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: "backscatter communications for internet of things theory and applications"
  Abstract: The Internet-of-Things (IoT) is an emerging concept of network connectivity at anytime and anywhere for billions of everyday objects, which has recently attracted tremendous attentions from both the industry and academia. The rapid growth of IoT has been driven by recent advancements in consumer electronics, wireless network densification, 5G communication technologies [e.g., millimeter wave and massive multiple-input and multiple-output (MIMO)], and cloud-computing enabled big-data analytics. One of the remaining key challenges for IoT is the limited network lifetime due to massive IoT devices being powered by batteries with finite capacities. The low-power and low-complexity backscatter communications (BackCom) has emerged to be a promising technology for tackling the challenge. In this article, we present an overview of the active area by discussing basic principles, system and network architectures and relevant techniques. Last, we describe the IoT applications for BackCom and how the technology can solve the energy challenge for IoT.

Connected through hyperedge HE-1 (induced by source paper "uav data collection over noma backscatter networks uav altitude and trajectory optimization"):
  with members:
    - "3 d placement of an unmanned aerial vehicle base station for maximum coverage of users with different qos requirements"
    - "ultra reliable uav communication using altitude and cooperation diversity"
    - "efficient 3d placement of a uav using particle swarm optimization"
    - "lora backscatter enabling the vision of ubiquitous connectivity"
    - "joint trajectory and communication design for multi uav enabled wireless networks"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "energy efficient data collection in uav enabled wireless sensor network"

Connected through hyperedge HE-2 (induced by source paper "ambient backscatter communications a contemporary survey"):
  with members:
    - "cooperative ambient backscatter communications for green internet of things"
    - "pixelated vlc backscattering for self charging indoor iot devices"
    - "wirelessly powered backscatter communications waveform design and snr energy tradeoff"
    - "lora backscatter enabling the vision of ubiquitous connectivity"
    - "ambient backscatter networking a novel paradigm to assist wireless powered communications"
    - "backscatter multiplicative multiple access systems fundamental limits and practical design"
    - "scatter radio receivers for extended range environmental sensing wsns"
    - "fm backscatter enabling connected cities and smart fabrics"

Connected through hyperedge HE-3 (induced by source paper "backscatter communications for the internet of things a stochastic geometry approach"):
  with members:
    - "multistatic scatter radio sensor networks for extended coverage"
    - "joint uplink and downlink coverage analysis of cellular based rf powered iot network"
    - "backscatter communications for wireless powered sensor networks with collision resolution"
    - "modeling and analysis of cellular networks using stochastic geometry a tutorial"
    - "downlink and uplink decoupling in two tier heterogeneous networks with multi antenna base stations"
    - "modulation in the air backscatter communication over ambient ofdm carrier"
    - "waveform design for wireless power transfer"
    - "the internet of things new interoperability management and security challenges"

Connected through hyperedge HE-4 (induced by source paper "backscatter multiplicative multiple access systems fundamental limits and practical design"):
  with members:
    - "cooperative ambient backscatter communications for green internet of things"
    - "modulation in the air backscatter communication over ambient ofdm carrier"
    - "full duplex backscatter interference networks based on time hopping spread spectrum"
    - "massive machine type communications in 5g physical and mac layer solutions"
    - "bounds on the lambert function and their application to the outage analysis of user cooperation"

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)