A radio is called full-duplex if it can both transmit and receive simultaneously. A radio is called half-duplex if it can either transmit or receive but cannot do both simultaneously. Consider a protocol between a sender node A and a receiver node B, where each node is equipped with a halfduplex radio. The protocol allows A to transmit periodically with a period of 50ms. That is, after every 50ms node A transmits a frame to node B. It takes 4ms for A to transmit each frame. As soon as the complete frame is received at B, it sends a piggybacked acknowledgement (ACK) to A. The transmission time of each piggybacked ACK is also 2ms. Assume a propagation delay of 0 in each direction. Also assume that no transmission fails.

(a) What is the channel utilization at sender node A?

(b) What is the channel utilization at receiver node B?