Tuesday, February 21, 2012

How near-infinite a speed?

kw: technical trends

We just had a Verizon tech spend a couple hours at our home adding Verizon FIOS TV to our phone and internet package. One part of the mix was boosting our internet speed. After running the wireless optimizer, the speed test showed download/upload speeds of about 20 and 6 million bits/sec (Mbps). I had a moment of reflection, not of nostalgia, really, because I have no desire to turn back the clock. Just recalling:

In 1979 I got my first home terminal, which came with a 300 baud modem, the kind you stuffed the phone handset into when phone handsets looked like earmuffs. I felt lucky; most affordable modems still ran at 110 baud. Baud is a term left over from Teletype days, when the standard had been 55 baud. For 5-level code with no parity or timing bits, that came to 11 characters/sec, the speed of a typist going 110 words per minute. ASCII, with its 8-bit characters, also had a parity bit and a timing bit, for 10 bits/character, so the standard was boosted to 110 baud, or bps, to keep the 11 char/sec rate. That is fast enough to stay ahead of nearly all typists, so it is perfect for data input.

However, 11 ch/s is rather slow for watching output arrive on a screen or paper (in a printing terminal), so 300 baud seemed luxurious. Then graphical applications began to spread, and 300 seemed slow. Prices fell and speeds rose, and by 1984 I had a 1200 baud modem that plugged into the phone jack through a splitter.

I don't recall my first 9600 baud modem, but I do remember adding a second phone line to my home in 1995, dedicated to a 56 kbps (baud no longer mentioned) modem. Speeds slowed down briefly two years later when the neighborhood was put on a multiplexer by the phone company—too many new phone lines had been added. Speed was limited to 28,800, or "28 kbps". It felt awful, so when DSL was offered I jumped at it.

DSL was troublesome at first, until they found that the piece of wire running from the pole to my house was fifty years old and badly oxidized. The phone company replaced the wire, and suddenly, I had rock solid 384 kbps, and it took only three minutes to download a 1 Mbyte file. Since I was still primarily into text computing, that was OK.

Not long thereafter, I learned about T1, the speed of a first-level trunk line, at 1.54 Mbps, and T3, at three times that speed. I remember wondering if I could make profitable use of that much bandwidth. When DSL speeds were boosted to 768 kbps, then to T1, over the next couple of years, at no extra cost, it became possible to go into music and photo sharing in a big way. It was about that time I got my first digital camera, in 2002 or 2003.

In 2004, FIOS was offered. We just got the phone plan and the most basic level of internet speed, which was close to T3, about 4 Mbps for download and 1 Mbps for upload. These speeds were doubled in 2008, or more than doubled because a speed test showed 9 down and 4 up. FIOS technology allows speeds as high as 150/50, but at a high price.

Now it is 2012, and speed has doubled again at my house. I don't know if the trend will continue. CPU speeds per core topped out at about 3.3 GHz about ten years ago. The current internet speed at our house is sufficient for three or four people to watch streaming HD video at once. I hear tell that "4x" technology is about to push video to a new level. HDTV has two formats, 1280x720 at 60 frames/sec and 1920x1080 at 30 frames interlaced. "4x" is in the range of 4000x2500 and requires about four times the data speed of HD. It is the format you see in many movie theaters. It is unlikely that data speeds need to exceed 30-50 Mbps for nearly all of us.

Screen prices have to come down a bit more before such a format becomes popular in the home. A 4x screen with about 100 dpi would be a 48-inch diagonal, but I expect the most likely screen size for 4x format to be 60 inches. I give it about ten years, by which time data speeds in the 20 to 50 Mbps range will be very widespread in America. But what do I know? Go ahead, technology, surprise me again!

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