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: "effect of los nlos propagation on ultra dense networks"
  Abstract: This paper aims at investigating the achievable performance and the issues that arise in ultra-dense networks (UDNs), when the signal propagation includes both the Line-of-Sight (LOS) and Non-Line-Of-Sight (NLOS) components. Backed by an analytical stochastic geometry-based model, we study the coverage, the Area Spectral Efficiency (ASE) and the energy efficiency of UDNs with LOS/NLOS propagation. We show that when LOS/NLOS propagation components are accounted for, the network suffers from low coverage and the ASE gain is lower than linear at high base station densities. However, this performance drop can partially be attenuated by means of frequency reuse, which is shown to improve the ASE vs coverage trade-off of cell densification, provided that we have a degree of freedom on the density of cells. In addition, from an energy efficiency standpoint, cell densification is shown to be inefficient when both LOS and NLOS components are taken into account. Overall, based on the findings of our work that assumes a more advanced system model compared to the current state-of-the-art, we claim that highly crowded environments of users represent the worst case scenario for ultra-dense networks. Namely, these are likely to face serious issues in terms of limited coverage.

Connected through hyperedge HE-1 (induced by source paper "tractable resource management with uplink decoupled millimeter wave overlay in ultra dense cellular networks"):
  with members:
    - "low power analog to digital conversion in millimeter wave systems impact of resolution and bandwidth on performance"
    - "why to decouple the uplink and downlink in cellular networks and how to do it"
    - "resource management and cell planning in millimeter wave overlaid ultra dense cellular networks"
    - "towards 1 gbps ue in cellular systems understanding ultra dense small cell deployments"
    - "tractable resource management in millimeter wave overlaid ultra dense cellular networks"
    - "are we approaching the fundamental limits of wireless network densification"
    - "downlink cellular network analysis with multi slope path loss models"
    - "tractable model for rate in self backhauled millimeter wave cellular networks"

Connected through hyperedge HE-2 (induced by source paper "the intensity matching approach a tractable stochastic geometry approximation to system level analysis of cellular networks"):
  with members:
    - "performance impact of los and nlos transmissions in dense cellular networks"
    - "stochastic geometry modeling and analysis of multi tier millimeter wave cellular networks"
    - "stochastic geometry modeling of cellular networks analysis simulation and experimental validation"
    - "performance impact of los and nlos transmissions in small cell networks"
    - "downlink cellular network analysis with multi slope path loss models"
    - "on the joint impact of beamwidth and orientation error on throughput in directional wireless poisson networks"
    - "on association cells in random heterogeneous networks"
    - "analysis of blockage effects on urban 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)