 results. If we may illustrate with an example from the personal computer (PC) industry, con- sider the industry standard architecture (ISA) standard. When IBM developed the IBM PC in the early 1980s, it broke ground by publicizing the standard instead of keeping it proprietary and requiring expensive licenses. IBM did this because it was not sure that PCs would succeed. IBM thought that making the standard open would encourage innovation, and it did. Many small vendors invented PC hardware and software and launched the PC revolution. Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. General Cellular Standards Standards for Cellular Systems However, this is not the end of the story. A few years later, IBM was upset about hav- ing to share such a rich pie with companies such as Compaq. (Perhaps IBM did not re- alize that when you open one side of a standard, you open the other side as well. IBM expected adapter cards, but not clones.) IBM tried to close off the PC clone market coming out with a new, better PS/2 standard, which it kept proprietary. The PC industry reacted first by getting together and declaring the original PC/AT standard the ISA. They could now produce and test equipment for compatibility and keep on selling even though IBM had left the fold it created. IBM went on to compete with the PS/2 interface by creating the extended ISA (EISA) standard. IBM's success kept innovation going, and prices dropping, in the face of a monopolistic effort to re- strict technology. The final chapter of this story is relevant to the cellular industry. The EISA standard outperformed the PS/2 standard, but it was less reliable. EISA told vendors what to build but not how to build it, and some of them got it wrong. It was all too easy to buy an EISA PC-compatible computer and an EISA card only to find that they did not work together. A competitor nam