A Hybrid Cache Placement Scheme for Multi-Hop Wireless Service Network

In this paper,a hybrid cache placement scheme for multihop wireless service networks is proposed. In this scheme,hot nodes in data transferring path are mined up by means of rout-ing navigation graph,and whole network is covered with network clustering scheme. A hot node has been chosen for cache place-ment in each cluster,and the nodes within a cluster access cache data with no more than two hops. The cache placement scheme reduces data access latency and workload of the server node. It also reduces the average length of data transferring,which means that fewer nodes are involved. The network system energy con-sumption decreased as involved relay nodes reduced. The per-formance analysis shows that the scheme achieves significant system performance improvement in network environment,with a large number of nodes.

Resource allocation for network profit maximization in NOMA-based F-RANs:a game-theoretic approach

Non-orthogonal multiple access(NOMA)based fog radio access networks(F-RANs)offer high spectrum efficiency,ultra-low delay,and huge network throughput,and this is made possible by edge computing and communication functions of the fog access points(F-APs).Meanwhile,caching-enabled F-APs are responsible for edge caching and delivery of a large volume of multimedia files during the caching phase,which facilitates further reduction in the transmission energy and burden.The need of the prevailing situation in industry is that in NOMA-based F-RANs,energy-efficient resource allocation,which consists of cache placement(CP)and radio resource allocation(RRA),is crucial for network performance enhancement.To this end,in this paper,we first characterize an NOMA-based F-RAN in which F-APs of caching capabilities underlaid with the radio remote heads serve user equipments via the NOMA protocol.Then,we formulate a resource allocation problem for maximizing the defined performance indicator,namely network profit,which takes caching cost,revenue,and energy efficiency into consideration.The NP-hard problem is decomposed into two sub-problems,namely the CP sub-problem and RRA sub-problem.Finally,we propose an iterative method and a Stackelberg game based method to solve them,and numerical results show that the proposed solution can significantly improve network profit compared to some existing schemes in NOMA-based F-RANs.

Caching and D2D Assisted Wireless Emergency Communications Networks with Statistical QoS Provisioning

Along with natural disasters,the destruction of communication infrastructures leads to the congestion or failure of communication networks.Unmanned aerial vehicles(UAVs),which are with a high flexibility,can be employed as temporary base stations to establish emergency networks.To relieve the backhaul burden of UAVs,some imperative contents can be cached by terrestrial cache-enabled rescuers(CERs)and provide for victims with device-to-device(D2D)transmissions.To support the effectiveness and timeliness of emergency communication,the delay-bounded quality-of-service(QoS)requirement and network throughput are desired to be comprehensively considered,which imposes a new challenge for caching placement and CER deployment.In this paper,we focus on joint caching placement and CER deployment to maximize the effective capacity subject to delay-bounded QoS requirement.The overall non-convex problem is transformed into the caching placement and the CER deployment sub-problems.Then,we develop the QoS-aware caching placement scheme with fixed CER deployment density and obtain the QoS-aware CER deployment density with fixed caching placement.Based on the block-coordinate descent method,we also propose the joint caching placement and CER deployment scheme,which can not only effectively enhance average effective capacity but also guarantee the delay-bounded QoS requirement.Also,numerical simulations are conducted to show the performances of the proposed schemes.