Surfing the Luminiferous Ether

Via Glenn Fleishman, I found this Sacramento Bee article describing a imminent deal between BART and Wi-Fi rail. (I tried the Wi-Fi Rail service, but wasn’t impressed.)

The article has two points worth noting. First, the initial trial will expand from the four downtown San Francisco stations to the big underground areas:

If a deal is struck, Lee says WiFi Rail will install the system on BART’s most heavily traveled underground routes – in Oakland, San Francisco and the Transbay Tube – within 120 days. Coverage for BART’s entire 103-mile system would follow.

The underground core of the BART system runs from the four downtown SF stations, the Transbay Tube, and the Oakland Wye (roughly West Oakland north to 19th Street and west to Lake Merritt).

The article then quotes Wi-Fi Rail’s corporate counsel as adding 45 minutes to a workday:

“Take a BART rider who gets on at Walnut Creek and spends 45 minutes going to downtown San Francisco” and back, says [Gilles] Attia [Wi-Fi Rail's corporate lawyer]. By plugging in, “he’s added 1 1/2 hours to his work day.”

Mr. Attia works in Sacramento, so he may not have first-hand experience with BART. Assuming that I’ve got the bounds of the expanded Wi-Fi Rail deployment right, it’s not that big. Lake Merritt to Civic Center (on my commute) is 16 minutes. 19th Street/Oakland to Civic Center is 18 minutes. 19th Street/Oakland to Lake Merritt is only 5 minutes.

Since my initial report on the unreliability of Wi-Fi Rail a year ago, I haven’t found that the service in train cars has improved. Service is faster and more robust on the platform, but I still find the service on the train spotty.

January’s IEEE 802.11 working group meeting was held in Taipei. Towards the end of my time in Taipei, I wandered through the grounds of the Sun Yat-Sen Memorial Hall. In a small area with a statue of Dr. Sun, there was a neat view of Taipei 101, shrouded in the heavy wet fog around the city at the time.

One of my favorite things to do with my camera is just to go wandering. On my January trip to Hong Kong, I stumbled across the Graham Street Market, which is one of the oldest (if not the oldest) in Hong Kong. Out of everything I saw, there were two scenes that particularly struck me.

The first was at a seafood shop. As typical for the Guangdong region, much of what’s on sale is alive and kept in polystyrene water containers. If you look closely at the photo below, you can see the aeration tubes. What really struck me about the photo, though, is the smile on the face of the woman helping a customer.

(As an aside, one of the reasons why I was shooting in black and white is because it doesn’t require me to color balance. Street market vendors use all kinds of lights, each of which has a slightly different color cast. Tungsten lamps are orange, fluorescent lamps have a sickly greenish cast, and the energy-efficient metal halide lamps that light streets the world over spread a yellowish light. Provided there is enough contrast, switching to black-and-white means that I don’t need to deal with the horrid color clash from all the lighting.)

The second scene, which I didn’t capture as well as I would have liked, illustrates the captivity of traffic to pedestrians. Only a small fraction of Hong Kong residents own cars because the government taxes automobiles very heavily and the transit system is possibly the best in the world. The street market is actually a street. As I wandered around, I noticed that trucks were making deliveries, but they sometimes had to move very slowly through single-lane streets that were choked with pedestrian traffic. At one point, I noticed a car moving slowly through the pedestrian crowd. It wasn’t just any car, either. I love the contrast of the immaculately polished white Bentley moving through a crowd of pedestrians.

In January, the IEEE 802.11 working group met in Taipei. The week before, I hosted a meeting for Task Group U in Hong Kong, a city that everybody should visit for its unique blend of traditional Chinese and Western culture.

I’ve been going to Hong Kong for over 15 years, though there was a gap of more than ten years between my first and second visits. In that time, one of the most notable changes is an unfortunate side effect of the rapid economic development in Hong Kong, Guangzhou, and the entire Pearl River Delta region. Air pollution has become much more prevalent, to the point where it can often be hard to see across the beautiful harbor.

After the meeting one night, I took one of the Star Ferry’s Harbour Cruises with some of my fellow attendees. As we passed by the Central district, I noticed flashes of light coming from up high on Victoria Peak. At this point, I am so accustomed to the seemingly permanent haze that it took me a while to realize that the flashes were tourist cameras going off on the peak.

