Throughout human progress, connections have been some of the most pronounced indicators of civilization. In fact, one could not speak of a society if there were no connections to define it – you can’t have a society with only disconnected members.

Society evolved when humans decided to group together in cities, and it again evolved when they decided to make connections between these cities. Greek and Roman societies are perhaps better characterized by their unprecedented ability to connect cities at unimaginable distances apart, both by land and by sea. Some of the roads and bridges built by the Romans to hold their empire together still stand today. But I won’t be talking about the Romans, as interesting as they might be.

There is much to discuss about connections. There’s a whole industry devoted to telecommunications, and millions are spent each year studying ways to improve how we communicate. So let’s just focus on one small aspect of connections, that of communications, and let’s concentrate on the evolution of cell phone technology. How did cell phones come about? How do they work? What’s in store for them?

The idea of a mobile phone certainly wasn’t new. If you’re a fan of war movies, you must have seen the use of radiophones to communicate the movements of the enemy. Walkie-talkies were already widespread at the time when the first mobile phone was developed. There had also been mobile phones for use in cars. You know, those fancy ones you see in limousines.

As is often the case with more modern inventions, the mobile phone was not developed in isolation. The one to patent the portable mobile phone, however, was Dr. Martin Cooper for Motorola in 1975. Kind of sad for Bell Labs, since most of the concepts were initially developed there. The first commercial cell phone network put in operation was in Tokyo, Japan, in 1979. The first in the US took about 4 more years.

Brief intermission. We all certainly have this unquenchable thirst to communicate, so why did it take so long? What was the difficulty? Many people fail to realize how hard it is to get spectrum. In actual fact, you can’t just go around broadcasting to whatever frequencies you want.

The use of frequencies is government regulated, and believe it or not, it is a very scarce resource that costs quite a bit of money. Even in recent years, you can hear about spectrum allocation – in 2008, there was a lot of noise about it in India, and just recently, AT&T bought some for 1.9 Billion Dollars. End of intermission.

The communication system used for cell phone communication in the early eighties was AMPS (Advanced Mobile Phone System). It was analog. The problem with analog is that whenever you make a call, it would take up a band of frequency for that communication channel. So, if you have limited frequencies, there is a limited number of channels you can use. Frequencies are expensive, so if you run out of channels, you’re stuck. You can’t get more subscribers, so you can’t make more money.

In the nineties, several new, digital, standards were established. As with most standards, the world couldn’t make up its mind on which standard to use. The three major ones are TDMA (time division multiple access), CDMA (code division multiple access) and GSM (Global System for Mobile Communications).

CDMA uses some convoluted encoding scheme that was originally developed during World War II by the military to prevent the enemy from intercepting transmissions. It splits up your data to a bunch of random spectrum bands, and it does the same for everybody else’s data, and since it’s random, they don’t overlap. These digital technologies are commonly referred to as 2G. Their use of spectrum is much more efficient than analog, and they allow for everyone’s favourite, SMS, or text messaging.

The next generation, 3G, uses a number of standards, but the most common one is W-CDMA, or wideband CDMA. Nothing much to say here – just another standard, with a few variations. The difference between 2G and 3G is mostly in the transmission speeds, and some other characteristics that must be satisfied. Chances are your phone right now uses 3G.

Speaking of phones, there has been one major shift in recent years – the advent of the smart phone. The standards mentioned so far were mostly developed to accommodate for voice traffic. This has changed, as people now use their phones to look at videos of cats. The transmission speed has become a bigger concern, but there is also another aspect. Voice calls usually use something called circuit switching. They would require a certain type of hardware. Data transfers usually use something called packet switching. They require a different type of hardware. Can you spot the problem?

Since the majority of traffic is now of the packet switched type, there is strong incentive to migrate everything over to the same hardware. You’ve probably heard about voice over IP (VoIP). That’s the general idea.

The newest arrival to the scene of cell phone standards is LTE. It’s the 4G everybody’s been talking about. The good thing about it is that a lot of people are saying they’re going to use it. Who knows? The world might make up its mind this time. Another good thing about it is that it’s very fast. We’re talking about more than 100 Mbit/s here. And that’s where we stand right about now.

Today, the number of our connections is growing at an exponential rate, and it’s never been easier to talk to someone on the other end of the globe. We grew up in this new era – the era of cell phones and the internet. And maybe we’ve become spoiled. I was traveling to Boston a few weeks ago, and my cell phone had no coverage. Scary, isn’t it? It’s not something that would kill me, but the thought is nevertheless a bit troubling. What would happen if someone pulled the plug?

