Fog devices are beginning to play a key role in relaying data and services within the Internet-of-Things (IoT) ecosystem. These relays may be static or mobile, with the latter offering a new degree of freedom for performance improvement via careful relay mobility design. Besides that, power conservation has been a prevalent issue in IoT networks with devices being power-constrained, requiring optimal power-control mechanisms. In this paper, we consider a multi-tier fog-based IoT architecture where a mobile/static fog node acts as an amplify and forward relay that transmits received information from a sensor node to a higher hierarchically-placed static fog device, which offers some localized services. The outage probability of the presented scenario was efficiently minimized by jointly optimizing the mobility pattern and the transmit power of the fog relay. A closed-form analytical expression for the outage probability was derived. Furthermore, due to the intractability and non-convexity of the formulated problem, we applied an iterative algorithm based on the steepest descent method to arrive at a desirable objective. Simulations reveal that the outage probability was improved by 62.7% in the optimized-location fixed-power (OLFP) scheme, 79.3% in the optimized-power fixed-location (OPFL) scheme, and 94.2% in the optimized-location optimized-power (OLOP) scheme, as against the fixed-location and fixed-power (FLFP) scheme (i.e., without optimization). Lastly, we present an optimal relay selection strategy that chooses an appropriate relay node from randomly distributed relaying candidates.

翻译：Fog装置开始在互联网(IoT)生态系统内传输数据和服务方面起关键作用。这些继电器可能是静态或移动式的,后者通过仔细的中继移动设计为改进性能提供了新的自由度;此外,在IoT网络中,电力保护已成为一个普遍问题,其装置受到电源限制,需要最佳的电控机制。在本文中,我们认为一个多层基于雾的IoT结构,移动/静态雾节点作为扩大和前向转发从传感器节点接收信息到更高等级的静态烟雾装置,提供一些局部服务。通过联合优化移动模式和喷雾中继的传输能力,可以有效地减少现有情景的失灵概率。此外,由于所拟订的问题不易感性和不趋同性,我们采用了一种基于最陡度下降方法的迭代算法,以达到一个理想的目标。模拟显示的是,从传感器节流系统接收的信息从一个较高等级的静态移动系统接收到一个提供某些局部服务的静态的静态烟雾装置。通过联合优化移动移动移动的移动模式和喷雾中继器传送电流机的频率,将最佳的概率提高了概率(优化的固定定位,优化的固定定位的频率定位的频率的频率定位)的频率-六百分之六二)。