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: "a survey of green networking research"
  Abstract: Reduction of unnecessary energy consumption is becoming a major concern in wired networking, because of the potential economical benefits and of its expected environmental impact. These issues, usually referred to as "green networking", relate to embedding energy-awareness in the design, in the devices and in the protocols of networks. In this work, we first formulate a more precise definition of the "green" attribute. We furthermore identify a few paradigms that are the key enablers of energy-aware networking research. We then overview the current state of the art and provide a taxonomy of the relevant work, with a special focus on wired networking. At a high level, we identify four branches of green networking research that stem from different observations on the root causes of energy waste, namely (i) Adaptive Link Rate, (ii) Interface proxying, (iii) Energy-aware infrastructures and (iv) Energy-aware applications. In this work, we do not only explore specific proposals pertaining to each of the above branches, but also offer a perspective for research.

Connected through hyperedge HE-1 (induced by source paper "energy efficient mechanism for smart communication in cellular networks"):
  with members:
    - "downlink performance of cellular systems with base station sleeping user association and scheduling"
    - "massive mimo for next generation wireless systems"
    - "what will 5g be"
    - "five disruptive technology directions for 5g"
    - "exploiting network cooperation in green wireless communication"
    - "transmission capacity of wireless networks"
    - "energy and spectral efficiency of very large multiuser mimo systems"

Connected through hyperedge HE-2 (induced by source paper "optimal policies of advanced sleep modes for energy efficient 5g networks"):
  with members:
    - "energy efficiency of downlink networks with caching at base stations"
    - "designing multi user mimo for energy efficiency when is massive mimo the answer"

Connected through hyperedge HE-3 (induced by source paper "greening geographical power allocation for cellular networks"):
  with members:
    - "convergence analysis of the information matrix in gaussian belief propagation"
    - "convergence analysis of belief propagation for pairwise linear gaussian models"
    - "distributed convergence verification for gaussian belief propagation"
    - "smart charging for electric vehicles a survey from the algorithmic perspective"
    - "distributed hybrid power state estimation under pmu sampling phase errors"
    - "distributed clock skew and offset estimation in wireless sensor networks asynchronous algorithm and convergence analysis"
    - "green cellular networks a survey some research issues and challenges"
    - "transmission with energy harvesting nodes in fading wireless channels optimal policies"

Connected through hyperedge HE-4 (induced by source paper "energy efficient adversarial routing in shared channels"):
  with members:
    - "the energy complexity of broadcast"
    - "packet latency of deterministic broadcasting in adversarial multiple access channels"
    - "exponential separations in the energy complexity of leader election"
    - "broadcasting in ad hoc multiple access channels"
    - "adversarial multiple access channels with individual injection rates"
    - "maximum throughput of multiple access channels in adversarial environments"

Connected through hyperedge HE-5 (induced by source paper "fundamental green tradeoffs progresses challenges and impacts on 5g networks"):
  with members:
    - "spectrum power trading for energy efficient small cell"
    - "power efficient resource allocation for full duplex radio distributed antenna networks"
    - "energy recycling full duplex radios for next generation networks"
    - "energy efficient resource allocation for wireless powered communication networks"
    - "multi objective optimization for robust power efficient and secure full duplex wireless communication systems"
    - "hybrid millimeter wave systems a novel paradigm for hetnets"
    - "coexistence of wi fi and heterogeneous small cell networks sharing unlicensed spectrum"
    - "on the spectral efficiency of full duplex small cell wireless systems"

Connected through hyperedge HE-6 (induced by source paper "software defined applications in cellular and optical networks"):
  with members:
    - "programming flows in dense mobile environments a multi user diversity perspective"
    - "system architecture and key technologies for 5g heterogeneous cloud radio access networks"
    - "renewable energy aware inter datacenter virtual machine migration over elastic optical networks"
    - "scalability and resilience of software defined networking an overview"

Connected through hyperedge HE-7 (induced by source paper "parameterized complexity of finding a spanning tree with minimum reload cost diameter"):
  with members:
    - "an fpt 2 approximation for tree cut decomposition"
    - "edge coloring with minimum reload changeover costs"
    - "solving connectivity problems parameterized by treewidth in single exponential time"

Connected through hyperedge HE-8 (induced by source paper "software defined optical networks sdons a comprehensive survey"):
  with members:
    - "survey on network virtualization hypervisors for software defined networking"
    - "network function virtualization state of the art and research challenges"
    - "fronthaul constrained cloud radio access networks insights and challenges"
    - "system architecture and key technologies for 5g heterogeneous cloud radio access networks"
    - "renewable energy aware inter datacenter virtual machine migration over elastic optical networks"
    - "software defined and virtualized future mobile and wireless networks a survey"
    - "wireless sensor network virtualization early architecture and research perspectives"
    - "software defined networking a comprehensive survey"

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)