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 content placement for offloading in cache enabled heterogeneous wireless networks"
  Abstract: Caching at base stations (BSs) is a promising way to offload traffic and eliminate backhaul bottleneck in heterogeneous networks (HetNets). In this paper, we investigate the optimal content placement maximizing the successful offloading probability in a cache-enabled HetNet where a tier of multi-antenna macro BSs (MBSs) is overlaid with a tier of helpers with caches. Based on probabilistic caching framework, we resort to stochastic geometry theory to derive the closed-form successful offloading probability and formulate the caching probability optimization problem, which is not concave in general. In two extreme cases with high and low user-to-helper density ratios, we obtain the optimal caching probability and analyze the impacts of BS density and transmit power of the two tiers and the signal-to-interference-plus-noise ratio (SINR) threshold. In general case, we obtain the optimal caching probability that maximizes the lower bound of successful offloading probability and analyze the impact of user density. Simulation and numerical results show that when the ratios of MBS-to-helper density, MBS-to-helper transmit power and user-to-helper density, and the SINR threshold are large, the optimal caching policy tends to cache the most popular files everywhere.

Connected through hyperedge HE-1 (induced by source paper "enhancing physical layer security of random caching in large scale multi antenna heterogeneous wireless networks"):
  with members:
    - "secure and energy efficient transmissions in cache enabled heterogeneous cellular networks performance analysis and optimization"
    - "enhancing performance of random caching in large scale wireless networks with multiple receive antennas"
    - "physical layer security in cache enabled cooperative small cell networks against randomly distributed eavesdroppers"
    - "a unified framework for the tractable analysis of multi antenna wireless networks"
    - "enhancing performance of random caching in large scale heterogeneous wireless networks with random discontinuous transmission"
    - "delivery secrecy tradeoff for cache enabled stochastic networks content placement optimization"
    - "random caching based cooperative transmission in heterogeneous wireless networks"
    - "caching at the wireless edge design aspects challenges and future directions"

Connected through hyperedge HE-2 (induced by source paper "enhancing performance of random caching in large scale heterogeneous wireless networks with random discontinuous transmission"):
  with members:
    - "enhancing performance of random caching in large scale wireless networks with multiple receive antennas"
    - "random caching based cooperative transmission in heterogeneous wireless networks"
    - "spatio temporal interference correlation and joint coverage in cellular networks"
    - "caching at the wireless edge design aspects challenges and future directions"
    - "effect of retransmissions on optimal caching in cache enabled small cell networks"
    - "wireless caching technical misconceptions and business barriers"
    - "a learning based approach to caching in heterogenous small cell networks"
    - "cache enabled heterogeneous cellular networks comparison and tradeoffs"

Connected through hyperedge HE-3 (induced by source paper "random caching based cooperative transmission in heterogeneous wireless networks"):
  with members:
    - "a learning based approach to caching in heterogenous small cell networks"
    - "edge caching for coverage and capacity aided heterogeneous networks"
    - "caching in wireless small cell networks a storage bandwidth tradeoff"
    - "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"
    - "caching placement in stochastic wireless caching helper networks channel selection diversity via caching"
    - "cooperative caching and transmission design in cluster centric small cell networks"

Connected through hyperedge HE-4 (induced by source paper "caching policy toward maximal success probability and area spectral efficiency of cache enabled hetnets"):
  with members:
    - "caching at the wireless edge design aspects challenges and future directions"
    - "edge caching for coverage and capacity aided heterogeneous networks"
    - "cache enabled heterogeneous cellular networks comparison and tradeoffs"
    - "energy efficiency of downlink networks with caching at base stations"
    - "optimal caching placement for d2d assisted wireless caching networks"
    - "analysis on cache enabled wireless heterogeneous networks"
    - "optimal geographic caching in cellular networks"
    - "analysis and optimization of caching and multicasting in large scale cache enabled wireless 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)