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: "coexistence of wi fi and heterogeneous small cell networks sharing unlicensed spectrum"
  Abstract: As two major players in terrestrial wireless communications, Wi-Fi systems and cellular networks have different origins and have largely evolved separately. Motivated by the exponentially increasing wireless data demand, cellular networks are evolving towards a heterogeneous and small cell network architecture, wherein small cells are expected to provide very high capacity. However, due to the limited licensed spectrum for cellular networks, any effort to achieve capacity growth through network densification will face the challenge of severe inter-cell interference. In view of this, recent standardization developments have started to consider the opportunities for cellular networks to use the unlicensed spectrum bands, including the 2.4 GHz and 5 GHz bands that are currently used by Wi-Fi, Zigbee and some other communication systems. In this article, we look into the coexistence of Wi-Fi and 4G cellular networks sharing the unlicensed spectrum. We introduce a network architecture where small cells use the same unlicensed spectrum that Wi-Fi systems operate in without affecting the performance of Wi-Fi systems. We present an almost blank subframe (ABS) scheme without priority to mitigate the co-channel interference from small cells to Wi-Fi systems, and propose an interference avoidance scheme based on small cells estimating the density of nearby Wi-Fi access points to facilitate their coexistence while sharing the same unlicensed spectrum. Simulation results show that the proposed network architecture and interference avoidance schemes can significantly increase the capacity of 4G heterogeneous cellular networks while maintaining the service quality of Wi-Fi systems.

Connected through hyperedge HE-1 (induced by source paper "power allocation in multi user cellular networks deep reinforcement learning approaches"):
  with members:
    - "learning to optimize training deep neural networks for interference management"
    - "a machine learning approach for power allocation in hetnets considering qos"
    - "fractional programming for communication systems part i power control and beamforming"
    - "power allocation in multi user cellular networks with deep q learning approach"
    - "an introduction to deep learning for the physical layer"
    - "policy gradient methods for reinforcement learning with function approximation and action dependent baselines"
    - "deep learning for wireless physical layer opportunities and challenges"
    - "deep reinforcement learning an overview"

Connected through hyperedge HE-2 (induced by source paper "iot u cellular internet of things networks over unlicensed spectrum"):
  with members:
    - "sub channel assignment power allocation and user scheduling for non orthogonal multiple access networks"
    - "long range communications in unlicensed bands the rising stars in the iot and smart city scenarios"
    - "mobile data offloading through a third party wifi access point an operator s perspective"

Connected through hyperedge HE-3 (induced by source paper "contract based incentive mechanism for lte over unlicensed channels"):
  with members:
    - "orla olaa orthogonal coexistence of laa and wifi in unlicensed spectrum"
    - "echo state networks for self organizing resource allocation in lte u with uplink downlink decoupling"
    - "network formation in the sky unmanned aerial vehicles for multi hop wireless backhauling"
    - "proactive resource management in lte u systems a deep learning perspective"
    - "the impact of unlicensed access on small cell resource allocation"
    - "breaking the economic barrier of caching in cellular networks incentives and contracts"
    - "caching in the sky proactive deployment of cache enabled unmanned aerial vehicles for optimized quality of experience"
    - "auction based coopetition between lte unlicensed and wi fi"

Connected through hyperedge HE-4 (induced by source paper "new radio beam based access to unlicensed spectrum design challenges and solutions"):
  with members:
    - "an e2e simulator for 5g nr networks"
    - "a tutorial on beam management for 3gpp nr at mmwave frequencies"
    - "consensus before talk distributed dynamic spectrum access via distributed spectrum ledger technology"
    - "ieee 802 11ay based mmwave wlans design challenges and solutions"
    - "listen before receive for coexistence in unlicensed mmwave bands"
    - "modeling and analyzing millimeter wave cellular systems"
    - "extending lte into the unlicensed spectrum technical analysis of the proposed variants"
    - "massive mimo unlicensed a new approach to dynamic spectrum access"

Connected through hyperedge HE-5 (induced by source paper "energy efficient and fair resource allocation for lte unlicensed uplink networks a two sided matching approach with partial information"):
  with members:
    - "stable marriage problem with ties and incomplete bounded length preference list under social stability"
    - "coordinated dynamic spectrum management of lte u and wi fi networks"
    - "matching theory for future wireless networks fundamentals and applications"

Connected through hyperedge HE-6 (induced by source paper "fundamental green tradeoffs progresses challenges and impacts on 5g networks"):
  with members:
    - "spectrum power trading for energy efficient small cell"
    - "power efficient resource allocation for full duplex radio distributed antenna networks"
    - "energy recycling full duplex radios for next generation networks"
    - "energy efficient resource allocation for wireless powered communication networks"
    - "multi objective optimization for robust power efficient and secure full duplex wireless communication systems"
    - "hybrid millimeter wave systems a novel paradigm for hetnets"
    - "on the spectral efficiency of full duplex small cell wireless systems"
    - "filter bank multicarrier for massive mimo"

Connected through hyperedge HE-7 (induced by source paper "power control in uav supported ultra dense networks communications caching and energy transfer"):
  with members:
    - "energy efficient user association and power allocation in millimeter wave based ultra dense networks with energy harvesting base stations"
    - "fog radio access networks mobility management interference mitigation and resource optimization"
    - "ultra dense small cell networks turning density into energy efficiency"
    - "caching in the sky proactive deployment of cache enabled unmanned aerial vehicles for optimized quality of experience"
    - "wireless communications with unmanned aerial vehicles opportunities and challenges"
    - "unmanned aerial vehicle with underlaid device to device communications performance and tradeoffs"

Connected through hyperedge HE-8 (induced by source paper "enhancing coexistence in the unlicensed band with massive mimo"):
  with members:
    - "operating massive mimo in unlicensed bands for enhanced coexistence and spatial reuse"
    - "massive mimo for maximal spectral efficiency how many users and pilots should be allocated"
    - "scaling up mimo opportunities and challenges with very large arrays"
    - "large system analysis of linear precoding in correlated miso broadcast channels under limited feedback"

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)