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: "load optimization with user association in cooperative and load coupled lte networks"
  Abstract: We extend the problem of optimizing user association for load balancing in cellular networks along two dimensions. First, we consider joint transmission (JT), which is one of the coordinated multipoint (CoMP) techniques, with which a user may be simultaneously served by multiple base stations. Second, we account for, mathematically, the coupling relation between the base stations' load levels that are dependent on each other due to inter-cell interference. We formulate two optimization problems, sum load minimization (MinSumL) and maximum load minimization (MinMaxL). We prove that both MinSumL and MinMaxL are NP-hard. We propose a mixed integer linear programming (MILP) based scheme by means of linearization. This approach also leads to a bounding scheme for performance benchmarking. Then, we derive a set of partial optimality conditions. Fulfillment of the conditions will guarantee performance improvement for both MinSumL and MinMaxL. A solution algorithm is then derived based on the conditions. Simulation results are provided to demonstrate the effectiveness of the approaches.

Connected through hyperedge HE-1 (induced by source paper "a note on decoding order in optimizing multi cell noma"):
  with members:
    - "a robust machine learning method for cell load approximation in wireless networks"
    - "a framework for optimizing multi cell noma delivering demand with less resource"
    - "resource optimization with load coupling in multi cell noma"
    - "on optimal power allocation for downlink non orthogonal multiple access systems"
    - "energy aware wireless relay selection in load coupled ofdma cellular networks"
    - "dynamic user clustering and power allocation for uplink and downlink non orthogonal multiple access noma systems"
    - "elementary properties of positive concave mappings with applications to network planning and optimization"
    - "power and channel allocation for non orthogonal multiple access in 5g systems tractability and computation"

Connected through hyperedge HE-2 (induced by source paper "context aware group buying in ultra dense small cell networks unity is strength"):
  with members:
    - "two sided matching based cooperative spectrum sharing"
    - "energy group buying with loading sharing for green cellular networks"
    - "user mobility evaluation for 5g small cell networks based on individual mobility model"
    - "5g ultra dense cellular networks"
    - "coalitional games with overlapping coalitions for interference management in small cell networks"

Connected through hyperedge HE-3 (induced by source paper "resource optimization with load coupling in multi cell noma"):
  with members:
    - "a robust machine learning method for cell load approximation in wireless networks"
    - "a framework for optimizing multi cell noma delivering demand with less resource"
    - "on optimal power allocation for downlink non orthogonal multiple access systems"
    - "energy aware wireless relay selection in load coupled ofdma cellular networks"
    - "sub channel assignment power allocation and user scheduling for non orthogonal multiple access networks"
    - "elementary properties of positive concave mappings with applications to network planning and optimization"
    - "power and channel allocation for non orthogonal multiple access in 5g systems tractability and computation"
    - "energy efficiency of distributed signal processing in wireless networks a cross layer analysis"

Connected through hyperedge HE-4 (induced by source paper "power control for multi cell networks with non orthogonal multiple access"):
  with members:
    - "resource optimization in multi cell noma"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "sub channel assignment power allocation and user scheduling for non orthogonal multiple access networks"
    - "energy efficient transmission design in non orthogonal multiple access"
    - "a minorization maximization method for optimizing sum rate in the downlink of non orthogonal multiple access systems"
    - "power and channel allocation for non orthogonal multiple access in 5g systems tractability and computation"
    - "non orthogonal multiple access in multi cell networks theory performance and practical challenges"
    - "power and load coupling in cellular networks for energy optimization"

Connected through hyperedge HE-5 (induced by source paper "resource optimization in multi cell noma"):
  with members:
    - "a framework for optimizing multi cell noma delivering demand with less resource"
    - "on optimal power allocation for downlink non orthogonal multiple access systems"
    - "energy aware wireless relay selection in load coupled ofdma cellular networks"
    - "elementary properties of positive concave mappings with applications to network planning and optimization"
    - "energy efficiency of distributed signal processing in wireless networks a cross layer analysis"
    - "non orthogonal multiple access in multi cell networks theory performance and practical challenges"
    - "power and load coupling in cellular networks for energy optimization"
    - "optimal cell clustering and activation for energy saving in load coupled wireless networks"

Connected through hyperedge HE-6 (induced by source paper "user centric performance optimization with remote radio head cooperation in c ran"):
  with members:
    - "joint precoding and rrh selection for user centric green mimo c ran"
    - "load balancing via joint transmission in heterogeneous lte modeling and computation"
    - "joint comp cell selection and resource allocation with fronthaul constrained c ran"
    - "dynamic joint uplink and downlink optimization for uplink and downlink decoupling enabled 5g heterogeneous networks"
    - "green ofdma resource allocation in cache enabled cran"
    - "cooperative interference mitigation and handover management for heterogeneous cloud small cell networks"
    - "system architecture and key technologies for 5g heterogeneous cloud radio access networks"
    - "analysis of cell load coupling for lte network planning and optimization"

Connected through hyperedge HE-7 (induced by source paper "association and load optimization with user priorities in load coupled heterogeneous networks"):
  with members:
    - "power and load coupling in cellular networks for energy optimization"
    - "distributed pricing based user association for downlink heterogeneous cellular networks"
    - "unified and distributed qos driven cell association algorithms in heterogeneous networks"
    - "what will 5g be"
    - "analysis of cell load coupling for lte network planning and optimization"
    - "user association for load balancing in heterogeneous cellular networks"
    - "modeling and analysis of k tier downlink heterogeneous cellular networks"

Connected through hyperedge HE-8 (induced by source paper "joint time allocation and power control in multi cell networks with load coupling energy saving and rate improvement"):
  with members:
    - "wireless networks with energy harvesting and power transfer joint power and time allocation"
    - "power and load coupling in cellular networks for energy optimization"
    - "what will 5g be"
    - "throughput maximization in wireless powered communication networks"
    - "analysis of cell load coupling for lte network planning and optimization"
    - "distributed robust multicell coordinated beamforming with imperfect csi an admm approach"

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)