Mistaken Identity

In "Iraq Goes Wireless " [March], Ahmad Chalabi is incorrectly identified as a shareholder in MTC Atheer, the wireless venture in southern Iraq. Chalabi is not and never was a shareholder in MTC Atheer. Our company prides itself on having built a mobile system operator with Iraqi shareholders and with an entirely Iraqi workforce. We believe that through Iraqi hands and the assistance and the backing of the MTC Group we can further develop the mobile communications market in Iraq and assist the Iraqi population economically and socially.

Ali Al Dahwee

Kuwait City, Kuwait

The writer is chief executive officer of MTC Atheer.

Executive editor Glenn Zorpette responds: In an interview with me on 1 October in Baghdad, an official of Iraq's National Communications and Media Commission described what he said was Chalabi's involvement in the MTC Atheer venture. However, it is possible that this official, who could not subsequently be reached for comment, was referring to Ali Mudhar Shawqat, who is a major Atheer shareholder and was once the deputy leader of Chalabi's political party, the Iraqi National Congress. IEEE Spectrum regrets the error.

No-Phone Zone

The article on the use of cellphones in airplanes "[Unsafe at Any Airspeed?" March] misses the point. The issue is not that cellphones generate interference, but, given the vast collection of inescapable sources of interference to any aircraft's electronics from the ground—from assorted other avionics and from passengers who will always forget to turn their cellphones off—shouldn't manufacturers and installers of avionics accept the facts of life and make their avionics more resistant to interference?

The correct course of action is to engineer, install, and periodically test the avionics in a manner that ensures that the avionics can cope with the real world, not just with a make-believe world.

Michael A. Caloyannides

IEEE Senior Member

Herndon, Va.

While flying home from a house-hunting trip in 1981 in a turboprop Short Bros. 360, I began feverishly working out possible mortgage payments on a cheap credit card calculator.

Soon the stewardess was walking down the aisle asking if anyone had anything "electrical" they were using. I replied that I had a calculator that was electronic but not electrical—that is, it had no motors or anything. She borrowed my calculator and took it to the cockpit. She returned in a few minutes and admonished me with words like, "Please don't use that anymore, because when you press the keys it makes the needles in the cockpit swing around." Needless to say, I complied.

As pointed out in "Plane Talk About Cellphones" [Spectral Lines, March], much of the data on signals interference in aircraft is informal and hearsay—but this is my anecdote; I witnessed it myself. I vote for keeping the ban on cellphones.

Chris Jones

Rochester, N.Y.

Is it safe to use cellphones on airplanes? The real question should be: "Is it safe for passengers to use any electronic equipment on airplanes?" My older notebook computer interferes with VHF Channel 11 on my TV. My newer notebook computer doesn't, but my older one didn't cause interference when it was new, either. And when I'm in my home office with the FM radio on, I always hear a buzz on the radio just before my cellphone rings. Granted, aircraft may not be using the VHF and FM bands, but if these devices cause interference on these bands, how can we be sure that they're not causing interference on other bands?

Michael L. Nelson

IEEE Member

Cape Coral, Fla.

Puzzle source: Michael Mepham's Sudoku Web site, www.sudoku.org.uk

Clarification

Several readers expressed skepticism about whether the Sudoku puzzle published in our February News section is solvable. Here is the solution. (The numbers in bold are those originally given.)

Correction

Contrary to what we reported in "Big Players in Chip Design Buy Into India" [News, March], Texas Instruments did not codevelop its single-chip cellphone with Freescale Semiconductor India and did not use Freescale's MXC architecture—which Freescale developed exclusively—in the phone.

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