  In mobile networks, Open Radio Access Network (ORAN) provides a framework for
implementing network slicing that interacts with the resources at the lower
layers. Both monitoring and Radio Access Network (RAN) control is feasible for
both 4G and 5G systems. In this work, we consider how data-driven resource
allocation in a 4G context can enable adaptive slice allocation to steer the
experienced latency of Virtual Reality (VR) traffic towards a requested
latency. We develop an xApp for the near real-time RAN Intelligent Controller
(RIC) that embeds a heuristic algorithm for latency control, aiming to: (1)
maintain latency of a VR stream around a requested value; and (2) improve the
available RAN allocation to offer higher bit rate to another user. We have
experimentally demonstrated the proposed approach in an ORAN testbed. Our
results show that the data-driven approach can dynamically follow the variation
of the traffic load while satisfying the required latency. This results in
15.8% more resources to secondary users than a latency-equivalent static
allocation.
