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: "coverage and economy of cellular networks with many base stations"
  Abstract: The performance of a cellular network can be significantly improved by employing many base stations (BSs), which shortens transmission distances. However, there exist no known results on quantifying the performance gains from deploying many BSs. To address this issue, we adopt a stochastic-geometry model of the downlink cellular network and analyze the mobile outage probability. Specifically, given Poisson distributed BSs, the outage probability is shown to diminish inversely with the increasing ratio between the BS and mobile densities. Furthermore, we analyze the optimal tradeoff between the performance gain from increasing the BS density and the resultant network cost accounting for energy consumption, BS hardware and backhaul cables. The optimal BS density is proved to be proportional to the square root of the mobile density and the inverse of the square root of the cost factors considered.

Connected through hyperedge HE-1 (induced by source paper "coverage analysis of 3 d dense cellular networks with realistic propagation conditions"):
  with members:
    - "downlink cellular network analysis with los nlos propagation and elevated base stations"
    - "sinr and throughput scaling in ultradense urban cellular networks"
    - "effect of los nlos propagation on area spectral efficiency and energy efficiency of small cells"
    - "what will 5g be"
    - "a stochastic geometry framework for los nlos propagation in dense small cell networks"
    - "a tractable approach to coverage and rate in cellular networks"

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 "promises and caveats of uplink iot ultra dense networks"):
  with members:
    - "performance impact of base station antenna heights in dense cellular networks"
    - "on the fundamental characteristics of ultra dense small cell networks"
    - "microscopic analysis of the uplink interference in fdma small cell networks"
    - "performance impact of idle mode capability on dense small cell networks"
    - "performance impact of idle mode capability on dense small cell networks with los and nlos transmissions"
    - "performance impact of los and nlos transmissions in dense cellular networks"
    - "uplink performance analysis of dense cellular networks with los and nlos transmissions"
    - "towards 1 gbps ue in cellular systems understanding ultra dense small cell deployments"

Connected through hyperedge HE-4 (induced by source paper "the major and minor factors in the performance analysis of ultra dense networks"):
  with members:
    - "study on the idle mode capability with los and nlos transmissions"
    - "microscopic analysis of the uplink interference in fdma small cell networks"
    - "nearest neighbour distance distribution in hard core point processes"
    - "throughput and coverage for a mixed full and half duplex small cell network"
    - "the intensity matching approach a tractable stochastic geometry approximation to system level analysis of cellular networks"
    - "what is the true value of dynamic tdd a mac layer perspective"
    - "please lower small cell antenna heights in 5g"
    - "performance impact of los and nlos transmissions in dense cellular networks"

Connected through hyperedge HE-5 (induced by source paper "caching policy toward maximal success probability and area spectral efficiency of cache enabled hetnets"):
  with members:
    - "caching at the wireless edge design aspects challenges and future directions"
    - "optimal content placement for offloading in cache enabled heterogeneous wireless networks"
    - "edge caching for coverage and capacity aided heterogeneous networks"
    - "cache enabled heterogeneous cellular networks comparison and tradeoffs"
    - "energy efficiency of downlink networks with caching at base stations"
    - "optimal caching placement for d2d assisted wireless caching networks"
    - "analysis on cache enabled wireless heterogeneous networks"
    - "optimal geographic caching in cellular networks"

Connected through hyperedge HE-6 (induced by source paper "on the performance of practical ultra dense networks the major and minor factors"):
  with members:
    - "study on the idle mode capability with los and nlos transmissions"
    - "microscopic analysis of the uplink interference in fdma small cell networks"
    - "throughput and coverage for a mixed full and half duplex small cell network"
    - "the intensity matching approach a tractable stochastic geometry approximation to system level analysis of cellular networks"
    - "performance impact of los and nlos transmissions in dense cellular networks"
    - "stochastic geometry modeling and analysis of multi tier millimeter wave cellular networks"
    - "towards 1 gbps ue in cellular systems understanding ultra dense small cell deployments"
    - "d2d enhanced heterogeneous cellular networks with dynamic tdd"

Connected through hyperedge HE-7 (induced by source paper "cache enabled device to device communications offloading gain and energy cost"):
  with members:
    - "optimal caching and scheduling for cache enabled d2d communications"
    - "wireless device to device caching networks basic principles and system performance"
    - "cache enabled heterogeneous cellular networks comparison and tradeoffs"
    - "energy efficiency of downlink networks with caching at base stations"
    - "energy costs for traffic offloading by cache enabled d2d communications"
    - "a survey on device to device communication in cellular networks"
    - "living on the edge the role of proactive caching in 5g wireless networks"
    - "base station assisted device to device communications for high throughput wireless video networks"

Connected through hyperedge HE-8 (induced by source paper "ultra dense networks is there a limit to spatial spectrum reuse"):
  with members:
    - "performance analysis of ultra dense networks with elevated base stations"
    - "on the performance of practical ultra dense networks the major and minor factors"
    - "performance impact of base station antenna heights in dense cellular networks"
    - "the intensity matching approach a tractable stochastic geometry approximation to system level analysis of cellular networks"
    - "performance impact of idle mode capability on dense small cell networks"
    - "performance impact of los and nlos transmissions in dense cellular networks"
    - "towards 1 gbps ue in cellular systems understanding ultra dense small cell deployments"
    - "downlink cellular network analysis with multi slope path loss models"

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)