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: "optimization of free space optical wireless network for cellular backhauling"
  Abstract: With densification of nodes in cellular networks, free space optic (FSO) connections are becoming an appealing low cost and high rate alternative to copper and fiber as the backhaul solution for wireless communication systems. To ensure a reliable cellular backhaul, provisions for redundant, disjoint paths between the nodes must be made in the design phase. This paper aims at finding a cost-effective solution to upgrade the cellular backhaul with pre-deployed optical fibers using FSO links and mirror components. Since the quality of the FSO links depends on several factors, such as transmission distance, power, and weather conditions, we adopt an elaborate formulation to calculate link reliability. We present a novel integer linear programming model to approach optimal FSO backhaul design, guaranteeing $K$-disjoint paths connecting each node pair. Next, we derive a column generation method to a path-oriented mathematical formulation. Applying the method in a sequential manner enables high computational scalability. We use realistic scenarios to demonstrate our approaches efficiently provide optimal or near-optimal solutions, and thereby allow for accurately dealing with the trade-off between cost and reliability.

Connected through hyperedge HE-1 (induced by source paper "a uav mounted free space optical communication trajectory optimization for flight time"):
  with members:
    - "uav aided offloading for cellular hotspot"
    - "an edge computing empowered radio access network with uav mounted fso fronthaul and backhaul key challenges and approaches"
    - "optimizing communication and computation for multi uav information gathering applications"
    - "wireless communication using unmanned aerial vehicles uavs optimal transport theory for hover time optimization"
    - "joint trajectory and communication design for multi uav enabled wireless networks"
    - "mobile unmanned aerial vehicles uavs for energy efficient internet of things communications"
    - "energy efficient uav communication with trajectory optimization"
    - "designing and implementing future aerial communication networks"

Connected through hyperedge HE-2 (induced by source paper "intelligent reflecting surfaces for free space optical communications"):
  with members:
    - "enabling secure wireless communications via intelligent reflecting surfaces"
    - "reflect and transmit array antennas for scalable and energy efficient mmwave massive mimo"
    - "intelligent reflecting surface enhanced wireless network via joint active and passive beamforming"
    - "intelligent reflecting surface enhanced wireless network joint active and passive beamforming design"
    - "statistical modeling of fso fronthaul channel for drone based networks"

Connected through hyperedge HE-3 (induced by source paper "environment aware minimum cost wireless backhaul network planning with full duplex links"):
  with members:
    - "hardware impairments aware transceiver design for full duplex amplify and forward mimo relaying"
    - "hardware impairments aware transceiver design for bidirectional full duplex mimo ofdm systems"
    - "sum rate analysis and optimization of self backhauling based full duplex radio access system"
    - "optimal joint power and subcarrier allocation for full duplex multicarrier non orthogonal multiple access systems"
    - "a survey of energy efficient techniques for 5g networks and challenges ahead"
    - "hardware impairments aware transceiver for full duplex massive mimo relaying"
    - "full duplex mimo small cell networks performance analysis"
    - "small cell in band wireless backhaul in massive mimo systems a cooperation of next generation techniques"

Connected through hyperedge HE-4 (induced by source paper "allocation of heterogeneous resources of an iot device to flexible services"):
  with members:
    - "flexible allocation of heterogeneous resources to services on an iot device"
    - "non stationary resource allocation policies for delay constrained video streaming application to video over internet of things enabled networks"
    - "a quantitative measure of fairness and discrimination for resource allocation in shared computer systems"

Connected through hyperedge HE-5 (induced by source paper "hybrid radio free space optical design for next generation backhaul systems"):
  with members:
    - "resilient backhaul network design using hybrid radio free space optical technology"
    - "what will 5g be"
    - "five disruptive technology directions for 5g"
    - "opportunistic third party backhaul for cellular wireless networks"
    - "topology control schema for better qos in hybrid rf fso mesh networks"

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)