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November 6, 2003

Corrected and refined some material in the DSL pages. Take a look. DSL or digital subscriber line is a very misleading name. The technology isn't truly digital, it just has that name.

On September 17, 2003, California Highway Patrol Officer Mike Terry was badly hurt in a motor vehicle accident while on the job, riding his bike. His recovery will be long and expensive. If you can send him a greeting, make a donation, or attend a November 14th fund raiser in the Sacramento, California area, I'm sure his family would appreciate it. To sign his guest book or to get further information, please visit his website: http://officerterry.com/ (external link)

November 5, 2003 Wednesday

What keeps the world from falling apart?

Gravity keeps loose objects grounded. Pencils on a desk, books on a shelf, water in a pond, would all be floating free if weren't for gravity, that downward pull to the earth's center. But what keeps attached objects grounded? Why don't buildings and rocks and trees fall to the planet's core? What keeps our own bodies from falling apart? It's because gravity is a wimp. Electromagnetism, that essential friend of telephony, is 10 to the 42'd power stronger than gravity. Sky and Telescope magazine's Stuart Goldman writes that, "It's this mutual repulsion of billions of electrons that prevent . . . everything . . . from plunging to the center of the Earth." Stuart was reviewing the new PBS series, The Elegant Universe, based on Brian Greene's book of the same name. Here's a paragraph from that book, along with a link for a much longer excerpt:

"The electromagnetic repulsion [compared to gravity on the Earth] is about a million billion billion billion billion (10 to the 42th) times stronger! If your right bicep represents the strength of the gravitational force, then your left bicep would have to extend beyond the edge of the known universe to represent the strength of the electromagnetic force. The only reason the electromagnetic force does not completely overwhelm gravity in the world around us is that most things are composed of an equal amount of positive and negative electric charges whose forces cancel each other out. On the other hand, since gravity is always attractive, there are no analogous cancellations -- more stuff means greater gravitational force. But fundamentally speaking, gravity is an extremely feeble force."

http://www.wwnorton.com/catalog/fall03/

greene1.htm (external link)

Unrelated graphic but still neat (Click for larger image 249K)

November 4, 2003 Tuesday

Words of art

Wireless has many odd terms, especially for measurement and test. Aslan Technologies performs the tests below. I wrote to Mark van der Hoek (not an Aslan employee) for an explanation. He writes,

"Sweep testing involves injecting a signal into an antenna system (cables with or without the antenna attached) and measuring the reflection. In theory, we want all of the energy to go out of the antenna into space. But in reality, some gets reflected, and these reflections indicate mis-matches in the system. If they are too severe, corrective action is needed."

"Antenna Loss, Return Loss, Fault Location, Insertion Loss, VSWR Measurement are all part of sweep testing. The 'sweep' part comes from the fact that the signal is 'swept' across the frequency band of the intended application, and results recorded. Sometimes you'll find that an antenna system has a bad spot at one frequency. Or it may fail across a wide band. Typically the cable is tested first, then the antenna is connected and the whole system is tested. The antenna may be tested by itself on the ground first, but some don't like this approach as nearby objects can affect the results.

"Backhaul Testing is testing the link back to the switch, whether that is a T-1 from the local telco or a microwave link."

"Base Station Testing is simply putting the site hardware through some diagnostics."

"Ground Resistance Testing is a standard test for any telecommunications site. It's testing the quality of the system's ground."

"System Drive Test is getting into my area. Test phones and (often a special scanner) are mounted in a vehicle and driven around the area. Usually an engineer has mapped out a drive route. The data is downloaded continuously into a laptop, along with GPS data. Then the data can be plotted out and analyzed. That's where  Data Analysis comes in. Problems like Pilot Pollution and Missing Neighbors show up here."

"If phones from several different operators are used, you are doing Competitive Comparison Analysis."

Mark.

