iORPL:Intermittency-aware Opportunistic Routing for IoT Networks

Abstract

Battery-free IoT devices operating under ambient energy harvesting experience frequent power failures that erase all volatile routing state. Conventional protocols either assume continuous power or engineer synchronised active windows, both of which fail under variable harvesting conditions. This paper presents iORPL, an intermittency-aware opportunistic routing protocol derived from three design requirements tailored to intermittent operation: stateless operation, asynchrony-first forwarding, and energy-gated transmission. Each incoming packet is evaluated against three criteria applied in sequence: an energy gate, a progress check, and a duplicate-suppression tuple carried in the packet header.iORPL is modelled in OMNeT++/INET using parameters representative of a battery-free device under indoor solar harvesting, and evaluated against RPL (the IPv6 Routing Protocol for Low-Power and Lossy Networks), ORPL (Opportunistic RPL), and the synchronisation-based RICS across three harvesting scenarios of increasing severity. iORPL achieves a packet delivery ratio of 89.1%, within 2.0 percentage points of RICS; reduces duplication overhead by 89.6% relative to ORPL; and maintains energy per delivered packet within 5.9% of RICS without any synchronisation infrastructure. The efficiency advantage over ORPL grows with intermittency severity.