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Planned Coverage Enhancements to Maritime Digital ServicesThis page keeps you up to date with the information regarding the migration and subsequent coverage enhancements planned as a result of moving Inmarsat maritime services from the existing Inmarsat 3 to the new Inmarsat 4 generation satellites. Due to the complexities of bringing the new I-4 satellites into service, the timings and enhancements outlined below may be subject to change depending upon a) I-4 F2 Launch timing and b) Success of I-4 F2 launch and In Orbit Testing (IOT) of I-4 F1 & F2.
1. Migration of Maritime Services
Based on current schedules it is planned that by the end of Q4 2005, Inmarsat-4 F1 (Located in the IOR at 64° East) and F2 (Located in the AOR-W at 53° West) will be carrying the following maritime services: Inmarsat B, C, D, D+, E, M, Mini-M, Fleet F77, F55 and F33.
2. Availability of Enhanced Spot Beam Coverage
Apart from providing the network infrastructure to ensure the long-term availability and continued evolution of our current and future maritime portfolio of services, the unrivalled power and flexibility of the I-4 satellites allow us to make service enhancements which will be of immediate benefit to the global maritime community. It is planned that within the ocean regions covered by F1 (IOR) & F2 (AOR-W), the spot beam coverage will be expanded for the services outlined below, to provide total coverage within the respective ocean regions (Please see Fig 1 & 1.1 over page)
Fleet F77 128 kbit/s – The current spot beam coverage will be enhanced in both the AOR-W & IOR, effectively giving total coverage in these ocean regions, allowing Fleet F77 users access to the 128 kbit/s service within the enhanced coverage area. Initially however, the service will operate in existing I-3 spot beam coverage areas, prior to I-4 F1 & F2 becoming available.
GMDSS Services – Inmarsat B, C, E and Fleet F77 services and coverage are already global and will remain unaffected.
Fleet F33 & F55 - The current spot beam coverage will be enhanced in both the AOR-W & IOR, effectively giving total coverage in these ocean regions, using the I-4 regional beams, to allow Data & Fax communications within this area. Globally accessible voice telephony will remain as currently defined.
Mini-M - The current spot beam coverage will be enhanced in both the AOR-W & IOR, effectively giving total coverage in these ocean regions, using the I-4 regional beams for Voice, Fax and Data communications.
To benefit from the enhanced coverage offered by I-4 F1 & F2 (IOR / AOR-W) terminals entering these ocean regions will have to re-point and log onto the appropriate satellite i.e. Ensure that they are pointing at an I-4. A revised bulletin board will be uploaded to the network on transition.
Based on current schedules, the following availability timing is envisaged, with the enhanced coverage becoming available as each I-4 enters service and starts carrying traffic, ocean region by ocean region: Enhanced coverage availability currently planned in IOR from end of Q2 2005Enhanced coverage availability currently planned in AOR-W from end of Q4 2005
Fig 1.0 Enhanced Coverage – Global View (Yellow Shading Depicts Enhanced Coverage Area)
Fig 1.1 Enhanced Coverage – By Ocean Region (Yellow Shading Depicts Enhanced Coverage Area)
3. Coverage Impact (POR & AOR-E)
Whilst covered by the I-3 at 178° East, POR coverage remains unchanged. Should I-4 F3 be launched and located near the current I-3 in the POR, coverage could be enhanced within this ocean region. It is should also be noted that the I-3 located at 15.5° West (AOR-E) will remain in service and carry its existing maritime services, although the coverage available via this satellite also remains unchanged.
Keep an eye on this page to stay updated on this issue.
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