Using WiFi in yet another context gave us the idea that given the enormous shipped volume of WiFi chips and the resulting cost reduction, and the huge knowledge base for embedding WiFi, it may well become much more of a generally applicable wireless system, like Ethernet has become for wired systems. Just as Ethernet continually increased its speed to 10Gbps and beyond, used for both wired and optical systems over increasing distances, so is WiFi providing wireless broadband access well beyond its original context of short range (home and office) networks. Long distance rural systems and meshes come to mind.

Even more interesting is the reality that in the off-load application, WiFi is also a “disruptive” technology to the backhaul business. Through off-load, WiFi will reduce traffic demand on backhaul capacity just as new, high density 60GHz and E-Band backhaul systems start deploying. This will emerge because even though WiFi has lower performance (bandwidth), it has very much lower costs. Thus, it is disruptive in the sense defined by Harvard Prof. Clayton Christiansen who first analyzed the disruptive phenomenon. Disruptive technologies provide good-enough quality at really low prices. MP3 immediately exemplifies this idea.

Check this link for details:

Sequans 4Sight Solution

This platform is a wonderful example of how adversity sometimes is just the pointer to a positive way forward.

Remember the wild days when “expert systems (ESs)” would replace your family physician or run a nuclear power plant? Remember how Campbell soup made a big ,splash by describing how ES was replacing the firm’s 80 year old uber-soup taster? Well I admit, I remember. I remember the “artificial Intelligence Company”.Where is the AI company now? Long gone, faded into general engineering practice.

I started thinking about all this a while back, but at our last WCA panel on “Commercial Status of CR and SDR”, on 11-9-10, it became obvious. There is no commercial system that declares itself as CR or SDR, but these technology methods and analyses are used in all the major standards!

By the way, there also seems to be negligible work going on, at least to public knowledge, on IEEE 802.22, which is the famous “white space” system.

So, in true engineering empirical fashion, we did an experiment-on Google Scholar. We examined four important technologies (CR, MIMO, OFDM, Turbo Codes), all of which have had their  major work within the last 20 years. The idea was to see how rapidly the number of articles and patents is growing, and compare the results. By getting a reasonable idea of the number of articles and patents generated by year, we can get an idea of the activity levels and see the growth rates.

Of course, some of these ideas have been worked on much longer than others, so the total number of articles and patents cannot be fairly compared. Here’s a rough indication of the age of these technologies. It will important to keep this in mind below.

CR emerged with Joe Mitola’s Ph.D. thesis in 1999 [see, e.g., G. Maguire and J. Mitola, “Cognitive Radio: Making PCS Personal”, IEEE PCS Magazine, August 99].

Turbo Codes were first described in a paper:  C. Berrou, et. al., “Near Shannon Limit Error Correcting Coding and Decoding: Turbo Codes”, Proc. IEEE Intl. Conf. Commun., pp 54-58, May, 1993

MIMO gained major attention with a paper by G. J. Foschini, “Layered Space-Time Architecture for Wireless Communication in Fading Environments when Using Multiple Antennas”, Bell System Technical Journal, pp41-59, Autumn, 1996

OFDM, the core of WiMax and LTE systems, is  an old technology, but it got a major boost with J.S. Chow, J.C. Tu, J. M. Cioffi, “A Discrete Multitone Transceiver System for HDSL Applications,”  IEEE  J. Sel. Areas Commun., pp 895-908, August 1991. Prof. Cioffi later formed a company Amati Communications which was acquired by Texas Instruments for around $1B in the 1990s.

Google Scholar provides, for a given search phrase, the number of articles and patents found since a year Y designated by the searcher. The earliest Y you could use is 1991. In our study, we simply recorded the number of articles and patents found now by Google Scholar since each year starting with 2002, which implicitly includes all history for that search. By tabulating these search results, we deduced the approximate number of articles and patents added each year for each technology. We note that this addition by year sometimes is negative, probably indicating fewer articles found in that year. But the variations due to negative increases were small.

On the other hand, it’s obvious we cannot compare the numbers found per year, since the scales are so different (ranging from 100s to thousands of articles and patents found). So we just normalized the search results by the number in our starting year for display. The normalization enables us to graphically compare the publications in the four technology ares and see which is growing fastest.

The raw search data and a graphic showing the rapid growth rate in CR research are shown below:

Raw Search Data

Growth Rates of Major Technology Research

The number N shown on the graph represents what Google calls the total number of articles and search results found “anytime” for the search phrase. This reflects the size of the knowledge base written about each technology. The size of CR knowledge is relatively small, but is growing incredibly fast.

It surely seems that CR research is rapidly growing compared to the three other more established, but also hugely important fields.

The speakers and topics are:

Dr. Steve Goldberg/Venrock will focus on what has constrained the technology
in the past and what market demands we might expect moving forward.

Dr. Ahmad Bahai/National Semiconductor will review some optimal statistical channel search and selection techniques to support effective spectral use and describe new architectures for software radio and mixed signal processing circuits.

Prof. Andrea Goldsmith/Stanford will survey the CR/SDR technologies, describe
some of the design and regulatory challenges behind them, and survey
some recent innovations in wireless technology that may provide
breakthroughs in commercializing smart radios.

Get the full description and details at the WCA site:

www.wca.org

Nokia Animation on Cognitive Radio.

Enjoy!

Our briefing on Cognitive Radio is here.

CR_SIG_2-25-10

Our major point is that to advance the effective use of limited spectrum, market and regulatory forces are more uncertain and dominant than technology, which is already being deployed within many standards.

The panelists and their presentations can be found here:

WCA Cognitive Radio presentations from panelists

Defined by Joseph Mitola, the original coiner of the term as, “a really smart radio that would be self-aware, RF-aware, user-aware, and that would include language technology and machine vision along with a lot of high-fidelity knowledge of the radio environment,” cognitive radio has become a catch-all bucket for all sorts of radio intelligence. Got transmit power control? Definitely CR. Have adaptive frequency hopping? You’re in! Can your radio operate in more than one band? You’re a CR pioneer!

While all these ‘features’ are elements of what Mitola had in mind, the true vision goes way beyond these singular advancements into truly ‘intelligent’ radios that can operate in and avoid interference in any band based on a priori knowledge to predict what bands are open, where interference may come from and what the user’s application may be. Much of the intelligence for this will reside at a higher level in software, but the capability to act upon and take advantage of that intelligence depends on advancing the state of the art in radio design. That’s where ISSCC comes in.

Even with the various interpretations of the term Cognitive Radio, it is a very lively product development activity. CR is real today and is most readily understood as a variety of techniques used to install adaption and goal seeking into transceivers. These advances will clearly use bandwidth more effectively.

At the layman level, the San Jose Mercury News has an article about the exploding demand for bandwidth and how the FCC’s efforts to provide more spectrum can collide with other FCC initiatives. For example, spectrum can be more effectively allocated by various pricing mechanisms, but these in turn affect the proposed policy of “net neutrality”, in which telecom operators are forbidden to distinguish types of traffic for purposes of network management.

Recently, the market research firm iSuppli released a “tear down” analysis” of several smart phones. Their teardown analysis of the actual phones reveals the costs in the end product’s bill of materials. You can read an article about this study in The Economist’s article: “The lowdown on teardowns” . The results are shown below in Table 1. In Table 2 we simply show the costs normalized to each firm’s total Cost.

Table 1: Comparison of Component Costs in Four Smart Phones

Table 2: Costs Normalized to each Firms’s Total Cost.

We take these quite low costs as signs current technology and design teams are competent to build any CR system desired over in the near future. Of course, we still don’t have clarity on the regulatory regime or markets…..such details!