SN User's Guide - ESC Home - NASA

service is supported through TDRS F3 – F7, TDRS F8 – F10 and K, L, M via the SN
ground terminal infrastructure, where the customer provides the receiver equipment and
the SN only provides the signal at the IF with the characteristics described in this
section. Paragraph 6.3.6.1 describes the aggregate channel characteristics of the TDRS
spacecraft and SN ground segment for understanding the IF interface.
The performance of the customer link greatly depends on the customer signal
characteristics and the receiver used. Paragraph 6.3.6.2 describes potential signal
characteristics and expected performance through the TDRS spacecraft and SN ground
segment. The expected performance is based upon simulation results only and has not
been verified by testing. Data rates and coding techniques should be carefully
considered and coordinated with Code 450 to achieve desired performance.
Changes to the operating conditions or configuration of a TDRSS SSAR IF service
during a scheduled service support period are initiated by a GCMR from the customer
MOC. The requested changes will be implemented within 35 seconds of receipt of the
GCMR at the SN ground terminal. The MOC will be notified upon initiation of the
requested changes via GCM. Additional information concerning SN ground terminal
response times for GCMRs is provided in Section 10. Table 6-13 lists the SSA IF return
service real-time configuration changes and their effects on the return service.
Table 6-13. SSA Return IF Service Real-Time Configuration Changes
Real-Time Configuration Changes GCMR OPM
Return Service
Interruption
Polarization 98/04 OPM 03 Yes
Note:
Items that are indicated to cause return service interruption will cause the SN
ground terminal receiver to discontinue signal tracking and attempt to
reacquire the return service signal after the appropriate reconfiguration. Any
other reconfigurations of the SN ground terminal may momentarily affect signal
tracking.
6.3.6.1 Channel Characteristics
As discussed above, this is not an end-to-end service so a set of customer platform
signal constraints is not available due to the dependencies on the exact customer signal
characteristics as well as receiver capabilities. The IF service provides a SSAR signal
through the TDRS spacecraft and SN ground segment, including IF output channel
characteristics as specified in Table 6-14. This will allow customers to be able to
understand the signal distortions that are outside of their control. For additional
characteristics applicable to the SSAR IF service, refer to Table 6-9.
Revision 10 6-47 450-SNUG