human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "ambient backscatter communications a contemporary survey"):
  Abstract: Recently, ambient backscatter communications has been introduced as a cutting-edge technology which enables smart devices to communicate by utilizing ambient radio frequency (RF) signals without requiring active RF transmission. This technology is especially effective in addressing communication and energy efficiency problems for low-power communications systems such as sensor networks. It is expected to realize numerous Internet-of-Things (IoT) applications. Therefore, this paper aims to provide a contemporary and comprehensive literature review on fundamentals, applications, challenges, and research efforts/progress of ambient backscatter communications. In particular, we first present fundamentals of backscatter communications and briefly review bistatic backscatter communications systems. Then, the general architecture, advantages, and solutions to address existing issues and limitations of ambient backscatter communications systems are discussed. Additionally, emerging applications of ambient backscatter communications are highlighted. Finally, we outline some open issues and future research directions.

Includes members:
  Member "cooperative ambient backscatter communications for green internet of things":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "capitalizing backscatter aided hybrid relay communications with wireless energy harvesting")
  Member "pixelated vlc backscattering for self charging indoor iot devices":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "opportunistic ambient backscatter communication in rf powered cognitive radio networks")
  Member "wirelessly powered backscatter communications waveform design and snr energy tradeoff":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "energy efficiency of distributed antenna systems with wireless power transfer")
  Member "lora backscatter enabling the vision of ubiquitous connectivity":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "towards flexible wireless charging for medical implants using distributed antenna system")
  Member "backscatter communications for internet of things theory and applications":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "uav data collection over noma backscatter networks uav altitude and trajectory optimization")
  Member "ambient backscatter networking a novel paradigm to assist wireless powered communications":
    also connected through other hyperedges:
      (none)
  Member "backscatter multiplicative multiple access systems fundamental limits and practical design":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "coverage probability analysis under clustered ambient backscatter nodes")
  Member "scatter radio receivers for extended range environmental sensing wsns":
    also connected through other hyperedges:
      (none)

Question: Please tell me which class the source paper 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)