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: "the capacity of two way relay channel"
  Abstract: This paper investigates the capacity of a wireless two way relay channel in which two end nodes exchange information via a relay node. The capacity is defined in the information-theoretic sense as the maximum information exchange rate between the two end nodes. We give an upper bound of the capacity by applying the cut-set theorem. We prove that this upper bound can be approached in low SNR region using "separated" multiple access for uplinks from the end nodes to the relay in which the data from the end nodes are individually decoded at the relay; and network-coding broadcast for downlinks from the relay to the end nodes in which the relay mixes the information from end nodes before forwarding. We further prove that the capacity is approachable in high SNR region using physical-layer network coding (PNC) multiple access for uplinks, and network-coding broadcast for downlinks. From our proof and observations, we conjecture that the upper bound may be achieved with PNC in all SNR regions.

Connected through hyperedge HE-1 (induced by source paper "on the capacity and diversity multiplexing tradeoff of the two way relay channel"):
  with members:
    - "approximate capacity of the two way relay channel a deterministic approach"
    - "optimal beamforming for two way multi antenna relay channel with analogue network coding"
    - "joint physical layer coding and network coding for bi directional relaying"
    - "achievable rate regions for bi directional relaying"
    - "physical network coding in two way wireless relay channels"
    - "performance bounds for bi directional coded cooperation protocols"
    - "optimal space time codes for the mimo amplify and forward cooperative channel"
    - "approximately universal optimality over several dynamic and non dynamic cooperative diversity schemes for wireless networks"

Connected through hyperedge HE-2 (induced by source paper "optimal beamforming for two way multi antenna relay channel with analogue network coding"):
  with members:
    - "broadcast capacity region of two phase bidirectional relaying"
    - "joint physical layer coding and network coding for bi directional relaying"
    - "capacity of gaussian mimo bidirectional broadcast channels"
    - "physical layer network coding"
    - "performance bounds for bi directional coded cooperation protocols"

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.IT(Information Theory)