Ubiquitous Interpersonal Communication over Ad-Hoc Networks and the Internet

摘要

The hardware and low-level software in many mobile de-vices are capable of mobile-to-mobile communication, in-cluding ad-hoc mode for 802.11, Bluetooth, and cognitiveradios.We have started to leverage this capability to provide in-terpersonal communication both over infrastructure networks(the Internet), and over ad-hoc and delay-tolerant networkscomposed of the mobile devices themselves.This network is fully decentralized so it can function with-out any infrastructure, but takes advantage of Internet con-nections when available. Devices may communicate when-ever they are able to exchange packets. All interpersonalcommunication is encrypted and authenticated so packetsmay be carried by devices belonging to untrusted others.One challenge in a fully decentralized network is rout-ing. Our design uses Rendezvous Points (RPs) and Dis-tributed Hash Tables (DHTs) for delivery over the Internet,and hop-limited broadcast and Delay Tolerant Networking(DTN) within the ad-hoc network.Each device has a policy that determines how many pack-ets may be forwarded, and a packet prioritization mecha-nism that favors packets likely to consume fewer networkresources. A goal of this design and implementation is toprovide useful interpersonal communications using at most1% of any given resource on mobile devices.