Underwater communications protocols and architecture developments at NURC

Two powerful trends in marine technology (autonomous assets and distributed sensing) are combining to create a dramatic pressure on the underwater (UW) communications industry to provide much less expensive modems with interoperable capability that can form ad-hoc networks. Currently, UW modem manufacturers use proprietary schemes that are mutually unintelligible, even if using the same frequency band. This can be regarded as a language issue, akin to different cultures each speaking their mother tongue and no other, despite the fact that the coding and transmission software and hardware (brain and vocal tract), as well as the reception and decoding (ears and brain), are largely similar between different cultures. We need a common language, which could be chosen by rational design (e.g. Esperanto) or by de-facto practicality (e.g. English). The difficulties associated with reaching large-scale consensus on standards suggest that we are more likely to see the latter process dominate. The lingua-franca that emerges may not be the most efficient, but it will have the property that it is simple enough to master at a basic working level, sufficient to achieve simple functionality from which more optimal choices can perhaps be bootstrapped. This paper describes such a standard, JANUS, being developed and promoted at NURC in collaboration with a network of international academia, research centres and companies. Similarly, NURC is pursuing related work on Media Access Control (MAC), Delay and Disruption-Tolerant Network (DTN) protocols and low-overhead routing, all of which are key components of ad-hoc networking. NURC is also actively engaged in communication architecture design (particularly to support cross-layer connectivity), performance metrics, realistic simulation capabilities, standardizing channel modelling and establishing canonical problems to test candidate protocols. There are many tasks, and NURC is too small to make a significant impact alone. NURC is theref- - ore pursuing a role as a multi-national, commercially-neutral hub, drawing together stakeholders and acting as a catalyzing agent for international collaborative efforts to move these solutions forward for the whole community.