The Answer:

Explanation:
In circuit switching, the resources are reserved between two communicating end systems before the actual communication takes place. This implies that a dedicated communication path is established between the sender and receiver, and this path remains reserved for the entire duration of the communication session. This results in guaranteed constant rate transmission.

Guaranteed Constant Rate Transmission:
When resources are reserved in circuit switching, it ensures a guaranteed constant rate of transmission between the sender and receiver. The reserved resources include the bandwidth, buffers, and processing capacity required for the communication session. As a result, the transmission rate remains constant throughout the session, ensuring a reliable and predictable communication experience.

Example:
For example, consider a traditional telephone call. When a person makes a phone call, the circuit-switched network establishes a dedicated physical connection between the caller and the receiver. During the call, the resources such as the bandwidth and processing capacity are allocated exclusively for that call. This guarantees a constant rate of transmission, ensuring that the voice signals are delivered in real-time without any interruptions or delays.

Benefits of Guaranteed Constant Rate:
1. Real-time Applications: Circuit switching is particularly suitable for real-time applications such as voice and video calls, where a constant and predictable transmission rate is essential.

2. Reliable Communication: By reserving resources, circuit switching ensures a reliable communication experience. The dedicated connection between the sender and receiver minimizes the chances of packet loss or interruptions.

3. Quality of Service: Circuit switching provides a guaranteed quality of service as the reserved resources ensure a consistent transmission rate and minimal delay.

4. Efficient Resource Utilization: Although circuit switching requires the reservation of resources, it allows for efficient resource utilization as the allocated resources are exclusively used by the communicating parties.

5. Connection-oriented: Circuit switching is a connection-oriented communication method, where a dedicated path is established before the communication takes place. This ensures a reliable and predictable communication experience.

Conclusion:
In circuit switching, the reservation of resources between two communicating end systems enables guaranteed constant rate transmission. This guarantees a reliable and predictable communication experience, making circuit switching suitable for real-time applications and ensuring efficient resource utilization.