Cross-layer routing on MIMO-OFDM underwater acoustic links

Abstract

Abstract-UnderWater Acoustic Sensor Networks (UW-ASNs) are experiencing a rapid growth, due to their high relevance to commercial and military applications such as oceanographic data collection, pollution monitoring, offshore exploration, disaster prevention, and tactical surveillance. However, the design of efficient communication protocols for underwater sensor networks is still an open research problem due to the unique characteristics of the underwater acoustic communication channel such as limited bandwidth, high and variable propagation delays, and significant multipath and scattering.In this paper, we consider multimedia underwater monitoring applications with heterogeneous traffic demands in terms of bandwidth and end-to-end reliability. Distributed routing algorithms are introduced for delay-insensitive and delay-sensitive applications, with the objective of reducing the energy consumption by i) leveraging the tradeoff between multiplexing and diversity gain that characterizes MIMO links, and ii) allocating transmit power on suitable subcarriers according to channel conditions and application requirements. To achieve the objective above, each node jointly i) selects its next hop, ii) chooses a suitable transmission mode, and iii) assigns optimal transmit power on different subcarriers to achieve a target level of Quality of Service (QoS) in a cross-layer fashion. Extensive simulation results demonstrate that our proposed protocol is adaptive to the unique characteristics of the underwater acoustic communication channel, and achieves excellent performance through local cooperations between transmitter and receiver.

A Modified CSMA/CA Protocol for OFDM Underwater Networks

“…Consider the near shore shallow water with heavy ship traffic, assume the noise level (NL) is between 80 and 100dB (6kHz bandwidth). According to the passive sonar equation, the received SNR can be estimated as 5.34dB<SNR=SL -TL -NL<25.34dB (8) Since the minimum SNR is 5.34dB, the proposed collision detection algorithm works reliably in our simulation scenario.…”

Underwater optical wireless communications, networking, and localization: A survey

“…Adaptive depth based routing protocols were introduced in [231], [232] which takes into account the speed of acoustic waves at different depth levels, depth of sink node, and distance to sink node. A MIMO-OFDM based routing protocol was introduced in [233] to take the advantage of multiplexing and diversity gain adaptively. The proposed cross-layer design in [233] adapts itself to the noise and interference for underwater acoustic channels and selects a suitable transmission mode for the subcarriers.…”

“…A MIMO-OFDM based routing protocol was introduced in [233] to take the advantage of multiplexing and diversity gain adaptively. The proposed cross-layer design in [233] adapts itself to the noise and interference for underwater acoustic channels and selects a suitable transmission mode for the subcarriers. An energy efficient and network topology aware greedy routing protocol was proposed in [234] which assigns adaptive weights to the highly connected nodes.…”

SEANet G2

“…The software architecture of SEANet G2 includes our libraries [3] to support IPv4 and IPv6 protocols through an adaptation layer that provides IP header compression, IP packet fragmentation, and optimizes the traditional IPv4 and IPv6 headers for underwater acoustic channels to minimize the overall network delay and energy consumption [3]. Moreover, it will incorporate implementation of different routing protocols including [25][26][27].…”