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: "coupled ieee 802 11ac and tcp goodput improvement using aggregation and reverse direction"
  Abstract: This paper suggests a new model for the transmission of TCP traffic over IEEE 802.11 using the new features of IEEE 802.11ac . The paper examines a first step in this direction and as such we first consider a single TCP connection, which is typical in a home environment. We show that when the IEEE 802.11ac MAC is aware of QoS TCP traffic, using Reverse Direction improves the TCP Goodput in tens of percentages compared to the traditional contention based channel access. In an error-free channel this improvement is 20% while in an error-prone channel the improvement reaches 60%, also using blind retransmission of frames. In our operation modes we also assume the use in Two-Level aggregation scheme, the ARQ protocol of the IEEE 802.11ac MAC layer and also assume the data rates and the four Access Categories defined in this standard.

Connected through hyperedge HE-1 (induced by source paper "advanced ieee 802 11ax tcp aware scheduling under unreliable channels"):
  with members:
    - "ap initiated multi user transmissions in ieee 802 11ax wlans"
    - "simultaneous transmit and receive operation in next generation ieee 802 11 wlans a mac protocol design approach"
    - "ieee 802 11ax high efficiency wlans"
    - "resource management for ofdma based next generation 802 11 wlans"
    - "future evolution of csma protocols for the ieee 802 11 standard"

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)