Propagation Modeling and Other Challenges for Non-Line-Of-Sight Wireless Systems in the 4-6 GHz Bands

In the early 1990´s, AT&T engaged in an ambitious experimental program to evaluate the use of the 6 GHz band for wireless voice services. This paper summarizes some of the challenges faced in the trial, the experiments conducted to explore them and findings from those tests. Many of the same issues examined in the AT&T 6 GHz trial needs to considered by system planners of next generation wireless systems attempting to operate in the 4 GHz to 6 GHz bands. It is hoped that the information presented here may help and encourage planners of next generation wireless systems to consider operation in these higher frequency bands as they search for available spectrum opportunities