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: "content placement in cache enabled sub 6 ghz and millimeter wave multi antenna dense small cell networks"
  Abstract: This paper studies the performance of cache-enabled dense small cell networks consisting of multi-antenna sub-6 GHz and millimeter-wave base stations. Different from the existing works which only consider a single antenna at each base station, the optimal content placement is unknown when the base stations have multiple antennas. We first derive the successful content delivery probability by accounting for the key channel features at sub-6 GHz and mmWave frequencies. The maximization of the successful content delivery probability is a challenging problem. To tackle it, we first propose a constrained cross-entropy algorithm which achieves the near-optimal solution with moderate complexity. We then develop another simple yet effective heuristic probabilistic content placement scheme, termed two-stair algorithm, which strikes a balance between caching the most popular contents and achieving content diversity. Numerical results demonstrate the superior performance of the constrained cross-entropy method and that the two-stair algorithm yields significantly better performance than only caching the most popular contents. The comparisons between the sub-6 GHz and mmWave systems reveal an interesting tradeoff between caching capacity and density for the mmWave system to achieve similar performance as the sub-6 GHz system.

Connected through hyperedge HE-1 (induced by source paper "edge cache assisted secure low latency millimeter wave transmission"):
  with members:
    - "securing downlink massive mimo noma networks with artificial noise"
    - "hybrid precoder design for cache enabled millimeter wave radio access networks"
    - "secure and energy efficient transmissions in cache enabled heterogeneous cellular networks performance analysis and optimization"
    - "two level transmission scheme for cache enabled fog radio access networks"
    - "optimized base station cache allocation for cloud radio access network with multicast backhaul"
    - "exploiting physical layer security for multiuser multicarrier computation offloading"
    - "random caching based cooperative transmission in heterogeneous wireless networks"
    - "cache enabled physical layer security for video streaming in backhaul limited cellular networks"

Connected through hyperedge HE-2 (induced by source paper "cloud edge coordinated processing low latency multicasting transmission"):
  with members:
    - "hybrid precoder design for cache enabled millimeter wave radio access networks"
    - "two level transmission scheme for cache enabled fog radio access networks"
    - "iteratively linearized reweighted alternating direction method of multipliers for a class of nonconvex problems"
    - "air ground integrated vehicular network slicing with content pushing and caching"
    - "distributed optimization for coordinated beamforming in multicell multigroup multicast systems power minimization and sinr balancing"
    - "fog aided wireless networks for content delivery fundamental latency tradeoffs"
    - "random caching based cooperative transmission in heterogeneous wireless networks"
    - "cache enabled physical layer security for video streaming in backhaul limited cellular networks"

Connected through hyperedge HE-3 (induced by source paper "on throughput optimization and bound analysis in cache enabled fiber wireless access networks"):
  with members:
    - "cache enabled hetnets with millimeter wave small cells"
    - "joint power allocation and caching optimization in fiber wireless access networks"
    - "energy efficiency of downlink networks with caching at base stations"
    - "caching placement in stochastic wireless caching helper networks channel selection diversity via caching"
    - "coverage in heterogeneous downlink millimeter wave cellular networks"
    - "stochastic geometry modeling and analysis of multi tier millimeter wave cellular networks"
    - "analysis on cache enabled wireless heterogeneous networks"
    - "tractable model for rate in self backhauled millimeter wave cellular 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.NI(Networking and Internet Architecture)