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: "femtocell networks a survey"
  Abstract: The surest way to increase the system capacity of a wireless link is by getting the transmitter and receiver closer to each other, which creates the dual benefits of higher-quality links and more spatial reuse. In a network with nomadic users, this inevitably involves deploying more infrastructure, typically in the form of microcells, hot spots, distributed antennas, or relays. A less expensive alternative is the recent concept of femtocells - also called home base stations - which are data access points installed by home users to get better indoor voice and data coverage. In this article we overview the technical and business arguments for femtocells and describe the state of the art on each front. We also describe the technical challenges facing femtocell networks and give some preliminary ideas for how to overcome them.

Connected through hyperedge HE-1 (induced by source paper "robust resource allocation for pd noma based miso heterogeneous networks with comp technology"):
  with members:
    - "radio resource allocation for device to device underlay communication using hypergraph theory"
    - "user association in 5g networks a survey and an outlook"
    - "optimal joint power and subcarrier allocation for full duplex multicarrier non orthogonal multiple access systems"
    - "optimal dynamic point selection for power minimization in multiuser downlink comp"
    - "optimal stochastic coordinated beamforming for wireless cooperative networks with csi uncertainty"
    - "low complexity delay constrained beamforming for multi user mimo systems with imperfect csit"
    - "robust monotonic optimization framework for multicell miso systems"
    - "worst case sinr constrained robust coordinated beamforming for multicell wireless systems"

Connected through hyperedge HE-2 (induced by source paper "power allocation in cache aided noma systems optimization and deep reinforcement learning approaches"):
  with members:
    - "resource allocation in noma based fog radio access networks"
    - "non orthogonal multiple access common myths and critical questions"
    - "joint power allocation and beamforming for non orthogonal multiple access noma in 5g millimeter wave communications"
    - "on optimal power allocation for downlink non orthogonal multiple access systems"
    - "noma assisted wireless caching strategies and performance analysis"
    - "a survey of downlink non orthogonal multiple access for 5g wireless communication networks"
    - "non orthogonal multiple access in multi cell networks theory performance and practical challenges"
    - "adam a method for stochastic optimization"

Connected through hyperedge HE-3 (induced by source paper "virtual cell clustering with optimal resource allocation to maximize capacity"):
  with members:
    - "virtual cell clustering with optimal resource allocation to maximize cellular system capacity"
    - "optimal resource allocation for cellular networks with virtual cell joint decoding"
    - "cloud radio access network virtualizing wireless access for dense heterogeneous systems"
    - "software defined networking a comprehensive survey"
    - "energy efficient scheduling and power allocation in downlink ofdma networks with base station coordination"
    - "uplink multicell processing with limited backhaul via per base station successive interference cancellation"

Connected through hyperedge HE-4 (induced by source paper "virtual cell clustering with optimal resource allocation to maximize cellular system capacity"):
  with members:
    - "optimal resource allocation for cellular networks with virtual cell joint decoding"
    - "cloud radio access network virtualizing wireless access for dense heterogeneous systems"
    - "energy efficient scheduling and power allocation in downlink ofdma networks with base station coordination"
    - "uplink multicell processing with limited backhaul via per base station successive interference cancellation"

Connected through hyperedge HE-5 (induced by source paper "optimal resource allocation for cellular networks with virtual cell joint decoding"):
  with members:
    - "fog optimization via virtual cells in cellular network resource allocation"
    - "cloud radio access network virtualizing wireless access for dense heterogeneous systems"
    - "uplink multicell processing with limited backhaul via per base station successive interference cancellation"

Connected through hyperedge HE-6 (induced by source paper "dynamic resource allocation and activity management for energy efficiency and fairness in heterogeneous networks"):
  with members:
    - "boost base station on off switching strategy for energy efficient massive mimo hetnets"
    - "activity management algorithm for improving energy efficiency of small cell base stations in 5g heterogeneous networks"

Connected through hyperedge HE-7 (induced by source paper "phy research is sick but curable an empirical analysis"):
  with members:
    - "what will 5g be"

Connected through hyperedge HE-8 (induced by source paper "cache enabled hetnets with millimeter wave small cells"):
  with members:
    - "modeling and analysis of mmwave communications in cache enabled hetnets"
    - "modeling and analysis of d2d millimeter wave networks with poisson cluster processes"
    - "modeling and analyzing millimeter wave cellular systems"
    - "coverage analysis for millimeter wave networks the impact of directional antenna arrays"
    - "non orthogonal multiple access in large scale heterogeneous networks"
    - "caching policy toward maximal success probability and area spectral efficiency of cache enabled hetnets"
    - "downlink and uplink cell association with traditional macrocells and millimeter wave small cells"
    - "downlink cell association and load balancing for joint millimeter wave microwave 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.NI(Networking and Internet Architecture)