SN User's Guide - ESC Home - NASA

Table 10-3. Schedule Request Descriptions
Schedule Request Type Description
Schedule Add Request (SAR) (message type
99, message class 10)
Alternate SAR (message type 99, message
class 21)
Schedule Delete Request (message type 99,
message class 11)
Schedule Replace Request (message type 99,
message class 12)
Specifies an event to be added to the schedule in
terms of:
1. Specific event start and stop times
2. Either a prototype event ID or one or more
SSC IDs together with service-level timerelated
information
References either a SAR or another Alternate SAR
to form a chain of requests. Specifies an event to
be added to the schedule.
Identifies an event to be deleted and does not
include information such as SSCs
Identifies an event to be deleted, and includes all
of the information needed to add a new event
d. Event scheduling in the NCCDS complies with the SN scheduling ground rules
as specified in paragraphs 2.2.2 and 2.2.3 of the Interface Control Document
(ICD) between the Network Control Center Data System (NCCDS) and the
White Sands Complex (WSC), 452-ICD-NCCDS-WSC. Compliance with these
ground rules ensures that the schedules generated by the NCCDS can be
supported by the TDRSS. In particular, these ground rules ensure adequate
time to configure a resource prior to its use. The actual time required to
configure a service within an event varies depending on the resources allocated
to the service. In general, the time scheduled by the NCCDS to configure a
service is the longest time needed to configure any one of the resources
allocated to the service. Additional rules also apply to event scheduling. Table
10-5 summarizes the SN scheduling ground rules with an emphasis on the
ground rules that apply to time relationships. In general, individual schedule
requests submitted by customers must comply with rules that apply to individual
events or services while rules that apply to the relationships between events are
beyond the control of individual customers.
e. Event scheduling in the NCCDS is performed when processing modifications
(add, replace and delete requests) to the active schedule and when generating
the next forecast schedule. The NCCDS Scheduling Operator (SO) is
responsible for monitoring and coordinating all scheduling activities within the
active period. The NCCDS Forecast Analyst (FA), who is chiefly responsible for
coordinating future scheduling requirements (forecast periods), assists the
NCCDS SO in monitoring schedule-related database information, analyzing
schedule resource problems, and coordinating alternative support solutions with
MOCCs.
Revision 10 10-7 450-SNUG