If you are internet-functional enough to be able to load this page on a browser, you have almost certainly seen a LOLcat before… probably forwarded a link to one and maybe made a few of your own. The phenomenon is fairly old in Internet terms: about two or three years as normal human beings reckon time. It has since spread out beyond its initial audience of geeks: the ecosystem has broadened to include lolhamsters, LOLCorgans (for fans of the Smashing Pumpkins frontman), and, o yes, lolgays.

LOLcats have two essential elements: a picture of a cat, and a caption in a sort of slang dialect sometimes referred to as LOLspeak (others use the pseudo-scientific term kitty pidgin). LOLspeak derives heavily from leetspeak and internet memes (as well as the bastard cousins of those two folkways: txt shorthand and image macros). embedding these wordlets, words and phrases into a loopy syntax that sort of smacks of engrish (which is, of course, another internet meme). LOLspeak is sufficiently mature that it makes sense to think of it as a language or dialect all its own: as one observer puts it, it is possible to get LOLspeak wrong.

Human society uses dialects, slang and argot as a way of establishing who’s in and who’s out, and as a way of maintaining connection among those in the in-group. Anybody who speaks a regional dialect has noticed that jokes (even ones that aren’t that good) are usually funnier when they’re said in dialect. In addition to the a-ha of the joke itself – the source of the humor – there’s the recognition of seeing your own subcultural signifiers.

LOLcats themselves, of course, have an appeal that transcends online geekiness. Even to those outside the subculture (say, your Mom), there’s enormous cuteness value to a picture of a cat with a caption, however cryptic (“Im in ur noun, verb-ing ur related noun”). In this way, much as sports culture, say, or the movies have fed back into the broader culture, so too has LOLling become increasingly part of the modern experience.

LOLcats are immediately recognizable as a type: self-aware, crazed with hunger, improbably mischievous, and terrible liars. They are, in short, quite possibly the template for 21st century American society, kulturbärers of our time. LOLSpeak sounds perfectly natural coming out of George Bush‘s mouth, and as we lose faith in the power of our institutions to manage the chaos of the world, we find a kind of solace in the buffoonery of loleconomists and lolgeeks.

In sum, there are clues we can draw from a scorned subculture with a weird ethos and a private set of symbols and signifiers: the early Christians of the first few centuries A.D. As the fish, the lamb, and utlimately the crucifix passed from secret sign to universal symbol, it carried the Christian message to millions.

LOLcat religion? DO NOT WANT. But, on the other hand… we could certainly do worse than to venerate Ceiling Cat.

kthxbai

Today, physicists announced that they found evidence of WIMPs for the first time. In an experiment in Antarctica, they detected electrons with the right amount of energy that would have been created by a WIMP crashing into a… normal thing.

Why do we care about what we can’t see? For one reason… most of the universe appears to be made up of it:

The standard model of the way the Universe was created hangs together pretty well if dark matter – about which we know, like, next to nothing – is included. If there’s no such thing as dark matter… well, what we know explains 4% of the Universe. Humbling.

If the experiment did actually find evidence of dark matter, it’s a big boost to the idea that there are many other “compact” dimensions in addition to the four we all know and love. The mathematics used in superstring theory, for example, needs at least 10 dimensions to begin to work out. Modern physics is based on two big theories – general relativity and quantum mechanics – that don’t fit together. As superstrings are one of the leading contenders to make the two pieces fit, this discovery could be big news.

WiMAX – also known as the IEEE 802.16 standard – is like WiFi but offers better throughput, longer shots and can support a great many more users. WiMAX seems ideally suited to areas where there is not currently a wireline infrastructure and pulling new cable is cost-prohibitive: in the developing world, sure, but also in the dense urban cores of much of Old Europe, where cable TV was never run.

­ A WiMAX system consists of two parts:

• A WiMAX base station, arranged in a sectoral (or cell-tower-like) configuration
• A WiMAX subscriber unit, either a gateway box like a home router, or a card in a laptop

WiMAX, like WiFi, carries data via wireless (radio) signals. While the fastest WiFi connection can transmit up to 54 megabits per second under the best conditions, the WiMAX protocols can support up to 70 megabits per second. Furthermore, WiMAX is capable of much greater distance transmissions: potentially covering a radius of up to 30 miles: subject, as all wireless systems are, to obstructions like terrain, weather and large buildings. With a well-planned, properly installed infrastructure, though, WiMAX can provide seamless coverage over extremely large areas.

WiMAX is also (archaically) known known as WirelessMAN, for Metropolitan Area Network. As the name implies, it is potentially a step along the path to a global area network (GAN). The proposed IEEE 802.20 standard lays out the guidelines for how a GAN would function. It would bear a lot of similarity to present-day cell phone networks, allowing people to travel long distances while retaining connection to the global Internet.

The technology has been in the ramp-up stage for a very long time, and it remains to be seen if providers can get a large number of WiMAX networks deployed so that it can be seen as a viable technology. Like the spread of faxes two decades ago, the more WiMAX networks there are, the more valuable the technology will become. Without wider adoption, there’s always the risk of it going the way of ISDN (remember that?)

Nevertheless, as a “last mile” technology with special applicability to rural comunities and the developing world, WiMAX can play an analogous role to cellular phones in spreading communications technology to underserved areas.

