Unformatted text preview: mber of systematic retransmissions is likely to be 2, 3 or 4. Should the standards
documents specify an explicit upper limit? Perhaps it would be best for the standards to state that the
upper limit is a mission-specific parameter of the Physical Channel. This would require missions to
make a decision, so setting their own upper limit on delays, etc. It would avoid putting an explicit value
in the standards, which might place an unnecessary restriction on applications such as the scenarios
described in section 1.3.2. TCretrans7 2008Sep09 I.B. + M.A. DE LANDE LONG
SOFTWARE + CONSULTANCY
Options for repeated retransmissions for telecommand Page 13 4.2.3 Systematic retransmission of type-BC frames
The systematic retransmissions are intended for type-AD frames.
retransmissions also apply to type-BC frames? Should the automatic A type-BC frame carries a COP-1 control command: either Unlock or Set V(R). The commands are
generated by FOP-1 following receipt of an Initiate AD Service (with Unlock) directive or an Initiate AD
Service (with Set V(R)) directive, and both directives require a confirming CLCW before the Initiate
action can be successfully completed.
There are different operating procedures that can be used to initiate the AD service and different
opinions about which procedures are more efficient or more secure. It therefore seems reasonable that
the standards should permit the use of systematic retransmissions for type-BC frames: missions do not
have to use the facility. The standards could state that the use of systematic retransmissions for typeBC frames is a mission-specific parameter of the Physical Channel or of the Virtual Channels. TCretrans7 2008Sep09...
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- Spring '14
- FOP-1, systematic retransmission