human: Given a node-centered hypergraph: <hypergraph>, where nodes represent papers and hyperedges represent sets of papers co-cited by a source paper.

Details of the hypergraph:
Center node: "energy efficiency of downlink networks with caching at base stations"
  Abstract: Caching popular contents at base stations (BSs) can reduce the backhaul cost and improve the network throughput. Yet whether locally caching at the BSs can improve the energy efficiency (EE), a major goal for fifth generation cellular networks, remains unclear. Due to the entangled impact of various factors on EE such as interference level, backhaul capacity, BS density, power consumption parameters, BS sleeping, content popularity, and cache capacity, another important question is what are the key factors that contribute more to the EE gain from caching. In this paper, we attempt to explore the potential of EE of the cache-enabled wireless access networks and identify the key factors. By deriving closed-form expression of the approximated EE, we provide the condition when the EE can benefit from caching, find the optimal cache capacity that maximizes the network EE, and analyze the maximal EE gain brought by caching. We show that caching at the BSs can improve the network EE when power efficient cache hardware is used. When local caching has EE gain over not caching, caching more contents at the BSs may not provide higher EE. Numerical and simulation results show that the caching EE gain is large when the backhaul capacity is stringent, interference level is low, content popularity is skewed, and when caching at pico BSs instead of macro BSs.

Connected through hyperedge HE-1 (induced by source paper "aoi delay tradeoff in mobile edge caching with freshness aware content refreshing"):
  with members:
    - "cooperative service caching and workload scheduling in mobile edge computing"
    - "ai assisted low information latency wireless networking"
    - "age of information aware radio resource management in vehicular networks a proactive deep reinforcement learning perspective"
    - "minimum age of information in the internet of things with non uniform status packet sizes"
    - "content popularity prediction towards location aware mobile edge caching"
    - "air ground integrated vehicular network slicing with content pushing and caching"
    - "cost effective cache deployment in mobile heterogeneous networks"
    - "edge caching wireless networks performance analysis and optimization"

Connected through hyperedge HE-2 (induced by source paper "edge cache assisted secure low latency millimeter wave transmission"):
  with members:
    - "securing downlink massive mimo noma networks with artificial noise"
    - "hybrid precoder design for cache enabled millimeter wave radio access networks"
    - "secure and energy efficient transmissions in cache enabled heterogeneous cellular networks performance analysis and optimization"
    - "two level transmission scheme for cache enabled fog radio access networks"
    - "optimized base station cache allocation for cloud radio access network with multicast backhaul"
    - "exploiting physical layer security for multiuser multicarrier computation offloading"
    - "content placement in cache enabled sub 6 ghz and millimeter wave multi antenna dense small cell networks"
    - "random caching based cooperative transmission in heterogeneous wireless networks"

Connected through hyperedge HE-3 (induced by source paper "cacheable and non cacheable traffic interplay in a relay assisted wireless network"):
  with members:
    - "learning to cache with no regrets"
    - "wireless caching technical misconceptions and business barriers"
    - "optimal caching placement for d2d assisted wireless caching networks"

Connected through hyperedge HE-4 (induced by source paper "modeling and performance analysis in cache enabled millimeter wave hetnets with access and backhaul integration"):
  with members:
    - "modeling and analysis of d2d millimeter wave networks with poisson cluster processes"
    - "a unified asymptotic analysis of area spectral efficiency in ultradense cellular networks"
    - "downlink cellular network analysis with los nlos propagation and elevated base stations"
    - "modeling analysis and optimization of coded caching in small cell networks"
    - "dense small cell networks from noise limited to dense interference limited"
    - "coverage in downlink heterogeneous mmwave cellular networks with user centric small cell deployment"
    - "caching at the wireless edge design aspects challenges and future directions"
    - "fundamentals of the downlink green coverage and energy efficiency in heterogeneous networks"

