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: "powering the next billion devices with wi fi"
  Abstract: We present the first power over Wi-Fi system that delivers power and works with existing Wi-Fi chipsets. Specifically, we show that a ubiquitous piece of wireless communication infrastructure, the Wi-Fi router, can provide far field wireless power without compromising the network's communication performance. Building on our design we prototype, for the first time, battery-free temperature and camera sensors that are powered using Wi-Fi chipsets with ranges of 20 and 17 feet respectively. We also demonstrate the ability to wirelessly recharge nickel-metal hydride and lithium-ion coin-cell batteries at distances of up to 28 feet. Finally, we deploy our system in six homes in a metropolitan area and show that our design can successfully deliver power via Wi-Fi in real-world network conditions.

Connected through hyperedge HE-1 (induced by source paper "towards flexible wireless charging for medical implants using distributed antenna system"):
  with members:
    - "living iot a flying wireless platform on live insects"
    - "netscatter enabling large scale backscatter networks"
    - "lora backscatter enabling the vision of ubiquitous connectivity"

Connected through hyperedge HE-2 (induced by source paper "robofly an insect sized robot with simplified fabrication that is capable of flight ground and water surface locomotion"):
  with members:
    - "an insect scale untethered laser powered jumping microrobot"

Connected through hyperedge HE-3 (induced by source paper "tunnelscatter low power communication for sensor tags using tunnel diodes"):
  with members:
    - "living iot a flying wireless platform on live insects"
    - "solargest ubiquitous and battery free gesture recognition using solar cells"
    - "lora backscatter enabling the vision of ubiquitous connectivity"
    - "fm backscatter enabling connected cities and smart fabrics"
    - "inter technology backscatter towards internet connectivity for implanted devices"

Connected through hyperedge HE-4 (induced by source paper "swipt using hybrid arq over time varying channels"):
  with members:
    - "channel sensing and communication over a time correlated channel with an energy harvesting transmitter"
    - "energy management for energy harvesting wireless sensors with adaptive retransmission"
    - "on distributed power control for uncoordinated dual energy harvesting links performance bounds and near optimal policies"
    - "on optimal policies in full duplex wireless powered communication networks"
    - "arq with adaptive feedback for energy harvesting receivers"
    - "communications and signals design for wireless power transmission"
    - "optimal policies for wireless networks with energy harvesting transmitters and receivers effects of decoding costs"
    - "wireless powered relays in cooperative communications time switching relaying protocols and throughput analysis"

Connected through hyperedge HE-5 (induced by source paper "optimization of power transfer efficiency and energy efficiency for wireless powered systems with massive mimo"):
  with members:
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"
    - "on the feasibility of wireless energy transfer using massive antenna arrays"
    - "communications and signals design for wireless power transmission"
    - "wireless powered communication opportunities and challenges"
    - "practical non linear energy harvesting model and resource allocation for swipt systems"
    - "energy harvesting wireless communications a review of recent advances"
    - "on the efficiency of far field wireless power transfer"
    - "is massive mimo energy efficient"

Connected through hyperedge HE-6 (induced by source paper "on maximizing sampling time of rf harvesting sensor nodes over random channel gains"):
  with members:
    - "robust resource allocation for mimo wireless powered communication networks based on a non linear eh model"
    - "joint beamforming design and time allocation for wireless powered communication networks"
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "throughput maximization in wireless powered communication networks"
    - "relaying protocols for wireless energy harvesting and information processing"
    - "multi antenna wireless powered communication with energy beamforming"

Connected through hyperedge HE-7 (induced by source paper "on maximizing energy and data delivery in dense wireless local area networks"):
  with members:
    - "wireless networks with rf energy harvesting a contemporary survey"
    - "throughput maximization in wireless powered communication networks"
    - "multi antenna wireless powered communication with energy beamforming"

Connected through hyperedge HE-8 (induced by source paper "lora backscatter enabling the vision of ubiquitous connectivity"):
  with members:
    - "lorea a backscatter reader for everyone"
    - "inter technology backscatter towards internet connectivity for implanted devices"

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)