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: "distributed mac protocol supporting physical layer network coding"
  Abstract: Physical-layer network coding (PNC) is a promising approach for wireless networks. It allows nodes to transmit simultaneously. Due to the difficulties of scheduling simultaneous transmissions, existing works on PNC are based on simplified medium access control (MAC) protocols, which are not applicable to general multihop wireless networks, to the best of our knowledge. In this paper, we propose a distributed MAC protocol that supports PNC in multihop wireless networks. The proposed MAC protocol is based on the carrier sense multiple access (CSMA) strategy and can be regarded as an extension to the IEEE 802.11 MAC protocol. In the proposed protocol, each node collects information on the queue status of its neighboring nodes. When a node finds that there is an opportunity for some of its neighbors to perform PNC, it notifies its corresponding neighboring nodes and initiates the process of packet exchange using PNC, with the node itself as a relay. During the packet exchange process, the relay also works as a coordinator which coordinates the transmission of source nodes. Meanwhile, the proposed protocol is compatible with conventional network coding and conventional transmission schemes. Simulation results show that the proposed protocol is advantageous in various scenarios of wireless applications.

Connected through hyperedge HE-1 (induced by source paper "reliable physical layer network coding supporting real applications"):
  with members:
    - "on the subtleties of q pam linear physical layer network coding"
    - "arq for physical layer network coding"
    - "building blocks of physical layer network coding"
    - "network coded multiple access"
    - "reliable physical layer network coding"
    - "physical layer network coding tutorial survey and beyond"
    - "implementation of physical layer network coding"

Connected through hyperedge HE-2 (induced by source paper "approaching single hop performance in multihop networks end to end known interference cancelation e2e kic"):
  with members:
    - "coding based data broadcasting for time critical applications with rate adaptation"
    - "blind known interference cancellation"
    - "coordinating interfering transmissions in cooperative wireless lans"
    - "pushing the limits of full duplex design and real time implementation"

Connected through hyperedge HE-3 (induced by source paper "arq for physical layer network coding"):
  with members:
    - "network codes for real time applications"
    - "joint channel estimation and channel decoding in physical layer network coding systems an em bp factor graph framework"
    - "asynchronous convolutional coded physical layer network coding"
    - "asynchronous physical layer network coding with quasi cyclic codes"
    - "building blocks of physical layer network coding"
    - "asynchronous physical layer network coding"
    - "reliable physical layer network coding"
    - "physical layer network coding tutorial survey and beyond"

Connected through hyperedge HE-4 (induced by source paper "wireless broadcast with physical layer network coding"):
  with members:
    - "physical layer network coding tutorial survey and beyond"
    - "channel coding and decoding in a relay system operated with physical layer network coding"

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)