Making Wireless Ubiquitous
What if wireless capabilities could be added to every device by integrating the radio circuits and systems directly into each component? To make this wireless vision a reality, researchers are working in a wide variety of technology research areas. Just as CMOS (complementary metal-oxide semiconductor) process technology has provided cost and scale advantages in the evolution of microprocessors and chipsets, it is now being applied to radio technology. CMOS technology will make new capabilities possible like Reconfigurable Radio Architectures, smart antennas and ‘agile’ radios. At the same time, new industry standards and worldwide regulatory guidelines will be needed to support future anytime, anywhere connectivity.
CMOS RadioMoore’s Law predicts that the number of transistors per unit area will double about every 2 years. This long-established trend and the improved device performance it generates are continuing to enable cost efficiency, greater volumes and interesting new applications in CMOS. Recently, it has become clear that the applicability of Moore’s Law is expanding to include new applications involving radio technology and networking.
Current research and development efforts include designing and manufacturing the necessary components of the radio’s Analog Front End and Digital Baseband / MAC (Media Access Control) on standard CMOS processes. As more digital processing is applied to the radio system, CMOS radios will follow the same decreasing cost and improving performance trajectories representative of the computing industry.
Reconfigurable Radio ArchitectureAs the application of Moore’s Law continues to produce the necessary transistors, and as analog RF (radio frequency) circuitry becomes feasible in CMOS technology, cost effective solutions are becoming possible to enable reconfigurable radio capabilities. Reconfigurable radio systems are radios that can change to different communication protocols as they move between different radio environments (i.e., 802.11b to 802.11a and then to W-CDMA). One possibility is a Reconfigurable Radio Architecture that will concurrently support multiple radio protocols over multiple frequency bands across multiple wireless networking environments.
Intel’s approach to a Reconfigurable Radio Architecture employs the use of computational elements optimized for specific compute functions, connected in a manner that implement the signal processing requirements of all wireless radio protocols. By employing an adequate number of specific computational elements, and programming different connection paths between these elements, multiple simultaneous protocols become possible.
At the same time, as analog RF CMOS circuitry becomes possible, the analog front end is expected to be produced more efficiently. This new efficiency will enable cost effective, multiple analog front-end solutions – and eventually reconfigurable solutions. The vision is that end users will have radio technology connecting them anytime, anywhere using single radio platforms integrated into any device they choose to use.
Smart Antenna SystemsAs part of wireless system development, the industry is continually looking at ways to increase radio efficiency. One way is to use multiple “smart” antennas.
Potential implementations range from simple to complex. One approach would employ very simple technology where the more effective of two antennas is selected. A more sophisticated approach would use complex signal processing algorithms across an array of antennas. Smart antenna technology may be applied to improve signal reliability and increase data throughput while increasing both frequency and spatial utilization.
On the receiver side, a smart antenna system may be used to provide a multiplicative factor for increasing signal gain while also canceling the effects of multipath fading. On the transmit side, a smart antenna system may be used to concentrate the transmitted energy in a specific direction based on the location of the receiver.
Directing the energy in this manner not only improves performance but also helps reduce interference by isolating other radios not associated with the transfer and outside the directed transmission path. Smart antenna technology may also help to increase efficiency by simultaneously supporting an arbitrarily large number of clients using a single fixed set of antenna elements. This capability improves frequency reuse, resulting in increased spatial capacity.
The application of smart antenna technology will result in more efficient use of spectrum, which should help to increase range, network throughput and spatial capacity while reducing interference in an already crowded frequency spectrum.
Convergence and Regulatory ReformIn the future, it is expected that computing devices will communicate and communications devices will compute. Examples of radio applications significant to computing and communications convergence include:
WWAN (wireless wide area networking), used for cellular telephone communications;
WLAN (wireless local area networking), used for computer connectivity
More recently, WPAN (wireless personal area networking), finding many uses with smaller personal devices like cellular phones, PDAs (personal digital assistants), and even cameras. As devices become more intelligent, applications requiring radio connectivity are beginning to converge. Devices increasingly need to connect through more than one radio implementation. An example of this trend would be a cellular phone where connectivity is required for a cellular carrier (WWAN), for wireless headsets and/or email, calendar synchronization (WPAN) and for access to networking resources such as email and Internet services (WLAN). This example translates into at least three radios required for a single personal device, and possibly more as different protocols and radio bands become relevant in different geographical areas. As new capabilities like CMOS Radio, Reconfigurable Architecture and smart antenna technologies become possible, new “agile” radios are expected to become possible. An agile radio will provide the ability to select any supported radio protocol or associated frequency band using a single radio implementation. This approach to radio solutions should greatly accelerate convergence and simplify the end user experience.
Introducing an ‘agile’ radio concept, however, presents regulatory challenges as well as technical challenges. Intel is working with United States, European, Russian, Japanese and Chinese regulatory authorities to adapt regulatory guidelines for ‘agile’ radio technology.