4 an abstract model of the master channel generation

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Unformatted text preview: s OCF_SDUs Commutation and Generation of Master Channel Frame Count MC Frames Master Channel Multiplexing Function Figure 4-9: Abstract Model of Master Channel Generation Function 4.2.6 MASTER CHANNEL MULTIPLEXING FUNCTION 4.2.6.1 The Master Channel Multiplexing Function shall be used to multiplex Transfer Frames of different Master Channels of a Physical Channel. NOTE – There is an instance of the Master Channel Multiplexing Function for each Physical Channel that has multiple Master Channels. 4.2.6.2 The Master Channel Multiplexing Function shall multiplex Transfer Frames received from the instances of the Master Channel Generation Function and, if present, the Master Channel Frame Service users, and shall put them into a queue of Transfer Frames in an appropriate order that is set by management. 4.2.6.3 The algorithm to be used to order the Transfer Frames is not specified by CCSDS but shall defined by project organizations considering factors such as priority, release rate, isochronous timing requirements, etc. CCSDS 132.0-B-1 Page 4-19 September 2003 CCSDS RECOMMENDATION FOR TM SPACE DATA LINK PROTOCOL 4.2.6.4 The Master Channel Multiplexing Function shall create an OID Transfer Frame to preserve the continuity of the transmitted stream in the event that there are no valid Transfer Frames available for transmission at a release time. NOTE – The OID Transfer Frame has its First Header Pointer set to ‘11111111110’, and its MCID and VCID set to those of a Virtual Channel that carries Packets but does not have the Transfer Frame Secondary Header or the Operational Control Field. 4.2.6.5 An abstract model of the Master Channel Multiplexing Function is illustrated in figure 4-10. MC Generation Function MC Frame Service User MC Frames Master Channel Multiplexing Function for a Physical Channel MC Frames Idle Frame Multiplexing All Frames All Frames Generation Function Figure 4-10: Abstract Model of Master Channel Multiplexing Function 4.2.7 ALL FRAMES GENERATION FUNCTION 4.2.7.1 The All Frames Generation Function shall be used to perform error control encoding defined by this Recommendation. NOTE – There is an instance of the All Frames Generation Function for each...
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This document was uploaded on 03/06/2014.

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