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: "proposed cellular network for indian conditions for enhancement of spectral density and reduction of power consumption rf pollution"
  Abstract: With the exponentially increasing demand for wireless communications the capacity of current cellular systems will soon become incapable of handling the growing traffic. Since radio frequencies are diminishing natural resources, there seems to be a fundamental barrier to further capacity increase. The solution can be found by using smart antenna systems. Smart or adaptive antenna arrays consist of an array of antenna elements with signal processing capability that optimizes the radiation and reception of a desired signal, dynamically. Smart antenna can place nulls in the direction of interferers via adapting adaptive updating of weights linked to each antenna element. They thus cancel out most of the co-channel interference resulting in better quality of reception and lower dropped calls. Smart antenna can also track the user within a cell via direction of arrival algorithms. This paper focuses on about the smart antenna in hierarchical cell clustering (overlay-underlay) with demand based frequency allocation techniques in cellular mobile radio networks in INDIA.

Connected through hyperedge HE-1 (induced by source paper "hybrid spectral efficient cellular network deployment to reduce rf pollution"):
  with members:
    - "r f pollution reduction in cellular communication"
    - "an intelligent approach for dense urban area in existing 2g 2 5g"
    - "hierarchical cellular structures in high capacity cellular communication systems"
    - "survey of latest wireless cellular technologies for enhancement of spectral density at reduced cost"

Connected through hyperedge HE-2 (induced by source paper "r f pollution reduction in cellular communication"):
  with members:
    - "smart antenna for cellular mobile communication"
    - "survey of latest wireless cellular technologies for enhancement of spectral density at reduced cost"
    - "femtocell networks a survey"

Connected through hyperedge HE-3 (induced by source paper "hierarchical cellular structures in high capacity cellular communication systems"):
  with members:
    - "femtocell networks a survey"

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.CY(Computers and Society)