01 March 2001

# Recap of the DAS/SWSI Working Group Meeting 

The following attended the meeting:

Tom Sardella NASA/583 <tom.sardella@gsfc.nasa.gov> 301 286-7686

Harshna Sampat CSC <hsampat@csc.com> 301 794-2427

Gerald Klitsch CSC <gklitsch@csc.com> 301 805-3735

Sergey Nikhinson CSC <sergey@rattler.gsfc.nasa.gov>

Riley Elwood CSOC/FHA <riley.j.elwood.1@gsfc.nasa.gov> 301-286-6492

Haresh Patel ITT-Reston <haresh.patel@itt.com> 703 438-7938

David Hsu ITT-Reston <david.hsu@itt.com> 703 438-7846

Ajay Kapoor ITT-Reston <ajay.kapoor@itt.com> 703-438-8085

Philip Message ITT-Reston <philip.message@itt.com> 703-438-2145

Charlie Hammond ITT-Reston <charlie.hammond@itt.com> 703-438-8016

Denise Gilliland ITT-Seabrook <denise.gilliland@gsfc.nasa.gov>
240-882-4505

Caren Corbett NASA <caren.corbett@gsfc.nasa.gov> 505-527-7026

The meeting agenda included:

1.  Review of last meeting minutes

2.  Issues that came out of the CDR discussions

3.  Review of the ICD

4.  Review of SWSI DAS Ops concept paper

5.  Address items related to DAS SWSI interface testing and schedule.

# REVIEW OF THE 02-15-01 MEETING MINUTES

-   The minutes were accepted without any modifications.

## REVIEW OF THE CDR ISSUES

-   During CDR, some discussion focused on ways to reduce the scheduling
    burden for the customers. For instance, a dedicated customer may
    want to request a recurring daily service over a long duration with
    a single request. Another example mentioned was the selection of
    multiple time segments for a single playback event, and at the
    meeting the group also considered being able to request multiple
    playback events with a single request. SWSI is considering these
    issues for design and cost impacts. Charlie Hammond suggested that
    before too much effort is expended in investigating these possible
    enhancements, that first we give consideration to the RFA inputs
    before addressing these comments from CDR in greater depth.

## REVIEW OF THE ICD

-   The DAS SWSI ICD draft final copy has been put back under ITT
    (Ajay's) control so that modifications may be incorporated in the
    ICD for any changes due to issues that came up during the CDR.

-   IBU Mode as part of Table 3.4-5. Caren Corbett has sent
    recommendations to Tom Gitlin regarding the IBU Modes that need to
    be available from SWSI and from the LCM. The current recommendation
    is to allow customers to select adaptive or pointing modes. Tom
    Gitlin to let ITT know what needs to be done.

-   The working group acknowledged that the full range of the PN Codes
    should be supported (US, Europe, and Asia) in the ICD. Currently,
    the NASA PN Codes (1 - 85) are supported by the DAS design. The SSC
    table is to be modified so DAS will support service for US, Europe,
    and Asia (NASA, NASDA, & ESA Codes) as follows:

PN Code -- I Channel Shift Register A Octal Value (4 digits)

PN Code -- Q Channel Shift Register C Octal Value (4 digits)

-   Add a change to ICD that shows the SIC ID for alert messages to all
    users in Message 100 is '0000'. This designator would cover alerts
    to all customers, but not groups of customers.

-   Message 501: Item #7 description needs to be clearly explained. The
    term "files" needs to be changed to "time segments", which are
    started and stopped based on periods of LOCK and NO-LOCK in the
    receivers.

-   The default number of days for storage of data on the PTP is to be
    30 days vice 7. Caren Corbett and Riley Elwood both recounted
    previous experiences with customers when storage periods of 7 days
    were inadequate.

-   SSC Table entries to be checked out for consistency with the UPD
    entries. In particular, this was related to the G2 symbol inversion
    parameters appearing in the UPD message Table 3.4-23 and not
    appearing in the SSC parameter Table 3.4-5. Ted Benjamin is
    investigating these parameter entries in each table more thoroughly.

-   Some background information on the DAS/SWSI ICD was discussed with
    Caren Corbett. In general, the message types and information content
    has been described completely, less any modifications resulting from
    CDR comments. And, implementation details are to be captured in an
    XML schema format. Valid concerns about the feasibility to use this
    XML format in implementing future software fixes and enhancements
    were discussed between Caren and Tom Sardella, and Caren agreed to
    review the XML documentation and provide comments back on its
    utility in making software fixes. What may be required is an
    addition to the ICD that provides a "bridge" between the high level
    detail captured in the CDR version of the ICD and the extremely
    detailed information in the XML portion of the document.

# REVIEW OF SWSI DAS OPS CONCEPT PAPER

-   No comments were made specifically on the SWSI DAS Ops Concept.

## 

# DAS/SWSI INTERFACE TESTING

This topic was not discussed at this meeting due to time limitations and
will be picked up at the next working group meeting.

# 

# NEXT MEETING

The next working group meeting will be held by telephone conference on
Thursday, 8th March 2001, at 1pm. ITT will initiate the conference call
and the \# is 301-286-0254.