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: "massive mimo unlicensed a new approach to dynamic spectrum access"
  Abstract: Nowadays, the demand for wireless mobile services is copious, and will continue increasing in the near future. Mobile cellular operators are therefore looking at the unlicensed spectrum as an economical supplement to augment the capacity of their soon-to-be overloaded networks. The same unlicensed bands are luring internet service providers, venue owners, and authorities into autonomously setting up and managing their high-performance private networks. In light of this exciting future, ensuring coexistence between multiple unlicensed technologies becomes a pivotal issue. So far this issue has been merely addressed via inefficient sharing schemes based on intermittent transmission. In this article, we present the fundamentals and the main challenges behind massive MIMO unlicensed, a brand-new approach for technology coexistence in the unlicensed bands, which is envisioned to boost spectrum reuse for a plethora of use cases.

Connected through hyperedge HE-1 (induced by source paper "cobeam beamforming based spectrum sharing with zero cross technology signaling for 5g wireless networks"):
  with members:
    - "operating massive mimo in unlicensed bands for enhanced coexistence and spatial reuse"
    - "sharing of unlicensed spectrum by strategic operators"

Connected through hyperedge HE-2 (induced by source paper "understanding uav cellular communications from existing networks to massive mimo"):
  with members:
    - "cellular connected uav potentials challenges and promising technologies"
    - "supporting uav cellular communications through massive mimo"
    - "the essential guide to realizing 5g connected uavs with massive mimo"
    - "the sky is not the limit lte for unmanned aerial vehicles"
    - "a tutorial on uavs for wireless networks applications challenges and open problems"
    - "interference mitigation methods for unmanned aerial vehicles served by cellular networks"
    - "reshaping cellular networks for the sky the major factors and feasibility"
    - "massive mimo for communications with drone swarms"

Connected through hyperedge HE-3 (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"
    - "extending lte into the unlicensed spectrum technical analysis of the proposed variants"
    - "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-4 (induced by source paper "supporting uav cellular communications through massive mimo"):
  with members:
    - "reshaping cellular networks for the sky the major factors and feasibility"
    - "massive mimo for communications with drone swarms"
    - "cell edge aware precoding for downlink massive mimo cellular networks"
    - "uplink sounding reference signal coordination to combat pilot contamination in 5g massive mimo"
    - "a stochastic geometry model of backhaul and user coverage in urban uav networks"
    - "pilot contamination is not a fundamental asymptotic limitation in massive mimo"
    - "wireless communications with unmanned aerial vehicles opportunities and challenges"
    - "operating massive mimo in unlicensed bands for enhanced coexistence and spatial reuse"

Connected through hyperedge HE-5 (induced by source paper "the essential guide to realizing 5g connected uavs with massive mimo"):
  with members:
    - "understanding uav cellular communications from existing networks to massive mimo"
    - "cellular connected uav potentials challenges and promising technologies"
    - "the sky is not the limit lte for unmanned aerial vehicles"
    - "a telecom perspective on the internet of drones from lte advanced to 5g"
    - "a tutorial on uavs for wireless networks applications challenges and open problems"
    - "interference mitigation methods for unmanned aerial vehicles served by cellular networks"
    - "reshaping cellular networks for the sky the major factors and feasibility"
    - "massive mimo for drone communications applications case studies and future directions"

Connected through hyperedge HE-6 (induced by source paper "indoor massive mimo deployments for uniformly high wireless capacity"):
  with members:
    - "cell edge aware precoding for downlink massive mimo cellular networks"
    - "massive mimo unlicensed for high performance indoor networks"
    - "enhancing coexistence in the unlicensed band with massive mimo"
    - "uplink sounding reference signal coordination to combat pilot contamination in 5g massive mimo"
    - "cell free massive mimo versus small cells"
    - "a stochastic analysis of network mimo systems"
    - "operating massive mimo in unlicensed bands for enhanced coexistence and spatial reuse"
    - "towards 1 gbps ue in cellular systems understanding ultra dense small cell deployments"

Connected through hyperedge HE-7 (induced by source paper "massive mimo unlicensed for high performance indoor networks"):
  with members:
    - "cell edge aware precoding for downlink massive mimo cellular networks"
    - "enhancing coexistence in the unlicensed band with massive mimo"
    - "operating massive mimo in unlicensed bands for enhanced coexistence and spatial reuse"
    - "receive combining vs multi stream multiplexing in downlink systems with multi antenna users"

Connected through hyperedge HE-8 (induced by source paper "uplink sounding reference signal coordination to combat pilot contamination in 5g massive mimo"):
  with members:
    - "fractional pilot reuse in massive mimo systems"
    - "massive mimo for next generation wireless systems"

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)