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: "downlink outage performance of heterogeneous cellular networks"
  Abstract: This paper derives tight performance upper and lower bounds on the downlink outage efficiency of K-tier heterogeneous cellular networks (HCNs) for general signal propagation models with Poisson distributed base stations in each tier. In particular, the proposed approach to analyze the outage metrics in a K-tier HCN allows for the use of general bounded path-loss functions and random fading processes of general distributions. Considering two specific base station (BS) association policies, it is shown that the derived performance bounds track the actual outage metrics reasonably well for a wide range of BS densities, with the gap among them becoming negligibly small for denser HCN deployments. A simulation study is also performed for 2-tier and 3-tier HCN scenarios to illustrate the closeness of the derived bounds to the actual outage performance with various selections of the HCN parameters.

Connected through hyperedge HE-1 (induced by source paper "a tractable framework for the analysis of dense heterogeneous cellular networks"):
  with members:
    - "stability and dynamic control of underlay mobile edge networks"
    - "sinr and throughput of dense cellular networks with stretched exponential path loss"
    - "ultra dense networks is there a limit to spatial spectrum reuse"
    - "performance limits of network densification"
    - "modeling and analysis of cellular networks using stochastic geometry a tutorial"
    - "poisson cluster process based analysis of hetnets with correlated user and base station locations"
    - "user association in 5g networks a survey and an outlook"
    - "tractable framework for the analysis of general multi tier heterogeneous cellular networks"

Connected through hyperedge HE-2 (induced by source paper "tractable framework for the analysis of general multi tier heterogeneous cellular networks"):
  with members:
    - "stability and dynamic control of underlay mobile edge networks"
    - "3gpp inspired hetnet model using poisson cluster process sum product functionals and downlink coverage"
    - "ultra dense networks is there a limit to spatial spectrum reuse"
    - "massive non orthogonal multiple access for cellular iot potentials and limitations"
    - "modeling and analysis of cellular networks using stochastic geometry a tutorial"
    - "low power wide area networks an overview"
    - "poisson cluster process based analysis of hetnets with correlated user and base station locations"
    - "user association in 5g networks a survey and an outlook"

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)