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: "exploiting directionality for millimeter wave wireless system improvement"
  Abstract: This paper presents directional and omnidirectional RMS delay spread statistics obtained from 28 GHz and 73 GHz ultrawideband propagation measurements carried out in New York City using a 400 Megachips per second broadband sliding correlator channel sounder and highly directional steerable horn antennas. The 28 GHz measurements did not systematically seek the optimum antenna pointing angles and resulted in 33% outage for 39 T-R separation distances within 200 m. The 73 GHz measurements systematically found the best antenna pointing angles and resulted in 14.3% outage for 35 T-R separation distances within 200 m, all for mobile height receivers. Pointing the antennas to yield the strongest received power is shown to significantly reduce RMS delay spreads in line-of-sight (LOS) environments. A new term, distance extension exponent (DEE) is defined, and used to mathematically describe the increase in coverage distance that results by combining beams from angles with the strongest received power at a given location. These results suggest that employing directionality in millimeter-wave communications systems will reduce inter-symbol interference, improve link margin at cell edges, and enhance overall system performance.

Connected through hyperedge HE-1 (induced by source paper "overview of millimeter wave communications for fifth generation 5g wireless networks with a focus on propagation models"):
  with members:
    - "indoor office wideband penetration loss measurements at 73 ghz"
    - "study on 3gpp rural macrocell path loss models for millimeter wave wireless communications"
    - "investigation and comparison of 3gpp and nyusim channel models for 5g wireless communications"
    - "millimeter wave small scale spatial statistics in an urban microcell scenario"
    - "a novel millimeter wave channel simulator and applications for 5g wireless communications"
    - "small scale local area and transitional millimeter wave propagation for 5g communications"
    - "5g 3gpp like channel models for outdoor urban microcellular and macrocellular environments"
    - "millimeter wave human blockage at 73 ghz with a simple double knife edge diffraction model and extension for directional antennas"

Connected through hyperedge HE-2 (induced by source paper "on capacity and delay of multichannel wireless networks with infrastructure support"):
  with members:
    - "caching in wireless multihop device to device networks"
    - "a survey on device to device communication in cellular networks"
    - "multi channel wireless networks with infrastructure support capacity and delay"

Connected through hyperedge HE-3 (induced by source paper "directional initial access for millimeter wave cellular systems"):
  with members:
    - "towards an appropriate receiver beamforming scheme for millimeter wave communication a power consumption based comparison"
    - "context information based initial cell search for millimeter wave 5g cellular networks"
    - "low power analog to digital conversion in millimeter wave systems impact of resolution and bandwidth on performance"
    - "beam searching and transmission scheduling in millimeter wave communications"
    - "context information for fast cell discovery in mm wave 5g networks"
    - "hybrid analog digital channel estimation and beamforming training throughput tradeoff"
    - "millimeter wave cellular networks a mac layer perspective"
    - "directional cell discovery in millimeter wave cellular networks"

Connected through hyperedge HE-4 (induced by source paper "local multipath model parameters for generating 5g millimeter wave 3gpp like channel impulse response"):
  with members:
    - "28 ghz millimeter wave ultrawideband small scale fading models in wireless channels"
    - "statistical channel model with multi frequency and arbitrary antenna beamwidth for millimeter wave outdoor communications"
    - "3 d statistical channel model for millimeter wave outdoor mobile broadband communications"

Connected through hyperedge HE-5 (induced by source paper "3 d statistical channel model for millimeter wave outdoor mobile broadband communications"):
  with members:
    - "millimeter wave channel modeling and cellular capacity evaluation"

Connected through hyperedge HE-6 (induced by source paper "directional cell discovery in millimeter wave cellular networks"):
  with members:
    - "3 d statistical channel model for millimeter wave outdoor mobile broadband communications"
    - "what will 5g be"
    - "millimeter wave cellular wireless networks potentials and challenges"
    - "millimeter wave channel modeling and cellular capacity evaluation"

Connected through hyperedge HE-7 (induced by source paper "optimal scheduling for interference mitigation by range information"):
  with members:
    - "joint ranging and clock parameter estimation by wireless round trip time measurements"
    - "cooperative localization by dual foot mounted inertial sensors and inter agent ranging"

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.IT(Information Theory)