment has demonstrated the feasibility of high-quality wireless relay and distribution of digital terrestrial broadcasting signals that are transmitted through optical fiber, even in the areas and over the transmission sections where installation of optical fibers is difficult.
1. Background
The Ministry of Internal Affairs and Communications has set a goal of realizing a nationwide spread of broadband environments by 2010, together with a total replacement of terrestrial analog broadcasting with terrestrial digital broadcasting by 2011. Optical fiber-based systems are drawing attention to implement such digital broadcasting and broadband communications systems, and the FTTH systems using optical fiber are being installed across the country. However, there are a number of adversely conditioned areas, such as mountainous areas and isolated islands, where installation of optical fiber cost a great deal, and it has been difficult to find practical solutions to this problem.
2. Outline of the Validation Experiment
In this experiment, the terrestrial digital broadcasting signals received at the Gifu Disaster Control Exchange Center are transmitted to Gero-city about 130 km apart (in optical fiber length) in the form of optical signal using the “Gifu Information Super Highway (*1).” The transmitted terrestrial digital broadcasting signals are again radio transmitted, using the 18/19-GHz frequency band, from the Gero-city Consolidated Office Building where key radio equipment is located to a secondary radio station 2.6 km away. This radio route crosses rivers and primary roads two and three times, respectively. From the secondary radio station, the signals are transmitted using the existing coaxial transmission line of community antenna facilities (i.e., optical-radio-coaxial system) and the FTTH line (i.e., optical-radio-FTTH system), enabling clear viewing of terrestrial digital broadcasting at the monitors’ premises in either case.
Moreover, the FTTH and wireless LAN facilities (IEEE802.11J+11G) were temporarily set up as access system to carry out an IP communication experiment, and it was confirmed that transmission over both the FTTH and wireless LAN facilities caused no problems.
In this experiment program, the radio links were provided with bidirectionality using 18/19GHz to enable not only terrestrial digital broadcasting reception but also bidirectional IP communications including Internet connections, in order to validate the direct transmission of data communication signals. As a result, it was confirmed that Internet services, IP announcement terminal services and VOD services were provided stably at the monitors’ premises.
The radio frequency used in this experiment is in the 18/19-GHz band allocated for local governments, whereby the signals for terrestrial digital broadcasting and IP data are multiplexed for transmission, so that subscribers can not only enjoy terrestrial digital broadcasting programs but also use bidirectional Internet services.
3. Roles of Participating Companies
| Company | Role |
|---|---|
| NTT Infranet | To provide know-how in optical fiber infrastructure, and to coordinate each system |
| KCCS | To provide wireless technologies for this system |
| Furukawa Electric | To provide technologies for long-haul optical relay system, FTTH system in the closed experimental network and transmission of terrestrial digital broadcasting |
4. Future Development
While this validation experiment used the frequency band of 18/19 GHz, we are studying multiplex transmission using the 23-GHz band, and implementation of the systems corresponding to each frequency is scheduled to take place in Spring, 2007 (*2).
In spite of the strengthened efforts by local governments aimed at eliminating the digital divide, a number of mountainous areas and isolated islands are facing difficulties of optical fiber installation due to cost problems. NTT Infranet and KCCS together with Furukawa Electric intend to develop this system further as one of the solutions to the issue of viewing digital terrestrial broadcasting in adversely conditioned areas, thereby playing a role in eliminating the digital divide.
[Remarks]
*1 A prefectural optical fiber network implemented by Gifu Prefecture as a regional public network to form the foundation of information-oriented regional community.
*2 This refers to technical confirmation of transmission method, but not ordinance enactment.
[Introduction to the Companies]
NTT Infranet Corporation
The company was established in 1999, when NTT began to provide open access to its underground information facilities such as duct line, utility tunnel and manhole, with the objective of integrally inheriting the function of a nationwide contact point for access applications as well as the management of these underground basic facilities. With its 1,851 employees in total (as of June, 2006) and taking advantage of its know-how and technologies that are built up during nationwide operation of 670 thousand km-long duct lines, 1,000 km-long utility tunnels and 700 thousand manholes, the company contributes to enhancement and upgrading of social infrastructures including various information and communications infrastructures. For more information on NTT Infranet, please visit its website at http://www.nttinf.co.jp/index.html
KYOCERA COMMUNICATION SYSTEMS Co., Ltd.
The company was established in September, 1995, as a member company of KYOCERA Group. The number of employees is 1,415 as of March, 2006. The company’s business areas have now horizontally expanded to include those related with information systems such as system integration and development and sales of software, design and construction of D@TA Center and networks as well as network systems involving security business, along with the ICT (Information and Communication Technology) business offering comprehensive solutions and communication engineering business offering construction and maintenance services of communication infrastructures. For more information on KCCS, please visit its website at http://www.kccs.co.jp/
The Furukawa Electric Co., Ltd.
The company was established in 1896. The number of employees is 4,350 as of March, 2006. The Broadband Products Division of Furukawa Electric develops various products and offers total system integration and engineering services in the business areas related with optical transmission. For more information on the broadband products of Furukawa Electric, please visit its website at http://www.furukawa.co.jp/broadband
[Relevant Information]
This product will be exhibited at the InterBEE2006 to be held at the Makuhari Messe from Wednesday, November 15 to Friday, November 17, 2006. Exhibition will be made at the booth of Broad Wireless Corporation, an affiliated company of Furukawa Electric. For more details please refer to the URL below.
