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: "distributed edge caching in ultra dense fog radio access networks a mean field approach"
  Abstract: In this paper, the edge caching problem in ultra-dense fog radio access networks (F-RAN) is investigated. Taking into account time-variant user requests and ultra-dense deployment of fog access points (F-APs), we propose a dynamic distributed edge caching scheme to jointly minimize the request service delay and fronthaul traffic load. Considering the interactive relationship among F-APs, we model the caching optimization problem as a stochastic differential game (SDG) which captures the temporal dynamics of F-AP states and incorporates user requests status. The SDG is further approximated as a mean field game (MFG) by exploiting the ultra-dense property of F-RAN. In the MFG, each F-AP can optimize its caching policy independently through iteratively solving the corresponding partial differential equations without any information exchange with other F-APs. The simulation results show that the proposed edge caching scheme outperforms the baseline schemes under both static and time-variant user requests.

Connected through hyperedge HE-1 (induced by source paper "distributed edge caching via reinforcement learning in fog radio access networks"):
  with members:
    - "user preference learning based edge caching for fog radio access network"
    - "optimal and scalable caching for 5g using reinforcement learning of space time popularities"
    - "ultra dense edge caching under spatio temporal demand and network dynamics"
    - "offloading content with self organizing mobile fogs"
    - "a cmdp based approach for energy efficient power allocation in massive mimo systems"
    - "context aware proactive content caching with service differentiation in wireless networks"
    - "fog computing based radio access networks issues and challenges"
    - "placing dynamic content in caches with small population"

Connected through hyperedge HE-2 (induced by source paper "user preference learning based edge caching for fog radio access network"):
  with members:
    - "context aware proactive content caching with service differentiation in wireless networks"
    - "a learning based approach to caching in heterogenous small cell networks"
    - "fog computing based radio access networks issues and challenges"
    - "big data caching for networking moving from cloud to edge"
    - "cooperative caching and transmission design in cluster centric small cell networks"
    - "a transfer learning approach for cache enabled wireless networks"
    - "system architecture and key technologies for 5g heterogeneous cloud radio access networks"
    - "analysis and optimization of caching and multicasting in large scale cache enabled wireless networks"

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.IT(Information Theory)