Maritime communication challenges in the High North

Transcription

1 Maritime communication challenges in the High North Fritz Bekkadal Maritime ICT Maritime Transport Systems Norsk Marinteknisk Forskningsinstitutt e-navigation Workshop, NCA West

2 Some Radio History 1895: World s first operating radio transceiver - Guglielmo Marconi 1901: First transatlantic wireless transmission (Cornwall-Newfoundland, s ) 1903: World s first wireless telegraph 1906: World s second wireless telegraph: Sørvågen-Røst in Lofoten (~ 60 km!) Prompted by the important fisheries in the area! Shortly after radio telegraphy to ships in the open seas followed 1911: The first radio telegraphy signals from Spitsbergen Radio were received at Ingøy near Hammerfest 2

3 MARINTEK Telecom Experience pertinent projects 1. MarCom 'Broadband at sea' ( ) Basic research on maritime communication needs vs. technological opportunities and limitations 2. MarSafe North ( ) Analyses and tests on navigation and communication systems around Svalbard and between Svalbard and the main land shows unstable performance and no coverage in several areas 3. ArctiCOM (ESA; )/ArkKOM (NSC; 2011) The satellite communication demand in areas above 75 N will in be larger than offered by existing systems Future potential systems should meet these demands (Iridium NEXT?, Canadian PCW and Russian PolarStar?) if they are implemented? 4. Present: MARENOR ( ) Maritime Radio Systems' Performance in the High North The maritime activity in the Arctic is increasing. High quality navigation and communication systems are important for the safety of people and the environment, as for safe and efficient operations.

4 Maritime communication challenges Limitations: Obviously wireless only to mobile platforms/ vessels Fiber/cable possible to fixed installations may be used as wireless base stations Terrestrial wireless preferred in coastal waters and in the vicinity of offshore base stations (< km, depending on capacity requirements) WiFi/WLAN (extremely short range; harbours & similar ) GSM/3G LTE/4G WiMAX Digital VHF (low bandwidth) Satellite communications (SatCom) at deep sea

5 The MARINTEK WiCAN Concept (Wireless Coastal Area Network) Satellites (HEO?) Mesh Networking Terrestrial: Cellular WBB WNB Mobile Multi-hop Relay (MMR)

6 6 Heterogeneous Wireless MultiCarrier Communication System (HMCS)

7 Satellite orbits HEO Apogeum Tundra LEO MEO GEO 7 Perigeum LEO: Low Earth Orbit MEO: Medium Elliptical Orbit GEO: Geostationary Orbit HEO: High Elliptical Orbit (Height: km) (Height: GEO, normally: km) (Height: km) (Height: km)

8 Major High North challenges: SatCom limitations GEO: Expensive Insufficient or no coverage in the High North LEO: Satellite Gateway Satellite transmission Low capacity/bandwidth (~ GSM GPRS???) Dubious latency? 8

9 9 The Earth's atmosphere

10 Electromagnetic waves penetrating the atmosphere 10

11 Propagation impairments over Earth - satellite slant path km L-band K u -band K a -band 11

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13 Ionospheric-induced GPS errors

14 Regions/services suffering from ionospheric disturbancies

15 GEO satellite atmospheric effects: Elevation vs. northern latitude Low Angle Experiments at Svalbard Ref. Odd Gutteberg

16 Signal blocking, reflections and multipath effects H L Blocking if: L H tan At Isfjorden the elevation angle is about 3, i. e. blocking for: L 20 H

17 Multipath effects - GEO 2 a b Antenna h S R E Figure 1 Illustration of radio signal propagation for GEO satellites applications

18 Multipath effects MEO/LEO Antenna h S R= R E H SAT R E Figure 1 Illustration of radio signal propagation for LEO and MEO satellites applications

19 Vessel movements Example: PCTC (Pure Car/Truck Carrier) M/V Aida Head sea with significant wave height 5-6 m, travelling with speed of 8-10 knots 6 degrees of freedom

