Wi-Fi is critical for supporting data growth as cellular networks cannot handle explosive growth alone. Cable companies have been the most aggressive in deploying Wi-Fi, with Comcast estimated to have 8 million in-home hotspots and 350,000 public hotspots. Cellular carriers have varying approaches to Wi-Fi, with AT&T actively pushing customers to offload and T-Mobile making all calls over Wi-Fi by default, while Verizon focuses on small cells. Wi-Fi operators like Boingo facilitate offload and roaming at airports and other locations.