The closest airport to ETSI is Nice International Airport.
From the airport it is a 25 minute journey by taxi to ETSI. The approximate cost of this is 60 €. Alternatively you can book in advance and benefit from an ETSI discounted rate.
A disabled taxi service is also available.
A shuttle bus service [n°230] is also available from the airport (Promenade outside Terminal 1) to Sophia Antipolis. You should ask the driver to stop at Place Sophie Laffitte, which is a 5' walk from ETSI. The bus ticket costs 1 euro.