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For a year and a half I had the chance and the luck of working among great minds at Columbia university in nanofabrication and interesting mechanical engineering-related projects. I was never myself involved in any graphene-related projects, but I did meet quite a few PhD students and faculty working with this fascinating material. Last night, when reading the IEEE Spectrum Magazine, I was happy to see some of these people I met featured with a very cool story.
A team under James Hone and Kenneth Shepard at Columbia University has built the tiniest FM transmitter in the world, which is made of graphene.
From the IEEE Spectrum Magazine:
Many research groups have built graphene transistors that could be used in future RF circuits such as signal processors. Hone and his colleagues decided to test a different radio application for graphene, by building a moving, vibrating, electromechanical device. The team reckons that such graphene-based nanoelectromechanical systems (NEMS) could be more compact and easier to integrate onto chips than silicon MEMS and quartz devices, which are used today to pick up and filter RF signals in smartphones and other gadgets.
To build a graphene transmitter, the team suspended a 2-4 micrometer-long strip of graphene above a metal electrode. By applying a voltage to the electrode, they could draw the strip of graphene down. The resulting strain altered the strip’s resonant frequency, tuning it up much as you might tighten a guitar string. By altering the voltage on the gate, the team found they could use the graphene device to generate a frequency-modulated electromagnetic signal. In a paper published this week in Nature Nanotechnology, they report the device could transmit radio signals at 100 MHz, right in the center of the FM band.
It is very interesting how the graphene acts as an oscillator, which moves and vibrates, providing a more compact, small and easier to integrate form than quarz oscillators. Very cool stuff. Specially the demo of the project, by transmitting Gagnam Style with the graphene FM transmitter and playing it on a normal FM radio. You can listen to the recording of the experiment here.
You’ll notice a fair amount of static in the audio clip. That’s partly because the graphene oscillator is quite sensitive to electrical noise: a small voltage on the gate electrode can dramatically shift the frequency, Hone says. The team didn’t add insulation in order to optimize their set-up for this demonstration. “We were also trying to operate at 100 MHz, right smack in the middle of the FM spectrum, where you can pick up a lot of FM signals,” he adds.
My brother recently forwarded me the information on Fairphone, a new smart phone that claims to put social values first. According to its description, it is priced right, letting the user know exactly what she/he is paying for. Also, Fairphone is sourcing raw materials that don’t fund armed forces or violent conflicts, from mines that treat people like the human beings they are. The phone is assembled in China, where a fair wage and fair benefits are provided for the workers.
From the mines to the factories, we want every worker involved in creating this smartphone to earn a fair wage. Beyond monetary benefits, our ultimate goal is to ensure that employees work in safe conditions that comply with environmental regulations.
For our first phone, we’ve focused on our factory in China, including creating a fund to improve worker’s wages and working conditions and open discussions between workers and their employers.
In terms of technical specifications, it is actually a quite interesting phone. It is compatible with all GSM bands and can pump up to 40MBps with HSPA+ compatibility. However, no LTE radio. The phone does not have NFC, but it is equipped with all the typical gadgets you expect from a high-end smart phone, such as sensors, a decent camera, etc. I find particularly interesting that it allows to install two SIMs, so you can keep using it when you travel abroad with a second, local, SIM without removing yours. Or perhaps you could use the same phone as a BYOB at work, having a leisure persona and a work persona. Something similar to AT&T’s Toggle.
In terms of security, though, the phone is rooted by default. This will allow people to do cool stuff with it and install the OS they want. However, I bet there is going to be a bunch of these phones getting infected by malware and trojans. And the end result will always be the same, surprises when you get your monthly bill or your phone turned into a spammer. After all, rooted phones are like candy for mobile fraudsters.
Anyhow, a very interesting and cool phone if used securely and cautiously.
I recently read a very interesting paper that discusses one of the coolest wireless comm-related projects I have seen around for a while. A team of researchers from University of Washington presented this paper at Sigcomm this summer in Hong Kong. The paper was, by the way, awarded with the best paper award.
