  Networked control systems (NCSs), which are feedback control loops closed
over a communication network, have been a popular research topic over the past
decades. Numerous works in the literature propose novel algorithms and
protocols with joint consideration of communication and control. However, the
vast majority of the recent research results, which have shown remarkable
performance improvements if a cross-layer methodology is followed, have not
been widely adopted by the industry. In this work, we review the shortcomings
of today's mobile networks that render cross-layer solutions, such as semantic
and goal-oriented communications, very challenging in practice. To tackle this,
we propose a new framework for 6G user plane design that simplifies the
adoption of recent research results in networked control, thereby facilitating
the joint communication and control design in next-generation mobile networks.
