Performance of a 10 Gbps QoS-based buffer in a FSO/RF IP network

摘要

A 10 Gbps aperture agnostic data buffer has been developed to mitigate packet loss over highly scintillated FSO links operating in a hybrid FSO/RF network. The buffer incorporates a custom IP packet inspection and scheduling processor. Packet buffering and transmission scheduling is determined from link availability and a QoS parameter in the IP header based upon RFC 2474 (Differentiated Services). Buffer metric parameters are monitored and could be provided to the network management system. Integration of the novel buffer into the FSO link along with improved network routers allows operation under strong scintillation conditions at fade margins as low as 8 dB. We present the salient performance characteristics of a buffered FSO modem with VOA-emulated atmospheric fading statistics. Application test cases, including a TCP/IP MPEG-4 video stream, have been emulated both to determine the effects of packet loss, latency and intra-packet jitter introduced by buffering and to optimize traffic flow settings.