A multilevel TDM system has ten sources, six with a bit rate of 200 Kbps and four with a bit rate of 400 Kbps. The frames generated by the system have 1 extra bit for synchronization. a. What is the size of a frame in bits? b. What is the frame rate? c. What is the duration of a frame? d. What is the data rate? e. What percent of the frame is overhead?

a) Frame size = 7 bits

b) frame rate = 400,000 frames/sec

c) Frame duration=2.5 microseconds

d) Data rate = 2.8 mbps

e) Percentage overhead frame = 14.29%

Explanation:

a) For consistency, the six 200kbps = three 400 kbps

three 400 kbps + four 400 kbps = seven 400 kbps

An output frame carries 1 bit from each line

Since there are 7 lines, the frame size = 7 * 1 bits = 7 bits

b) 400 kbps = 400000 bps

Since 1 frame carries 1 bit, frame rate = 400,000 frames/sec

c) Frame duration = 1/frame rate

Frame duration = 1/400000

Frame duration= 2.5 * 10^-6 = 2.5 microseconds

d) Data rate = bit rate * number of frames

Data rate = 400 kbps * 7 = 2.8 mbps

e) percentage overhead frame = (bit rate/data rate * 100)

                                                    = 400kbps/2.8 mbps * 100

                                                    = 14.29%