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 speculative study on 6g"
  Abstract: While 5G is being tested worldwide and anticipated to be rolled out gradually in 2019, researchers around the world are beginning to turn their attention to what 6G might be in 10+ years time, and there are already initiatives in various countries focusing on the research of possible 6G technologies. This article aims to extend the vision of 5G to more ambitious scenarios in a more distant future and speculates on the visionary technologies that could provide the step changes needed for enabling 6G.

Connected through hyperedge HE-1 (induced by source paper "joint power allocation and load balancing optimization for energy efficient cell free massive mimo networks"):
  with members:
    - "scalable cell free massive mimo systems"
    - "ubiquitous cell free massive mimo communications"
    - "optimal design of energy efficient cell free massive mimo joint power allocation and load balancing"
    - "making cell free massive mimo competitive with mmse processing and centralized implementation"
    - "downlink spectral efficiency of cell free massive mimo with full pilot zero forcing"
    - "distributed power control in downlink cellular massive mimo systems"
    - "energy efficiency maximization for c rans discrete monotonic optimization penalty and ell _ 0 approximation methods"
    - "on the total energy efficiency of cell free massive mimo"

Connected through hyperedge HE-2 (induced by source paper "from a human centric perspective what might 6g be"):
  with members:
    - "towards 6g networks use cases and technologies"
    - "capacity and coverage enhancement using long endurance tethered airborne base stations"
    - "enabling smart buildings by indoor visible light communications and machine learning"
    - "a key 6g challenge and opportunity connecting the remaining 4 billions a survey on rural connectivity"
    - "6g the next frontier"
    - "evolution of physical layer communications research in the post 5g era"
    - "ultrareliable and low latency communication techniques for tactile internet services"
    - "a vision of 6g wireless systems applications trends technologies and open research problems"

Connected through hyperedge HE-3 (induced by source paper "6g wireless communication systems applications requirements technologies challenges and research directions"):
  with members:
    - "towards 6g networks use cases and technologies"
    - "blockchain for internet of things a survey"
    - "uav communications for 5g and beyond recent advances and future trends"
    - "a vision of 6g wireless systems applications trends technologies and open research problems"
    - "on the effect of temporal correlation on joint success probability and distribution of number of interferers in mobile uav networks"
    - "six key enablers for machine type communication in 6g"
    - "integrated rf optical wireless networks for improving qos in indoor and transportation applications"
    - "6g the wireless communications network for collaborative and ai applications"

Connected through hyperedge HE-4 (induced by source paper "power efficient irs assisted noma"):
  with members:
    - "multi antenna covert communications in random wireless networks"
    - "resource allocation for secure irs assisted multiuser miso systems"
    - "beamforming optimization for wireless network aided by intelligent reflecting surface with discrete phase shifts"
    - "intelligent reflecting surface assisted non orthogonal multiple access"
    - "smart radio environments empowered by ai reconfigurable meta surfaces an idea whose time has come"
    - "a vision of 6g wireless systems applications trends technologies and open research problems"
    - "a simple design of irs noma transmission"
    - "energy efficient multi user miso communication using low resolution large intelligent surfaces"

Connected through hyperedge HE-5 (induced by source paper "the potential short and long term disruptions and transformative impacts of 5g and beyond wireless networks lessons learnt from the development of a 5g testbed environment"):
  with members:
    - "the current state of affairs in 5g security and the main remaining security challenges"
    - "blockchain for internet of things a survey"
    - "a vision of 6g wireless systems applications trends technologies and open research problems"
    - "5g nr jamming spoofing and sniffing threat assessment and mitigation"
    - "a concise review of 5g new radio capabilities for directional access at mmwave frequencies"
    - "mutual heterogeneous signcryption schemes for 5g network slicings"
    - "ultra reliable and low latency communications in 5g downlink physical layer aspects"
    - "towards massive connectivity support for scalable mmtc communications in 5g networks"

Connected through hyperedge HE-6 (induced by source paper "machine intelligence at the edge with learning centric power allocation"):
  with members:
    - "edge intelligence paving the last mile of artificial intelligence with edge computing"
    - "a vision of 6g wireless systems applications trends technologies and open research problems"
    - "the roadmap to 6g ai empowered wireless networks"
    - "machine learning in the air"
    - "wireless network intelligence at the edge"
    - "adaptive federated learning in resource constrained edge computing systems"
    - "deep learning in mobile and wireless networking a survey"
    - "massive connectivity with massive mimo part i device activity detection and channel estimation"

Connected through hyperedge HE-7 (induced by source paper "the roadmap to 6g ai empowered wireless networks"):
  with members:
    - "6g the next frontier"
    - "optimizing space air ground integrated networks by artificial intelligence"
    - "a hardware efficient analog network structure for hybrid precoding in millimeter wave systems"
    - "learning to communicate in uav aided wireless networks map based approaches"
    - "applications of deep reinforcement learning in communications and networking a survey"
    - "data shuffling in wireless distributed computing via low rank optimization"
    - "propagation measurement system and approach at 140 ghz moving to 6g and above 100 ghz"
    - "a survey on mobile edge computing the communication perspective"

Connected through hyperedge HE-8 (induced by source paper "uav aided jamming for secure ground communication with unknown eavesdropper location"):
  with members:
    - "securing uav communications via joint trajectory and power control"
    - "cellular enabled uav communication a connectivity constrained trajectory optimization perspective"
    - "network connected uav communications potentials and challenges"
    - "robust trajectory and transmit power design for secure uav communications"
    - "energy efficient uav communication with trajectory optimization"
    - "a survey on wireless security technical challenges recent advances and future trends"

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)