How Typical is the "Typical Urban" channel model?

Channel models for urban deployments are among the most commonly used in research, standardization, and dimensioning of cellular networks. The time dispersion has ever been an important characteristic of the channel, often being the determining factor when assessing performance such as bit error rate and achievable throughput. A related measure is the channel orthogonality factor. In this paper the urban radio channel is revisited and the measurement data is compared to well-known models. We find that rms delay spread and channel orthogonality factor derived from the measurement data are significantly lower than predicted by the "typical urban" radio channel model. Corresponding implications on e.g. capacity and coverage calculations and dimensioning guidelines are also discussed.