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SAM ATN ‐ Study for the Implementation of a New Digital Network in the SAM Region (REDDIG II) – Chapter 2 ‐ Appendix 2F
2.2 For the first two cases, these are AFTN messages generated/received by the
automated systems and that travel through the respective AFTN or AMHS systems (or a combination
of the two). Therefore, the increase in information will be reflected only as an increase in the number
of AFTN messages circulating over the ATN.
2.3 Since ATS traffic historically accounts for only 15% of the total AFTN traffic, a
hypothetical 300% increase in ATS messages will only be reflected in a 30% increase of AFTN
traffic.
2.4 For the third case, each centre will send the information to the corresponding
adjacent centre, and the increase in bandwidth will depend on the number of control messages that
each switched centre will generate, which obviously will depend on the surrounding air traffic.
2.5 Furthermore:
2.5.1 As the service is installed in the various States, the need for greater bandwidth for this
service will gradually and slightly increase.
2.5.2 A greater bandwidth will be required once this service has been operationally
disseminated throughout the Region, while voice handover of flights continues to be temporarily
mandatory.
2.5.3 Once this phase is completed and voice communications gradually are deactivated,
bandwidth consumption drops until there is no longer the need to continue using speech circuits.
2.6 At that moment, the net bandwidth (increase through AIDC – reduction of ATS
speech) will be negative, that is, there will be a reduction of bandwidth requirement.
3. Additional bandwidth for AIDC
3.1 No additional bandwidth is required for this service.
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