Fair and Throughput-Optimal Routing in Multi-Modal Underwater Networks

TL;DR

This paper introduces a novel routing protocol for multi-modal underwater networks that intelligently leverages acoustic, optical, and radio-frequency technologies to optimize throughput and fairness, demonstrated through simulations and field tests.

Contribution

It proposes a distributed routing protocol that dynamically chooses technologies and routes to prevent bottlenecks and ensure fair resource allocation in multi-modal underwater networks.

Findings

Protocol effectively leverages multiple technologies for data delivery.

Successful in preventing bottlenecks and ensuring fairness.

Works well even with imperfect topology information.

Abstract

While acoustic communications have been considered the prominent technology to communicate under water for several years, other technologies are being developed based, e.g., on optical and radio-frequency electro-magnetic waves. Each technology has its own advantages and drawbacks: for example, acoustic signals achieve long communication ranges at order-of-kbit/s bit rate, whereas optical signals offer order-of-Mbit/s transmission rates but only over short transmitter--receiver distances. Such a technological diversity can be leveraged by multi-modal systems, which integrate different technologies and provide intelligence to decide which one should be used at any given time. In this paper, we address a fundamental part of this intelligence by proposing a novel routing protocol for networks of multi-modal nodes. The protocol makes distributed decisions about the flow in each link and over each technology at any given time, in order to advance a packet towards its destination. Our routing protocol prevents bottlenecks and allocates resources fairly to different nodes. We analyze the performance of our protocol via simulations and in a field experiment. The results show that our protocol successfully leverages all technologies to deliver data, even in the presence of imperfect topology information. To permit the reproduction of our results, we share our simulation code.