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: "optimal fairness aware time and power allocation in wireless powered communication networks"
  Abstract: In this paper, we consider the sum $\alpha$-fair utility maximization problem for joint downlink (DL) and uplink (UL) transmissions of a wireless powered communication network (WPCN) via time and power allocation. In the DL, the users with energy harvesting receiver architecture decode information and harvest energy based on simultaneous wireless information and power transfer. While in the UL, the users utilize the harvested energy for information transmission, and harvest energy when other users transmit UL information. We show that the general sum $\alpha$-fair utility maximization problem can be transformed into an equivalent convex one. Tradeoffs between sum rate and user fairness can be balanced via adjusting the value of $\alpha$. In particular, for zero fairness, i.e., $\alpha=0$, the optimal allocated time for both DL and UL is proportional to the overall available transmission power. Tradeoffs between sum rate and user fairness are presented through simulations.

Connected through hyperedge HE-1 (induced by source paper "cache placement in two tier hetnets with limited storage capacity cache or buffer"):
  with members:
    - "energy efficient resource allocation in machine to machine communications with multiple access and energy harvesting for iot"
    - "cooperative edge caching in user centric clustered mobile networks"
    - "association and load optimization with user priorities in load coupled heterogeneous networks"
    - "on consideration of content preference and sharing willingness in d2d assisted offloading"
    - "stochastic content centric multicast scheduling for cache enabled heterogeneous cellular networks"
    - "caching at the wireless edge design aspects challenges and future directions"
    - "wireless caching technical misconceptions and business barriers"
    - "optimal caching and user association in cache enabled heterogeneous wireless 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.IT(Information Theory)