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: "optimal caching and user association in cache enabled heterogeneous wireless networks"
  Abstract: Heterogenous wireless networks (Hetnets) provide a powerful approach to meet the massive growth in traffic demands, but also impose a significant challenge on backhaul. Caching at small base stations (BSs) and wireless small cell backhaul have been proposed as attractive solutions to address this new challenge. In this paper, we consider the optimal caching and user association to minimize the total time to satisfy the average demands in cached-enabled Hetnets with wireless backhaul. We formulate this problem as a mixed discrete-continuous optimization for given bandwidth and cache resources. First, we characterize the structure of the optimal solution. Specifically, we show that the optimal caching is to store the most popular files at each pico BS, and the optimal user association has a threshold form. We also obtain the closed-form optimal solution in the homogenous scenario of pico cells. Then, we analyze the impact of bandwidth and cache resources on the minimum total time to satisfy the average demands. Finally, using numerical simulations, we verify the analytical results.

Connected through hyperedge HE-1 (induced by source paper "joint optimization of file placement and delivery in cache assisted wireless networks with limited lifetime and cache space"):
  with members:
    - "joint downlink scheduling for file placement and delivery in cache assisted wireless networks with finite file lifetime"
    - "optimal caching designs for perfect imperfect and unknown file popularity distributions in large scale multi tier wireless networks"
    - "online user scheduling and resource allocation for mobile edge computing systems"
    - "cooperative job dispatching in edge computing network with unpredictable uploading delay"
    - "mdp based scheduling design for mobile edge computing systems with random user arrival"
    - "modeling analysis and optimization of coded caching in small cell networks"
    - "stochastic content centric multicast scheduling for cache enabled heterogeneous cellular networks"
    - "wireless device to device caching networks basic principles and system performance"

Connected through hyperedge HE-2 (induced by source paper "joint downlink scheduling for file placement and delivery in cache assisted wireless networks with finite file lifetime"):
  with members:
    - "modeling analysis and optimization of coded caching in small cell networks"
    - "stochastic content centric multicast scheduling for cache enabled heterogeneous cellular networks"
    - "wireless device to device caching networks basic principles and system performance"
    - "mobility aware caching for content centric wireless networks modeling and methodology"
    - "analysis and optimization of caching and multicasting in large scale cache enabled heterogeneous wireless networks"
    - "caching placement in stochastic wireless caching helper networks channel selection diversity via caching"
    - "placing dynamic content in caches with small population"
    - "cache enabled heterogeneous cellular networks optimal tier level content placement"

Connected through hyperedge HE-3 (induced by source paper "cache placement in two tier hetnets with limited storage capacity cache or buffer"):
  with members:
    - "optimal fairness aware time and power allocation in wireless powered communication networks"
    - "energy efficient resource allocation in machine to machine communications with multiple access and energy harvesting for iot"
    - "cooperative edge caching in user centric clustered mobile networks"
    - "association and load optimization with user priorities in load coupled heterogeneous networks"
    - "on consideration of content preference and sharing willingness in d2d assisted offloading"
    - "stochastic content centric multicast scheduling for cache enabled heterogeneous cellular networks"
    - "caching at the wireless edge design aspects challenges and future directions"
    - "wireless caching technical misconceptions and business barriers"

Connected through hyperedge HE-4 (induced by source paper "joint and competitive caching designs in large scale multi tier wireless multicasting networks"):
  with members:
    - "ultra dense edge caching under spatio temporal demand and network dynamics"
    - "random caching based cooperative transmission in heterogeneous wireless networks"
    - "on optimal geographical caching in heterogeneous cellular networks"
    - "caching in wireless small cell networks a storage bandwidth tradeoff"
    - "a stackelberg game for incentive proactive caching mechanisms in wireless networks"
    - "cache enabled heterogeneous cellular networks comparison and tradeoffs"
    - "optimization and analysis of probabilistic caching in n tier heterogeneous networks"
    - "analysis and optimization of caching and multicasting in large scale cache enabled heterogeneous wireless networks"

Connected through hyperedge HE-5 (induced by source paper "cost effective cache deployment in mobile heterogeneous networks"):
  with members:
    - "on optimal geographical caching in heterogeneous cellular networks"
    - "cache size allocation in backhaul limited wireless networks"
    - "a learning based approach to caching in heterogenous small cell networks"
    - "on the delay of geographical caching methods in two tiered heterogeneous networks"
    - "mobility aware caching for content centric wireless networks modeling and methodology"
    - "wireless content caching for small cell and d2d networks"
    - "energy efficiency of downlink networks with caching at base stations"
    - "content centric sparse multicast beamforming for cache enabled cloud ran"

Connected through hyperedge HE-6 (induced by source paper "analysis and optimization of caching and multicasting in large scale cache enabled heterogeneous wireless networks"):
  with members:
    - "stochastic content centric multicast scheduling for cache enabled heterogeneous cellular networks"
    - "caching in wireless small cell networks a storage bandwidth tradeoff"
    - "cache enabled heterogeneous cellular networks comparison and tradeoffs"
    - "cooperative caching and transmission design in cluster centric small cell networks"
    - "caching with unknown popularity profiles in small cell networks"
    - "analysis on cache enabled wireless heterogeneous networks"
    - "optimizing mds codes for caching at the edge"
    - "optimal geographic caching in 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)