1. How to explain what is ss7?

Common Channel Signaling System No. 7 (i.e., SS7 or C7) is a global standard for telecommunications defined by the International Telecommunication Union (ITU) Telecommunication Standardization Sector (ITU-T). The standard defines the procedures and protocol by which network elements in the public switched telephone network (PSTN) exchange information over a digital signaling network to effect wireless (cellular) and wireline call setup, routing and control.

2. What is a matrix in Telecommunication?

It is a rectangular table of elements, which may be any abstract quantities that can be added an multiplied i.e m*n where m is row and n is columns.

3. What is the best Rx power and Tx power at good RF Conditions?

If u r talking in the sense of Satellite then
it is 6 GHz uplink that is for transmitter and 4 Ghz for downlink frequency that is receiver frequency.

4. Buffering is?
a) the process of temporarily storing the data to allow for small variation in device speeds
b) a method to reduce cross talks
c) storage of data within transmitting medium until the receiver is ready to receive.
d) a method to reduce routing overhead.

storage of data within transmitting medium until the receiver is ready to receive.
in my opinion the following procedure buffering follws so ans is c not a.
The following procedure follows:-

1 An alarm is written into the buffer.
2The alarm is read from the buffer, sent, and re-sent until it successfully reaches the destination(receiver).

3 The alarm is removed from the buffer.

9. What is TCSM ?


11. Line of sight is?
a) Straight Line
b) Parabolic
c) Tx & Rx should be visible to each other
d) none of the above

The line of sight is the distance or the path up to which the the TX and the RX is visible to each other because for the proper transmission there should be a ink or connectivity b/w the TX and the RX e.g. at the RF transmission the microwave links are required for the connectivity and data transmission.

12. What is the need of CPG message in ISUP protocol?

Consider any call forwarding scenario.As soon as switch receives Setup, it checks that the Called_Party has forwarded option activated and so tries to forward the call. Meanwhile, Switch sends CPG message towards originator saying that Call is in Progress.

15. What is the nominal voltage required in subscriber loop connected to local exchange
a) +48 volts
b) -48 volts
c) 230 volts
d) 110 volts

48 volts. This -48 volts is required by the copper wires to prevent it from corroded & eluded.

17. What is the maximal decimal number that can be accommodated in a byte?
a) 128
b) 256
c) 255
d) 512

ITS 256.



18. Frequency at which VOICE is sampled is?
a) 4 KHz
b) 8 KHz
c) 16 KHz
d) 64 KHz

The voice signals have a bandwidth of 4Khz (300hz-3400hz signal bandwidth + 450*2hz guard bands= 4000hz) according to Nyquist criteria, the sampling rate must be at least double of this total bandwidth. thus sampling rate= 2*4Khz = 8Khz. this is the required sampling rate to avoid loss of voice signals in transmission.

21. How many T1 facilities the company needs between its office and the PSTN if it has 47 digital telephones, each operating at 64kbps
3 low-speed video machines, each operating at 384kbps
1 interactive video system, requiring 1.536 mbps.

Need 4 T1's.

Each T1 can accomodate 28 channels.
► 47 digital channels

► 3 low speed V.machines at 384 kbps.

► 1 interactive video systemat 1.536mbps.
=153664=24 channels.

So total=47+6+24=89 channels
each T1 requires 1 synchronizing channel & 1 signalling channel.
So 4 T1 requires 8 channels.
Total=89+8=97 channels.

4T1's =112 channels-96 channels=15 channels(remains free)