Bharti Airtel Ltd., India’s top wireless carrier, plans 600 billion rupees ($9 billion) of investment to improve voice and data quality as India’s richest man, Mukesh Ambani, prepares to shake up the local industry with a $15 billion fourth-generation service. Billionaire Sunil Mittal’s Bharti Airtel said the so-called Project Leap would invest the money over three years, adding the outlay is on top of the 1.6 trillion rupees the company has already put into network infrastructure such as spectrum, fiber and submarine cables.