A high school teacher named Kristen wrote to say that her students had been using some web pages from the patrickWeb blog as a source of information for their studies and projects. The posting below is one of the pages they found useful. The story was originally posted on June 10, 2003. One of the students in Kristen’s class, Brian, contributed an additional link to the blog that he has found particularly valuable in using Linux. I am grateful to all readers for using patrickWeb and especially appreciate it when they make suggestions or report errors in the site. Having just updated the site to an all new design, I am sure there will be some bugs that are discovered.
WiFi is such a clean and user-friendly name. WiFi stands for “wireless fidelity” and it is based on a standard called 802.11 — but who cares? It is becoming a household name, more and more available, and extremely useful. The information technology and telecommunications industries often get enamored with the technical name or the name of a standard and then these “tech-names” take on a life of their own — even though they may be next to impossible to remember, spell, or understand. An example is the technology used in the Sprint PCS wireless service which I use with my ThinkPad. It is referred to as 1xRTT. Somewhat like R2D2 except that I think most people know what R2D2 is.
According to Webopedia.com, 1xRTT is short for single carrier (1x) radio transmission technology, a 3G wireless technology based on the CDMA platform. 1xRTT has the capability of providing ISDN-like speeds of up to 144 Kbps. 1xRTT is also referred to as CDMA2000. Clear as mud? What are 3G and CDMA? Again, according to Webopedia.com, 3G is an ITU specification for the third generation (analog cellular was the first generation, digital PCS the second) of mobile communications technology. 3G promises increased bandwidth, up to 384 Kbps when a device is stationary or moving at pedestrian speed, 128 Kbps in a car, and 2 Mbps in fixed applications. 3G will work over wireless air interfaces such as GSM, TDMA, and CDMA. The new EDGE air interface has been developed specifically to meet the bandwidth needs of 3G. Seems that each definition leads to several others.
CDMA is short for Code-Division Multiple Access, a digital cellular technology that uses spread-spectrum techniques. Unlike competing systems, such as GSM, that use TDMA, CDMA does not assign a specific frequency to each user. Instead, every channel uses the full available spectrum. Individual conversations are encoded with a pseudo-random digital sequence. CDMA is a military technology first used during World War II by the English allies to foil German attempts at jamming transmissions. The allies decided to transmit over several frequencies, instead of one, making it difficult for the Germans to pick up the complete signal. Because Qualcomm Inc. created communications chips for CDMA technology, it was privy to the classified information. Once the information became public, Qualcomm claimed patents on the technology and became the first to commercialize it.
As for what to use, I’ll stick with WiFi. When on the train or other places that don’t have WiFi yet, I continue to use the Sprint PCS service. Or is it 1xRTT? Or 3G? Or CDMA? It really is a good service, albeit expensive. I rarely get the advertised 100 kbps+ speed but it is usually at least 50 kbps. The best part is that there are no wires and if the signal is lost, it reconnects when a strong enough signal reappears. I hope the definitions were useful to those may have been curious like me. I found them at Webopedia, which is one of internet.com‘s network of more than 160 Web sites. They have the sites organized into 16 channels. You can find further information at Internet.com.
