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: "open closed and shared access femtocells in the downlink"
  Abstract: A fundamental choice in femtocell deployments is the set of users which are allowed to access each femtocell. Closed access restricts the set to specifically registered users, while open access allows any mobile subscriber to use any femtocell. Which one is preferable depends strongly on the distance between the macrocell base station (MBS) and femtocell. The main results of the this article are lemmas which provide expressions for the signal-to-interference-plus-to-noise ratio (SINR) distribution for various zones within a cell as a function of this MBS-femto distance. The average sum throughput (or any other SINR-based metric) of home users and cellular users under open and closed access can readily be determined from these expressions. We show that unlike in the uplink, the interests of home and cellular users are in conflict, with home users preferring closed access and cellular users preferring open access. The conflict is most pronounced for femtocells near the cell edge, when there are many cellular users and fewer femtocells. To mitigate this conflict, we propose a middle way which we term shared access in which femtocells allocate an adjustable number of time-slots between home and cellular users such that a specified minimum rate for each can be achieved. The optimal such sharing fraction is derived. Analysis shows that shared access achieves at least the overall throughput of open access while also satisfying rate requirements, while closed access fails for cellular users and open access fails for the home user.

Connected through hyperedge HE-1 (induced by source paper "optimizing the mimo cellular downlink multiplexing diversity or interference nulling"):
  with members:
    - "a stochastic analysis of network mimo systems"
    - "spectral efficiency of dynamic coordinated beamforming a stochastic geometry approach"
    - "large scale mimo versus network mimo for multicell interference mitigation"
    - "user centric intercell interference nulling for downlink small cell networks"
    - "a tractable model for noncoherent joint transmission base station cooperation"
    - "sparse beamforming and user centric clustering for downlink cloud radio access network"
    - "a stochastic geometry analysis of inter cell interference coordination and intra cell diversity"
    - "interference coordination random clustering and adaptive limited feedback"

Connected through hyperedge HE-2 (induced by source paper "structured spectrum allocation and user association in heterogeneous cellular networks"):
  with members:
    - "joint resource partitioning and offloading in heterogeneous cellular networks"
    - "understanding the benefits of open access in femtocell networks stochastic geometric analysis in the uplink"
    - "offloading in heterogeneous networks modeling analysis and design insights"
    - "heterogeneous cellular networks with flexible cell association a comprehensive downlink sinr analysis"
    - "user association for load balancing in heterogeneous cellular networks"
    - "mechanism design for base station association and resource allocation in downlink ofdma network"
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"
    - "a tractable approach to coverage and rate in cellular networks"

Connected through hyperedge HE-3 (induced by source paper "understanding the benefits of open access in femtocell networks stochastic geometric analysis in the uplink"):
  with members:
    - "uplink interference analysis for two tier cellular networks with diverse users under random spatial patterns"
    - "offloading in heterogeneous networks modeling analysis and design insights"
    - "analytical modeling of uplink cellular networks"
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"
    - "open vs closed access femtocells in the uplink"
    - "uplink capacity and interference avoidance for two tier femtocell networks"

Connected through hyperedge HE-4 (induced by source paper "multi channel hybrid access femtocells a stochastic geometric analysis"):
  with members:
    - "a tractable approach to coverage and rate in cellular networks"
    - "transmission capacity of spectrum sharing ad hoc networks with multiple antennas"
    - "open vs closed access femtocells in the uplink"
    - "interference and outage in clustered wireless ad hoc networks"
    - "femtocell networks a survey"
    - "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)