As illustrated in Figure 5.21, consider a hexagonal cellular system with omnidirectional base stations and a static channel allocation scheme. The average SNR at the cell corner is 40 dB. In order to...

As illustrated in Figure 5.21, consider a hexagonal cellular system with omnidirectional base stations and a static channel allocation scheme. The average SNR at the cell corner is 40 dB. In order to deliver a certain service the SINR has to be better than γ = 13 dB. a) The operator can use 128 channels and has decided to use the following path loss model: LdB = 48+40log10(r)[m] If we are aiming for at least 5 users/km2, estimate how many base stations are needed to cover a region of 1000 km2. Assume all transmitters have the same power, use a downlink calculation and reasonable simplifications. b) Now choose a stochastic model for the SINR, = Gγ0, where γ0 is the average SINR and G is log-normal with expectation value 0 dB and standard deviation 4 dB. We want 98% availability (downlink) at the cell corner. How will this affect the number of base stations needed? The information in Figure 5.22 can be used for the calculations.