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: "a flexible wideband millimeter wave channel sounder with local area and nlos to los transition measurements"
  Abstract: This paper presents a millimeter-wave (mmWave) wideband sliding correlator channel sounder with flexibility to operate at various transmission rates. The channel sounder can transmit and receive up to 1 GHz of RF null-to-null bandwidth while measuring a 2 nanosecond multipath time resolution. The system architecture takes advantage of field-programmable gate arrays (FPGAs), high-speed digital-to-analog converters (DACs), and low phase noise Rubidium (Rb) references for synchronization. Using steerable narrowbeam antennas, the system can measure up to 185 dB of path loss. The channel sounder is used to measure the directional and omnidirectional received power as a receiver transitions from line-of-sight to non-line-of-sight conditions down an urban canyon. A 25 dB drop in omnidirectional received power was observed as the receiver transitioned from line-of-sight (LOS) conditions to deeply shadowed non-LOS (NLOS) conditions. The channel sounder was also used to study signal variation and spatial consistency for a local set of receiver locations arranged in a cluster spanning a 5 m x 10 m local area, where the omnidirectional received power in LOS and NLOS environments is found to be relatively stable with standard deviations of received power of 2.2 dB and 4.3 dB, respectively. This work shows that when implementing beamforming at the transmitter at mmWave, the omnidirectional received power over a local area has little fluctuation among receiver locations separated by a few to several meters.

Connected through hyperedge HE-1 (induced by source paper "propagation measurement system and approach at 140 ghz moving to 6g and above 100 ghz"):
  with members:
    - "simulating motion incorporating spatial consistency into the nyusim channel model"
    - "millimeter wave extended nyusim channel model for spatial consistency"
    - "verification and calibration of antenna cross polarization discrimination and penetration loss for millimeter wave communications"
    - "position locationing for millimeter wave systems"
    - "indoor office wideband penetration loss measurements at 73 ghz"
    - "investigation and comparison of 3gpp and nyusim channel models for 5g wireless communications"
    - "a novel millimeter wave channel simulator and applications for 5g wireless communications"
    - "comparing radio propagation channels between 28 and 140 ghz bands in a shopping mall"

Connected through hyperedge HE-2 (induced by source paper "small scale local area and transitional millimeter wave propagation for 5g communications"):
  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"
    - "overview of millimeter wave communications for fifth generation 5g wireless networks with a focus on propagation models"
    - "stationarity region of mm wave channel based on outdoor microcellular measurements at 28 ghz"
    - "millimeter wave human blockage at 73 ghz with a simple double knife edge diffraction model and extension for directional antennas"

Connected through hyperedge HE-3 (induced by source paper "base station diversity propagation measurements at 73 ghz millimeter wave for 5g coordinated multipoint comp analysis"):
  with members:
    - "a novel millimeter wave channel simulator and applications for 5g wireless communications"
    - "small scale local area and transitional millimeter wave propagation for 5g communications"
    - "overview of millimeter wave communications for fifth generation 5g wireless networks with a focus on propagation models"
    - "millimeter wave human blockage at 73 ghz with a simple double knife edge diffraction model and extension for directional antennas"
    - "investigation of prediction accuracy sensitivity and parameter stability of large scale propagation path loss models for 5g wireless communications"
    - "synthesizing omnidirectional antenna patterns received power and path loss from directional antennas for 5g millimeter wave communications"
    - "five disruptive technology directions for 5g"

Connected through hyperedge HE-4 (induced by source paper "stationarity region of mm wave channel based on outdoor microcellular measurements at 28 ghz"):
  with members:
    - "millimeter wave small scale spatial statistics in an urban microcell scenario"
    - "small scale local area and transitional millimeter wave propagation for 5g communications"
    - "5g 3gpp like channel models for outdoor urban microcellular and macrocellular environments"
    - "28 ghz millimeter wave ultrawideband small scale fading models in wireless channels"
    - "what will 5g be"
    - "millimeter wave cellular wireless networks potentials and challenges"

Connected through hyperedge HE-5 (induced by source paper "indoor office wideband penetration loss measurements at 73 ghz"):
  with members:
    - "5g 3gpp like channel models for outdoor urban microcellular and macrocellular environments"
    - "in building wideband partition loss measurements at 2 5 and 60 ghz"

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)