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: "optimized base station cache allocation for cloud radio access network with multicast backhaul"
  Abstract: The performance of cloud radio access network (C-RAN) is limited by the finite capacities of the backhaul links connecting the centralized processor (CP) with the base-stations (BSs), especially when the backhaul is implemented in a wireless medium. This paper proposes the use of wireless multicast together with BS caching, where the BSs pre-store contents of popular files, to augment the backhaul of C-RAN. For a downlink C-RAN consisting of a single cluster of BSs and wireless backhaul, this paper studies the optimal cache size allocation strategy among the BSs and the optimal multicast beamforming transmission strategy at the CP such that the user's requested messages are delivered from the CP to the BSs in the most efficient way. We first state a multicast backhaul rate expression based on a joint cache-channel coding scheme, which implies that larger cache sizes should be allocated to the BSs with weaker channels. We then formulate a two-timescale joint cache size allocation and beamforming design problem, where the cache is optimized offline based on the long-term channel statistical information, while the beamformer is designed during the file delivery phase based on the instantaneous channel state information. By leveraging the sample approximation method and the alternating direction method of multipliers (ADMM), we develop efficient algorithms for optimizing cache size allocation among the BSs, and quantify how much more cache should be allocated to the weaker BSs. We further consider the case with multiple files having different popularities and show that it is in general not optimal to entirely cache the most popular files first. Numerical results show considerable performance improvement of the optimized cache size allocation scheme over the uniform allocation and other heuristic schemes.

Connected through hyperedge HE-1 (induced by source paper "secure millimeter wave cloud radio access networks relying on microwave multicast fronthaul"):
  with members:
    - "hybrid precoding based millimeter wave massive mimo noma with simultaneous wireless information and power transfer"
    - "safeguarding millimeter wave communications against randomly located eavesdroppers"
    - "energy efficient power allocation in millimeter wave massive mimo with non orthogonal multiple access"
    - "adaptive coding and modulation for large scale antenna array based aeronautical communications in the presence of co channel interference"
    - "robust an aided beamforming and power splitting design for secure miso cognitive radio with swipt"
    - "energy efficient joint congestion control and resource optimization in heterogeneous cloud radio access networks"
    - "content centric sparse multicast beamforming for cache enabled cloud ran"
    - "secure communications in millimeter wave ad hoc networks"

Connected through hyperedge HE-2 (induced by source paper "mobile communications computing and caching resources optimization for coded caching with device computing"):
  with members:
    - "bandwidth gain from mobile edge computing and caching in wireless multicast systems"
    - "minimizing latency to support vr social interactions over wireless cellular systems via bandwidth allocation"
    - "communications caching and computing for mobile virtual reality modeling and tradeoff"
    - "edge computing meets millimeter wave enabled vr paving the way to cutting the cord"
    - "coded caching with distributed storage"
    - "the three primary colors of mobile systems"
    - "energy efficient resource allocation for mobile edge computation offloading"
    - "optimization and analysis of probabilistic caching in n tier heterogeneous networks"

Connected through hyperedge HE-3 (induced by source paper "caching at base stations with multi cluster multicast wireless backhaul via accelerated first order algorithm"):
  with members:
    - "caching at base stations with heterogeneous user demands and spatial locality"
    - "modeling analysis and optimization of coded caching in small cell networks"
    - "noisy broadcast networks with receiver caching"
    - "caching at the wireless edge design aspects challenges and future directions"
    - "content centric sparse multicast beamforming for cache enabled cloud ran"
    - "cloud radio access network virtualizing wireless access for dense heterogeneous systems"
    - "cloud radio access networks with coded caching"
    - "analysis and optimization of caching and multicasting in large scale cache enabled wireless networks"

Connected through hyperedge HE-4 (induced by source paper "edge cache assisted secure low latency millimeter wave transmission"):
  with members:
    - "securing downlink massive mimo noma networks with artificial noise"
    - "hybrid precoder design for cache enabled millimeter wave radio access networks"
    - "secure and energy efficient transmissions in cache enabled heterogeneous cellular networks performance analysis and optimization"
    - "two level transmission scheme for cache enabled fog radio access networks"
    - "exploiting physical layer security for multiuser multicarrier computation offloading"
    - "content placement in cache enabled sub 6 ghz and millimeter wave multi antenna dense small cell networks"
    - "random caching based cooperative transmission in heterogeneous wireless networks"
    - "cache enabled physical layer security for video streaming in backhaul limited cellular networks"

Connected through hyperedge HE-5 (induced by source paper "joint beamforming and power splitting design for c ran with multicast fronthaul"):
  with members:
    - "beamforming design for max min fair swipt in green cloud ran with wireless fronthaul"
    - "joint millimeter wave fronthaul and ofdma resource allocation in ultra dense cran"
    - "energy efficient joint congestion control and resource optimization in heterogeneous cloud radio access networks"
    - "wireless powered communication opportunities and challenges"
    - "collaborative wireless energy and information transfer in interference channel"
    - "outage constrained robust transmit optimization for multiuser miso downlinks tractable approximations by conic optimization"

Connected through hyperedge HE-6 (induced by source paper "hybrid precoder design for cache enabled millimeter wave radio access networks"):
  with members:
    - "hybrid beamforming based on implicit channel state information for millimeter wave links"
    - "two level transmission scheme for cache enabled fog radio access networks"
    - "spatial and frequency wideband effects in millimeter wave massive mimo systems"
    - "joint precoding and rrh selection for user centric green mimo c ran"
    - "energy efficient transceiver design for hybrid sub array architecture mimo systems"
    - "joint design of digital and analog processing for downlink c ran with large scale antenna arrays"
    - "codebook based hybrid precoding for millimeter wave multiuser systems"
    - "joint optimization of user association data delivery rate and precoding for cache enabled f rans"

Connected through hyperedge HE-7 (induced by source paper "bandwidth gain from mobile edge computing and caching in wireless multicast systems"):
  with members:
    - "communication computing and caching for mobile vr delivery modeling and trade off"
    - "joint communication computation caching and control in big data multi access edge computing"
    - "modeling and trade off for mobile communication computing and caching networks"
    - "toward low latency and ultra reliable virtual reality"
    - "a survey on mobile edge computing the communication perspective"
    - "energy efficient resource allocation for cache assisted mobile edge computing"
    - "joint pushing and caching for bandwidth utilization maximization in wireless networks"
    - "dynamic computation offloading for mobile edge computing with energy harvesting devices"

Connected through hyperedge HE-8 (induced by source paper "economical caching for scalable videos in cache enabled heterogeneous networks"):
  with members:
    - "cost effective cache deployment in mobile heterogeneous networks"
    - "random caching based cooperative transmission in heterogeneous wireless networks"
    - "fundamental tradeoff between storage and latency in cache aided wireless interference networks"
    - "cache enabled physical layer security for video streaming in backhaul limited cellular networks"
    - "cache enabled device to device communications offloading gain and energy cost"
    - "modeling analysis and optimization of coded caching in small cell networks"
    - "stochastic content centric multicast scheduling for cache enabled heterogeneous cellular networks"
    - "caching in wireless small cell networks a storage bandwidth tradeoff"

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)