Communicating digitally over a satellite connection can often feel a lot like using an old-school modem: your sleek, digital broadband datastream gets snarled in a slow, often balky analog link. Indeed, the mechanics are the same – data is modulated, passed over a long (in this case, very long) distance, where it is demodulated and passed along to its destination. When you begin to get a sense of all the things that can (and often do) happen to an electromagnetic signal on the way to and from a satellite 35,000 kilometres above the Earth, you may be struck, as I was, at what a miracle it is that the data can pass at all, let alone at a decent speed and error rate!

Our fundamental obstacle in bouncing our signals off a spacecraft in geosynchronous orbit is signal loss due to the distance involved and the absorption of signal by atmospheric gases. “Noise,” or interference to the signal, is introduced at various points along the link, and it’s the job of a radio frequency (RF) engineer to determine the right amount of power to overcome the signal without saturating the receiver. Think of this optimization as being like trying to shout to be heard in a noisy room: if you speak too softly, no one can hear you, but if you scream your head off, your “signal” will be distorted, and no one will understand you. So there’s a fairly delicate balance at work here; there needs to be enough power to get the signal through the various sources of loss without over-driving it while leaving enough “extra” power available to overcome transient sources of loss like rain.

I often find it useful to follow the path from source to receiver as a way of understanding how a given link works. So, in a drastically simplified model, let’s travel along with a packet as it traverses a satellite link between two terrestrial networks.

As in any digital-analog-digital transmission, the first thing that happens is the conversion from a digital bitstream to an analog bandpass channel. The details of this process are way beyond the scope of this brief introduction, but let’s leave it that our packet has now been magically transformed into a series of symbols. Depending on the type of modulation we are using, our symbol rate may vary (we used to call this “baud rate” back in the day). Now our structured, discrete bitstream has fallen through the rabbit hole into the often confusing world of continuous waveforms. Things are about to get much more interesting.

Our waveform is now traveling across the inter-facility link, which we might think of the “runway” the signal needs to traverse before it takes off into space at the satellite dish. Because it is traveling across a shielded coaxial cable, it can use a lower frequency than it will later require. This  is, for the VSAT (Very Small Aperture Terminal) satcom I am used to, is typically 70 or 140 MHz L-band. Before it gets to the dish, it will be upconverted to a much higher frequency. The Ku band used by the equipment that I work with operates anywhere between 12 and 18 GHz; other equipment uses C-band, at lower frequencies. This microwave signal is then dramatically boosted (by many orders of magnitude) with a high-power amplifier and transmitted into space.

The feed on a satellite dish is placed at the dish’s focal point, which directs most of the signal in the direction of the spacecraft. Because this is a radio transmission, of course, it does not travel in a straight line, like a laser, but rather radiates out in other directions. In general, the larger the antenna, the better the ability to concentrate power. The measurement of the effectiveness of a directed antenna is called gain, and it becomes of crucial importance as we attempt to get our signal out to the satellite.

When planning a satellite link, an RF engineer uses what’s called a “link budget” to predict the performance of the link. The link budget takes into account the loss and gain of power along the link, as well as the various impairments (noise) that affect the signal. Given a specific power level at the transmit terminal, the link performance at the receive terminal can be calculated – and, thereby, the necessary power on the transmit side in order to achieve a desired performance on the receive side.

As our packet – now a series of symbols – rises from the Earth, it must first fight its way through the atmosphere. In addition to rain (a notorious absorber of microwave signal) and thermal interference, our signal may also have to contend with other signals, or “interferers,” as it heads out to space. By the time a signal reaches the satellite, even the most effective antenna cannot prevent it from spreading out hundreds of miles. Each satellite has multiple transponders located in its payload, and so, with the signal drastically attenuated so far out in space, after being battered by noise, a key consideration now becomes adjacent interference, or the effect of other signls passing to and from the target satellite… or to and from other satellites (it is getting crowded out there). Regulations require that your own signal minimize this adjacency, so your concern now becomes how to get the most out of your own performance while being mindful of those on adjacent transponders. Here, being a good neighbor is not just a good idea… it’s the law.

The satellite is usually used as a “bent-pipe” repeater; that is to say, it receives the signals sent to it, filters and amplifies them, and transmits it back to Earth over its downlink. The satellite receiver is a major source of noise in the link that must be taken into consideration. Here, a stray signal can become intermodulated with your signal – this noise is then injected into your signal and blasted back to Earth.

At the ground receiver, the signal is received in whatever state, and then error correction is applied to it to counteract the effects of signal degradation over its long journey. The reconstruction of a noisy carrier into its original signal is one of the great miracles of this whole process. Remember that we do not, at this level, simply ask for re-transmission of garbled signals – if at all, such transmission control must be handled by digital protocols. Rather, the signal is reconstructed from protocols inherent in the transmission (which are, again, out of the scope of this introduction).

Once recieved, this signal is beat against a local oscillator to convert it back down to L-band, and returned to the demodulator for conversion back to its bits. Only now can the bithead’s beloved internet protocols do their magic – and yet, with the high latency of the space link, TCP SYN/ACK becomes a joke. One must assume a window size of 1 for acknowledgement to have any meaning… which means that transmission would slow to a crawl as each and every packet goes through the link, is acknowledged, and the next packet allowed to transmit. There are various IP aceleration schemes that are done to more or less spoof TCP so that speeds approaching the broadband transfer rates we have grown accustomed to can be achieved. The most famous of these is the Space Communications Protocol Suite or SCPS (pronounced “skips”), though there are newer (and better) commercial implementations being released all the time.

This introduction is presented in draft form, and I welcome – in fact am begging for – your comments and clarifications.