Communication systems Terrestrial (VHF & HF) Marine Radios Satellite Services Cellular Networks

Strengths of a common distress channel Common channel for all vessels whether commercial or recreational. Distress calls go out as a broadcast to many stations rather than to an individual – as in the case when using a Cellphone. Distress/Urgency calls are not reliant on a Coast station hearing the call but can be answered and relayed by any station within VHF range of the distress vessel. Is recognised by international and domestic mariners as a common channel, so no need to know what local channels (which vary region by region) are. The loss of a coast station receiver does not remove all assets from the radio coverage area. i.e. other vessels can still hear each other. Does not rely on repeaters and thus removes the single point of failure. i.e. if a repeater fails that particular channel is rendered ineffective.

High Frequency 2182 kHz 4125 kHz 6215 kHz 8291 kHz kHz kHz Plus HF DSC

Satellite Communications Inmarsat Iridium Globalstar

Inmarsat Only GMDSS approved satellite system. Inmarsat – B (voice, fax, data) GMDSS type approved Inmarsat – C (telex, data) EGC SafteyNET GMDSS type approved Fleetnet 77 (voice, fax, data, ) GMDSS type approved Fleetnet 55 (voice, fax, data, ) Fleetnet 33 (voice, fax, data, ) FleetBroadband (simultaneous voice & broadband data) Fleetphone (voice)

Iridium Voice services Data services Encryption Fleet management Personnel tracking Asset tracking

Globalstar Voice services Data services Encryption Marine and Aviation fit outs

Perceived weakness of Satellites Setup costs (equipment, above board and below deck) Call costs (voice and data services) Solar radiation damage (caused by sunspots and solar flares) Earth bound interference (rain fade and volcanic eruptions) Satellite life spans (7.5 to 15 years) Financial markets. Due to the high costs of establishing, building and running a satellite network companies can become debt ridden very quickly.

Cellphones Cellphones can provide a convenient, simple to use and inexpensive means of communications. However in a distress situation they have some significant drawbacks:  Most Cellphones are not designed for wet operations.  They are point to point contact only not a broadcast radio like VHF.  Response times by rescue services or other vessels will be delayed as Police must first process the call and follow their standard operating procedures.  Network coverage at sea can be limited and short range.

Technology

VHF DSC

GPS Cellphones

TETRA – Trunked Radio Networks