Thanks, Mark! I note that Ericsson says Missing Neighbors are incorrectly configured neighborhood cell relations. And that Pilot Pollution means evaluating the primary Common Pilot Channel or CPICH. The Common Pilot Channel is fine tuned to balance cell call loads or volume. Increasing power means accepting more calls into a cell, decreasing power to the CPICH means taking fewer. The URL was here:

http://www.ericsson.com/services

/tems/articles/March_02_Investigation-WCDMA_SE.pdf (external link)

November 3, 2003 Monday

Update from the fire line

Can you tell what this picture shows? It's a cellular antenna tower, made of wood to make it less obvious. Note the metal brackets. That's where the fake limbs were attached. Mike Lyons of Aslan Technologies took the photograph. Several days ago he reported "Maybe wooden cell tower antennas weren't such a good idea after all. The fire crews had no idea a cellular telephone site was there. We are on the emergency restoration crew for several carriers. We are all working 24 hours a day to get these sites on air as the fires clear them. We are literally just off the fire line, as soon as the fire is out on the sites, we go in."

November 2, 2003

International Telephone and Telegraph, Cable and Wireless

IT&T tried being the world-wide equivalent to AT&T. In some ways they succeeded. Little exists about IT&T on the web but you'll find many good books about them in any large library. They had two eras, the first, founding and development, led by the Behn brothers, and the second, a rebirth and expansion, led by Harold Geneen. How did they start?

In 1925 Western Electric sold its overseas manufacturing plants to a small company with a big name and even bigger ideas: International Telephone and Telegraph. A controversial decision within the Bell System. AT&T sold factories in 11 countries, fearing a United States anti-trust lawsuit. Western kept one foreign company: Canadian Northern Electric, holding it until 1957. AT&T would not return officially to the international market until 1977.

ITT's owners, the curious, conspiratorial Behn brothers, Sosthenes and Hernand, bought Western Electric International for 30 million dollars and renamed it International Standard Electric. Their purchase, backed by J.P. Morgan's bank, included Western's large British manufacturer, renamed Standard Telephones and Cable. The Behns agreed not to compete in America against Western Electric, and to be the export agent for AT&T products abroad. AT&T agreed in return not to compete internationally against the Behns. Now equipped with a large manufacturing arm, IT&T spread across the globe, buying and influencing telephone companies (and their governments) on nearly every continent.

IT&T reorganized and moved into new industries in the late1950s after Sosthenes Behn died. Harold Geneen, an obsessive and ruthless man, at times criminal, took charge. Don Kimberlin relates,

"Harold Geneen's arrival put accountants clearly in charge. During my own time there, the engineers were still reeling from the way in which Geneen trashed all their technology heritage, both figuratively and literally. If it didn't make money in the current accounting cycle, it wasn't worth having around."

"I have my own perfect example, having been the project engineer who found a revolutionary way to improve telegraphy on the then worldwide Telex network. My technique was highly successful, and increased the capacity of an analog voice channel from at first 24 TTY's, then 46, then 92, and ultimately 184 as the serial data modems that supported it increased in capacity from 2400 to 4800 and then 9600 bps."

"That project impressed Park Avenue enough that they featured that 'ITT World's First' on the cover of the annual report....then forgot about it. Geneen was the sort who'd say, 'OK, so what did you do for me this year?' He wouldn't invest in people whose creativity didn't match the accounting cycle. I left ITT to utlimately work for a developer who had me take the new technology to Africa and the Mid-East."

"In that regard, we had to solve a number of marketing problems. One of them was Saddam Hussein, who wanted our Time Division Multiplexing technique because we'd proved and sold it to the Saudis. However, Iraq had alrady embargoed American goods."

"Cable and Wireless stepped into the transaction to broker it and sanitize the deal. At the time, it was interesting because the Iraqis actually came to us, even visiting our company and factory run by American Jews, but then they backed off to have CandW make the purchase and install the goods. No small part of it was the Arab embargo on components from 'corporate supporters of Zionism.' That included most of our semiconductor suppliers -- Fairchild, Motorola and such. The Iraqis sent people from their embassy to our plant, negotiating the price and having us paint out all offending parts ID's in the product, the drawings and the parts lists, to make a special product for them. They paid dearly for us to make our products acceptable to their inspectors -- and CandW benefited from the increased cash flow in the deal."

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