The idea is simple but could lead to a whole new technology with a great spectrum of applications. These researchers have designed a simple communication system that operates with no need for battery or power. Essentially, the nodes use the signals that are transmitted around them (for example TV signals) and modulate them in such a way that they are able to communicate with each other. Essentially, is a further step more from, for example, RFID tags that use the power of the transmitted signal to power themselves and send a reply. Although ambient backscatter (which is the name the authors give to this technology) has very short range, it could potentially be used for multiple applications, including certain types of wireless sensor networks.
The ambient backscatter project website presents the following video. One can observe the huge antennas these small devices have, which indicate that they operate at not too high frequencies and give an idea of the very low power they operate at. No room for inefficiencies of small twisted or patched antennas. They keep it simple for now with a dipole tuned at the wavelength.
By the way, this project is lead, among others, by Prof. Shyam Gollakota. He was recently awarded with the prestigious ACM Doctoral Dissertation Award and shortly after got a position as Assistant Professor at the University of Washington. Good stuff.
[UPDATE]
While browsing more stuff for this post I found about another project from Gollakota: WiSee. Again, really cool stuff. They are using subtle variations in wireless signals when a person moves to do gesture control. Very interesting. Check it out here.
I recently read a very interesting and detailed article that a colleague at work recommended. The article presents a very thorough overview of the latest revolution in consumer electronics combined with wireless communications: the Internet of Things (IoT).
The concept of the IoT defines a (near) future scenario where most (if not all) things on our physical world and lives will be interconnected with each other using all kinds of wireless protocols, such as WiFi, ZigBee, ZigWave, etc. On top of this myriad of interconnected sensors and actuators, a new playground for developers and people with ideas will be ready for new services (and even entire businesses) to be created, all following a similar “mobile OS – app” scheme. And all these new services will be based, according to the article’s author, on simple “if – then” rules:
“If the sun hits your computer screen, then you lower a shade. If someone walks in the door, then you turn down your music. If there’s too much noise outside, then you close your window. If you have a Word document open but haven’t finished writing a sentence in 10 minutes, then you brew another pot of coffee.”
But all these cool new applications will result on new challenges. One of them (the main one, according to the author), will be battery and wireless charging technologies. Indeed, while semiconductors and transistor technology has evolved steadily following Moore’s law, battery technology has been pretty much stale (What time in the afternoon you have to charge your smart-phone on a day you go to work? If it is after 4pm, I want to know what phone you have). There is a great need for better and longer lasting batteries for mobile devices, as well as some kind of technology that feeds itself wirelessly through the signals it receives. Something similar to an RFID tag. Perhaps some day the power consumption of electronic devices will be low enough to get them to charge the battery by means of the actual power the wireless signal carries. Until then, some proposals might help us along the way. For example the wireless electric transmission proposed by the MIT start-up WiTricity.
I am a bit surprised that the author does not highlight too much the security challenges that the IoT will bring to communication systems. In do not think that “[…] Just as with social networking, the privacy concerns of a sensor-connected world will be fast outweighed by the strange pleasures of residing in it“. I would definitively not feel comfortable at all with my garage door opening when my IoT hub at home, after receiving a message from my car’s geo-location system, sends an “open” command over ZeeWave… specially knowing that someone will show how to hack ZeeWave this summer at Blackhat. I agree with the author, however, in the fact that “[…] our recent hacking epidemic has largely exploited the human interface—the password. We’re always the weak link in online security […]“.
Anyhow, one thing I do know is that in the near future the IoT will change things and our day-to-day lives will look much like the movie Minority Report, with cereal boxes with displays and interactive commercials, personalized advertisements in the subway and smart stores.
My girlfriend sent me yesterday a link to some really interesting news. She is aware of my geekyness and knew that I would like this a lot (yeah, she is a very cool girlfriend). A group of scientist have created the first and world’s smallest movie. This 60 second cartoon, named “A boy and his atom”, is made with about 200 frames of about 25nm in size, and each pixel is a single atom. It took the IBM researchers 10 days to put together such a cool video.
This reminds me the year and a half that I had the pleasure and fun to work in an area related to nanotechnology. Believe it or not, despite having my background on wireless communications, I did once spend many hours in the clean-room building and testing substrates with microscopical features to be used on cell assay tests for medical applications. I did not cure cancer, but I am sure that, some day, great medical achievements will be possible thanks to the excellent work by the folks in the Nanomedicine Center for Mechanobiology. I would like to thank the member of the center who gave me the opportunity to spend a year and a half there.
