Performance analysis of optical communication networks with cascaded buffered optical switches

Abstract The increasing demand for high-speed data transmission has accelerated the adoption of multistage optical switching architectures. Cascaded buffered optical switches improve scalability and routing efficiency but suffer from packet contention and limited buffer capacity, leading to increased blocking probability, packet loss, and transmission delay under heavy traffic. This paper presents an analytical performance evaluation of cascaded buffered optical switching networks by modeling each switching node as a finite-capacity queue. Mathematical models are developed to analyze blocking probability, throughput, and average end-to-end delay, along with a generalized expression for cumulative blocking probability across multiple switching stages. The impact of traffic intensity, buffer size, and the number of cascaded switches on network performance is systematically investigated. Simulation results show that increasing buffer capacity significantly improves network performance by reducing packet loss and maintaining high throughput. For a buffer size of 16 packets, throughput decreases by only about 10 % as the number of cascaded switches increases from 5 to 20, demonstrating good scalability. Although end-to-end delay increases with additional switching stages, it remains within acceptable limits for high-speed optical communication systems. The proposed analysis provides useful guidelines for buffer dimensioning and the design of scalable next-generation optical switching networks.