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: "uplink capacity and interference avoidance for two tier femtocell networks"
  Abstract: Two-tier femtocell networks-- comprising a conventional macrocellular network plus embedded femtocell hotspots-- offer an economically viable solution to achieving high cellular user capacity and improved coverage. With universal frequency reuse and DS-CDMA transmission however, the ensuing cross-tier cochannel interference (CCI) causes unacceptable outage probability. This paper develops an uplink capacity analysis and interference avoidance strategy in such a two-tier CDMA network. We evaluate a network-wide area spectral efficiency metric called the \emph{operating contour (OC)} defined as the feasible combinations of the average number of active macrocell users and femtocell base stations (BS) per cell-site that satisfy a target outage constraint. The capacity analysis provides an accurate characterization of the uplink outage probability, accounting for power control, path-loss and shadowing effects. Considering worst case CCI at a corner femtocell, results reveal that interference avoidance through a time-hopped CDMA physical layer and sectorized antennas allows about a 7x higher femtocell density, relative to a split spectrum two-tier network with omnidirectional femtocell antennas. A femtocell exclusion region and a tier selection based handoff policy offers modest improvements in the OCs. These results provide guidelines for the design of robust shared spectrum two-tier networks.

Connected through hyperedge HE-1 (induced by source paper "a brief history on the theoretical analysis of dense small cell wireless networks"):
  with members:
    - "optimal base station antenna downtilt in downlink cellular networks"
    - "sinr and throughput of dense cellular networks with stretched exponential path loss"
    - "ultra dense networks is there a limit to spatial spectrum reuse"
    - "wireless powered dense cellular networks how many small cells do we need"
    - "inter operator base station coordination in spectrum shared millimeter wave cellular networks"
    - "downlink cellular network analysis with los nlos propagation and elevated base stations"
    - "performance impact of base station antenna heights in dense cellular networks"
    - "modeling infrastructure sharing in mmwave networks with shared spectrum licenses"

Connected through hyperedge HE-2 (induced by source paper "5g massive mimo architectures self backhauled small cells versus direct access"):
  with members:
    - "performance analysis for practical unmanned aerial vehicle networks with los nlos transmissions"
    - "performance of massive mimo self backhauling for ultra dense small cell deployments"
    - "performance of dynamic and static tdd in self backhauled millimeter wave cellular networks"
    - "uplink sounding reference signal coordination to combat pilot contamination in 5g massive mimo"
    - "joint backhaul access analysis of full duplex self backhauling heterogeneous networks"
    - "analysis of massive mimo enabled downlink wireless backhauling for full duplex small cells"
    - "the new frontier in ran heterogeneity multi tier drone cells"
    - "performance impact of los and nlos transmissions in dense cellular networks"

Connected through hyperedge HE-3 (induced by source paper "a game theoretical approach for qos provisioning in heterogeneous networks"):
  with members:
    - "call admission control based on adaptive bandwidth allocation for wireless networks"
    - "cost effective frequency planning for capacity enhancement of femtocellular networks"
    - "open vs closed access femtocells in the uplink"
    - "power control in two tier femtocell networks"

Connected through hyperedge HE-4 (induced by source paper "analytical model of wireless cell with superposition coding"):
  with members:
    - "superposition coding is almost always optimal for the poisson broadcast channel"
    - "long range communications in unlicensed bands the rising stars in the iot and smart city scenarios"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"
    - "fundamentals of throughput maximization with random arrivals for m2m communications"

Connected through hyperedge HE-5 (induced by source paper "a 3 d spatial model for in building wireless networks with correlated shadowing"):
  with members:
    - "sinr and throughput scaling in ultradense urban cellular networks"
    - "downlink cellular network analysis with multi slope path loss models"
    - "coverage and rate analysis for millimeter wave cellular networks"
    - "analysis of blockage effects on urban cellular networks"
    - "offloading in heterogeneous networks modeling analysis and design insights"
    - "load aware modeling and analysis of heterogeneous cellular networks"
    - "heterogeneous cellular networks with flexible cell association a comprehensive downlink sinr analysis"
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"

Connected through hyperedge HE-6 (induced by source paper "analyzing dependent placements of small cells in a two layer heterogeneous network with a rate coverage constraint"):
  with members:
    - "analyzing the impact of access point density on the performance of finite area networks"
    - "stochastic geometry modeling of cellular networks analysis simulation and experimental validation"
    - "a versatile dependent model for heterogeneous cellular networks"
    - "downlink mimo hetnets modeling ordering results and performance analysis"
    - "equivalence and comparison of heterogeneous cellular networks"
    - "average rate of downlink heterogeneous cellular networks over generalized fading channels a stochastic geometry approach"
    - "heterogeneous cellular networks with flexible cell association a comprehensive downlink sinr analysis"
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"

Connected through hyperedge HE-7 (induced by source paper "on modeling coverage and rate of random cellular networks under generic channel fading"):
  with members:
    - "a stochastic geometry analysis of inter cell interference coordination and intra cell diversity"
    - "average rate of downlink heterogeneous cellular networks over generalized fading channels a stochastic geometry approach"
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"
    - "a tractable approach to coverage and rate in cellular networks"
    - "analytical evaluation of fractional frequency reuse for ofdma cellular networks"

Connected through hyperedge HE-8 (induced by source paper "outage probability and capacity for two tier femtocell networks by approximating ratio of rayleigh and log normal random variables"):
  with members:
    - "femtocell networks a survey"
    - "the effect of fading channel inversion and threshold scheduling on ad hoc 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)