Chuyển đến nội dung chính

Cognitive radio technology optimises use of scarce spectrum

Cognitive radio technology optimises use of scarce spectrum


Cognitive radio technology optimises use of scarce spectrum
As the number and variety of smartphones and other connected devices keeps growing, the need for radio spectrum grows with it. Cognitive radio technology developed under the EU-funded QOSMOS project could help meet these needs while controlling telecom costs, improving service and driving the development of new markets.
In the near future, the telecom industry will be faced with three challenges: a need for more radio spectrum, an ever-increasing demand for data, and consumers' increasing unwillingness to pay for it. Spectrum, however, is a finite resource.

The QOSMOS project addressed the twin problems of scarcity and cost by developing cognitive radio technology that dynamically optimises the use of radio spectrum, by accessing under-utilised portions of the spectrum and sharing spectrum across devices.

The idea is to break down silos,' says Michael Fitch of British Telecom, who coordinated the QOSMOS project. Every new service and technology needs a new spectrum, and silos are formed when there are umpteen different devices that use umpteen different parts of the spectrum.' This diversity does not make for efficient spectrum management. The project partners therefore developed three technologies: a central manager that controls the spectrum 'portfolio' in real-time for a region or country; a resource manager that allocates the spectrum to individual systems and senses the environment; and a cognitive radio terminal.

The project also developed a prototype transceiver to generate FBMC (Filter Bank Multicarrier transmission) waveforms. FBMC is expected to replace the OFDM (Orthogonal Frequency Division Multiplexing) technology that is more commonly in use today. With FBMC transmission, spectrum is carved out in rectangular blocks so that it is tightly packed for more efficient spectrum use.
Avoiding interference

Since the idea behind QOSMOS is to use underutilised portions of the already-allocated spectrum, a key issue is avoiding interference. An early pilot led by UK telecommunications regulator Ofcom, for example, would use some of the technology developed in QOSMOS to access TV white spaces, which are unused spaces in the UHF band allocated to TV broadcasters. Without intelligent spectrum management, interference by 'secondary spectrum users' could degrade broadcast quality for viewers.

Avoiding interference calls for more spectrum management,' says Fitch. 'And it's not just a case of choosing the optimum spectrum, but also the appropriate waveform.' He also notes that the number and variety of devices that attach to the network and one cell is enormous, and that each device has a different need. A home automation sensor, for example, may periodically transmit state information with a low data requirement, while a television set top box may require much higher bandwidth and more complex spectrum management.

More than technology Members of the QOSMOS consortium did not only develop the technology, they also gave serious thought to how it could be deployed. They conducted a value chain analysis and developed business 'use cases' that compared the costs of accessing under-utilised spectrum against that of buying new spectrum, and identified the areas where cognitive radio technology could be commercialised.

Existing owners of spectrum, for example, could rent out their spectrum assets for short periods of time, while network managers could offer premium spectrum management services. An entirely new market in micro-trading spectrum could develop over time.

The project culminated in events hosted by BT in the United Kingdom and Microsoft in Washington, DC. The Commissariat à l'Energie Atomique in France is continuing development work on the FBMC transceiver and several consortium members are likely to commercialise the spectrum manager technology. Meanwhile, according to Fitch, UK regulator Ofcom is in position to commercialise TV white spaces from 2015.
Source: www.ict-qosmos.eu/
Read more at: http://testtek.com

Nhận xét

Đăng nhận xét

Bài đăng phổ biến từ blog này

Understanding phase noise in signal generators

Source:  http://www.testtek.com/en/detail-info.php?id=2151 Signal generators manufacturers set great store by specifying phase noise, such that, regardless of the application, phase noise is frequently taken as a proxy of the equipment's overall performance. However, phase noise performance might have little or no affect in some applications. For example, 'close in' phase noise creates problems when the signal generator is used as a local oscillator, limiting its sensitivity or impairing bit error rate (BER) performance if used as a clock. 'Far out' phase noise, on the other hand, affects wideband communications systems by raising the noise floor and limiting the reception of poor signals. Choosing a signal generator to match phase noise performance to the requirements of the application can be difficult as manufacturers often characterise phase noise performance at different carrier wave frequencies and at different offsets from the carrier signal. ...
Đăng nhận xét
Đọc thêm

What is Internet of Things (IoT)?

Source:  http://testtek.com/en/detail-info.php?id=2139 The  Internet of Things  ( IoT , sometimes  Internet of Everything ) is the network of physical objects or "things" embedded with electronics, software, sensors and connectivity to enable it to achieve greater value and service by exchanging data with the manufacturer, operator and/or other connected devices based on the infrastructure of International Telecommunication Union's Global Standards Initiative.  Internet of Things connect physically and remotely by individuals, for both public sector and private sector,  in the sense of a computer network grid, of a created electrical device that is in place, with economic benefit and potential usefulness.  Each thing is uniquely identifiable through its embedded computing system but is able to interoperate within the existing  Internet  infrastructure. Experts estimate that the IoT will consist of almost 50 billion obj...
Đăng nhận xét
Đọc thêm
Looking inside supercapacitors could help to build higher performing parts Researchers from the University of Cambridge, together with French collaborators based in Toulouse, have developed a method that allows the inside of supercapacitors to be viewed at the atomic level. The team says this approach could be used in order to optimise and improve the devices. By using a combination of nuclear magnetic resonance (NMR) spectroscopy and scales sensitive enough to detect changes in mass of a 1µg, the researchers could visualise how ions move around in a supercapacitor. They found that, while charging, different processes are at work in the two identical pieces of carbon 'sponge' which function as the electrodes. Dr John Griffin, a postdoctoral researcher in the Department of Chemistry, said: "[Supercapacitors are] much better at absorbing charge than batteries, but since they have much lower density, they hold far less of that charge. Being able to see wh...
Đăng nhận xét
Đọc thêm