Back in the days, I was barely aware of the growing environmental concerns surrounding the disposal of old computers. Yet the need to get rid of old computer parts, whether it’s peripherals, old boards or even entire machines, is not that uncommon. If you’ve owned a computer within the past fi ve years, you’ve probably encountered this problem.

There has been so much talk about pollution, global warming, the situation in third world countries and all that, so much that it’s starting to turn into a boring subject. Putting two and two together, however, is not always obvious. It might not be that obvious, in fact, how great of an impact replacing your old CRT monitor by a shiny new 24 inch LED might have on your surroundings.

Did you know that a CRT monitor can easily contain over 2 kg of lead? If not disposed of properly, this lead will eventually end up in water sources, and even small (almost undetectable) concentrations of its ions can have devastating consequences on the human nervous system.

CRT monitors are not the only potentially dangerous components in a computer system. As a general rule of thumb, throwing away computers should not be done the same way you throw away your other garbage.

Thankfully, McGill University is very responsible in its disposal policies. If you have unwanted equipment on McGill campus, McGill Waste Management will come pick it up for you, so make sure to take advantage of their services to ensure the proper, environmentally responsible, disposal of old equipment.

Unfortunately, this service is only for McGill campus, so you’ll have to seek other means to recycle your computer at home. With all this fi nally out of the way, let’s look into what Reboot McGill is, and what it means to you.

When McGill Waste Management gets a hold of your old electronics, there is one last step in their glorious journey that took them from a bubble-wrapped package to the hands of an enthusiastic user, through the faithful fulfi lment of their task for several years and on to their eventual redirection towards computer Nirvana.

That step is Reboot. Recycling computers costs money. Getting new computers costs money. There are McGill Clubs and Mc- Gill faculty members in need of computer equipment, whether that’s because they don’t have any at all, or are struggling with a relic that would serve better in a museum. You see where this is going, don’t you? Reboot’s goals are to reduce the amount of equipment recycled by McGill and to provide campus institutions with free machines. And no, they don’t ship equipment to Africa.

But who are the people behind Reboot? Who makes it all possible? Why, it’s McGill students, of course!

Reboot McGill is one of the EUS committees, so its main members are engineering undergrads who have a passion for breaking computers apart.

During the semester, Reboot has scheduled meetings where students can show up and quickly get down to business – wipe hard drives, assemble computers, install operating systems, etc. It’s not hard, so whatever your skills, there will be something for you to do.

Getting involved is quick and easy – just get on the website at

reboot.mcgilleus.ca

and let Reboot know you are interested.

There are other useful links on that website, so feel free to look around. And how can you get a computer from Reboot? Easy, just fi ll out a request form on their website.

As the technology enthusiast that I am, ever curious about cool stuff and always sharing my non-existent expertise, allow me to take a moment of your time and tell you about what’s in store for TV. First, let’s start by examining television technology of the past. The first countries to adopt television (late 20s, early 30s) were the United States, the United Kingdom, Germany, France and the Soviet Union. All using a mechanical system. This was later replaced by electric systems using cathode ray tubes, which shouldn’t be that surprising. Initial broadcasting was done using analog signal. In analog broadcasting, the video information is sent using amplitude modulation (information contained in the amplitude of the signal), while the audio signal is sent using frequency modulation (information contained in the instantaneous frequency of the signal). The audio signal was mono until the advent of NICAM and MTS in the eighties, when stereo sound transmission also became possible. The video was originally monochromatic. Later on, color information was tacked on. This gave rise to the three analog encoding standards: NTSC, PAL and SECAM. You probably know about these if you like travelling or watching foreign movies. These standards allowed for color information to be piggybacked on top of a regular monochromatic signal while remaining backwards compatible (so old black and white TVs would still work). These standards are all really awesome, so you should look into them if you are interested.

Digital television is a more modern transmission method. Using just ones and zeroes, as well as various encoding standards, you can transmit audio and video signals with greater flexibility. Canada still used analog signals for over-the-air broadcasting, but this has been officially over since August 31st 2011. The video codecs used are MPEG-2, H.264 and AVS, while some of the audio codecs used are AC-3, MP3 and
AAC. DVDs use MPEG-2 video and AC-3 audio.

