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 relaying in wireless body area networks coexistence performance"
  Abstract: In this paper, a cooperative two-hop communication scheme, together with opportunistic relaying (OR), is applied within a mobile wireless body area network (WBAN). Its effectiveness in interference mitigation is investigated in a scenario where there are multiple closely-located networks. Due to a typical WBAN's nature, no coordination is used among different WBANs. A suitable time-division-multiple-access (TDMA) is adopted as both an intra-network and also an inter-network access scheme. Extensive on-body and off-body channel gain measurements are employed to gauge performance, which are overlaid to simulate a realistic WBAN working environment. It is found that opportunistic relaying is able to improve the signal-to-interference-and-noise ratio (SINR) threshold value at outage probability of 10% by an average of 5 dB, and it is also shown that it can reduce level crossing rate (LCR) significantly at a low SINR threshold value. Furthermore, this scheme is more efficient when on-body channels fade less slowly.

Connected through hyperedge HE-1 (induced by source paper "cross layer designs for body to body networks adaptive csma ca with distributed routing"):
  with members:
    - "cross layer optimized routing with low duty cycle tdma across multiple wireless body area networks"
    - "effective static and adaptive carrier sensing for dense wireless csma networks"

Connected through hyperedge HE-2 (induced by source paper "cross layer optimized routing with low duty cycle tdma across multiple wireless body area networks"):
  with members:
    - "cooperative communications for sleep monitoring in wireless body area networks"
    - "an overview of ieee 802 15 6 standard"

Connected through hyperedge HE-3 (induced by source paper "dynamic channel access scheme for interference mitigation in relay assisted intra wbans"):
  with members:
    - "ubiquitous healthcare in wireless body area networks a survey"
    - "coexistence and interference mitigation for wireless body area networks improvements using on body opportunistic relaying"

Connected through hyperedge HE-4 (induced by source paper "interference avoidance algorithm iaa for multi hop wireless body area network communication"):
  with members:
    - "ubiquitous healthcare in wireless body area networks a survey"
    - "coexistence and interference mitigation for wireless body area networks improvements using on body opportunistic relaying"

Connected through hyperedge HE-5 (induced by source paper "dynamic channel allocation for interference mitigation in relay assisted wireless body networks"):
  with members:
    - "ubiquitous healthcare in wireless body area networks a survey"

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)