A Few Bytes are Worth a Thousand Words: Run-Time Compilation of High Level Scripts in Sensor Networks

Over the air reprogramming has become a vital requirement of wireless sensor networks due to the infeasibility and inaccessibility of deployed sensor nodes. The transmission of whole software binaries consumes a substantial amount of energy and therefore a more efficient means of updating software on sensor nodes is required. Virtual machines allow for smaller sized update scripts due to the higher level instructions. However, they also incur higher execution overheads introduced by the required interpretation. Native code on the other hand provides faster execution however at the cost of a larger code size. In this paper we demonstrate that it is possible to leverage small update sizes achieved using high level scripts without incurring high interpretation overheads, by translating the scripts to native code in situ.