محققان بخش تحقیقاتی شرکت Alcatel-Lucent به نام Bell Labs به تازگی موفق شدند اطلاعات را با حداکثر سرعت ۱۰ گیگابیت در ثانیه بر روی کابلهای مسی معمولی که در بستر مخابراتی فعلی منازل استفاده میشود، انتقال دهند. این رکورد فوق العاده با استفاده از یک فناوری خاص که هنوز در مراحل آزمایشی خود به سر میبرد قادر است سرعتی معادل یک گیگابیت در ثانیه را بطور متقارن (Upload و Download) با استفاده از سیم های مسی معمولی در اختیار کاربران قرار دهد.
دستیابی به سرعت ۱۰ گیگابیت در ثانیه برای نقل و انتقال متقارن اطلاعات بر روی کابلهای مسی معمولی، دستاوردی مهم در استفاده از این نوع کابلها برای ارائه سرویس های پرسرعت به شمار میرود. سرویس دهندگان با بهره گیری از این فناوری قادر خواهند بود خدمات خود را با سرعتی برابر فیبر نوری بر روی کابل های تلفن معمولی به مشترکین خود ارائه دهند. این مسئله زمانی اهمیت پیدا میکند که در برخی مناطق، از نظر اقتصادی و یا مشکلات مربوط به زیر ساخت، استفاده از فیبر نوری میسر و یا مقرون به صرفه نباشد.
البته با در نظر گرفتن اینکه در بعضی شهرها و یا مناطقی که زیر ساخت فیبر نوری از قبل در آنجا وجود دارد این امکان نیز هست که خدمات اینترنت پرسرعت را تا نزدیکی محل مسکونی و یا تا درب منازل از طریق فیبر نوری و چند متر باقی مانده داخل ساختمان و طبقات را از همان شبکه کابل مسی که برای تلفن استفاده میشود، بدست کاربران رساند تا دیگر نیازی به راه اندازی شبکه فیبر نوری در داخل منازل نباشد.
منبع : alcatel-lucent
Bell Labs prototype technology also demonstrates potential for 1 Gbps symmetrical services, paving the way for fiber-speed services where fiber cannot be deployed all the way to the premises.
Paris, France, July 09, 2014
Bell Labs, the research arm of Alcatel-Lucent (Euronext Paris and NYSE: ALU), has set a new broadband speed record of 10 gigabits-per-second (Gbps) using traditional copper telephone lines and a prototype technology that demonstrates how existing copper access networks can be used to deliver 1Gbps symmetrical ultra-broadband access services.
Achieving 1 Gbps ‘symmetrical’ services – where bandwidth can be split to provide simultaneous upload and download speeds of 1 Gbps – is a major breakthrough for copper broadband. It will enable operators to provide Internet connection speeds that are indistinguishable from fiber-to-the-home services, a major business benefit in locations where it is not physically, economically or aesthetically viable to lay new fiber cables all the way into residences. Instead, fiber can be brought to the curbside, wall or basement of a building and the existing copper network used for the final few meters.
The Bell Labs tests used a prototype technology called XG-FAST. This is an extension of G.fast technology, a new broadband standard currently being finalized by the ITU. When it becomes commercially available in 2015, G.fast will use a frequency range for data transmission of 106 MHz, giving broadband speeds up to 500 Mbps over a distance of 100 meters. In contrast, XG-FAST uses an increased frequency range up to 500 MHz to achieve higher speeds but over shorter distances. Bell Labs achieved 1 Gbps symmetrical over 70 meters on a single copper pair. 10 Gbps was achieved over a distance of 30 meters by using two pairs of lines (a technique known as “bonding”). Both tests used standard copper cable provided by a European operator.
Marcus Weldon, President of Bell Labs: “Our constant aim is to push the limits of what is possible to ‘invent the future’, with breakthroughs that are 10 times better than are possible today. Our demonstration of 10 Gbps over copper is a prime example: by pushing broadband technology to its limits, operators can determine how they could deliver gigabit services over their existing networks, ensuring the availability of ultra-broadband access as widely and as economically as possible.”
Commenting on the achievement, Federico Guillén, President of Alcatel-Lucent’s Fixed Networks business said: “The Bell Labs speed record is an amazing achievement, but crucially in addition they have identified a new benchmark for ‘real-world’ applications for ultra-broadband fixed access. XG-FAST can help operators accelerate FTTH deployments, taking fiber very close to customers without the major expense and delays associated with entering every home. By making 1 gigabit symmetrical services over copper a real possibility, Bell Labs is offering the telecommunications industry a new way to ensure no customer is left behind when it comes to ultra-broadband access.”
Technical background information
The primary factors influencing broadband speeds over copper are:
Distance: the longer the copper connection between the access node and the customer’s telephone socket, the slower the broadband speed. This is dictated by attenuation.
Frequency: the wider the frequency range, the faster the broadband speed that can be achieved. The Shannon Limit dictates the maximum possible speed for a given medium and frequency spectrum (watch the video below).
Higher frequencies attenuate more quickly than lower frequencies, meaning there are diminishing returns in speed as the frequency range increases.
During testing, Bell Labs showed that XG-FAST technology can deliver 1 Gbps symmetrical services over 70 meters (for the cable being tested). This was achieved using a frequency range of 350 MHz. Signals at higher frequencies were completely attenuated after 70 meters.
In practical situations, other significant factors that can influence actual speeds (not taken into account during these tests but which have been studied extensively elsewhere) include the quality and thickness of the copper cable and cross-talk between adjacent cables (which can be removed by vectoring).
ABOUT ALCATEL-LUCENT (EURONEXT PARIS AND NYSE: ALU)
We are at the forefront of global communications, providing products and innovations in IP and cloud networking, as well as ultra-broadband fixed and wireless access to service providers and their customers, and to enterprises and institutions throughout the world.
Underpinning us in driving the industrial transformation from voice telephony to high-speed digital delivery of data, video and information is Bell Labs, an integral part of the Group and one of the world’s foremost technology research institutes, responsible for countless breakthroughs that have shaped the networking and communications industry. Our innovations have resulted in our Group being recognized by Thomson Reuters as a Top 100 Global Innovator, as well as being named by MIT Technology Review as amongst 2012’s Top 50 “World’s Most Innovative Companies”. We have also been recognized for innovation in sustainability, being named Industry Group Leader in the Technology Hardware & Equipment sector in the 2013 Dow Jones Sustainability Indices review, for making global communications more sustainable, affordable and accessible, all in pursuit of the Group’s mission to realize the potential of a connected world.
With revenues of Euro 14.4 billion in 2013, Alcatel-Lucent is listed on the Paris and New York stock exchanges (Euronext and NYSE: ALU). The company is incorporated in France and headquartered in Paris.