Jio won 4G mobile airwaves in 2010 and is expected to start nationwide commercial services by end of this year, joining leading Indian carriers Bharti Airtel Ltd and Vodafone Group Plc's India unit.
Refer to the input text as context and select the correct relationship between 'Bharti Airtel' and 'Vodafone' from the available options.
Options: owned by, distributed by, product/material produced, subsidiary