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: "an overview of sustainable green 5g networks"
  Abstract: The stringent requirements of a 1,000 times increase in data traffic and one millisecond round trip latency have made limiting the potentially tremendous ensuing energy consumption one of the most challenging problems for the design of the upcoming fifth-generation (5G) networks. To enable sustainable 5G networks, new technologies have been proposed to improve the system energy efficiency and alternative energy sources are introduced to reduce our dependence on traditional fossil fuels. In particular, various 5G techniques target the reduction of the energy consumption without sacrificing the quality-of-service. Meanwhile, energy harvesting technologies, which enable communication transceivers to harvest energy from various renewable resources and ambient radio frequency signals for communi- cation, have drawn significant interest from both academia and industry. In this article, we provide an overview of the latest research on both green 5G techniques and energy harvesting for communication. In addition, some technical challenges and potential research topics for realizing sustainable green 5G networks are also identified.

Connected through hyperedge HE-1 (induced by source paper "cross layer scheduling and beamforming in smart grid powered cellular networks with heterogeneous energy coordination"):
  with members:
    - "deep reinforcement learning for adaptive caching in hierarchical content delivery networks"
    - "optimal 3d trajectory design and resource allocation for solar powered uav communication systems"
    - "robust energy efficient beamforming in misome swipt systems with proportional secrecy rate"
    - "dynamic cross layer beamforming in hybrid powered communication systems with harvest use trade strategy"
    - "a hybrid energy sharing framework for green cellular networks"
    - "ergodic energy management leveraging resource variability in distribution grids"
    - "comp meets smart grid a new communication and energy cooperation paradigm"
    - "power delay tradeoff with predictive scheduling in integrated cellular and wi fi networks"

Connected through hyperedge HE-2 (induced by source paper "energy and spectral efficiency tradeoff in ofdma networks via antenna selection strategy"):
  with members:
    - "joint user association and resource allocation in the uplink of heterogeneous networks"
    - "energy efficiency maximization via joint sub carrier assignment and power control for ofdma full duplex networks"
    - "multi objective optimization for energy and spectral efficiency tradeoff in in band full duplex ibfd communication"
    - "downlink energy efficiency of power allocation and wireless backhaul bandwidth allocation in heterogeneous small cell networks"
    - "spectral and energy efficiency trade offs in cellular networks"
    - "optimal joint power and subcarrier allocation for full duplex multicarrier non orthogonal multiple access systems"
    - "energy efficient heterogeneous cellular networks with spectrum underlay and overlay access"

Connected through hyperedge HE-3 (induced by source paper "multiple antenna technologies for beyond 5g"):
  with members:
    - "intelligent reflecting surface versus decode and forward how large surfaces are needed to beat relaying"
    - "robust trajectory and resource allocation design for secure uav aided communications"
    - "a new look at cell free massive mimo making it practical with dynamic cooperation"
    - "scalability aspects of cell free massive mimo"
    - "cascaded channel estimation for large intelligent metasurface assisted massive mimo"
    - "robust and secure wireless communications via intelligent reflecting surfaces"
    - "channel estimation for intelligent reflecting surface assisted multiuser communications framework algorithms and analysis"
    - "resource allocation for secure irs assisted multiuser miso systems"

Connected through hyperedge HE-4 (induced by source paper "timely updates in energy harvesting two hop networks offline and online policies"):
  with members:
    - "using erasure feedback for online timely updating with an energy harvesting sensor"
    - "online timely status updates with erasures for energy harvesting sensors"
    - "optimal status updating for an energy harvesting sensor with a noisy channel"
    - "coded status updates in an energy harvesting erasure channel"
    - "status updates in a multi stream m g 1 1 preemptive queue"
    - "age minimal online policies for energy harvesting sensors with random battery recharges"
    - "sending information through status updates"
    - "age minimal transmission for energy harvesting sensors with finite batteries online policies"

Connected through hyperedge HE-5 (induced by source paper "online policies for throughput maximization of energy constrained wireless powered communication systems"):
  with members:
    - "optimization of energy constrained wireless powered communication networks with heterogeneous nodes"
    - "wireless power meets energy harvesting a joint energy allocation approach in ofdm based system"
    - "resource allocation and fairness in wireless powered cooperative cognitive radio networks"
    - "battery powered devices in wpcns"
    - "on optimal policies in full duplex wireless powered communication networks"
    - "dynamic base station operation in large scale green cellular networks"
    - "optimal design of non orthogonal multiple access with wireless power transfer"
    - "energy efficient resource allocation for wireless powered communication networks"

Connected through hyperedge HE-6 (induced by source paper "towards smart and reconfigurable environment intelligent reflecting surface aided wireless network"):
  with members:
    - "beamforming optimization for wireless network aided by intelligent reflecting surface with discrete phase shifts"
    - "weighted sum power maximization for intelligent reflecting surface aided swipt"
    - "intelligent reflecting surface assisted secrecy communication via joint beamforming and jamming"
    - "enabling large intelligent surfaces with compressive sensing and deep learning"
    - "achievable rate maximization by passive intelligent mirrors"
    - "intelligent reflecting surface enhanced wireless network via joint active and passive beamforming"
    - "spectral and energy efficient wireless powered iot networks noma or tdma"
    - "beyond massive mimo the potential of data transmission with large intelligent surfaces"

Connected through hyperedge HE-7 (induced by source paper "beamforming optimization for wireless network aided by intelligent reflecting surface with discrete phase shifts"):
  with members:
    - "over the air computation via intelligent reflecting surfaces"
    - "miso wireless communication systems via intelligent reflecting surfaces"
    - "secure wireless communication via intelligent reflecting surface"
    - "passive beamforming and information transfer via large intelligent surface"
    - "towards smart and reconfigurable environment intelligent reflecting surface aided wireless network"
    - "achievable rate maximization by passive intelligent mirrors"
    - "intelligent reflecting surface enhanced wireless network via joint active and passive beamforming"
    - "beamforming optimization for intelligent reflecting surface with discrete phase shifts"

Connected through hyperedge HE-8 (induced by source paper "secure hybrid digital and analog precoder for mmwave systems with low resolution dacs and finite quantized phase shifters"):
  with members:
    - "energy efficiency of mmwave massive mimo precoding with low resolution dacs"
    - "secure hybrid analog and digital receive beamforming schemes for efficient interference reduction"
    - "hybrid analog and digital beamforming for mmwave ofdm large scale antenna arrays"
    - "alternating minimization algorithms for hybrid precoding in millimeter wave mimo systems"
    - "an overview of signal processing techniques for millimeter wave mimo systems"
    - "millimeter wave receiver efficiency a comprehensive comparison of beamforming schemes with low resolution adcs"
    - "dynamic subarrays for hybrid precoding in wideband mmwave mimo systems"
    - "achievable rate and energy efficiency of hybrid and digital beamforming receivers with low resolution adc"

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)