Traffic Shaping With Optical-Wireless Cooperative Control to Reduce Uplink Jitter Due to Radio Transmission

Beyond 5th generation (5G) and 6th generation (6G) mobile systems require not only low latency but also low jitter for deterministic services such as remote operation. Since remote operation requires high-definition video streaming in the uplink, the uplink transmission performance will become more important. However, current new radio (NR) mobile systems cause jitter in the uplink traffic of the mobile backhaul (MBH) network because of the radio transmission schemes such as downlink/uplink separation of time division duplexing (TDD) and medium access control (MAC) service data unit (SDU) concatenation to compose transport blocks. Thus, we propose MBH uplink jitter reduction techniques with optical-wireless cooperative control. Our proposed techniques execute traffic shaping at a router in the MBH network to reduce uplink jitter. The shaping rate that reduces jitter while minimizing latency increase is calculated with mobile scheduling information forwarded from a next generation node B (gNB) via an extended cooperative transport interface (eCTI). The eCTI provides an interface between gNBs and network equipment to achieve optical-wireless cooperative control. In this paper, we experimentally validate our proposed jitter reduction techniques through a combination of simulations for radio transmission and experiments with a shaper prototype we developed. The results regarding end-to-end (E2E) jitter performance indicate that the proposed techniques reduce the maximum jitter by 88%, from 1.1 ms to
$137 ~\mu \text{s}$
.