In a wireless system a base station transmits a $100$W signal from an antenna

located on top of a $15$m tall building and with a gain of $12$dB$.$ System losses are $3$dB$.$ The

receiver is located in a delivery truck with an antenna atop the truck at $3$m above the ground. The

receiver antenna gain is $8$dB and the system operates at $5$GHz$.$

a$)$ Considering the flat Earth $($two$-$ray$)$ model of the transmission, find the received signal

power when the truck is at $25$km from the base station. Express your answer in dBm$.$

$4$

$4$

$2$

$5$

$2$

$3$

$1$

$1$

$2$

A

D

C

B

GF

E

H

HF

delay

is $5$

HD

delay

is $6$

HG

delay

is $8$

new

delay

from H

LineTo F D G

A $123020$

B $211528$

C $101614$

D $32017$

E $82513$

F $02219$

G $18200$

H $30188$

b$)$ What would be the received signal power in the absence of ground reflection $($one$-$ray

model$)?$ Compare the results of the two cases considered above.

c$)$ If the wireless system described above operates in an urban environment, use the Hata

model to calculate the median path loss and the corresponding received power.

d$)$ If the city considered is San Francisco, use the Lee model to calculate the median path loss

and the received power.