In order to provide radio communication at a horse-race event, a base station is placed in the middle of the arena, so that any spectator is at exactly d = 500 m from the base station. However, each...

In order to provide radio communication at a horse-race event, a base station is placed in the middle of the arena, so that any spectator is at exactly d = 500 m from the base station. However, each spectator experiences a log-normal distributed fading with standard deviation σ = 5.102 dB; assume that the fading values experienced by any two spectators are uncorrelated. On the uplink, the system uses CDMA with ideal SIR-target power control and provides two types of services. The voice service requires an SIR target γv = −20 dB, while the data service requires γd = −14 dB. One out of five users uses data services. If only one terminal were active, transmitting with the maximum allowed power, the median would be γ0 = 6 dB. a) Find an expression for the largest 1 η so that the users have access to the data service with probability 97.5%. b) How many users can be served in this single-cell system under the conditions at point a)?