GSM

Question 1

How many bits in first slot of RAB? What is it called?

Answer 1

8. Trailing b.

Question 2

How many bits in second slot of RAB? What is it called?

Answer 2

41 b. Synchronization sequence.

Question 3

How many bits in third slot of RAB? What is it called?

Answer 3

36 b. Encrypted bits.

Question 4

How many bits in fourth slot of RAB? What is it called?

Answer 4

3 b. Trail bits.

Question 5

How many bits in fifth slot of RAB? What is it called?

Answer 5

No bits but gap of 68.25 b equivalenty.

Question 6

Which parts of frame does initate equalizer within RAB? With what features?

Answer 6

First trailing bits with its long sequence. Syncronization bits without appearant feature.

Question 7

Which parts of frame does calculate approximate distance of MS from BTS within RAB? With what features?

Answer 7

GP with its long silence.

Question 8

What is purpose of RAB?

Answer 8

Packet Random Access Channel (PRACH) is used by an MS to initiate a transfer of packet signaling or data in the uplink. Howerver, it’s for register only according to our lectures notes.

Question 9

How many bits at dataword voice frames?

Answer 9

260.

Question 10

How many bits are in codeword voice frames? How are they formed from dataword?

Answer 10

456. Dataword has 260 bits. First three bits are CRC for next 50. Then second 132 bits followed by four zeros. These 189 bits are doubled with convluotional algorithm to produced 378 then, rest of 260, 78 remaining bits are appended completing 456 bits.

Question 11

How many bits at dataword data frames?

Answer 11

192.