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: "opportunistic interference alignment for random access networks"
  Abstract: An interference management problem among multiple overlapped random access networks (RANs) is investigated, each of which operates with a slotted ALOHA protocol. Assuming that access points and users have multiple antennas, a novel opportunistic interference alignment (OIA) is proposed to mitigate interference among overlapped RANs. The proposed technique intelligently combines the transmit beamforming technique at the physical layer and the opportunistic packet transmission at the medium access control layer. Transmit beamforming is based on interference alignment, and opportunistic packet transmission is based on the generating interference of users to other RANs, which can be regarded as a joint optimization of the physical layer and the medium access control layer. It is shown that the proposed OIA protocol significantly outperforms the conventional schemes such as multipacket reception and interference nulling.

Connected through hyperedge HE-1 (induced by source paper "interference aware opportunistic random access in dense iot networks"):
  with members:
    - "opportunistic downlink interference alignment for multi cell mimo networks"
    - "mu mimo mac protocols for wireless local area networks a survey"
    - "massive machine type communications in 5g physical and mac layer solutions"
    - "maximum sum rate of slotted aloha with capture"
    - "coded slotted aloha a graph based method for uncoordinated multiple access"
    - "cooperative slotted aloha for multi base station systems"
    - "scalable synchronization and reciprocity calibration for distributed multiuser mimo"
    - "can one achieve multiuser diversity in uplink multi cell networks"

Connected through hyperedge HE-2 (induced by source paper "multi cell aware opportunistic random access for machine type communications"):
  with members:
    - "opportunistic downlink interference alignment for multi cell mimo networks"
    - "massive machine type communications in 5g physical and mac layer solutions"
    - "maximum sum rate of slotted aloha with capture"
    - "coded slotted aloha a graph based method for uncoordinated multiple access"
    - "cooperative slotted aloha for multi base station systems"
    - "scalable synchronization and reciprocity calibration for distributed multiuser mimo"
    - "can one achieve multiuser diversity in uplink multi cell networks"
    - "opportunistic interference mitigation achieves optimal degrees of freedom in wireless multi cell uplink 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)