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: "software defined hyper cellular architecture for green and elastic wireless access"
  Abstract: To meet the surging demand of increasing mobile Internet traffic from diverse applications while maintaining moderate energy cost, the radio access network of cellular systems needs to take a green path into the future, and the key lies in providing elastic service to dynamic traffic demands. To achieve this, it is time to rethink RAN architectures and expect breakthroughs. In this article, we review the state-of-the-art literature, which aims to renovate RANs from the perspectives of control- traffic decoupled air interface, cloud-based RANs, and software-defined RANs. We then propose a software-defined hyper-cellular architecture (SDHCA) that identifies a feasible way to integrate the above three trends to enable green and elastic wireless access. We further present key enabling technologies to realize SDHCA, including separation of the air interface, green base station operations, and base station functions virtualization, followed by our hardware testbed for SDHCA. In addition, we summarize several future research issues worth investigating.

Connected through hyperedge HE-1 (induced by source paper "smart soft ran for 5g dynamic resource management in comp noma based systems"):
  with members:
    - "coordinated multi point comp transmission in downlink multi cell noma systems models and spectral efficiency performance"
    - "design of massive mimo noma with limited feedback"
    - "fog computing based radio access networks issues and challenges"
    - "collaborative mobile edge computing in 5g networks new paradigms scenarios and challenges"
    - "a minorization maximization method for optimizing sum rate in the downlink of non orthogonal multiple access systems"
    - "energy efficient resource assignment and power allocation in heterogeneous cloud radio access networks"
    - "heterogeneous cloud radio access networks a new perspective for enhancing spectral and energy efficiencies"
    - "concert a cloud based architecture for next generation cellular systems"

Connected through hyperedge HE-2 (induced by source paper "remote channel inference for beamforming in ultra dense hyper cellular network"):
  with members:
    - "seeing the unobservable channel learning for wireless communication networks"
    - "achievable rates of fdd massive mimo systems with spatial channel correlation"
    - "what will 5g be"
    - "downlink training techniques for fdd massive mimo systems open loop and closed loop training with memory"
    - "coding the beams improving beamforming training in mmwave communication system"

Connected through hyperedge HE-3 (induced by source paper "statistical multiplexing gain analysis of heterogeneous virtual base station pools in cloud radio access networks"):
  with members:
    - "redesigning fronthaul for next generation networks beyond baseband samples and point to point links"
    - "cloud radio access network virtualizing wireless access for dense heterogeneous systems"
    - "on the statistical multiplexing gain of virtual base station pools"
    - "concert a cloud based architecture for next generation cellular systems"

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)