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 radio implementation of signaling splitting in hyper cellular network"
  Abstract: This paper presents the design and implementation of signaling splitting scheme in hyper-cellular network on a software defined radio platform. Hyper-cellular network is a novel architecture of future mobile communication systems in which signaling and data are decoupled at the air interface to mitigate the signaling overhead and allow energy efficient operation of base stations. On an open source software defined radio platform, OpenBTS, we investigate the feasibility of signaling splitting for GSM protocol and implement a novel system which can prove the proposed concept. Standard GSM handsets can camp on the network with the help of signaling base station, and data base station will be appointed to handle phone calls on demand. Our work initiates the systematic approach to study hyper-cellular concept in real wireless environment with both software and hardware implementations.

Connected through hyperedge HE-1 (induced by source paper "separation framework an enabler for cooperative and d2d communication for future 5g networks"):
  with members:
    - "d2d enhanced heterogeneous cellular networks with dynamic tdd"
    - "algorithms for enhanced inter cell interference coordination eicic in lte hetnets"
    - "software defined networking a comprehensive survey"
    - "a survey on device to device communication in cellular networks"
    - "what will 5g be"
    - "cache enabled opportunistic cooperative mimo for video streaming in wireless systems"
    - "millimeter wave cellular wireless networks potentials and challenges"
    - "hierarchical radio resource optimization for heterogeneous networks with enhanced inter cell interference coordination eicic"

Connected through hyperedge HE-2 (induced by source paper "hycell enabling green base station operations in software defined radio access networks"):
  with members:
    - "concert a cloud based architecture for next generation cellular systems"

Connected through hyperedge HE-3 (induced by source paper "concert a cloud based architecture for next generation cellular systems"):
  with members:
    - "on the statistical multiplexing gain of virtual base station pools"

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)