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: "roaming charges for customers of cellular wireless entrant and incumbent providers"
  Abstract: In some countries, cellular wireless roaming charges are prohibitive possibly#R##N#because the incumbent access-provider is actually or essentially state-run,#R##N#unlike potential entrants, i.e., the regulator (state) is in a con#R##N#ict of inter-#R##N#est. In other countries, e.g., France, there is a lot of competition among#R##N#Internet Service (access) Providers (ISPs). Recently, Free purchased a spec-#R##N#trum license to compete in the 4G market. Free is an established discount#R##N#broadband (wired) ISP likely intending to bundle its existing oerings with#R##N#cellular wireless. The cellular-wireless incumbents such as Orange disputed#R##N#Free's position on roaming charges for its customers while Free builds out#R##N#its wireless infrastructure and oers highly discounted access rates to attract#R##N#customers (though Free's service is quota limited and considered of poorer#R##N#quality and support, the latter particularly through physical store-fronts) [3].#R##N#Orange does lease some of its existing infrastructure to third-party discount#R##N#providers such as Virgin Wireless (which does not oer bundled services in#R##N#direct competition with Orange).

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)