Idea Cellular ( commonly referred to as simply Idea, and stylised as ! dea) is an Indian mobile network operator based in Mumbai, Maharashtra. Idea is a pan-India integrated GSM operator offering 2G, 3G and 4G mobile services. Idea is India’s third largest mobile operator by subscriber base, After Vodafone India.good Idea: Company Backgrounder. Idea Cellular is an Aditya Birla Group Company, India’s first truly multinational corporation. Idea is a pan-India integrated GSM operator offering 2G and 3G services, and has its own NLD and ILD operations, and ISP license.