propagation model serves here to test scenarios in urban and suburban areas outside the high rise core where the buildings are of nearly uniform height as dis- cussed in Chapter 2 and [7]. (5.6) where R is the base station - UE separation in kilometres, f is the carrier frequency of 2000 MHz and Dhb is the base station antenna height, in metres, measured from the average rooftop level. When the BS antenna height gets fixed at 15 m above the average rooftop (i.e. Dhb = 15 m) and when considering a carrier frequency of 2000 MHz, the macro cell propaga- tion model formula becomes: L = =128.1+37.6 log,(R). (5.7) Once we calculate L we add a log-normally distributed shadowing (log F) with stan- dard deviation of 10 dB to obtain the path loss as follows: Pathloss 1 = L logF. = (5.8) To complete the definition of the path loss for our analysis we should note from [5] that: L shall in no circumstances be less than free space loss, and this model applies only to the Non-Line-of-Sight (NLOS) case and describes worse case propagation for the examples in this section. The path loss model is valid for a range of Dhb from 0 to 50 m. This model concerns designs mainly for distance from a few hundred metres to kilometres. Thus, it may not accurately apply to short distances. 5.5.2.3 Micro Cell Propagation Model We use the micro cell propagation model (also covered in Chapter 2) for spectrum effi- ciency evaluations in urban environments modelled through a Manhattan-like structure. It allows us to appropriately evaluate the performance in micro cell situations that will be typical for example in European like cities at the time of UMTS deployment. In this case, this recursive model calculates the path loss as a sum of LOS and NLOS segments. We find the shortest path along streets between the BS and the UE within the Manhattan environment. The path loss in dB is thus given by the well-known formula The UMTS Network and Radio Access Technology (5.9) where dn is the 'illusory' distance, a is the wavelength, and n is the number of st