ance throughout the control process by simulation analysis, where the control process can be divided into two stages with different QoS service and the power consumption can be significantly reduced. Furthermore, in [27] and [28], the authors analyzed control stability with unreliability of communications in V2X communications. However, without close form expression indicating the relationship between communication and control by co-design, a high overall system performance cannot be obtained. 14.2 System Model with Latency and Reliability Constraints This chapter aims to optimize communication resource allocation by joint communi- cation-control design. Taking uplink transmission as an example, our goal is to find the optimal communication bandwidth, communication power consumption, and control convergence rate¹ by maximizing the spectral efficiency (SE) while guaranteeing the control requirement. However, the idea can be extended into the downlink transmission scenario in a straightforward manner. Our problem formulation considers both URLLC QoS and control convergence rate constraints, while such a co-design is still an open problem to be explored. To achieve the goal, the key is to find a method to convert the constraints on the control subsystem into constraints that the communication subsystem can adopt to solve the optimization problem. The main contributions of this chapter are summarized as follows. We propose an optimal resource allocation scheme to maximize the SE by communica- tion and control co-design, where both URLLC requirements and control convergence rate requirement are taken into account. The proposed scheme allows us to use optimal resource to support URLLC while guaranteeing the required control performance level. We analyze the effect of the relationship between the control convergence rate require- ment and communication requirement on URLLC quality. We find that the lower bound of the communication reliability decreases linearly with the control convergence rate. Then, the requirement on