In my case, despite I was decently good at using the electron beam writer and the electron beam microscope (not as good at all as my colleagues, though), I never got to do anything on the nanoscale. If I remember well, the smallest thing I did was about 100 micro-meters in size.
Anyhow, you can learn more about the world’s smallest movie ever here.
Recently I had the pleasure to meet Dr. Ted Rappaport and attend to a very interesting talk he gave at NYU Poly. The topic of the talk was his proposed “renaissance of wireless communications“. It was very exciting to meet him in person given the fact that I pretty much started learning all I know from his book “Wireless Communications: Principles and practices“. I actually realized, when sitting there listening to his talk, that I should have bought my copy of the book to get it signed. After all, his book and Proakis’ “Digital Communications” are the two pillars of everything I like. Learning about the Fourier Transform when I was 19 in school was an eye opening and told me that, indeed, I was in the right place (right major). A couple of classes I took over the following years (COM-1, COM-2 and RadioCom at the ETSETB) required me to read those two books and then I knew that I was on the right major and I also knew what I wanted to do.
Anyhow, back to Rappaport’s talk. I find his view very interesting. Essentially he is proposing to design communication systems on the milliliter-wave range, at very high frequencies, and he is actually proving it possible at NYU Wireless.
These frequency ranges are known for, in some cases, suffer of extreme propagation attenuation due to the interaction of the electromagnetic waves with oxygen molecules, which brings down the signal well over 10dB per kilometer. In this cases with high attenuation, Rappaport is proposing to create “wisper nets” that die off quickly in way less than a meter of propagation. This way, multiple parts of a complex system can be connected, making wires unnecessary. And the fact that these networks have such a short range, one does not have to worry about external attackers sniffing the traffic or injecting stuff in them.
The other frequency ranges suffer from a still reasonable attenuation that, according to some initial results, could host the future 5G wireless systems. These systems would have a huge bandwidth (BW), allowing for great throughput. Although I had the chance to ask a couple of questions, I forgot to ask him whether he thinks that the huge increase in throughput will come purely from increased BW (plenty of available BW at the frequency ranges he is proposing!) or he expects advanced modulation techniques to play a substantial role as well. After all, we are getting close to Shannon’s limits in terms of bits per second per Hertz (bps/Hz).
Based on the observations of Martin Cooper, the capacity of wireless systems has been somehow steadily doubling every 30 months. This increase has been due to (these numbers are extracted from: M.–S Alouini and A.J. Goldsmith, “Area Spectral Efficiency of Cellular Mobile Radio Systems,” IEEE Transactions on Vehicular Technology, vol. 48, no. 4, pp. 1047 – 1066, July 1999) a wider spectrum (25x gain), spectrum splicing (5x), better modulations (5x… these, I believe, was before OFDMA. I wonder if OFDMA increased capacity more than 5 times…) and a huge gain (x1600) by reducing the size of the cells. Although there’s a huge improvement by making cells smaller, it does not make sense to make them much smaller than now (metro-, pico- and femto-cells), so I guess sooner or later we’ll have to look into new directions. And spatial diversity, another topic discussed in Rappaport’s talk, has always been the one I have always seen more promising and suitable. If to that you add a huge BW at the millimeter-wave range, even better!
I read this weekend a very interesting article from someone I actually had the pleasure to meet in person. In the article, published in the latest issue of the Communications of the ACM, William Cheswick discusses over the “state of the art” of password-related security issues. It is not often that you read such an interesting article that is, at the same time, so much fun to read.
[…]
The simplest way to recover from the compromise of a password is to change it. Ah, the good old days! This is just wrong now. Once an account is compromised, the rot sets in and spreads through further attacks and transitive trust. Other accounts are attacked with the same password, often successfully. Bank accounts are drained (at least temporarily—personal exposure has declined on this,3 plasma screens ordered, billing addresses changed, and identities stolen.)
[…]
You can also check out this presentation Ches did in RSA back in 2011 about the same topic:
Last night I was reading a story from the IEEE Spectrum Magazine that I found very interesting. I recently read a very good book about the history of Bell Labs and AT&T and I don’t think this incident was mentioned at all.
[…]
By the time Barclay finished reading it, the vulnerability in AT&T’s network had crystallized in his mind: “I thought, this is a better way than using a pay phone…this is a way to get around all that other stuff and do it directly.”