Connected through hyperedge HE-5 (induced by source paper "wireless caching helper system with heterogeneous traffic and random availability"):
  with members:
    - "modeling and performance analysis of full duplex communications in cache enabled d2d networks"
    - "a survey on mobile edge networks convergence of computing caching and communications"
    - "optimal caching and scheduling for cache enabled d2d communications"
    - "cache enabled device to device communications offloading gain and energy cost"
    - "spatially correlated content caching for device to device communications"
    - "wireless caching technical misconceptions and business barriers"
    - "on the delay of geographical caching methods in two tiered heterogeneous networks"
    - "content caching and distribution in smart grid enabled wireless networks"

Connected through hyperedge HE-6 (induced by source paper "caching at base stations with heterogeneous user demands and spatial locality"):
  with members:
    - "when exploiting individual user preference is beneficial for caching at base stations"
    - "optimal cache leasing from a mobile network operator to a content provider"
    - "3gpp inspired hetnet model using poisson cluster process sum product functionals and downlink coverage"
    - "caching policy optimization for d2d communications by learning user preference"
    - "modeling analysis and optimization of coded caching in small cell networks"
    - "understanding performance of edge content caching for mobile video streaming"
    - "wireless caching technical misconceptions and business barriers"
    - "big data caching for networking moving from cloud to edge"

Connected through hyperedge HE-7 (induced by source paper "full duplex enabled mobile edge caching from distributed to cooperative caching"):
  with members:
    - "modeling and performance analysis of full duplex communications in cache enabled d2d networks"
    - "fundamental tradeoff between storage and latency in cache aided wireless interference networks"
    - "edge caching wireless networks performance analysis and optimization"
    - "cache aided full duplex small cells"
    - "delivery time minimization in edge caching synergistic benefits of subspace alignment and zero forcing"
    - "wireless device to device caching networks basic principles and system performance"
    - "octopus a cooperative hierarchical caching strategy for cloud radio access networks"
    - "wireless content caching for small cell and d2d networks"

Connected through hyperedge HE-8 (induced by source paper "economical caching for scalable videos in cache enabled heterogeneous networks"):
  with members:
    - "optimized base station cache allocation for cloud radio access network with multicast backhaul"
    - "cost effective cache deployment in mobile heterogeneous networks"
    - "random caching based cooperative transmission in heterogeneous wireless networks"
    - "fundamental tradeoff between storage and latency in cache aided wireless interference networks"
    - "cache enabled physical layer security for video streaming in backhaul limited cellular networks"
    - "cache enabled device to device communications offloading gain and energy cost"
    - "modeling analysis and optimization of coded caching in small cell networks"
    - "stochastic content centric multicast scheduling for cache enabled heterogeneous cellular networks"

Question: Please tell me which class the center node belongs to. The 40 classes are: cs.NA(Numerical Analysis), cs.MM(Multimedia), cs.LO(Logic in Computer Science), cs.CY(Computers and Society), cs.CR(Cryptography and Security), cs.DC(Distributed, Parallel, and Cluster Computing), cs.HC(Human-Computer Interaction), cs.CE(Computational Engineering, Finance, and Science), cs.NI(Networking and Internet Architecture), cs.CC(Computational Complexity), cs.AI(Artificial Intelligence), cs.MA(Multiagent Systems), cs.GL(General Literature), cs.NE(Neural and Evolutionary Computing), cs.SC(Symbolic Computation), cs.AR(Hardware Architecture), cs.CV(Computer Vision and Pattern Recognition), cs.GR(Graphics), cs.ET(Emerging Technologies), cs.SY(Systems and Control), cs.CG(Computational Geometry), cs.OH(Other Computer Science), cs.PL(Programming Languages), cs.SE(Software Engineering), cs.LG(Machine Learning), cs.SD(Sound), cs.SI(Social and Information Networks), cs.RO(Robotics), cs.IT(Information Theory), cs.PF(Performance), cs.CL(Computation and Language), cs.IR(Information Retrieval), cs.MS(Mathematical Software), cs.FL(Formal Languages and Automata Theory), cs.DS(Data Structures and Algorithms), cs.OS(Operating Systems), cs.GT(Computer Science and Game Theory), cs.DB(Databases), cs.DL(Digital Libraries), cs.DM(Discrete Mathematics). Directly output the class name.

gpt: cs.IT(Information Theory)