The National Institute of Information and Communications Technology (NICT, President: Dr. Masao Sakauchi) and Hitachi Kokusai Electric Inc. (Hitachi Kokusai, President and Chief Executive Officer: Manabu Shinomoto) recently succeeded in the world's first field trial in which long-range broadband communications in the TV white space was confirmed by using IEEE 802.22-based and IEEE 802.11af-based systems. In the trial, NICT and Hitachi Kokusai observed successful downstream and upstream data transmission at 12.7 km distance between IEEE 802.22-based base station and customer premises equipment, at speeds of 5.2 Mbps and 4.5Mbps, respectively. In addition, NICT and Hitachi Kokusai constructed a multihop network by using IEEE 802.22 as a backbone link and IEEE 802.11af, which is connected to it, to expand its connection area. They demonstrated some applications such as video monitoring of roads and cliffs and video telephone in a mountainous area where there is no wired Internet connection available or broadband wireless Internet connection. These achievements show feasibility of broadband services in rural areas and supporting communications in case of disasters.

This trial was conducted under a contract of R&D for broadband access in white space that was entrusted to NICT and Hitachi Kokusai by the Ministry of Internal Affairs and Communications, Japan.

Background

Demand for broadband communication services has been growing in rapidly diffused information society. Unfortunately, the services have not sufficiently provided in many areas such as mountainous areas and remote islands. To provide the services, a wireless system is required as a cost effective service comparing to wired networking. The wireless system is also required for flexible and quick construction of network, when a disaster strikes and infrastructure is damaged. White space in TV band (470-710 MHz, in Japan) is expected for long-range communication whereas a legacy system using higher frequency such as wireless LAN and cellular systems cover shorter range, since lower frequency has generally low impact on distance decay toward obstacles. In these circumstances, NICT and Hitachi Kokusai are developing IEEE 802.11af and IEEE 802.22 based wireless systems, respectively.

Achievement

NICT and Hitachi Kokusai had confirmed a success in long-range wireless communications by using IEEE 802.22 and IEEE 802.11af based systems in Tono City, Iwate Prefecture, Japan. They have observed following results:

1. IEEE 802.22-based system successfully communicated over a 12.7-km stretch between the base station and customer premises equipment. Throughput was 5.2 Mbps in downstream and 4.5 Mbps in upstream.

2. Multihop network is successfully constructed. The network is constructed using IEEE 802.22 wireless link and IEEE 802.11af wireless link. IEEE 802.22 is used for backbone link and IEEE 802.11af is used for expansion of service area. Wireless LAN, based on conventional IEEE 802.11b/g/n in 2.4 GHz band, is attached to IEEE 802.11af station through which conventional off-the-shelf devices are connected to the Internet. Using the devices, NICT and Hitachi Kokusai have demonstrated availability of web access and conversation via video telephone.

3. An original function has been developed based on IEEE 802.22 to operate in multiple channels. With two discontinuous TV channels to operate at the same time, they have succeeded in achieving throughput of 15.5 Mbps in downstream and 9.0 Mbps in upstream over 6.3 km.

Additional information about the trial will be presented at the Super WiFi Summit in Miami, Florida, from January 29 to 31, 2014.