1. We are building a network using radios that operate at 1Ghz in an urban area. Once end of the link will have the antenna mounted on a 40 meter (approximately 43 feet) tower. The other end will be hand held at head height by people walking up to 3.75 miles (6Km) away. Which model should I use to estimate path loss over the link? Why?
Model: _______________________
Reason: _______________________
2. A sharp edge on a building or a sharp mountain ridge is likely to give rise to what propagation mechanism?
Answer: _______________________
3. If moving 4 or 5 feet clears up a noise broadcast FM signal, what type of interference am I likely to be experiencing?
Answer: _______________________
4. Stating your answer in complete sentences explain fully what was causing the problem in question 3 and how my movement caused the signal to go from noisy to clear.
5. What is the formula for the correction factor for mobile antenna height when using the Hata model with the location pictured?
Answer: ___________________________________
6. ________________ and __________________ are really the sam epropagation mechanism viewed from different perspectives.
7. Given the folloiwng equation: Ch = 3.20(log(11.75Hm))2 - 4.97 and this set of solutions using that equation:
Hm = 1.8m: Ch = +0.77dB
Hm = 3m: Ch = +3.81dB
Hm = 5m: Ch = +8.66dB
Explain fully what this equation predicts with respect to the system operation as measured by received signal strength and explain the physical reasons for this prediction.
8. The term for the overall shape or physical characteristics of the space through which a terrestrial radio wave must pass is:
Answer: _______________________
9. What is the formula for the correction factor for mobile antenna height when using the Cost231 model with the location pictured?
Answer: ___________________________________________________
10. When a signal interacts with a boundry by bouncing off and changing direction with little or no loss of power the propagation mode is:
Answer: _______________________
11. We are building a network using radios that operate at 850Mhz in a rural area. One end of the link will have the antenna mounted on a 50 meter (approximately 165 feet) tower. The other end will be mounted on the roof of a large truck at a height of 4m (approximately 13 feet) at a range of up to 12 miles (19Km). Which model should use to estimate path loss over the link? Why?
Answer: _______________________
Answer: _______________________
12. A radio installation has the antenna on the base station end at a height of 10 meters, the receive antenna at a height of 2m and a power output of 10 watts. Given the following equation:
L = 46.3 + 33.9logF - 13.82logHb - a(Hm) + [44.9-6.55logHb]logD + C
And given this set of solutions using that equation:
Base Antenna Height = 10m, Mobile Antenna Height = 2m, L = 164.84dB
Base Antenna Height = 20m, Mobile Antenna Height = 2m, L = 159.49dB
Base Antenna Height = 30m, Mobile Antenna Height = 2m, L = 156.36dB
Base Antenna Height = 40m, Mobile Antenna Height = 2m, L = 154.14dB
Base Antenna Height = 10m, Mobile Antenna Height = 3m, L = 161.94dB
Base Antenna Height = 20m, Mobile Antenna Height = 3m, L = 156.59dB
Base Antenna Height = 30m, Mobile Antenna Height = 3m, L = 153.47dB
Base Antenna Height = 40m, Mobile Antenna Height = 3m, L = 151.25dB
To improve the signal you have been given only three choices.
A. Raise the base station antenna to a height of 20 meters
B. Raise the mobile station antenna to a height of 3 meters
C. Increase transmit power to 20 watts.
To improve the signal you may do one - but only one - of the these choices. Which do you choose? Answer:______
Explain fully why you chose that solution, why it is of more advantage than the other solutions. Explain what other specific (how high, how much power, etc.) choices you might suggest to increase system performance as measured by received signal strength.