Subject: Data Communication

Topic: Multiplexing

Question: Twenty two sources, four with a bit rate of 400 Mbps, ten with a bit rate of 200 Mbps and eight with a bit rate of 100 Mbps are to be combined using TDM. If the unit size is 20 bits determine the following questions:

i. How this can be achieved?

ii. Input time slot

iii. Frame Size

iv. Output time slot

1. Input Bit Duration 2. Input Time Slot (T) = 3. No. of links at input 4. Frame Duration Il 5. Frame Size 6. Output Time Slot = Duration of 1 bit before multiplexing Time to transmit 1 bit before multiplexing 1 sec Input Speed = Duration of 1 unit data before multiplexing Time to transmit 1 unit data before multiplexing 1 Unit sec Input Speed No. of slots in the frame Duration of 1 frame after multiplexing = Time to transmit 1 frame after multiplexing Input Time Slot (T) Unit Size * No of slots (links) bits Frame Duration sec No.of Slots Duration of 1 bit after multiplexing Time to transmit 1 bit after multiplexing Frame Duration sec Frame Size Output Time Slot sec Unit Size No. of frames per second 1 frames/sec Frame Duration Bits per second 1 bps Output bit duration Frame Rate * Frame Size bps = 7. Output Bit Duration 8. Frame Rate = 9. Bit Rate/ Data Rate Il