EEB862 – Mobile and Personal Communication
Assignment-2
Semester 1-2023
1. A cell was measured during a busy hour period. The average number of users
in the 1 hr was 200 and the call duration was 10 minutes.
a) Calculate the number of channels needed if area is a residential area and
the mobile company requires that 7% of the calls be blocked during the
busy period.
b) What would be the change in the dimensioning of the number of channels
if the area is a business area for which the company wants only 1%
blocking?
[10 marks]
2. GSM is a TDMA/FDD system that uses 25 MHz for the forward link, with
channels of 200 KHz. If 8 speech channels are supported on a single radio
channel, and if no guard band is assumed, find the number of simultaneous
users that can be accommodated in GSM.
[5 marks]
3. Measurements for a typical wireless system found that the delay in receiving
the first component of a signal over the channel between a steady
transmitter and a receiver is 50 ms. The maximum excess delay observed is
65 µs. The transmission bandwidth is 10 MHz with RF carrier frequency 2.4
GHz. Check whether frequency-selective or flat fading will occur over the
channel. If the mobile receiver is in vehicular mobility condition at a speed of
50 km/h, check whether fast fading or slow fading will occur.
[7 marks]
4. One of the standard interfaces defined for ISDN (Integrated Services Digital
Network) is the basic interface, which provides a data rate of 192 kbps and
uses a frame size of 48 bits. Suppose we use TDD with a block size equal to
the frame size. Assume the distance between the subscriber and the network
switch is 1 km and a guard time is used. What is the actual data rate?
.
[5 marks]
5. Explain how the system capacity is related with the cluster size? Assume fixed
available bandwidth and service area.
[3 marks]