Slotless Protocols for Fast and Energy-Efficient Neighbor Discovery

TL;DR

This paper introduces a novel continuous-time neighbor discovery protocol for mobile ad-hoc networks that outperforms existing slotted protocols by decoupling beaconing and listening, leading to faster and more energy-efficient device discovery.

Contribution

The paper proposes a new continuous-time discovery protocol that breaks from traditional slotted schemes, optimizing intervals for improved performance and energy efficiency.

Findings

Outperforms slotted protocols like DISCO, U-Connect, Searchlight

Reduces discovery time by up to 740%

Applicable to protocols like ANT and Bluetooth Low Energy

Abstract

In mobile ad-hoc networks, neighbor discovery protocols are used to find surrounding devices and to establish a first contact between them. Since the clocks of the devices are not synchronized and their energy-budgets are limited, usually duty-cycled, asynchronous discovery protocols are applied. Only if two devices are awake at the same point in time, they can rendezvous. Currently, time-slotted protocols, which subdivide time into multiple intervals with equal lengths (slots), are considered to be the most efficient discovery schemes. In this paper, we break away from the assumption of slotted time. We propose a novel, continuous-time discovery protocol, which temporally decouples beaconing and listening. Each device periodically sends packets with a certain interval, and periodically listens for a given duration with a different interval. By optimizing these interval lengths, we show that this scheme can, to the best of our knowledge, outperform all known protocols such as DISCO, U-Connect or Searchlight significantly. For example, Searchlight takes up to 740 % longer than our proposed technique to discover a device with the same duty-cycle. Further, our proposed technique can also be applied in widely-used asymmetric purely interval-based protocols such as ANT or Bluetooth Low Energy.