Q. The peak cell rate (PCR), sustainable cell rate (SCR), and maximum burst size (MBS) are used for measurement of ? 
Answer: Bandwidth
Notes: The peak cell rate (PCR), sustainable cell rate (SCR), and maximum burst size (MBS) are parameters used in Asynchronous Transfer Mode (ATM) networks to measure bandwidth. PCR defines the maximum rate at which cells can be transmitted, SCR indicates the average rate that can be sustained over time, and MBS specifies the maximum amount of data that can be sent in a burst. These metrics are crucial for managing network traffic and ensuring Quality of Service (QoS) in telecommunications.