We consider a system where multiple sensors communicate timely information about various random processes to a sink. The sensors share orthogonal sub-channels to transmit such information in the form of status update packets. A central controller can control the sampling actions of the sensors to trade-off between the transmit power consumption and information freshness which is quantified by the Age of Information (AoI). We jointly optimize the sampling action of each sensor, the transmit power allocation, and the sub-channel assignment to minimize the average total transmit power of all sensors subject to a maximum average AoI constraint for each sensor. To solve the problem, we develop a dynamic control algorithm using the Lyapunov drift-plus-penalty method and provide optimality analysis of the algorithm. According to the Lyapunov drift-plus-penalty method, to solve the main problem we need to solve an optimization problem in each time slot which is a mixed integer non-convex optimization problem. We propose a low-complexity sub-optimal solution for this per-slot optimization problem that provides near-optimal performance and we evaluate the computational complexity of the solution. Numerical results illustrate the performance of the proposed dynamic control algorithm and the performance of the sub-optimal solution for the per-slot optimization problems versus the different parameters of the system. The results show that the proposed dynamic control algorithm achieves more than $60~\%$ saving in the average total transmit power compared to a baseline policy.
翻译:我们考虑一个系统,让多个传感器及时向下水道传送关于各种随机过程的信息。传感器共享正方形子通道,以状态更新包的形式传输这些信息。中央控制器可以控制传输动力消耗量和信息新鲜度之间的交换传感器的抽样动作,以信息时代(AoI)为量化。我们共同优化每个传感器的取样动作、传输动力分配和子通道分配,以尽量减少所有传感器的平均总传输功率,但以每个传感器的最大平均 AoI 限制为条件。为了解决问题,我们使用 Lyapunov 流动附加平流法开发了动态控制算法,并提供算法的最佳性分析。根据Lyapunov 流动加平流法,解决我们需要解决的每个时段的优化问题,即混合整型非conversion 优化问题。我们提议了一个低兼容性次最佳化解决方案,为每个传感器提供近于最佳性的工作表现,我们比较了算式基线参数,并对算法进行优化分析。根据Lyapunov-plical-foral assalal assal assal assal magal magal magal magal mabal magal magal magal magal magal mamal magal dal masal magal maismaldaldal magal magaldaldaldaldal madal masal masaldaldaldaldal maismaldal madaldaldal madal madal madal madaldal ma madal madaldaldal madal madal madaldal madal madal madaldal madal madaldal ma madal madal madaldaldal madaldal ma madal madal ma madal madal madal madaldal madal madaldaldaldaldaldal masaldal mas ma