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: "extending lte into the unlicensed spectrum technical analysis of the proposed variants"
  Abstract: The commercial success of the Long Term Evolution (LTE) and the resulting growth in mobile data demand have urged cellular network operators to strive for new innovations. LTE in unlicensed spectrum has been proposed to allow cellular network operators to offload some of their data traffic by accessing the unlicensed 5 GHz frequency band. Currently, there are three proposed variants for LTE operation in the unlicensed band, namely LTE-U, Licensed Spectrum Access (LAA), and MulteFire. This paper provides a comparative analysis of these variants and explains the current regulations of the 5 GHz band in different parts of the world. We present the technical details of the three proposed versions and analyze them in terms of their operational features and coexistence capabilities to provide an R\&D perspective for their deployment and coexistence with legacy systems.

Connected through hyperedge HE-1 (induced by source paper "unlicensed spectrum sharing for massive internet of things communications"):
  with members:
    - "spectrum sharing for internet of things a survey"
    - "uncoordinated access schemes for the iot approaches regulations and performance"
    - "low power wide area networks an overview"

Connected through hyperedge HE-2 (induced by source paper "new radio beam based access to unlicensed spectrum design challenges and solutions"):
  with members:
    - "an e2e simulator for 5g nr networks"
    - "a tutorial on beam management for 3gpp nr at mmwave frequencies"
    - "consensus before talk distributed dynamic spectrum access via distributed spectrum ledger technology"
    - "ieee 802 11ay based mmwave wlans design challenges and solutions"
    - "listen before receive for coexistence in unlicensed mmwave bands"
    - "modeling and analyzing millimeter wave cellular systems"
    - "massive mimo unlicensed a new approach to dynamic spectrum access"
    - "inter technology coexistence in a spectrum commons a case study of wi fi and lte in the 5 ghz unlicensed band"

Connected through hyperedge HE-3 (induced by source paper "security and protocol exploit analysis of the 5g specifications"):
  with members:
    - "defeating the downgrade attack on identity privacy in 5g"
    - "formal analysis of 5g authentication"
    - "the 5g aka authentication protocol privacy"
    - "lte phy layer vulnerability analysis and testing using open source sdr tools"
    - "performance analysis of a mission critical portable lte system in targeted rf interference"
    - "lte security protocol exploits and location tracking experimentation with low cost software radio"
    - "practical attacks against privacy and availability in 4g lte mobile communication systems"
    - "five disruptive technology directions for 5g"

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)