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: "an iot architecture for wide area measurement systems a virtualized pmu based approach"
  Abstract: Internet of Things (IoT) technologies are pervading different application domains by relying on sensing and actuating devices that share, process and present meaningful real-world information. One of the most important of these domains is certainly the Smart Grid (SG), where the use of advanced measurement and control equipment and the diffusion of communication technologies are making an adaptive, reliable, and efficient management of the energy possible, with several new applications. In this scenario, this paper focuses on one of the major IoT features, which is the virtualization, and proposes an IoT solution for wide area measurement systems where virtualized phasor measurement resources are introduced. Such a solution is intended to make a programmable and smart environment fostering interoperability, reusability and flexibility of SG services. The performance of the system is evaluated for both the traffic generated and the latency to understand which scenarios can benefit from its deployment.

Connected through hyperedge HE-1 (induced by source paper "software defined networks based smart grid communication a comprehensive survey"):
  with members:
    - "response time and availability study of raft consensus in distributed sdn control plane"
    - "software defined microgrid control for resilience against cyber attacks"
    - "enabling hard service guarantees in software defined smart grid infrastructures"
    - "survey on network virtualization hypervisors for software defined networking"
    - "iot cloud based distribution system state estimation virtual objects and context awareness"
    - "network function virtualization state of the art and research challenges"
    - "software defined optical networks sdons a comprehensive survey"
    - "smart grid communications overview of research challenges solutions and standardization activities"

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)