As the boat docked, I debated whether to head to the peak at 10 pm, since I was quite tired. My companions provided the needed encouragement, and I’m glad I went. By the time I made it up, many of the buildings had turned off their colorful night lights but it was still the best view I’ve ever had of the harbor:

I later spoke with my colleagues who live in Hong Kong, and they told me that a night so clear almost never happens. I feel very fortunate that I happened to be in the city at the time.

Yesterday morning, I was awakened at 2:08 am by the incoming text message indication sound from my phone. I am traveling in Europe and my local time is +10 hours relative to my home, so it was a perfectly reasonable time to send a message to me in California. As I stumbled across the room, I wondered which of my friends or colleagues I had forgotten to tell about my trip.

The answer was “none of them.” T-Mobile had sent me a text message with the following contents:

Free T-Mobile Msg: Use your T-Mobile HotSpot account at Starbucks for years to come with no additional charges. Learn more at hotspot.t-mobile.com.

As I have often said before, T-Mobile knows where I am. Their roaming database knows that I’m in Europe because I’m attached to the Vodafone Greece network. Therefore, the T-Mobile network is perfectly capable of knowing what time it is where I am. Sending me text messages in the early hours of the morning is just aggressively stupid customer service. At 2 am, I do not care about how long I can use the hotspots at Starbucks, and in fact, coffee is not something I remotely want to consider.

(Early morning disturbances from the phone were the driving force behind the time zone processing feature I developed for my home PBX. Read part 1 and part 2 of the Linux Journal description.)

If anything, this text message is yet another illustration of why I can’t wait to get an OpenMoko phone. The first thing I’ll do is develop a “turn off ringing and text messages within the hours of X pm to Y am” feature, so that I’m not bothered by this ever again.

Earlier this week, we published our technology road map for the Open1X supplicant. They are now available for download in either PDF or Microsoft Word.

In the discussions that the project team held, our biggest goal was to get the supplicant running on as many platforms as we could. The first step is the common desktop operating systems (Windows, Mac OS X, Linux). However, there’s a long term trend at work with computers infiltrating everything. When I first started doing wireless LANs, it was something that was nice to have for laptops. In the past several years, we’ve seen 802.11 go from an esoteric data link to the most obvious way to connect a plethora of devices from laptops to game devices (the Xbox and PSP both have 802.11) to phones (I carry a Nokia E61) and PDAs.

Each time a wireless LAN interface gets put into a device, you need the entire protocol stack complete with all the security protocols. Wireless security protocols can be complex, and expertise hasn’t kept up with the wide diversity in available products. Often, a product will have a wireless LAN interface that lags behind the rest of the product in functionality.

One of the best examples of the “wireless feature lag” is our #1 feature request. Everybody who’s interested in our work has asked us to port the supplicant to the iPhone to get better interoperability with wireless LANs. Most university networks require user credentials (WPA-Enterprise) instead of pre-shared keys (WPA-Personal), but the iPhone lacks that feature. Back in October, there was an iPhone SDK announced, with details to follow in February. We’re waiting to see what features the SDK will bring, and hope to start working on an iPhone shortly. (If you’re interested in 802.1X on the iPhone, sign the on-line petition.)

I recently upgraded to an HDTV set, and I am finally displaying the HD recordings on my MythTV system in HD glory. Like most of my tasks with MythTV, though, it wasn’t just a straightforward connection to the HD set and away we go.

MythTV assumes that the display device has 100 dots per inch of resolution, even though TVs do not. The Sony KDS-50A3000 is a 50″ set with a resolution of 1920×1080, or about 44 dots per inch. (Interestingly, this isn’t all that different from the 40-45 dots per inch of the small standard definition TV I had been using with MythTV.)

The nVidia graphics display drivers calculate dots per inch based on the EDID information. In the case of the KDS-50A3000, it calculated a value of 30 dpi. The resulting font was so tiny I could barely read it with my nose pressed up against the screen. The MythTV wiki describes using the DisplaySize directive to get to the magic 100 dpi. Once I put in the appropriate directive and restarted X, the fonts in the Myth front end were nicely readable.

