Tutorial 7 900 MHz GSM system is using FDD (frequency division duplex). Uplink channels are in the frequency band of 890.2MHz to 915MHz, and the downlink channels are in frequency band of 935.2MHz to 960MHz. Each channel requires a frequency band of 0.2MHz including the guard frequency. How many channels can be defined for uplink and downlink? Assuming that a service area is defined to be consisted of 21 cells with the same size. Calculate the number of uplink channels that defined for a system using 3 cells in a cluster and 7 cells in a cluster. Which one can support more users? What is the assumption in your calculation? Suggest a way to further increase the performance of the system. Discuss the main tradeoffs in using hierarchical cells. Which type of cell (i.e., micro or macro) should a mobile station connect to if (a) it is a fast moving object; (b) it is a stationary object; and (c) it is no information about the mobile behavior of the mobile station?

Tutorial 7 Draw the frequency assignment pattern for (i) a 3 cell cluster; (ii) 4 cell cluster, and (iii) 7 cell cluster. What are the values of i and j for K equal to 3, 4 and 7? Suppose that the SIR is required to be greater than 12dB only and the total number of channels available is 124. What is the maximum number of frequencies that can be allocated to a single cell? (assume a=4, only first tier interference cells are considered).