Network: Any physical infrastructure network that forms a telecom-related network and occupies physical space in/on the ground.
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Viettel DSL network. Viettel offers ADSL over copper in areas lacking fiber, with speeds up to 24 Mbps down / 1.5 Mbps up; legacy service being phased out in favor of FTTH (Source). No URL gives a specific Viettel ADSL launch date; service confirmed by 2005 but start not sourced. Establishment date checked but not reliably determined.