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: "experimental evaluation of multihop cellular networks using mobile relays accepted from open call"
  Abstract: Future wireless networks are expected to provide high bandwidth multimedia services in extended areas with homogeneous quality of service levels. Conventional cellular architectures might not be able to satisfy these requirements due to the effect of surrounding obstacles and the signal attenuation with distance, in particular under non-line-of-sight propagation conditions. Recent studies have investigated the potential of multihop cellular networks (MCNs) to overcome the traditional cellular architecture limitations through the integration of cellular and ad hoc networking technologies. However, these studies are generally analytical or simulation-based. On the other hand, this article reports the first experimental field tests, which validate and quantify the benefits MCNs using mobile relays can provide over traditional cellular systems.

Connected through hyperedge HE-1 (induced by source paper "optimal relay probing in millimeter wave cellular systems with device to device relaying"):
  with members:
    - "exploiting device to device communications to enhance spatial reuse for popular content downloading in directional mmwave small cells"
    - "spectrum sharing for device to device communication in cellular networks"
    - "connectivity of millimeter wave networks with multi hop relaying"
    - "an overview of load balancing in hetnets old myths and open problems"
    - "tractable model for rate in self backhauled millimeter wave cellular networks"
    - "coverage and rate analysis for millimeter wave cellular networks"
    - "what will 5g be"
    - "millimeter wave cellular wireless networks potentials and challenges"

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)