Quiz answers revealed

I’m hoping you’ll find a review of the year-end 2002 quiz helpful, even if you didn’t take the quiz. Below, in revealing the answers, I’m embellishing a bit to provide some extra education.

1 – C.   A hot spot is a public place with broadband Internet access. Note that a service doesn’t have to be wireless to be called a hot spot, though in the context of this newsletter, that’s what we’re usually talking about.

2 – D.  802.11a and 802.11b differ in all of the ways mentioned. They operate in different bands, 802.11a is faster, and they use different modulation techniques.

3 – E. Nearly all of you knew that actress Hedy Lamarr invented spread spectrum.

4 – D. The GSM/GPRS network operators in the U.S. are AT&T, Cingular, and T-Mobile. Sprint and Verizon run CDMA-based networks. Boingo and Surf&Sip are Wi-Fi service providers; they don’t operate WANs.

5 – C. The average per-user throughput (key words: “per-user”) of 2.5G mobile packet networks is about 20K to 40K bit/sec. Uplinks can be slower; downlinks can be slightly higher, depending on the technology in use and the network operator’s design. Not too encouraging, huh? Many of you chose (b), 144K to 384K bit/sec, but this is the theoretical aggregate speed, shared by multiple users.

6 – B. The security feature that won’t be required for Wi-Fi certification this year is AES encryption, because this requires a hardware upgrade. The clue here was “in 2003,” as AES will eventually be required.

7 – E. Most of you knew that “mesh networking” is using client devices to relay wireless signals.

8 – E. We covered last time that broadband wireless access (BWA) can be wireless fixed last-mile or public wireless LAN Internet access services. Shockingly, no one mistook BWA as part of Elmer Fudd’s vocabulary (a woman’s undergarment, pronounced “bwa”).

9 – D. Bluetooth is BEST described as a short-range, low-speed cable replacement. You can argue that whether speeds are low or high is a subjective call. But I’m the teacher, and anything that only goes a few feet and runs 1M bit/sec is slow, in my book. Remember Arcnet?

10 – E. The mobile WAN operators running commercial Wi-Fi services today are AT&T Wireless and T-Mobile. This tripped up many of you. The key words here are “commercial” and “today.” Sprint PCS has said it will offer them, but no launch date or prices are available yet (as of this writing). AT&T Wireless, at quiz press time, did offer commercial services (called “GoPort”) in the Denver airport. And T-Mobile, of course, is the shining star in this space, with more than 2,000 hot-spot enabled locations.