20 Icing Icing on antennas deteriorates the performance of navigation and communication systemsparticularly layers of salty snow/sleet/ice

21 Antennas Antennas are utilized in two different functions, depending on their application: In communication they provide a radio channel with maximum gain in the desired signal direction ('boresight'), while rejecting radiation in unwanted directions In radar and similar sensors their function is to provide an image of the external scene, and their performance is crucial to the quality of this image Antennas enable any radio system contact with the outside world, and thus represent the most crucial elements regarding system performance A poorly performing antenna deteriorates a radio system's performance significantly, and may disable it completely These facts seem currently to be disremembered, as antennas and other decisive radio sub-units have become assembly-line products, which comprise increasingly more entities being highly important to our everyday life - our electromagnetic environment thus becoming progressively dense with the proliferation of unintentional and intentional signals and interferences Consequently ever more information and sophistication are required from radio systems, and the demands on antenna performance are steadily increasing

22 Antenna degradation effects due to icing Beam squinting Boresight alteration/loss of track Beamwidth deterioration/sidelobes' & backlobes' escalation Interfering signals enter/leave via sidelobes/backlobes Mutual coupling to other antennas in the vicinity Frequency detuning alteration of 'electrical size' VSWR increase; signal unmatched/reflection loss X-polarization/depolarization loss Attenuation loss particularly severe with layers of salty snow/sleet/ice Increase of wind load and weight structural stress

23 GEO satellites limitations Theoretical limit for geostationary (GEO) satellites (0 o elevation, ~81 o N ) 5 o elevation with optimum GEO satellite position (same longitude) (~76 o N) Practical problems with standard GEO SatCom beyond ~70-75 o N (< 6-8 o elevation) Only low-rate data Iridium!

24 Summary of the MARENOR project Main objective: MARENOR shall assess and quantify the system performance of the most common navigation and communication systems being used by maritime users in the Arctic This will be achieved through measurement campaigns and analysis of: System parameters Signal propagation (L-, C-, K u - and K a- band) Signal degrading factors Atmospheric (ionospheric, tropospheric..) Multipath interference & blocking of signals Weather impact (wind, rain/sleet, snow ) Platform/vessel movements Icing on antennas (both atmospheric icing and icing caused by sea spray) Expected results: A tool for Quality-of-System assessment on navigation and communication performance at high latitudes Frequency bands L-band: 1-2 GHz. Utilized by navigation systems (GPS, GLONASS, Galileo) and low Earth Orbit (LEO) satellite communications, such as Iridium: Traditionally used for telephony via small hand-held terminals with small antennas, but currently also using more advanced terminals and antennas providing low data rate digital communications (Iridium OpenPort). C-band: 4-8 GHz. Utilised primarily for maritime information (MSI - Maritime Safety Information) via satellite, and VSAT Very Small Aperture Terminals) communication K u -band: GHz. Used for digital communications with higher bandwidth, primarily from satellites that orbit around the equator (geostationary (GEO) satellites). Applying relatively small steerable antennas (VSAT) to keep track of the satellite. K a -band: GHz. Also used for communication via VSAT terminals and GEO satellites.

25 Initial test installation on MV Atlantic Guardian

26 Inmarsat (L-band) (Saturn B) Seapath 330 VSAT (K u -band) MARENOR log PC Iridium OpenPort (L-band)

27 Future Northern hemisphere SatCom system HEO s! Quasi-stationary perspective Apogee height GEO GEO technology can be reused (slightly modified) Cost savings Risk reduction Best possible high-latitude coverage per satellite Fully complements GEO data; no LEO-like latitudinal coverage gaps Little time wasted over lower latitudes adequately seen from GEO Relatively simple ground segment; real-time dissemination can be achieved with a single primary ground station, as for GEO 27

28 The Earth seen from satellites GEO HEO: Molniya orbit (apogeum) 28

29 Thank you! Questions? Comments?

30 "The Northern Dimension and Challenges"