7: In a cellular system, we have three neighboring cells C1, C2, and C3, served by base stations BS1, BS2, and BS3, respectively. A mobile station, currently present in cell C1, receives a power of -90 dBm from BS1. The mobile station also receives powers of -85 dBm and -91 dBm from BS2 and BS3, respectively. The mobile station has a receiver sensitivity of -100 dBm. If the system uses "Relative Signal Strength with Hysteresis" method for the hard handoff with the hysteresis margin (h) of 7 dBms, will a handoff occur at the mobile station's current location? If yes, to which base station the mobile station will be connected after the handoff? Explain your answer in at most two lines. 

Question 8 [15 points]: Suppose a mobile unit is currently present in cell C1 which is served by the base station B1. Base station B1 transmits signals at frequency 1GHz towards the mobile unit. There are two neighboring cells C2 and C3 served by the base stations B2 and B3, respectively. At a certain point in time, stations B2 and B3 also transmit signals at frequency 1 GHz. The mobile user receives a power of -50 dBm from B1, while it receives powers of -90 dBm and -80 dBm from B2 and B3, respectively, at 1 GHz. Compute the Signal-to-Interference Ratio (SIR) in dBs at the mobile unit. Assume free space pathloss, isotropic antennas at all base stations and the mobile unit.