 At the first ACM Symposium on Operating Systems Principles in October 1967, Roberts presented a proposal for the "ARPA net", based on Wesley Clark's proposal for using Interface Message Processors to create a message switching network.At the conference, Roger Scantlebury presented Donald Davies' work on packet switching for data communications and mentioned the work of Paul Baran at RAND.Roberts incorporated the packet switching concepts into the ARPANET design and upgraded the proposed communications speed from 2.4 kbps to 50 kbps.