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Japanese researchers use the 120 GHz band to transmit multiple uncompressed HDTV streams at 10 GBit/s

From "Multiplexed Transmission of Uncompressed HDTV Signals Using 120-GHz-band Millimeter-Wave Wireless Communications System," by Akihiko Hirata, Ryoichi Yamaguchi, Yasuhiro Sato, Takeaki Mochida and Kenji Shimizu, NTT Technical Review, Volume 4, Number 3 (March 2006), pages 64-70:

Abstract

"We have succeeded in the world's first trial of transmitting six-channel uncompressed high-definition television (HDTV) streams over a wireless system in joint experiments with Fuji Television. The wireless communications system is composed of (1) a 120-GHz-band millimeter-wave wireless link that can transmit either 10GbE (10 Gigabit Ethernet) or OC-192 signals and (2) an i-Visto system that can deliver and store uncompressed HDTV streams over IP (Internet protocol) networks in real time. The wireless link meets the increasing demands in TV stations for an ultrabroadband wireless communication system that can transmit multiplexed HDTV signals in large-scale live relay broadcasting of HDTV programs.

Introduction

"A wireless link system that can transmit uncompressed high-definition television (HDTV) signals has been strongly desired, because TV program production based on the HDTV standard is spreading rapidly in TV stations due to the start of digital TV broadcasting... An uncompressed HDTV signal (HD-SDI: high definition serial digital interface) requires a data rate of 1.5 Gbit/s. For wireless transmission of broadcast materials, a 7- or 10-GHz-band microwave field pick-up unit (FPU) is commonly used. The data rate of the state-of-the-art FPU is 3 - 80 Mbit/s, so no existing microwave wireless communications systems can transmit uncompressed HD-SDI signals. Therefore, current microwave wireless communications systems must compress the HD-SDI signal with MPEG or JPEG2000 encoders. This compression causes a time delay, which makes it difficult to edit programs or switch cameras in a live broadcast....

"Millimeter-wave (MMW) technologies are suitable for increasing the data rate of wireless communications systems because the data rate depends on the carrier frequency. Wireless communications systems using 60-GHz-band MMWs have a data rate of over 1.5 Gbit/s and can thus transmit one channel of uncompressed HD-SDI signals. However, large-scale live relay broadcasts, such as golf tournaments and music concerts, need multiple channels of uncompressed HD-SDI signals. No existing wireless communications systems using a carrier frequency below the 60-GHz band have the capacity for multiplexed uncompressed HD-SDI transmission...

"We have been developing a 120-GHz-band wireless link system that has a data rate of 10 Gbit/s...

2.2 Transmission characteristics

"We obtained an experimental radio station license from the Japanese Ministry of Internal Affairs and Communications on August 2005 because legal controls are imposed on the emission of radio waves outdoors... The center frequency is 125 GHz, the occupied bandwidth is from 116.5 to 133.5 GHz, and the maximum output power is 10 dBm. The radio station is registered as a Cassegrain antenna with an antenna gain of 48.8 dBi...

"The transmission distance was 200 m. Between the transmitter and receiver, we placed a glass window with transmission loss of about 9 dB, which suggests that the link could transmit 10-Gbit/s data over a free-space distance of 600 m... In fair conditions, the maximum transmission distance was about 1.5 km to achieve a [bit error rate] of less than 10^-12...

"We intend to promote the effectiveness of the 120-GHz-band wireless link in cooperation with internal and external users and begin standardization activities..."

[Spectrum Policy 14 November 2006]