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: "millimeter wave communications with oam sm scheme for future mobile networks"
  Abstract: The orbital angular momentum (OAM) technique provides a new degree of freedom for information transmissions in millimeter wave communications. Considering the spatial distribution characteristics of OAM beams, a new OAM spatial modulation (OAM-SM) millimeter wave communication system is first proposed for future mobile networks. Furthermore, the capacity, average bit error probability and energy efficiency of OAM-SM millimeter wave communication systems are analytically derived for performance analysis. Compared with the conventional multi-input multi-output (MIMO) millimeter wave communication systems, the maximum capacity and energy efficiency of OAM-SM millimeter wave communication systems are improved by 36% and 472.3%, respectively. Moreover, numerical results indicate that the proposed OAM-SM millimeter wave communication systems are more robust to path-loss attenuations than the conventional MIMO millimeter wave communication systems, which makes it suitable for long-range transmissions. Therefore, OAM-SM millimeter wave communication systems provide a great growth space for future mobile networks.

Connected through hyperedge HE-1 (induced by source paper "a survey on spatial modulation in emerging wireless systems research progresses and applications"):
  with members:
    - "spatial modulation assisted multi antenna non orthogonal multiple access"
    - "adaptive spatial modulation based visible light communications ser analysis and optimization"
    - "two high performance schemes of transmit antenna selection for secure spatial modulation"
    - "receive spatial modulation for massive mimo systems"
    - "polarization shift keying polarsk system scheme and performance analysis"
    - "space time channel modulation"
    - "on the achievable spectral efficiency of spatial modulation aided downlink non orthogonal multiple access"
    - "spectral efficient analog precoding for generalized spatial modulation aided mmwave mimo"

Connected through hyperedge HE-2 (induced by source paper "channel capacity enhancement of swipt based cnoma downlink transmission with orbital angular momentum over rician fading channel"):
  with members:
    - "on the performance of noma based cooperative relaying systems over rician fading channels"
    - "wireless powered communications with non orthogonal multiple access"
    - "relaying protocols for wireless energy harvesting and information processing"

Connected through hyperedge HE-3 (induced by source paper "capacity improvement of non orthogonal multiple access downlink transmission by orbital angular momentum based mode division multiple access"):
  with members:
    - "non orthogonal multiple access noma for downlink multiuser mimo systems user clustering beamforming and power allocation"

Connected through hyperedge HE-4 (induced by source paper "communicating using spatial mode multiplexing potentials challenges and perspectives"):
  with members:
    - "spatial mode diversity and multiplexing for fso communication with direct detection"
    - "optical communication in space challenges and mitigation techniques"

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)