Modeling of DSN Services
One of the challenges of modeling the DSN schedul-
ing domain is the wide range of options available for
making use of the network. As previously described,
one of the primary attributes of a scheduling request
is the specification of the DSN services that are need-
ed, which must be transformed into a set of specific
resource reservations to satisfy the request. It has
been a key element of the DSE design that users can
specify their needs at a more general and abstract lev-
el, and that the system will translate into the details,
ensuring the right antennas and equipment are
scheduled. This has the obvious advantage that there
is flexibility in the implementation of a request that
can be used by the DSN systems, for example, to
optimize the schedule or to reschedule on short
notice in case assets go down. At the same time, the
scheduling system needs to handle a very detailed
specification of requested tracking time, down to the
selection of individual antennas and equipment
types to be reserved. A design to accommodate this
spectrum of possibilities has been developed and
implemented in the DSE, and is illustrated in figure 5.
Each DSN service user or mission must define one
or more service configurations, which are referred to
by a name or alias. Each configuration specifies the
following information: ( 1) one or more choices for
how antennas and equipment can be allocated to
meet the user’s DSN requirements; ( 2) for each
choice, which sets of antenna and equipment are
acceptable; and ( 3) for each antenna/equipment
combination, what are the default values for associated tracking parameters, such as setup and teardown
time before and after the track, the 16-character
activity description for the track, a standardized work
category used to identify the kind of activity, and if
applicable, a specific sequence of events that define
all steps that occur during the track.
Import:
- events
- requests
Reports
Noti;cations
Database
(Oracle)
Scheduling Engine (DSE) SSS (S3) Collaboration GUI/DB
User Interface
SSS web app
SSS Wiki
(Con;uence)
JMS messagebus
HTTP
DSE
client
session
DSE
engine
(AMA/
Aspen)
DSE
manager
(SMA)
Figure 4. An Overview of the S3 System Architecture.
The DSN scheduling engine manages and provides a set of servers that respond to users’ requests for scheduling services through the S3 web
application.
