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: "cooperative cognitive relaying with ordered cognitive multiple access"
  Abstract: We investigate a cognitive radio system with two secondary users who can cooperate with the primary user in relaying its packets to the primary receiver. In addition to its own queue, each secondary user has a queue to keep the primary packets that are not received correctly by the primary receiver. The secondary users accept the unreceived primary packets with a certain probability and transmit randomly from either of their queues if both are nonempty. These probabilities are optimized to expand the maximum stable throughput region of the system. Moreover, we suggest a secondary multiple access scheme in which one secondary user senses the channel for $\tau$ seconds from the beginning of the time slot and transmits if the channel is found to be free. The other secondary user senses the channel over the period $[0,2\tau]$ to detect the possible activity of the primary user and the first-ranked secondary user. It transmits, if possible, starting after $2\tau$ seconds from the beginning of the time slot. It compensates for the delayed transmission by increasing its transmission rate so that it still transmits one packet during the time slot. We show the potential advantage of this ordered system over the conventional random access system. We also show the benefit of cooperation in enhancing the network's throughput.

Connected through hyperedge HE-1 (induced by source paper "a particle filtering approach for enabling distributed and scalable sharing of dsa network resources"):
  with members:
    - "wideband spectrum sensing for cognitive radio networks a survey"
    - "joint scheduling and resource allocation in ofdma downlink systems via ack nak feedback"
    - "a quantitative measure of fairness and discrimination for resource allocation in shared computer systems"

Connected through hyperedge HE-2 (induced by source paper "optimal spectrum access for a rechargeable cognitive radio user based on energy buffer state"):
  with members:
    - "dynamic spectrum access in cognitive radio networks with rf energy harvesting"
    - "on spectrum sharing between energy harvesting cognitive radio users and primary users"
    - "power optimal feedback based random spectrum access for an energy harvesting cognitive user"
    - "on the coexistence of a primary user with an energy harvesting secondary user a case of cognitive cooperation"
    - "optimal selection of spectrum sensing duration for an energy harvesting cognitive radio"
    - "optimal random access and random spectrum sensing for an energy harvesting cognitive radio"
    - "green cellular networks a survey some research issues and challenges"
    - "optimal utilization of a cognitive shared channel with a rechargeable primary source node"

Connected through hyperedge HE-3 (induced by source paper "relay assisted primary and secondary transmissions"):
  with members:
    - "optimal random access and random spectrum sensing for an energy harvesting cognitive radio"
    - "buffers improve the performance of relay selection"

Connected through hyperedge HE-4 (induced by source paper "maximum secondary stable throughput of a cooperative secondary transmitter receiver pair protocol design and stability analysis"):
  with members:
    - "optimal random access and random spectrum sensing for an energy harvesting cognitive radio"
    - "random access broadcast stability and throughput analysis"

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)