Name the defence company who signed a MoU with the Airports Authority of India to explore Air Traffic Management (ATM) solutions for airports operating under the UDAN Regional Connectivity Scheme.

Swedish aerospace and defence company SAAB signed a MoU with the Airports Authority of India (AAI) on 23 January 2019. The MoU was signed to explore Air Traffic Management (ATM) solutions for airports operating under the UDAN Regional Connectivity Scheme. SAAB's ATM solutions are now deployed in Ahmedabad, Amritsar, Guwahati, Jaipur, Lucknow, Chennai, Kolkata, Mumbai, New Delhi, and Cochin.