NTT Docomo Mobile network. NTT Docomo owns Japan's largest mobile network (2G/3G/4G/5G) (Source).
Japan
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Network: Any physical infrastructure network that forms a telecom-related network and occupies physical space in/on the ground.
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NTT Docomo Mobile network. NTT Docomo owns and operates Japan's largest mobile network (2G/3G/4G/5G) for voice and data services. Took over NTT wireless operations July 1992 (Source), (Source).