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: "simulation analysis of medium access techniques"
  Abstract: This paper presents comparison of Access Techniques used in Medium Access Control (MAC) protocol for Wireless Body Area Networks (WBANs). Comparison is performed between Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA), Pure ALOHA and Slotted ALOHA (S-ALOHA). Performance metrics used for comparison are throughput (T), delay (D) and offered load (G). The main goal for comparison is to show which technique gives highest Throughput and lowest Delay with increase in Load. Energy efficiency is major issue in WBAN that is why there is need to know which technique performs best for energy conservation and also gives minimum delay.

Connected through hyperedge HE-1 (induced by source paper "energy optimization and performance analysis of cluster based routing protocols extended from leach for wsns"):
  with members:
    - "eddeec enhanced developed distributed energy efficient clustering for heterogeneous wireless sensor networks"
    - "on energy efficiency and delay minimization in reactive protocols in wireless multi hop networks"
    - "beenish balanced energy efficient network integrated super heterogeneous protocol for wireless sensor networks"
    - "improving network efficiency by removing energy holes in wsns"
    - "e horm an energy efficient hole removing mechanism in wireless sensor networks"
    - "divide and rule scheme for energy efficient routing in wireless sensor networks"
    - "towards lp modeling for maximizing throughput and minimizing routing delay in proactive protocols in wireless multi hop networks"
    - "srp ms a new routing protocol for delay tolerant wireless sensor networks"

Connected through hyperedge HE-2 (induced by source paper "imod leach improved modified leach protocol for wireless sensor networks"):
  with members:
    - "ach away cluster heads scheme for energy efficient clustering protocols in wsns"
    - "advanced leach a static clustering based heteroneous routing protocol for wsns"
    - "modleach a variant of leach for wsns"
    - "heer hybrid energy efficient reactive protocol for wireless sensor networks"
    - "energy efficient mac protocols in wireless body area sensor networks a survey"
    - "east energy efficient adaptive scheme for transmission in wireless sensor networks"
    - "e horm an energy efficient hole removing mechanism in wireless sensor networks"
    - "density controlled divide and rule scheme for energy efficient routing in wireless sensor networks"

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)