Изучение технологий доступа для широкополосной электросвязи (стр. 35 )

8)        Research and development efforts in Canada

To support the government of Canada’s priorities for connecting Canadians, the Communications Research Centre (CRC), an agency of Industry Canada, established an R&D programme called the Rural and Remote Broadband Access (RRBA) Programme. The Programme began in April 2002 and will run until March 2007. The RRBA Programme’s mandate is to conduct innovative R&D on tech­no­lo­gies and systems that will facilitate rural and remote access to interactive broadband multimedia services.

The RRBA Programme focuses on finding tech­no­lo­gical solutions in areas of satellite communications, terrestrial wireless, fibre optics, etc., that can extend broadband services to rural and remote areas in a cost effective manner; especially where there is currently little interest by the private industry because of the perceived small return on investment. Proof-of-concept systems and subsystems will be developed with the participation of public - and private-sector partners to demonstrate the feasibility and advantages of broadband access in rural and remote areas. Collaborative demonstrations of broadband applications will also be conducted. Participation in international standards activities will take place with the aim of lowering the costs of broadband equipment through harmonized operating rules and large-volume manufacturing.

A number of critical issues have been identified by the programme; these include equipment cost, flexibility, reach, spectrum availability and interference, stand­ardization and potential international markets. This results in the need to support a variety of R&D projects dealing with:

–        Terrestrial wireless tech­no­lo­gies such as WiFi, WiMax and other similar tech­no­lo­gies for transport and “last mile” access.

–        Wireless broadband access using frequencies below 1 GHz for better reach in rural and remote areas due to better propagation characteristics.

–        Broadcast transmission tech­no­lo­gies such as the use of DTV and an adequate wireless return channel for broadband access.

–        Satellite broadband access tech­no­lo­gies, especially related to low cost bidirectional Ka‑band (20‑30 GHz) terminals.

–        Other broadband tech­no­lo­gies such as distribution of RF signals over optical fibre and application of Software Defined Radio to flexible broadband access terminal.

More details are available from the programme website: http://www. crc. ca/broadband.

9)        Nemiah Valley, British Columbia, Canada100

The Nemiah Aboriginal Wilderness Reserve, in isolated mountain-rimmed Nemiah Valley in central British Columbia, Canada is the homeland of the Xeni Gwet’in (pronounced “Awney Gwateen”) Native American Indian community. Within the Reserve, the community government prohibits construction of paved roads, electric power and telephone pole lines, and commercial logging. To replace the sole narrowband radio-telephone link then available to community government and residents, the Canadian and British Columbia governments two years ago jointly funded deployment of wireless medium-speed Internet access (including feeder/backhaul) to the medical clinic, the school, the community and tourist office (www. ), and to several clusters of residences. Telus Communications deployed by helicopter solar-plus-battery-powered broadband wireless equipment that included one 40-mile, 3.5 GHz feeder/backhaul link, and four 950 MHz Mbit/s “WL500” multi-sector, point-to-multipoint fixed-access links. The government and many residents now enjoy Internet services plus multi-channel fax and voice applications. Telus Communications’ mobile business recently announced a USD 20 million expansion to bring high-speed mobile voice and data communications to 90% of Canadian communities.101

10)        Wi-Fi in Ontario Canada”102

In rural and remote areas where population density prohibits the cost-effective use of wireline broadband distribution, inexpensive wireless solutions have been used to create broadband access networks of sufficient size to achieve the economies necessary to sustain the network. Being scaleable, portable, and easy to deploy, fixed wireless in parti­cu­lar has proven to be a popular technology choice for a number of demand aggregation community initiatives such as those in Leeds and Grenville Country, South Dundas and Simcoe County in Ontario.

