Experimental evaluation of low-latency features in optical access networks and home gateways

Abstract

With widespread 10 Gbps-capable PON technologies in the access network and Wi-Fi 6E/7 in the home network, final customers can easily enjoy a gigabit experience at home. However, with such enormous bandwidth provided, customers are not always satisfied with their experience, particularly for real-time services, such as VR gaming, cloud gaming, or visio-conferencing, due to network latency issues. In this paper, we focus on optimizing congestion latency that can arise in both home gateway and access networks while keeping an eye on bandwidth-sharing fairness without strictly prioritizing certain traffic. To assess end-to-end performance, our setup includes Internet servers, access/home networks, and customers’ equipment. Transport layer protocols in the TCP/IP model are deployed in both Internet servers and end-user equipment. TCP Prague is implemented to represent time-sensitive services that require a high bitrate, such as VR, and TCP Cubic is used for other common services without low-latency criteria. We create a two-level congestion scenario, configuring different QoS parameters within access equipment and home gateways to compare performance. In our best case, the latency of time-sensitive traffic is at least 10 times lower than other applications and gains more than 30 ms E2E RTT during full congestion scenarios.