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: "ambient rf energy harvesting in ultra dense small cell networks performance and trade offs"
  Abstract: In order to minimize electric grid power consumption, energy harvesting from ambient RF sources is considered as a promising technique for wireless charging of low-power devices. To illustrate the design considerations of RF-based ambient energy harvesting networks, this article first points out the primary challenges of implementing and operating such networks, including non-deterministic energy arrival patterns, energy harvesting mode selection, energy-aware cooperation among base stations, and so on. A brief overview of recent advances and a summary of their shortcomings are then provided to highlight existing research gaps and possible future research directions. To this end, we investigate the feasibility of implementing RF-based ambient energy harvesting in ultra-dense small cell networks and examine the related trade-offs in terms of the energy efficiency and signal-to-interference-plus-noise ratio outage probability of a typical user in the downlink. Numerical results demonstrate the significance of deploying a mixture of on-grid small base stations (powered by electric grid) and off-grid small base stations (powered by energy harvesting), and optimizing their corresponding proportions as a function of the intensity of active small base stations in the network.

Connected through hyperedge HE-1 (induced by source paper "full duplex mimo ofdm communication with self energy recycling"):
  with members:
    - "non orthogonal multiple access in large scale heterogeneous networks"
    - "wireless information and energy transfer for two hop non regenerative mimo ofdm relay networks"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "wireless information and power transfer in multiuser ofdm systems"
    - "wireless information and power transfer energy efficiency optimization in ofdma systems"
    - "relaying protocols for wireless energy harvesting and information processing"

Connected through hyperedge HE-2 (induced by source paper "nonorthogonal multiple access for beamforming in energy harvesting enabled networks"):
  with members:
    - "power allocation for energy efficiency and secrecy of interference wireless networks"
    - "achievable rate region of non orthogonal multiple access systems with wireless powered decoder"
    - "non orthogonal multiple access in large scale heterogeneous networks"
    - "joint beamforming and power splitting control in downlink cooperative swipt noma systems"
    - "wireless powered communications with non orthogonal multiple access"
    - "waveform design for wireless power transfer"
    - "path following algorithms for beamforming and signal splitting in rf energy harvesting networks"
    - "wireless information and power transfer nonlinearity waveform design and rate energy tradeoff"

Connected through hyperedge HE-3 (induced by source paper "power beacon assisted millimeter wave ad hoc networks"):
  with members:
    - "modeling and analyzing millimeter wave cellular systems"
    - "adaptively directional wireless power transfer for large scale sensor networks"
    - "performance analysis of outdoor mmwave ad hoc networks"
    - "device to device millimeter wave communications interference coverage rate and finite topologies"
    - "the intensity matching approach a tractable stochastic geometry approximation to system level analysis of cellular networks"
    - "communications and signals design for wireless power transmission"
    - "millimeter wave energy harvesting"
    - "stochastic geometry modeling and analysis of multi tier millimeter wave cellular networks"

Connected through hyperedge HE-4 (induced by source paper "wirelessly powered crowd sensing joint power transfer sensing compression and transmission"):
  with members:
    - "privacy management and optimal pricing in people centric sensing"
    - "wirelessly powered urban crowd sensing over wearables trading energy for data"
    - "wirelessly powered backscatter communication networks modeling coverage and capacity"
    - "communications and signals design for wireless power transmission"
    - "resource allocation in wireless powered relay networks a bargaining game approach"
    - "simultaneous wireless information and power transfer under different csi acquisition schemes"
    - "energy efficient mobile cloud computing powered by wireless energy transfer"
    - "wireless networks with rf energy harvesting a contemporary survey"

Connected through hyperedge HE-5 (induced by source paper "robust chance constrained optimization for power efficient and secure swipt systems"):
  with members:
    - "probabilistically robust swipt for secrecy misome systems"
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"
    - "robust an aided beamforming and power splitting design for secure miso cognitive radio with swipt"
    - "safe and secure wireless power transfer networks challenges and opportunities in rf based systems"
    - "wireless powered communication networks an overview"
    - "multi objective resource allocation in full duplex swipt systems"
    - "secrecy wireless information and power transfer challenges and opportunities"
    - "secrecy transmit beamforming for heterogeneous networks"

Connected through hyperedge HE-6 (induced by source paper "5g ultra dense networks with non uniform distributed users"):
  with members:
    - "ultra dense small cell networks turning density into energy efficiency"
    - "tractable resource management with uplink decoupled millimeter wave overlay in ultra dense cellular networks"
    - "performance impact of los and nlos transmissions in dense cellular networks"
    - "spatial spectrum and energy efficiency of random cellular networks"
    - "towards 1 gbps ue in cellular systems understanding ultra dense small cell deployments"
    - "user mobility evaluation for 5g small cell networks based on individual mobility model"
    - "5g ultra dense cellular networks"
    - "mmwave massive mimo based wireless backhaul for the 5g ultra dense network"

Connected through hyperedge HE-7 (induced by source paper "optimizing wirelessly powered crowd sensing trading energy for data"):
  with members:
    - "wireless charging technologies fundamentals standards and network applications"
    - "wirelessly powered urban crowd sensing over wearables trading energy for data"
    - "resource allocation in wireless powered relay networks a bargaining game approach"
    - "energy efficient mobile cloud computing powered by wireless energy transfer"
    - "interactive joint transfer of energy and information"
    - "opportunistic wireless energy harvesting in cognitive radio networks"
    - "mimo broadcasting for simultaneous wireless information and power transfer"

Connected through hyperedge HE-8 (induced by source paper "power availability aware cell association for energy harvesting small cell base stations"):
  with members:
    - "distributed user association in energy harvesting small cell networks an exchange economy with uncertainty"
    - "distributed user association in energy harvesting small cell networks a probabilistic bandit model"
    - "distributed multi relay selection in accumulate then forward energy harvesting relay networks"
    - "user association in 5g networks a survey and an outlook"
    - "online ski rental for on off scheduling of energy harvesting base stations"
    - "a survey of energy efficient techniques for 5g networks and challenges ahead"
    - "millimeter wave energy harvesting"
    - "relay selection in wireless powered cooperative networks with energy storage"

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)