• Session: 05. Underwater Communications and Networking
    Organiser(s): Tsimenidis Charalampos, Mitchell Paul, Pelekanakis konstantinos
    Paper ID: 896
    Author(s): Blom Koen, Dol Henry
    Presenter: Blom Koen
    Presentation type: oral
    Abstract: There is a growing interest in the use of untethered underwater vehicles to perform safe, sustainable and cost-effective underwater operations. For most applications, the bandwidth utilization of these vehicles can be maximized by concurrently transmitting data with configurable Quality-of-Service (QoS) constraints, e.g., high-QoS telemetry data and low-QoS compressed image snapshots in a single transmission. To support such QoS-enabled underwater communication, the MSFRSS modulation was introduced [1].\n\nPreviously, MSFRSS has been tested in a real-time demonstrator in a harbour and a fjord [2]. To evaluate the performance of MSFRSS in offshore conditions, a short sea trial was conducted at the North Sea on 10 October 2018. During a series of communication and channel-sounding runs, the unidirectional link between a boat and a bottom node was assessed. In each communication run, MSFRSS was employed to transmit image snapshots and telemetry data (GPS-NMEA strings) from the boat to the bottom node.\n\nInitially, very few correct demodulations were obtained for the high-QoS payload and none for the low-QoS payload, which was caused by the channel’s significant surface-wave-induced delay and Doppler spread, being amplified by the boat’s crane deploying the transmitter. When bringing in the crane and gently streaming the transmitter behind the boat, most of the high-QoS payload could be correctly demodulated, but still none of the low-QoS payload. So far, only the top hydrophone of the bottom node’s tetrahedron array had been processed. When, subsequently, all four hydrophone channels were coherently combined, also some correct demodulations (~10%) were obtained for the low-QoS payload. Actually quite some more images received with bit errors were still recognizable.\n\nThe full paper will focus on the above-explained use of spatial diversity to improve reception of MSFRSS transmissions in offshore environments. A selection of equalizer configurations will be compared and evaluated for the North Sea trial data.\n\n[1] K.C.H. Blom, H.S. Dol and M.K. Prior, “Development of a wideband underwater acoustic modulation providing quality-of-service support,” MTS/IEEE OCEANS 2017, Anchorage (AK), USA, 2017, pp. 1-4\n[2] K.C.H. Blom and H.S. Dol, “QoS-enabled underwater acoustic communications,” MTS/IEEE OCEANS 2018, Charleston (SC), USA, 2018, pp. 1-7\n
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  • Corresponding author: Dr Blom Koen
    Affiliation: TNO
    Country: Netherlands