Page 17 - Integrated Wireless Propagation Models

P r e f a c e XV

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A software tool was created using the ° by ° tape for inputting the terrain data and
my prediction tool for system planning. It was called ACE, later renamed ADMS.
The planning engineers at AT&T and later the Baby Bells were trained to use the tool in
their cellular markets starting in 1983. On October 30, 1979, Mr. C. S. Phelan, patent
attorney of Bell Labs, wrote me a letter (printed on page 20 of Lee's Essentials of Wireless
Communications [McGraw-Hill, 2001]) and acknowledged my contribution from a Bell
Labs internal memorandum, " A New Mobile Radio Propagation Model," Case 39445-7,
March 30, 1979, written by me. The use of the terrain contour data maps with the
effective antenna height gain to predict the signal strength at any known location was
the invention of my point-to-point prediction model. Bell Labs did not want to patent
this model but rather wanted to keep it for internal use.
In 1980, Hata wrote a paper on his area-to-area model and I was one of the reviewers.
Also, I was the associate editor of IEEE Transactions on Vehicular T e chnology to accept his
paper. Later, the Hata model was adopted by CCIR. I am very glad that it became an
internationally well-known model. Readers may not know that I have been working in
this field for 50 years. If you are interested in the past, I have many stories to tell and
most of them are good ones.
This is my fourth book that has been published by McGraw-Hill. I hope this book
will provide readers with clear guidelines to further implement the propagation models
in future 4G or SG systems.

William C. Y. Lee, Ph.D.