5441336875

following formula

SIR= 10log [^(<?~ ¹⁾⁷]    (3)

By applying our freąuency reuse factor iV = 4 to (2) we can calculate the value of q

q = vS= x/3 x 4 = 3.464

We can now find the SIR in the two cities by using the specified path loss value of 7 = 3.5 like this

(3.464 - l)³’⁶ 6

SIRdty = 10 log

= 10 log = 6.318 dB

SIRdty is less than the 14 dB we reąuire so we cannot use omni directional antennas in the cities.

We use a similar formula to calculate the SIR for the highway. Since the highway does not use a hexagonal celi layout, but rather a linear celi layout, we use the following formula

sm_MghWay = 10 log [(2JV + ly + (2N - 1)T]

= 10 log [(2x4 + l)²'⁷ + (2x4- l)²'⁷]

= 27.55 dB

We find that SIRhighway is well above the reąuired 14 dB. This means that we can safely use omni directional antennas for the highway.

5