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: "self optimized coverage coordination in femtocell networks"
  Abstract: This paper proposes a self-optimized coverage coordination scheme for two-tier femtocell networks, in which a femtocell base station adjusts the transmit power based on the statistics of the signal and the interference power that is measured at a femtocell downlink. Furthermore, an analytic expression is derived for the coverage leakage probability that a femtocell coverage area leaks into an outdoor macrocell. The coverage analysis is verified by simulation, which shows that the proposed scheme provides sufficient indoor femtocell coverage and that the femtocell coverage does not leak into an outdoor macrocell.

Connected through hyperedge HE-1 (induced by source paper "green networking in cellular hetnets a unified radio resource management framework with base station on off switching"):
  with members:
    - "green 5g heterogeneous networks through dynamic small cell operation"
    - "power control in two tier femtocell networks"
    - "femtocell networks a survey"

Connected through hyperedge HE-2 (induced by source paper "load balancing in two tier cellular networks with open and hybrid access femtocells"):
  with members:
    - "a tractable approach to coverage and rate in cellular networks"

Connected through hyperedge HE-3 (induced by source paper "adaptive resource management for multimedia applications in femtocellular and macrocellular networks"):
  with members:
    - "handover between macrocell and femtocell for umts based networks"
    - "call admission control based on adaptive bandwidth allocation for wireless networks"
    - "cost effective frequency planning for capacity enhancement of femtocellular networks"
    - "network evolution and qos provisioning for integrated femtocell macrocell networks"
    - "interference mitigation using dynamic frequency re use for dense femtocell network architectures"
    - "femtocell networks a survey"

Connected through hyperedge HE-4 (induced by source paper "handover management in high dense femtocellular networks"):
  with members:
    - "handover between macrocell and femtocell for umts based networks"
    - "cost effective frequency planning for capacity enhancement of femtocellular networks"
    - "network evolution and qos provisioning for integrated femtocell macrocell networks"
    - "femtocell networks a survey"

Connected through hyperedge HE-5 (induced by source paper "open closed and shared access femtocells in the downlink"):
  with members:
    - "heterogeneous cellular networks with flexible cell association a comprehensive downlink sinr analysis"
    - "fundamentals of inter cell overhead signaling in heterogeneous cellular networks"
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"
    - "open vs closed access femtocells in the uplink"
    - "power control in two tier femtocell networks"
    - "coverage in multi antenna two tier networks"
    - "interference mitigation using uplink power control for two tier femtocell networks"
    - "femtocell networks a survey"

Connected through hyperedge HE-6 (induced by source paper "heterogeneous cellular networks with flexible cell association a comprehensive downlink sinr analysis"):
  with members:
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"
    - "a tractable approach to coverage and rate in cellular networks"
    - "coverage in multi antenna two tier networks"
    - "interference mitigation using uplink power control for two tier femtocell networks"
    - "femtocell networks a survey"
    - "spectrum allocation in two tier networks"
    - "uplink capacity and interference avoidance for two tier femtocell 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)