The goals of the Accelerating Research through International Network-to-Network Collaborations (AccelNet) program are to accelerate the process of scientific discovery and prepare the next generation of U.S. researchers for multiteam international collaborations. The AccelNet program supports strategic linkages among U.S. research networks and complementary networks abroad that will leverage research and educational resources to tackle grand scientific challenges that require significant coordinated international efforts. The program seeks to foster high-impact science and engineering by providing opportunities to create new collaborations and new combinations of resources and ideas among linked global networks. This solicitation invites proposals for the creation of international networks of networks in research areas aligned either with one of the NSF Big Ideas or a community-identified scientific challenge with international dimensions. AccelNet awards are meant to support the connections among research networks, rather than supporting fundamental research as the primary activity.  Each network of networks is expected to engage in innovative collaborative activities that promote synergy of efforts across the networks and provide professional development for students, postdoctoral scholars, and early-career researchers. There are two proposal categories covered by this solicitation: Catalytic and Full-Scale Implementation. Full proposal deadline date: January 31, 2020.