“It,” of course, was making free calls.
The ability to absorb 64 pages of dry, technical mumbo jumbo and spot the vulnerability is a rare one. The engineers from Bell Labs who designed the system and wrote the article didn’t see it. Thousands of engineers in the future would read that article and not see it. But 18-year-old Ralph Barclay did. The funny thing about it is, once the hole is explained to you, it’s obvious. But until it’s explained to you, most people would never think of it. Certain people have minds that are tuned in a particular way to see things like that. Ralph Barclay was one of those people.
[…]
The paper from the Bell System Technical Journal that inspired the hack can be found here.
By the way, if you are interested in learning about an important part of the history of current technology, finding out about how the transistor was really invented, how Shannon spent weeks home working on something “secret” that ended up becoming the theory of communications and the basis of information theory… you should read this book.
The Idea Factory: Bell Labs and the Great Age of American Innovation
Maybe I should have known about it, but finding out that the very first satellite communications experiment was carried out by Bell Labs with a huge balloon covered with a thin metallic layer was a revelation for me.
Happy new year everyone!
Let’s hope 2013 will be as good or better than 2012. So far things look good. I just got back from a trip back to the most gorgeous city in the universe (Barcelona), Madrid is 16 points behind Barcelona in the Spanish League, Messi scored 91 goals in 2012 (not 90 like Marca claims… funny that their statistics decide individual trophies but differ from the official ones from LFP, UEFA or FIFA…), work is going well and I am feeling very good. Plus some very cool concerts and shows coming up in the next couple of months…
I wanted to start the year sharing some first impressions (from the media, not mine) about what 2013 might be preparing for us in terms of technology and mainly wireless:
- Mobile industry predictions: Some late players will enter the arena releasing their very own smart-phones. Devices from Amazon, Microsoft and Facebook (partnering with HTC) are expected to be released. Amazon and Microsoft seem to be partnering with Foxconn in this new venture. Also, new gadgets and cool devices are expected to connect to cellular networks, such as watches that track fitness levels or digital cameras that can connect to the web and take a better photo than a smartphone can. Read more at CNN and Washington Post.
- The Mobile World Congress in Barcelona rocks: The mobile technology showcase held in Barcelona every February has been, is and will remain the flagship congress for mobile technology. To the point that CTIA, its main US counterpart, will move its main event to fall 2014 and discontinue their second yearly event in an effort to get out from under the shadow of the Mobile World Congress. They better find a good location or it will be complicated… If you want to know why hundreds of thousands of people keep attending, year after year, a conference in the exact same location, go visit Barcelona. Trust me, you’ll understand. Read more about the changes in CTIA here.
Have a nice day!
Yesterday was the 20th anniversary of the first SMS ever sent. Initially designed as a way to send messages for internal carrier operations, the first “personal” SMS message was sent on Dec. 3rd 1992 between two Vodafone employees. The content of that message was “Merry Christmas”. About a year later, Nokia introduced the first cell-phone capable of sending text messages. A fever was just started.
Those early messages, limited to 160 characters, influenced society in such a way that new frms of language were created. TTL, LOL, 10Q, BRB… we learned to summarize long speeches in short messages and, slowly but steadily, SMS usage outgrew that of mobile phone calls. And the trend has stayed like this until now when, at the time it is turning 20, the SMS seems to be finally slowing down. WhatsApp, iMessage, Viber… too much competition. Perhaps the SMS will be retiring soon. Anyhow, happy birthday SMS!
Read more at CNN and Wall Street Journal.
Six billion SMS (short message service) messages are sent every day in the United States, according to Forrester Research, and over 2.2 trillion are sent a year. Globally, 8.6 trillion text messages are sent each year, according to Portio Research.
It seems tacky to bring this up on its birthday, but this may also be the year the text message peaks. After two decades of constant growth, text messaging is finally slowing down as people move to smartphones and use third-party messaging tools to circumvent wireless carriers’ costly per-text charges.
SMS messaging is expected to be a $150 billion-a-year industry in 2013, with carriers charging set monthly fees for unlimited texting, or as much as 20 cents per text. The actual cost to carriers for sending a text message is about 0.03 cents.
Soft Handover 