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: "secure communications in millimeter wave ad hoc networks"
  Abstract: Wireless networks with directional antennas, like millimeter wave (mmWave) networks, have enhanced security. For a large-scale mmWave ad hoc network in which eavesdroppers are randomly located, however, eavesdroppers can still intercept the confidential messages, since they may reside in the signal beam. This paper explores the potential of physical layer security in mmWave ad hoc networks. Specifically, we characterize the impact of mmWave channel characteristics, random blockages, and antenna gains on the secrecy performance. For the special case of uniform linear array (ULA), a tractable approach is proposed to evaluate the average achievable secrecy rate. We also characterize the impact of artificial noise in such networks. Our results reveal that in the low transmit powerregime, the use of low mmWave frequency achieves better secrecy performance, and when increasing transmit power, a transition from low mmWave frequency to high mmWave frequency is demanded for obtaining a higher secrecy rate. More antennas at the transmitting nodes are needed to decrease the antenna gain obtained by the eavesdroppers when using ULA. Eavesdroppers can intercept more information by using a wide beam pattern. Furthermore, the use of artificial noise may be ineffective for enhancing the secrecy rate.

Connected through hyperedge HE-1 (induced by source paper "secure millimeter wave cloud radio access networks relying on microwave multicast fronthaul"):
  with members:
    - "hybrid precoding based millimeter wave massive mimo noma with simultaneous wireless information and power transfer"
    - "optimized base station cache allocation for cloud radio access network with multicast backhaul"
    - "safeguarding millimeter wave communications against randomly located eavesdroppers"
    - "energy efficient power allocation in millimeter wave massive mimo with non orthogonal multiple access"
    - "adaptive coding and modulation for large scale antenna array based aeronautical communications in the presence of co channel interference"
    - "robust an aided beamforming and power splitting design for secure miso cognitive radio with swipt"
    - "energy efficient joint congestion control and resource optimization in heterogeneous cloud radio access networks"
    - "content centric sparse multicast beamforming for cache enabled cloud ran"

Connected through hyperedge HE-2 (induced by source paper "secrecy outage analysis of non orthogonal spectrum sharing for heterogeneous cellular networks"):
  with members:
    - "security reliability tradeoff for distributed antenna systems in heterogeneous cellular networks"
    - "intelligent interference exploitation for heterogeneous cellular networks against eavesdropping"
    - "power domain non orthogonal multiple access noma in 5g systems potentials and challenges"
    - "a new look at physical layer security caching and wireless energy harvesting for heterogeneous ultra dense networks"
    - "physical layer security for spectrum sharing systems"
    - "artificial noise aided secure transmission in large scale spectrum sharing networks"
    - "location based beamforming and physical layer security in rician wiretap channels"
    - "physical layer security in millimeter wave cellular networks"

Connected through hyperedge HE-3 (induced by source paper "secure communication for spatially sparse millimeter wave massive mimo channels via hybrid precoding"):
  with members:
    - "secure massive mimo communication with low resolution dacs"
    - "secure users oriented downlink miso noma"
    - "a hardware efficient analog network structure for hybrid precoding in millimeter wave systems"
    - "performance analysis of multi cell millimeter wave massive mimo networks with low precision adcs"
    - "low complexity reconfigurable mimo for millimeter wave communications"
    - "a survey of physical layer security techniques for 5g wireless networks and challenges ahead"
    - "millimeter wave communications with reconfigurable antennas"
    - "millimeter wave mimo channel estimation using overlapped beam patterns and rate adaptation"

Connected through hyperedge HE-4 (induced by source paper "fixed region beamforming using frequency diverse subarray for secure mmwave wireless communications"):
  with members:
    - "a survey of physical layer security techniques for 5g wireless networks and challenges ahead"
    - "safeguarding millimeter wave communications against randomly located eavesdroppers"
    - "a survey on wireless security technical challenges recent advances and future trends"
    - "multi antenna relay aided wireless physical layer security"
    - "robust beamforming for secure communication in systems with wireless information and power transfer"
    - "millimeter wave channel modeling and cellular capacity evaluation"

Connected through hyperedge HE-5 (induced by source paper "a survey of physical layer security techniques for 5g wireless networks and challenges ahead"):
  with members:
    - "secure massive mimo systems with limited rf chains"
    - "secure transmission with large numbers of antennas and finite alphabet inputs"
    - "probabilistically robust swipt for secrecy misome systems"
    - "exploiting full duplex receivers for achieving secret communications in multiuser miso networks"
    - "full duplex bidirectional secure communications under perfect and distributionally ambiguous eavesdropper s csi"
    - "safeguarding decentralized wireless networks using full duplex jamming receivers"
    - "physical layer security aware routing and performance tradeoffs in ad hoc networks"
    - "hybrid procoder and combiner design for secure transmission in mmwave mimo systems"

Connected through hyperedge HE-6 (induced by source paper "an overview of physical layer security with finite alphabet signaling"):
  with members:
    - "a survey of physical layer security techniques for 5g wireless networks and challenges ahead"
    - "physical layer cryptography through massive mimo"
    - "linear precoding of data and artificial noise in secure massive mimo systems"
    - "sum secrecy rate maximization for full duplex two way relay networks using alamouti based rank two beamforming"
    - "performance of lattice coset codes on universal software radio peripherals"
    - "secure m psk communication via directional modulation"
    - "finite blocklength bounds for wiretap channels"
    - "physical layer security in millimeter wave cellular networks"

Connected through hyperedge HE-7 (induced by source paper "a brief history on the theoretical analysis of dense small cell wireless networks"):
  with members:
    - "optimal base station antenna downtilt in downlink cellular networks"
    - "sinr and throughput of dense cellular networks with stretched exponential path loss"
    - "ultra dense networks is there a limit to spatial spectrum reuse"
    - "wireless powered dense cellular networks how many small cells do we need"
    - "inter operator base station coordination in spectrum shared millimeter wave cellular networks"
    - "downlink cellular network analysis with los nlos propagation and elevated base stations"
    - "performance impact of base station antenna heights in dense cellular networks"
    - "modeling infrastructure sharing in mmwave networks with shared spectrum licenses"

Connected through hyperedge HE-8 (induced by source paper "beam domain secure transmission for massive mimo communications"):
  with members:
    - "free deterministic equivalents for the analysis of mimo multiple access channel"
    - "linear precoding of data and artificial noise in secure massive mimo systems"
    - "massive mimo ten myths and one critical question"
    - "pilot reuse for massive mimo transmission over spatially correlated rayleigh fading channels"
    - "massive mimo for next generation wireless systems"
    - "downlink training techniques for fdd massive mimo systems open loop and closed loop training with memory"
    - "principles of physical layer security in multiuser wireless networks a survey"
    - "on capacity of large scale mimo multiple access channels with distributed sets of correlated antennas"

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)