Large Data Transfer Transmitter Protocol

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" colspan=2 height=110 BGCOLOR="#777777" TEXT="#080000"> <div> <B><IMG SRC="0097c660.gif" border=0 width="124" height="102" ALIGN="RIGHT" HSPACE="0" VSPACE="0"></B></div> <div> <FONT SIZE="6" COLOR="#FFFFFF" FACE="Arial" ><B>Large Data Transfer Transmitter Protocol</B></FONT><B>     |     </B><A HREF="index.htm" TARGET="_top" TITLE="HighLevel Design Specification"><U><B>home</B></U></A></div> <div> back to<B>  </B><A HREF="id4.htm" TARGET="_top" TITLE="Large Data Transfer Service Design"><U><B>Large Data Transfer Service Design</B></U></A></div> <div> </div> </td> </tr><tr> <td valign="top" width=210 BGCOLOR="#777777" TEXT="#080000"> <div> <A HREF="id9.htm" TARGET="_top" TITLE="Large Data Transfer Service Context"><U>Large Data Transfer Service Context</U></A></div> <div> <A HREF="id11.htm" TARGET="_top" TITLE="Large Data Transfer Receiver Protocol"><U>Large Data Transfer Receiver Protocol</U></A></div> <div> <B>Large Data Transfer Transmitter Protocol</B></div> <div> <A HREF="id13.htm" TARGET="_top" TITLE="Large Data Transfer Decomposition"><U>Large Data Transfer Decomposition</U></A></div> <bR> </td> <td valign="top" height=370 BGCOLOR="#FFFFFF" TEXT="#080000"> <div> The implemented sending and receiving protocol is specified by two action/state diagrams. When viewing the diagrams it shall be noted that:</div> <div> <IMG BORDER="0" SRC="Symb075c00b700f077777700.gif" HEIGHT="16" WIDTH="24" ALIGN="bottom" HSPACE="0" VSPACE="0">The diagrams are similar to UML state diagrams</div> <div> <IMG BORDER="0" SRC="Symb075c00b700f077777700.gif" HEIGHT="16" WIDTH="24" ALIGN="bottom" HSPACE="0" VSPACE="0">All states are named after the activity they carry out.</div> <div> <IMG BORDER="0" SRC="Symb075c00b700f077777700.gif" HEIGHT="16" WIDTH="24" ALIGN="bottom" HSPACE="0" VSPACE="0">All state changes are the result of either "receiving a telecommand" or "an action carried out in the state".</div> <div> The protocol implemented for the sending sub-service is depicted below.</div> <bR> <div> <IMG SRC="023d4ce0.gif" border=0 width="1236" height="974" ALT="Transmitter State Diagram" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> <bR> <div> When an onboard application process/service, using the large data transfer sending sub-service, generates a telemetry packet, it is routed via the large data transfer service. If the entire packet length of the telemetry packet is longer than the mission constant TMPKT_MAX_LENGTH, the service automatically downlinks the telemetry packet as a service data unit. The telemetry packet is transformed into a service data unit and downlinked in service data unit part telemetry packets.</div> <bR> <div> <B>Transferring the first part of a service data unit</B></div> <bR> <div> Downlink the first service data unit part telemetry packet.</div> <bR> <div> <B>Transferring an intermediate part of a service data unit</B></div> <bR> <div> Downlink an intermediate service data unit part telemetry packet.</div> <bR> <div> <B>Transferring the last part of a service data unit</B></div> <bR> <div> Downlink the last service data unit part telemetry packet.</div> <bR> <div> <B>Re-transferring a part of a service data unit</B></div> <bR> <div> Downlink a repeated service data unit part telemetry packet.</div> <bR> <div> <B>Transfer abort initiated by the sending end</B></div> <bR> <div> The large data transfer service initiates abort of the current service data unit downlink.</div> <bR> <div> <B>Acknowledging the successful reception up to a part (all parts)</B></div> <bR> <div> The ground system acknowledges the successful reception of all service data unit parts, specifying the sequence number of the last part, to the large data transfer unit.</div> <bR> <div> <B>Notifying which parts have not been properly received</B></div> <bR> <div> The ground system notifies the large data transfer service which service data unit parts have not been properly received, requesting re-downlink of said parts.</div> <bR> <div> <B>Transfer abort initiated by the receiving end</B></div> <bR> <div> The ground system requests abort of the current service data unit downlink.</div> <bR> <bR> </td> </tr></table></body>