Catching up on my blog reading, I found a post where Richard Florida writes about immigration in the heartland. He relates a story from when he served on a panel in 2003 for the governor of Iowa on the future of the state’s economy, where a conference attendee stated:

I’m the son of Mexican immigrants, both low-skilled. I’m also a recent graduate of Grinnell College[one of the most respected small liberal arts colleges in the country]. Of my graduating class, only five of us have decided to stay in state of Iowa.

I’m a not-so-recent graduate of Grinnell. Many of my peers pursued graduate school, and many left Iowa for the workforce. A large number of graduates stayed in Iowa, where the career office’s connections were strongest. When I graduated, the career office pushed me to stay in Iowa, and didn’t seem to want to help me leave the state. I find it highly improbable that several years later, only five of roughly 300 to 400 graduates would stay in the state, so I wish there was a bit more context given for the number five.

I’ve been working with digital TV for almost four years now. I first started using it to feed my TiVo a digital signal to kill analog ghosts by downconverting a high-def signal to standard definition for my TiVo. A few months later, I built my built my first MythTV system to record the full high-definition signal. Even though I have been recording high-definition TV broadcasts for three years, I have only begun displaying the recordings in high-definition this week.

One of my holiday presents to myself was a Sony KDS-50A3000 HDTV. I love it. It’s vibrant, has wide viewing angles, and a ton of inputs. I anticipated being able to push a DVI signal to one of the three available HDMI inputs. After ordering an DVI-to-HDMI cable from Blue Jeans Cable, it was time to get everything going.

Displaying HDTV is remarkably easy with recent nVidia drivers under Linux. In the recent (8xxx) builds, there are predefined modes for HD: “1920×1080_60i” is 1080i, “1920×1080_60″ is 1080p, and so on. They go in the Display section of xorg.conf.

All is well and good. After running the cable from the DVI port to the HDMI input and restarting the X server, the TV reports that I’m giving it a 720p signal. I have HD, but not at the TV’s native resolution. A check of the log shows me why:

Something is wrong with the 1080p and 1080i modes. The MythTV system is still using the GeForce FX5200 card, which is perfectly competent to drive any SDTV display, but many posts indicate it has problems pushing 1080i out the DVI port.

So, it’s time to get down and dirty. Running Xorg -logverbose 10 -probeonly will cause the server to dump everything. It’s interesting reading.

First of all, I note that the card is detected correctly, and, though it’s a bit confusing, the FX5200 has a maximum pixel clock of 135 MHz. (As an aside, a 135 MHz is sufficient to do 1280×1024@75 Hz.)

A bit further down, the server probes the TV using the Extended Display Information Data (EDID) protocol. In the section it reports, I learn that it wasn’t made long before I bought it, and that it really, really wants to be fed a signal with a 60 Hz refresh rate.

Continuing down the log, I see why the 1080p mode was rejected. 1080p requires that you feed the TV pixels at almost 150 MHz, which is too fast for the pixel clock:

However, the 1080i mode is rejected because the interlaced mode is

By adding 120 Hz as a refresh rate and overriding the information from the display, I could push a 1080i signal to the TV. However, what I found is that a 720p signal on MythTV looked awful when converted by MythTV to 1080i. There is some loss of picture quality when displaying a 1080i signal as 720p, but it is much less noticeable. Therefore, I will stick with 720p until I can figure out how to switch video modes on the fly between 1080i and 720p.

When you’re stuck in the airport, sometimes you just need to kill some time. With a big flight delay, all I could really do was hang out at the Admiral’s Club and surf the web. In the course of a random walk through the Internet that I’d rather not divulge too much about, I wound up coming across this Mythbusters segment on the drive-the-car-into-the-semi-trailer stunt that was a staple of Knight Rider. The show was one of my early favorites, though it is painful now watching reruns with the knowledge that I would anxiously await new episodes each week. (Of course, I had an excuse. I was eight.)

At any rate, for your viewing pleasure, here’s the video of the stunt actually working:

(If the video is no longer available, just search “mythbusters knight rider” on YouTube and you’re sure to find it again.)