In addition to the core functionality of POSIT, we are working on some experimental features that are not yet in the trunk.

Phone-to-phone syncing

In the field, you can't always count on a cellular or wifi infrastructure being available. This is especially true in disaster areas. An experimental version of POSIT includes an ad-hoc mode. In ad-hoc mode, devices communicate directly with each through Android's 802.11 hardware, even if cell towers are knocked out.

Routing through the ad-hoc network is done using a random walk gossip (RWG) algorithm. RWG is a low-power, partition-tolerant, manycast protocol that allows small amounts of information to spread through the network. 

A current POSIT prototype allows the RWG algorithm to be run within POSIT.  Although the RWG protocol is not yet tightly integrated with POSIT's main functions -- i.e., with adding, listing, mapping, and synching of finds -- the prototype provides a proof-of-concept for RWG on the Android platform on a rooted phone.

Developed by Dr. Simin Nadjm-Tehrani and her students, Mikael Asplund and Gustav Nyqvist, at Real-time Systems Lab at Linköping University in Sweden, the RWG algorithm can function with reasonable latency and with  little or no global knowledge of the system, preserving messages in the network's nodes when they are not in range of each other.  

For more on the RWG algorithm and how it can be used in crisis scenarios, see the RTS lab's publications page.