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: "non orthogonal multiple access noma in cellular uplink and downlink challenges and enabling techniques"
  Abstract: By combining the concepts of superposition coding at the transmitter(s) and successive interference cancellation (SIC) at the receiver(s), non-orthogonal multiple access (NOMA) has recently emerged as a promising multiple access technique for 5G wireless technology. In this article, we first discuss the fundamentals of uplink and downlink NOMA transmissions and outline their key distinctions (in terms of implementation complexity, detection and decoding at the SIC receiver(s), incurred intra-cell and inter-cell interferences). Later, for both downlink and uplink NOMA, we theoretically derive the NOMA dominant condition for each individual user in a two-user NOMA cluster. NOMA dominant condition refers to the condition under which the spectral efficiency gains of NOMA are guaranteed compared to conventional orthogonal multiple access (OMA). The derived conditions provide direct insights on selecting appropriate users in two-user NOMA clusters. The conditions are distinct for uplink and downlink as well as for each individual user. Numerical results show the significance of the derived conditions for the user selection in uplink/downlink NOMA clusters and provide a comparison to the random user selection. A brief overview of the recent research investigations is then provided to highlight the existing research gaps. Finally, we discuss the potential applications and key challenges of NOMA transmissions.

Connected through hyperedge HE-1 (induced by source paper "on the performance of non orthogonal multiple access in the finite blocklength regime"):
  with members:
    - "on the effective energy efficiency of ultra reliable networks in the finite blocklength regime"
    - "short packet communications in non orthogonal multiple access systems"
    - "on the effective capacity of mtc networks in the finite blocklength regime"
    - "ultra reliable communication via optimum power allocation for type i arq in finite block length"
    - "low latency ultra reliable 5g communications finite blocklength bounds and coding schemes"
    - "finite block length analysis of the incremental redundancy harq"
    - "ultra reliable communication in 5g wireless systems"
    - "quasi static simo fading channels at finite blocklength"

Connected through hyperedge HE-2 (induced by source paper "non orthogonal multiple access for 5g and beyond"):
  with members:
    - "downlink non orthogonal multiple access with limited feedback"
    - "optimal user scheduling and power allocation for millimeter wave noma systems"
    - "coordinated multi point comp transmission in downlink multi cell noma systems models and spectral efficiency performance"
    - "low complexity receiver for multi level polar coded modulation in non orthogonal multiple access"
    - "massive non orthogonal multiple access for cellular iot potentials and limitations"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "modulation and multiple access for 5g networks"
    - "robust beamforming techniques for non orthogonal multiple access systems with bounded channel uncertainties"

Connected through hyperedge HE-3 (induced by source paper "optimized resource provisioning and operation control for low power wide area iot networks"):
  with members:
    - "poisson cluster process bridging the gap between ppp and 3gpp hetnet models"
    - "a survey on non orthogonal multiple access for 5g networks research challenges and future trends"
    - "grant free radio access iot networks scalability analysis in coexistence scenarios"
    - "multiple access for 5g new radio categorization evaluation and challenges"
    - "wireless access for ultra reliable low latency communication urllc principles and building blocks"
    - "energy efficient scheduling and grouping for machine type communications over cellular networks"
    - "2d time frequency interference modelling using stochastic geometry for performance evaluation in low power wide area networks"
    - "interference and outage in clustered wireless ad hoc networks"

Connected through hyperedge HE-4 (induced by source paper "performance evaluation and optimization of lpwa iot networks a stochastic geometry approach"):
  with members:
    - "optimized resource provisioning and operation control for low power wide area iot networks"
    - "grant free radio access for short packet communications over 5g networks"
    - "poisson cluster process bridging the gap between ppp and 3gpp hetnet models"
    - "grant free radio access iot networks scalability analysis in coexistence scenarios"
    - "network lifetime maximization for cellular based m2m networks"
    - "e 2 mac energy efficient medium access for massive m2m communications"
    - "2d time frequency interference modelling using stochastic geometry for performance evaluation in low power wide area networks"
    - "interference and outage in clustered wireless ad hoc networks"

Connected through hyperedge HE-5 (induced by source paper "on user pairing in noma uplink"):
  with members:
    - "an optimization perspective of the superiority of noma compared to conventional oma"
    - "design of massive mimo noma with limited feedback"
    - "optimal joint power and subcarrier allocation for mc noma systems"
    - "a survey of downlink non orthogonal multiple access for 5g wireless communication networks"
    - "the application of mimo to non orthogonal multiple access"
    - "fairness for non orthogonal multiple access in 5g systems"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"
    - "uplink non orthogonal multiple access for 5g wireless networks"

Connected through hyperedge HE-6 (induced by source paper "exploiting multiple antenna techniques for non orthogonal multiple access"):
  with members:
    - "on optimal power allocation for downlink non orthogonal multiple access systems"
    - "dynamic user clustering and power allocation for uplink and downlink non orthogonal multiple access noma systems"
    - "non orthogonal multiple access noma for downlink multiuser mimo systems user clustering beamforming and power allocation"
    - "cooperative non orthogonal multiple access with simultaneous wireless information and power transfer"
    - "the application of mimo to non orthogonal multiple access"
    - "fairness for non orthogonal multiple access in 5g systems"
    - "a general mimo framework for noma downlink and uplink transmission based on signal alignment"
    - "on the performance of non orthogonal multiple access in 5g systems with randomly deployed users"

Connected through hyperedge HE-7 (induced by source paper "modeling and analysis of uplink non orthogonal multiple access noma in large scale cellular networks using poisson cluster processes"):
  with members:
    - "fundamentals of cluster centric content placement in cache enabled device to device networks"
    - "energy efficiency of distributed signal processing in wireless networks a cross layer analysis"
    - "modeling and performance analysis of clustered device to device networks"
    - "cooperative non orthogonal multiple access with simultaneous wireless information and power transfer"
    - "fairness for non orthogonal multiple access in 5g systems"
    - "on stochastic geometry modeling of cellular uplink transmission with truncated channel inversion power control"
    - "interference statistics and capacity analysis for uplink transmission in two tier small cell networks a geometric probability approach"
    - "characterizing spatial patterns of base stations in cellular networks"

Connected through hyperedge HE-8 (induced by source paper "non orthogonal multiple access in multi cell networks theory performance and practical challenges"):
  with members:
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "approximate capacity region of the mac ic mac"
    - "the application of mimo to non orthogonal multiple access"
    - "analytical evaluation of fractional frequency reuse for ofdma cellular 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)