Final answer:
The main concern with Taking-Turn MAC protocols is inefficiency, which occurs due to idle time in low load situations and overhead in high load conditions, such as in Polling and Token-Passing systems.
Step-by-step explanation:
A major concern regarding Taking-Turn MAC Protocol is inefficiency in both low and high load conditions. The protocol can lead to idle time when no station is sending, which causes inefficiency in low load situations. Similarly, in high load situations, the concern is that the overhead of managing the taking turns can become significant, leading to a decrease in network throughput. Examples of taking-turns protocols include Polling and Token-Passing. In Polling, a master node invites slave nodes to transmit in turns, but if there are many nodes and little data, the polling can become burdensome. Token-Passing controls access to the shared channel by passing a token around the network; however, if the token is lost or there are delays in passing it, the system can become inefficient.