So here we are, today’s television – High Definition. Although it’s nothing that novel (Japan had it in the works since 1964), it only became easily accessible in recent years, especially with the advent of HD DVD and Blu-ray. The two principal resolutions use line heights of 720 or 1080. The difference between 1080i and 1080p (as you may have wondered) is that one uses interlaced video, whereas the other uses progressive scan. Interlaced means you only draw half the lines of each frame (odd ones first, even ones next, etc.) Hence, today’s television roughly stands at 1080p and that’s the best available – or is it?

The future isn’t that far away. There are already screens capable of displaying quad full high definition. That’s 2160p, four times the size of current HD. If current broadcasters could handle the throughput, we would probably be using it already. Don’t think it’s too far off, though, broadcasters are already way ahead of us and are upgrading their infrastructure. It might take a few years for the change to happen, but it will happen. It doesn’t end here, though. There are already talks of Ultra High Definition Television (UHDTV). That would be 4320p, or 16 times the current maximum in terms of pixels. And SHARP already has a TV capable of displaying it. Wouldn’t you know it, Japan is leading the way once again.

The prime supporter of UHDTV is NHK, the Japanese equivalent to the CBC, and they are seriously considering ways to broadcast in that resolution. With the way things stand now, though, it sounds pretty much impossible. Let’s just hope Bell starts selling unmetered Internet before the rest of the world gets all the cool stuff.

References
- http://www.emimusic.com/about/
- http://www.bairdtelevision.com/firstdemo.html
- http://www.nhk.or.jp/strl/aboutstrl/evolution-oftv-en/p16/index.html
- http://www.crtc.gc.ca/eng/info_sht/bdt14.htm
- http://pro.sony.com/bbsc/ssr/product-SRML560/
- http://solidlystated.com/hardware/sharp-4320phi-vision-television/
- http://china.nikkeibp.co.jp/china/news/edit/mobi200505300113.html

Twelve year olds know more about pop music than I do (literally), so I am by no means a walking music encyclopaedia. I just listen to music for the pure enjoyment of it, without getting too much into the details. That’s why I found it a bit overwhelming when I decided to buy my first pair of “real” headphones, but I also learned a great deal while researching, so I’d like to share some of it with you.

Amplifiers

First, it might be relevant to talk about how amplifiers work. They do pretty much exactly what you’d think they do—they amplify. Commonly, this is achieved using transistors. The basic idea is rather simple: you hook up a relatively high DC source to the transistor on either end, while the signal you want to amplify is connected to the base. Because the transistor usually acts like an open circuit, there will be no current flowing; however, when you supply the base of the transistor with even a small voltage, you allow more current to flow from the DC source. This is a gross oversimplification, but you get the idea.

Amplifiers have several specs of interest: power rating, impedance and fidelity. The output impedance of the amplifier is its impedance perceived at the output—we generally want this to be as low as possible. The power rating is the amount of power the amplifier can supply—we want this to be high. Finally, fidelity is how accurately the signal is amplified—with zero distortion if possible. Naturally, we don’t want our amplifier to add noise or make our music sound like me singing.

I mention this because when it comes to sound, you find amplifiers everywhere. Even if you don’t have a stereo system, you still use them —a simple radio receiver, your computer’s sound card, possibly even your speakers. Ultimately, you should pick your headphones based on how you are going to be using them. It might not be worth it spending hundreds of dollars on headphones that you will end up plugging into a cheap sound card.

Digital audio
A second step to our quest of finding the right headphones is understanding how digital audio works. Most of you probably don’t listen to analog audio: vinyl records, tape recordings, etc. Yet few actually understand how digital audio works (myself included, to be honest). Let us examine what analog and digital mean, exactly.

Sound propagates through air as a wave of varying amplitude and frequency. So, to reproduce sound, you need to make the speakers’ drivers move at exactly that frequency, and adjust the pressure they exert according to the sound intensity. Since the speakers operate using magnets, all you really need to do is feed the speakers a voltage with amplitude and frequency corresponding to that of the desired sound wave (with enough power to make them produce audible sound, of course).

Although analog sound recording came quite a bit before digital recording, it is actually better in terms of accurately describing an audio signal. It poses some problems, though: it is more difficult to store, more difficult to transmit and generally more difficult to work with than with a digital signal. Also, the circuits needed to work with an analog signal need to be a lot more sensitive and well tuned than those used for digital. To put it simply, digital is much cheaper. But how exactly do you represent an analog wave of such high complexity simply in terms of ones and zeroes?

