human: Given a hyperedge-centered hypergraph: <hypergraph>, where the center hyperedge is induced by one source paper and its member nodes are the cited papers.

Details of the hypergraph:
Center hyperedge (induced by source paper "random access protocols for massive mimo"):
  Abstract: 5G wireless networks are expected to support new services with stringent requirements on data rates, latency and reliability. One novel feature is the ability to serve a dense crowd of devices, calling for radically new ways of accessing the network. This is the case in machine-type communications, but also in urban environments and hotspots. In those use cases, the high number of devices and the relatively short channel coherence interval do not allow per-device allocation of orthogonal pilot sequences. This article motivates the need for random access by the devices to pilot sequences used for channel estimation, and shows that Massive MIMO is a main enabler to achieve fast access with high data rates, and delay-tolerant access with different data rate levels. Three pilot access protocols along with data transmission protocols are described, fulfilling different requirements of 5G services.

Includes members:
  Member "a random access protocol for pilot allocation in crowded massive mimo systems":
    also connected through other hyperedges:
      - Hyperedge HE-1 (induced by source paper "massive mimo asymptotics for ray based propagation channels")
  Member "rrh based massive mimo with on the fly pilot contamination control":
    also connected through other hyperedges:
      - Hyperedge HE-2 (induced by source paper "random access for massive machine type communications")
  Member "random access in uplink massive mimo systems how to exploit asynchronicity and excess antennas":
    also connected through other hyperedges:
      - Hyperedge HE-3 (induced by source paper "timing advance estimation and beamforming of random access response in crowded tdd massive mimo systems")
  Member "coded pilot access a random access solution for massive mimo systems":
    also connected through other hyperedges:
      - Hyperedge HE-4 (induced by source paper "towards massive connectivity support for scalable mmtc communications in 5g networks")
  Member "random access for massive mimo systems with intra cell pilot contamination":
    also connected through other hyperedges:
      - Hyperedge HE-5 (induced by source paper "efficient pilot allocation for urllc traffic in 5g industrial iot networks")
  Member "random access protocol for massive mimo strongest user collision resolution sucr":
    also connected through other hyperedges:
      - Hyperedge HE-6 (induced by source paper "efficient pilot allocation for urllc traffic in 5g industrial iot networks")
  Member "coded random access applying codes on graphs to design random access protocols":
    also connected through other hyperedges:
      - Hyperedge HE-7 (induced by source paper "massive unsourced random access based on uncoupled compressive sensing another blessing of massive mimo")
  Member "coded random access how coding theory helps to build random access protocols":
    also connected through other hyperedges:
      - Hyperedge HE-8 (induced by source paper "wireless access in ultra reliable low latency communication urllc")

Question: Please tell me which class the source paper 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)