Time-Sliced Flexible Resource Allocation for Optical Low Earth Orbit Satellite Networks

In future optical satellite networks with various service requirements, the bandwidth of a single traffic request occupies part of an inter-satellite link (ISL) channel capacity, thus leading to a greater demand for flexible resource allocation. The switching scheme is the most important determinant for flexible resource allocation in optical satellite networks, whereas the widely used optical switching techniques, including wavelength switching (WS) and electronic packet switching (EPS), have their own drawbacks such as bandwidth underutilization and high power consumption. In this paper, we utilize optical time slice switching (OTSS) to provide enormous transparent fine-grained connections for various traffic requests. To implement OTSS into low earth orbit (LEO) satellite networks, where the lengths of inter-orbit ISLs vary along time, we propose a distance-varying routing and time slice allocation (DV-RTSA) scheme. The simulation results demonstrate that the OTSS-based DV-RTSA scheme not only utilizes less active transponders when compared with the traditional schemes, but also achieves a significant throughput increase over the WS-based scheme and reaches the level of the EPS-based scheme exempting from its defects.