The analog wave is stored as a point of amplitude and position in time. There are two main aspects you need to be aware of: the sampling rate and the bits per sample. A higher sampling rate is better, since it means you have points closer to each other and are throwing out less of the analog signal. A Compact Disc has a sampling rate of 44,100 Hz, meaning there are 44,100 points of amplitude measured inside of one second. Bits per sample, on the other hand, is how many bits you use to store the information about each point. Since we use ones and zeros, we can’t really store every possible value of amplitude. Instead, we break it up in several groups. A Compact Disc recording uses 16 bits per sample, or 65,536 possible amplitude values. Some higher quality recordings have 24 bits per sample, or 16,777,216 possible amplitude values. Wow! Of course, it’d be kind of useless to output a stream of ones and zeroes to your speakers… sound is still analog, so we need analog-to-digital and digital-to-analog converters to make sense of our digital signals.

But what about all those mp3′s you have on your computer or your mp3 player? Are they any different from the digital signal we discussed? Yes and no… Ultimately, they’re still based on the same principles, but with one important distinction: they use various techniques to reduce the size of the digital signal. With a CD, a song of 4 minutes takes up roughly 40.4 MB. We want to try making this 5 MB instead. We achieve it by reducing the bits per sample and by disregarding parts of the signal that are in the higher or lower frequency ranges (that the human ear can’t detect anyway). This is the case for all the “lossy” formats (such as mp3), but lossless formats exist too. Those only compress the original wave to make it take up less space, without throwing out any of the information.

OK, that’s enough technical gibberish. All you need to understand from all this is that digital wave signals are dumbed down version of analog signals, and that lossy encoding is a dumbed down version of digital signals. If you’re only going to listen to 128 kbps mp3, it might not be worth it spending a lot on sound equipment.

And sound equipment can be quite expensive. There are headphones out there in the thousands of dollars range! Do you need something like that? Probably not… but it’s always nice to get something with at least half-decent specs.

Let’s just discuss some headphone specs before we finish:

Frequency Response. The human ear can hear sound roughly in the 15 to 20,000 Hz range. You might see a value such as 8-25000 Hz put as the frequency response for some headphones, and that’s the most info you will usually get. Some headphones will have a flat response (will produce comparable output at different frequencies in the range), while others will deliberately output different frequencies differently (e.g. enhance bass). Even looking at frequency response graphs, you can’t really say much about how good the headphones are. It’s best to just listen to the headphones before buying, if possible.

Impedance. Most will give you a value such as 32 ohms. It varies with frequency, some manufacturers provide something like Impedance (1kHz): 32 Ω, where 1kHz would be the frequency it was measured at. You generally want this to be lower, but it hardly matters, as the amplifier’s power output is of much greater importance when it comes to volume levels. Some of the higher grade headphones have even higher input impedances, such as 300 ohms, while a typical speaker system has an impedance of about 8 ohms.

Sensitivity. This is sometimes referred to as Sound Pressure Level, and is given in dB (decibels). In simple terms, it’s how strong of a sound the headphones produce when supplied with one mW (milliwatt) of power. Typically this is about 100 dB.

Total Harmonic Distortion. This is related to the fidelity, and is considered inaudible if less than 1%.

Load Rating. Probably not of a huge concern, this is the maximum power the headphones can handle over an extended period of time. A common value is about 500 mW.

Transducer Principle, Driver Size, etc. These relate to the driver, the part of the headphones that vibrates and creates sound. You’ll often see something like Dynamic neodymium magnet; it just means the headphones produce sound using magnets that cause a membrane to vibrate.

Cable. I personally find this quite important. Cables can be of varying lengths and thicknesses. If you are going to listen to your headphones at home, a longer cable (or maybe even wireless…) would be better, but if you’re going to be listening to an mp3 player on the go, you actually might want the length to be shorter. The headphones I got had a thick and detachable cable, so I can eventually replace it if it breaks.

In the end, which pair of headphones should you choose? Get ones that suit your taste and meet your needs. I think it’s more important to choose them based on physical characteristics (such as the cable, the size and comfort of the headphones, their appearance, their durability, etc.) than to look for frequency response in the 50 kHz range. I hope this can be of some use to the ones who find themselves in a similar position as me, and that I haven’t bored the music enthusiasts out there

REFERENCES
http://sound.westhost.com/amp-basics.htm
http://sound.westhost.com/impedanc.htm
http://communication.howstuffworks.com/analog-digital3.htm
http://www.sennheiser.com/sennheiser/home_en.nsf/root/spec_hd800
http://www.headphone.com/learning-center/build-a-graph.php

Well, I may have lied a little bit. What I am getting ready to tell you about isn’t some kind of animal or plant, or even some bug or bacteria. But most of you probably already knew that… The organic conductors in question are simply polymers that conduct electricity, which by itself might be a bit surprising to some. After all, we grow up used to the idea that plastic is a good insulator yet here I am telling you about plastic that acts like a copper wire. In actual fact, we’ve known about conductive polymers for quite some time, it’s just that they weren’t as conductive and as useful until recently.

