Comtec CDM-840 - ECM (Entry Channel Mode) Operation

CDM-840 Remote Router MN-CDM840
Appendix A Revision 3
A–5
A.5 ECM (Entry Channel Mode) Operation
ECM (Entry Channel Mode) operation is available in the CDM‐840 and ODM‐840 Remote
Routers, and in the CDD
‐8
80 Multi Receiver Router. ECM is a feature based on slotted Aloha
with random retransmission backoff. It supports multiple carriers through frequency
assignments, which provide simplified deployment and scalability.
While a Remote Router is in Entry Channel Mode, it allows the passing of management traffic
only – it will not transmit user data traffic. An ECM
‐en
abled Remote Router may remain in the
entry channel for an extended period if “online” communications are not required, or if dSCPC
(dynamic Single Carrier Per Channel) resources are unavailable. While idle or waiting in the entry
channel, the Remote Router sends periodic health status messages to the CTOG
‐2
50 and
Vipersat Management System (VMS) while it continues to service VMS recovery logic timers.
• A
ppendix G. ECM (ENTRY CHANNEL MODE) in this manual.
• Appendix F. ECM (ENTRY CHANNEL MODE) in the Comtech EF Data ODM-840
Remote Router / ODMR-840 Reduced Form Factor Remote Router / ODMR-
840B Remote Router Board Set Installation and Operation Manual (CEFD P/N
MN-ODM840)
• Appendix D. ECM (ENTRY CHANNEL MODE) in the Comtech EF Data CDD-880 Multi
Receiver Router Installation and Operation Manual (CEFD P/N MN-CDD880)