Combined protocol and Basic protocol

Question

Write the differences between combined protocol and Basic protocol.

Answer 1

Basic Protocol (BP):

a) It is a Periodic Mode or Aperiodic Mode.

It provides an equal priority access for each terminal to transmit either periodic or aperiodic data. If no bus overload exists and transmission lengths are constant, terminals transmit at a constant interval (Periodic Mode). If the bus is overloaded, it will automatically switch to an aperiodic mode with no loss of data

Combined Protocol (CP):

a) It is a Periodic and Aperiodic Mode.

b) It permits the Prioritized Data.

It offers Priority Access for the Periodic data transmission (Priority 1) and two levels of lower priority access for the Aperiodic data transmission (Levels 2 & 3). At every level all the terminals are provided with the equal opportunity in order to access the bus. It permits the substantial levels of aperiodic data to be transmitted without having any risk of affecting the frequency of periodic transmission.