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: "the cost of free spectrum"
  Abstract: There has been growing interest in increasing the amount of radio spectrum available for unlicensed broad-band wireless access. That includes "prime" spectrum at lower frequencies, which is also suitable for wide area coverage by licensed cellular providers. While additional unlicensed spectrum would allow for market expansion, it could influence competition among providers and increase congestion (interference) among consumers of wireless services. We study the value (social welfare and consumer surplus) obtained by adding unlicensed spectrum to an existing allocation of licensed spectrum among incumbent service providers. We assume a population of customers who choose a provider based on the minimum delivered price, given by the weighted sum of the price of the service and a congestion cost, which depends on the number of subscribers in a band. We consider models in which this weighting is uniform across the customer population and where the weighting is either high or low, reflecting different sensitivities to latency. For the models considered, we find that the social welfare depends on the amount of additional unlicensed spectrum, and can actually decrease over a significant range of unlicensed bandwidths. Furthermore, with nonuniform weighting, introducing unlicensed spectrum can also reduce consumer welfare.

Connected through hyperedge HE-1 (induced by source paper "price competition with lte u and wifi"):
  with members:
    - "contract based incentive mechanism for lte over unlicensed channels"
    - "ruin theory for dynamic spectrum allocation in lte u networks"
    - "the impact of bundling licensed and unlicensed wireless service"
    - "ltfi cross technology communication for rrm between lte u and ieee 802 11"
    - "a multi game framework for harmonized lte u and wifi coexistence over unlicensed bands"
    - "auction based coopetition between lte unlicensed and wi fi"
    - "quality sensitive price competition in spectrum oligopoly"

Connected through hyperedge HE-2 (induced by source paper "pricing for collaboration between online apps and offline venues"):
  with members:
    - "the geography of pokemon go beneficial and problematic effects on places and movement"
    - "public wi fi monetization via advertising"
    - "mobile augmented reality survey a bottom up approach"

Connected through hyperedge HE-3 (induced by source paper "competition with three tier spectrum access and spectrum monitoring"):
  with members:
    - "the impact of bundling licensed and unlicensed wireless service"
    - "competition between wireless service providers pricing equilibrium and efficiency"

Connected through hyperedge HE-4 (induced by source paper "investment in ev charging spots for parking"):
  with members:
    - "optimal pricing to manage electric vehicles in coupled power and transportation networks"
    - "distributed demand response and user adaptation in smart grids"

Connected through hyperedge HE-5 (induced by source paper "the impact of unlicensed access on small cell resource allocation"):
  with members:
    - "competition between wireless service providers pricing equilibrium and efficiency"

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.GT(Computer Science and Game Theory)