Now where exactly can you find these organic conductors? They might actually be closer to you than you think. Because organic conductors tend to be transparent, light, durable and flexible, their possible applications range from solar panels to LCD displays. Those e-book readers that have been getting popular lately? Chances are there are at least a few organic conductors in them. That touch screen phone or music player everybody wants to get a hold of? Touch screens can contain these polymers too. You can also use them to protect sensitive devices (i.e. as antistatic agents) or use them to light up the keys of your phone. And the good part is, they work even when bent, wet or worn out. Of course, that would really depend on the material, but you get the idea.

A big inconvenience of using these kinds of materials has been their rather inconsistent properties – conductivity can vary greatly depending on the manufacturing process. It can also be difficult to produce them, since they are not very soluble, not to mention that many polymers can be quite toxic and harmful to humans and the environment. Currently, one of the most commercially available organic conductor is the polymer PEDOT. However, it is rarely used by itself; rather, it is usually combined with other materials to slightly change its properties, for example to make it more soluble. Because of conducting polymers’ promising future and wide range of possible applications, companies and universities all over the world are working towards improving the technology and discovering newer, better materials.

A couple of months ago, there was some breakthrough research involving McGill’s Dr. Dmitrii Perepichka, who worked in collaboration with Dr. Federico Rosei of the Institut national de la recherche scientifique to discover and engineer organic conductors with new properties. What they were able to achieve is a greater control over PEDOT’s structure. Why is that such a big deal? If you’ve ever taken a Biology or a Chemistry class, you are probably aware of how important structure can be. The main reason for the inconsistency in conductive polymer properties is their lack of structure. In this case, by controlling how the PEDOT molecules get ordered during synthesis, not only can conductivity be improved, it is quite possible to create circuits, where certain parts would be conducting and certain parts would not. The difference from regular circuits would be that this here happens at the molecular level!

So, you could potentially make memory and chips that are even smaller than what we are used to. This would be particularly exciting to those who are trying to develop nanomachines or very sensitive sensors.
Going in line with this thought, other McGill researchers , namely Dr. Gonzalo Cosa and Dr. Isabelle Rouiller from the departments of Chemistry and Anatomy and Cell Biology, respectively, recently unveiled their remarkable progress: the ability to study electron transport on the molecular level. This will no doubt help us understand how these materials work and allow great improvements to their design and application. Another great advancement for nanotechnology.

It might still be too early for this new research to bear fruit, but the message is clear: the technology is improving. Companies are recognizing the benefits of organic conductors and some products are already on the market.

I may not be the most talented diviner out there, but I expect these conductors to become increasingly important and present in everyday applications, so keep an eye out.

BIBLIOGRAPHY
● Bolduc, Gisèle and William Raillant-Clark. “Organic nanoelectronics a step closer.” McGill. 15 Jun. 2010. <http://www.mcgill.ca/newsroom/news/item/?item_id=163963>.
● Miller, Paul. “LG’s 31-inch OLED prototype to slice through IFA.” Engadget. 30 Aug. 2010. <http://www.engadget.com/2010/08/30/lgs-31-inch-oled-prototype-to-slice-through-ifa/>.
● Nezu, Tadashi. “Conductive Polymers Improve Characteristics; PEDOT Surges Ahead.” Nikkei Electronics Asia. 20 Oct. 2009.<http://techon.nikkeibp.co.jp/article/HONSHI/ 20090929/175766>
● Raillant-Clark, William . “Striding toward a new dawn for electronics.” McGill. 28
Sep. 2010. <http://www.mcgill.ca/newsroom/news/item/?item_id=168188>.
● Rogers, Dan. “PEDOT findings open opportunities for organic nanoelectronic circuits.” Plastic Electronics. 24 Jun. 2010. <http://www.plusplasticelectronics.com/consumer electronics/pedot-findings-open-opportunities-for-organic-nanoelectronic-circuits-14834.aspx>