8 February 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

Tom Gitlin NASA/451 <tom.gitlin@gsfc.nasa.gov> 301-286-9257

Donald Murray NASA <donald.t.murray.1@gsfc.nasa.gov>

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

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

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

Mike Todaro ITT-Seabrook <mike.todaro@class.gsfc.nasa.gov> 301-809-2249

Denise Gilliland ITT-Seabrook <denise.Gilliland@gsfc.nasa.gov>
204-882-4505

The meeting agenda included:

1.  Review of last meeting minutes

2.  Discuss the SWSI/DAS Ops Concept

3.  Continuing the review of the ICD messages

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

# REVIEW OF THE 02-01-01 MEETING MINUTES

The minutes were accepted without any modifications. It was decided that
the SQPN-dual channel modulation with two events and two streams of UPD
messages would not work for SWSI. SWSI would generate a single request
for the SQPN-dual channel modulation and DAS would have to send a single
UPD message that would cover both the I and Q channels.

Second issue that came up was the PN Codes being supported by DAS.
Currently, DAS supports PN Codes 1 through 85 for the US. Support for
the additional NASDA and ESA codes would be an enhancement to the DAS
system and would require further analysis.

# REVIEW OF SWSI DAS OPS CONCEPT PAPER

The following comments were discussed about the SWSI DAS Ops Concept and
some of these comments have a direct bearing on the final version of the
ICD:

-   Discussion about the number of SSCs stored by SWSI. SRD spells out a
    maximum limit of 10 SSCs per SIC. DAS does not store any SSCs and
    relies upon SWSI for creation and storage of SSCs. SWSI will not put
    a hard limit of 10 SSCs instead the DBA will assign the limit for
    the customer.

-   The IBU Mode parameter should be sent back as part of the UPD
    parameters.

-   Figure 3: Beamforming mode (IBU Mode) will stay as part of the SSC
    with the adaptive Mode being the default mode. The other mode
    options will stay as part of the SSC but may not be modified by the
    customer from SWSI screens.

-   Figure 3: Full range of the PN Codes should be supported (US,
    Europe, and Asia). Currently the NASA PN Codes (1 - 85) are
    supported by the DAS design.

-   Figure 4: Additional parameter messages will be forth coming for the
    Data Format specifications (i.e. SFDU etc.).

-   Details of the playback events, currently no provision is made for
    this report. Modifications to messages 208 and 209 would allow for
    playback event details to be viewed by the customer.

## 

## REVIEW OF THE ICD

-   To generate events from the DAS LCM, the 1% of IDs are reserved for
    DAS (100,000). The reserved ID numbers range from 8,900,000 to
    8,999,999.

-   The maximum data rate in the SSC table should be specified for both
    the I and the Q channels

-   Currently the Lock Status flag is passed in the UPD table. Is it
    possible to get the Carrier Lock, Bit-sync Lock, and the Decoder
    Lock flags from the receiver? Dave to discuss with Gene/Bob and
    report back.

-   Message 506: Add the IP Address and the Port Number to this message.

-   Messages (202) and (504): The Delete request from the customer will
    stop a service (active or playback) that is in progress or may not
    have started with this request.

-   Add a Configuration parameter to message 402. This parameter
    specifies the type of Modulation and the channel indicator (I or Q
    or both).

-   UPD message cleanup (remove Acquisition Frequency, Acquisition Time,
    and the Loss of Lock Time).

# 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, 15th February 2001, at 1pm. ITT will initiate the conference
call and the \# is 301-286-0254.