Longtime leader in mobile offload AT&T has partnered with Helium Network to use the latter’s decentralized hotspot network. This will connect users of its public network to Helium’s ad hoc WiFi hotspots across the US. The so-called decentralized physical infrastructure network (DePIN) on offer from Helium has been on the cards for a few years, but this deal with AT&T gives Helium its most significant seal of approval yet. The move fits into AT&T’s wheelhouse. It has long been a fan of convergence and is close pals with Wireless Broadband Alliance (WBA – see separate article, this week). AT&T already uses WiFi hotspots. It has around 20,000 of its own in cafes, airports, and other public spaces that automatically connect…