Although still in a nascent state of deployment, cooperative solutions based on “Wi-Fi” technology present a possible avenue through which high-speed network access can be deployed at low cost. 44 Informal Internet access-sharing cooperatives, grounded in websites, at which information on participating is exchanged and provided, have already sprung up in a number of cities in Canada. Examples include cooperatives such as the Waterloo Wireless project, whose users have attempted to create a mesh of uninterrupted connectivity via a dense clustering of nodes, or “hot spots”, and the BC Wireless project which, alongside the usual node maps and do-it-yourself deployment instructions, has declared an interest in using high-gain antennae to create point‑to-point intercity links that would cobble together community networks into an inter­con­nected system 45. Current attempts in Canada to extend Wi-Fi networking to the 10 km and even 20 km range on a point‑to-point basis indicate the possible extension of Wi-Fi as an alternative means for remote community-dwellers to aggregate demand and share backbone connectivity. Stretching the reach of “Wi-Fi” technology in a point-to-multipoint arrangement is also being investigated by CRC. One appealing approach is to down‑convert “Wi-Fi” transmission to lower frequencies in the UHF range to take advantage of better RF propagation characteristics (see subsection 8).

Conclusion

A number of programmes and initiatives are being carried out in Canada to deliver wireless broadband connections to Canadians in rural and remote communities. Government programmes such as the Broadband for Rural and Northern Development Pilot Programme and the National Satellite Initiative are only two of the many programmes that Canada has initiated to promote broadband connections in rural communities. A number of frequency bands are currently being used, in Canada, for broadband transmission to rural areas including the 900 MHz, 1.4 GHz, 2.3 GHz, 2.4 GHz, 3.5 GHz and 5 GHz bands. Nonetheless, a number of issues including cost, climate and propagation (the need for spectrum with propagation characteristics more suitable for rural areas) can be challenging in the deployment of systems in rural areas.

III.2.3        Ecuador

Broadband Wireless Point-to-Point Enterprise Network, Banco del Pichincha, Machala Zone, Ecuador

The Banco Del Pichincha, the largest bank in Ecuador, has established 200 branch offices spread across Ecuador. To inter­con­nect these, the bank has deployed an extensive private network, containing many wireless links. The bank stipulates that each link be available 365 days of the year, 24 hours per day, with reliability at least 99.96%. For many critical links, the bank has deployed “VIP 110-24” broadband wireless links offered by Wi-LAN. Installed in 2001, these wireless links now have demonstrated reliability exceeding that stipulation. The VIP 110-24 product incorporates routers, are called “anypoint-to-multipoint”, or “VINE” routers, which have enabled Banco Del Pichincha to adopt a deployment approach wherein any endpoint or repeater node already in the network can become the centre of one or more point-to-multipoint branches. This approach minimizes up-front costs for its evolving network.

III.2.4        Mexico

Fixed Wireless Access, Mexico City, Mexico

Mexico City, containing 20 million residents, is one of the densest, largest urban markets in the world. Fast Internet access (Mbit/s) has not been readily available within much of the metropolitan area. MVS Comunicaciones, for many years a principal deliverer of TV programming throughout the metropolitan area and the nation, now is delivering high speed fixed wireless Internet access within the city, across 220 sq. miles encompassing approximately 10 million of its residents, and including its central business district. Within Mexico City, many prospective customers are located down in high-building street canyons or mountain-ridge canyons, and many behind extensive foliage, thus not within wireless line-of-sight of current and prospective base stations. Hence MVS sought a NLOS wireless technology effective in demanding terrain. It deployed the MMDS-band 2.5-2.686 GHz broadband NLOS wireless equipment. Within forthcoming months, the MVS Mexico City network likely will become the world’s largest NLOS network.

III.2.5        Peru

“USE OF VSAT SYSTEMS FOR TELECOMMUNICATIONS SERVICE RENDERING IN RURAL AREAS IN PERU”

Introduction

In August 1998, the Guidelines for Telecommunications Market Opening in Peru were approved through the Supreme Act No. 20-98-MTC, which defined the universal access as a group of essential tele­com­mu­ni­cations services to promote the development and integration of the furthermost areas in Perъ.

Additionally, the following universal access goals were defined until the year 2003:

•        The installation of 5 000 public telephones in an equal number of rural towns lacking this service, capable of transmitting voice, fax and data at a low speed, as well as making free calls to emergency centres.

•        The installation of Internet access in 500 rural district capitals103 comprised in the 5 000 towns previously mentioned.