Spatial Modeling and Reliability Analyzing of Reconfigurable Intelligent Surfaces-Assisted Fog-RAN with Repulsion

Reconfigurable Intelligent Surface(RIS),fog computing,and Cell-Free(CF)network architecture are three promising technologies for application to the Ultra-Reliable Low Latency Communication(URLLC)scenario in 6G mobile communication systems.This paper considers a RIS-assisted FogRadio Access Network(Fog-RAN)architecture where a)the repulsively distributed Fog-Access Points(FAPs)communicate in a CF manner to suppress intercell interference,b)RISs are introduced into the CF network to avoid shadowing and enhance the system performance,and c)fog computing evolved as cloud services providers at the edge of the network and an enabler for constructing a multi-layer computing power RAN.Then,we derive and validate the integral form of the maximum F-AP offloading probability and Successful Delivery Probability(SDP)of this RIS-assisted Fog-RAN over composite FisherSnedecor F fading,where the spatial effects are reconsidered with the assumption that the F-APs are modelled as a Beta Ginibre Point Process(β-GPP).The numeric and simulation results indicate that for the investigated RIS-assisted Fog-RAN,theβ-GPP-based deployment of F-APs can increase maximum of 8%of the SDP within the repulsion-effective range,compared with the Matern Cluster Process(MCP)-based ones.Also,deploying more RISs per F-AP offers more significant SDP improvements.

Caching modeling and energy analyzing of cell-free wireless heterogeneous networks with beta Ginibre point process

Cell-free Wireless Heterogeneous Networks(HetNets)have emerged as a technological alternative for conventional cellular networks.In this paper,we study the spatially correlative caching strategy,the energy analysis,and the impact of parameter β on the total energy cost of the cell-free wireless HetNets with Access Points distributed by Beta Ginibre Point Process(β-GPP).We derive the approximate expression of Successful Delivery Probability(SDP)based on the Signal-to-Interference-plus-Noise Ratio coverage model.From both analytical and simulation results,it is shown that the proposed caching model based on β-GPP placement,which jointly takes into account path loss,fading,and interference,can closely simulate the caching performance of the cell-free HetNets in terms of SDP.By guaranteeing the outage probability constraints,the analytical expression of the uplink energy cost is also derived.Another conclusion is that with AP locations modeled by β-GPP,the power consumption is not sensitive to β,but is sensitive to the dimension of the kernel function;hence β is less restrictive,and only the truncation of the Ginibre kernel has to be appropriately modified.These findings are new compared with the existing literature where the nodes are commonly assumed to be of Poisson Point Process,Matern Hard-Core Process,or Poisson Cluster Process deployment in cell-free systems.