[Smwg] Response to AI 2017-0512-47 (Provide Service Catalog input on statements of service performance)

Barkley, Erik J (3970) erik.j.barkley at jpl.nasa.gov
Thu Oct 26 21:26:27 UTC 2017


At the the San Antonio meetings I took an action item to provide service catalog inputs with regard to statements of service.

Below are a couple of examples that I had in mind when we discussed this at the San Antonio meetings. It strikes me that for missions that are investigating whether or not to use a particular service provider the kind of characteristics below are going to be very useful in determining whether or not the service provider is of interest for the particular Mission.  The first table provides the kind of service performance parameters I was thinking about for command service, and the second table provides an example of performance parameters for the telemetry service.

In going through the draft service catalog material to date, it struck me that it is more akin to stating a service catalog per se rather than specifying how a service catalog is stated. I think that ultimately to be of use in guiding CCSDS member agencies the best practice needs to state the overall template to follow and then requirements in each section as to what shall be provided (descriptions, service characteristics/parameters at a minimum), what should be provided (things that are very desirable for a mission to know about) and things that may be provided (nice to have but not critical in determining mission supportability). For what it's worth, I have provided a few more comments on the service catalog example that are kind of in line with this thinking, which I have uploaded to the CWE (new structure).

Although I won't be at the meetings I do hope that perhaps this can serve as a useful part of discussion at the upcoming meetings.

Best regards,

---Command Service Table Example----



Frequency Bands Supported

Near-Earth S, X
Deep space S[1], X

EIRP and Transmitting Power


34m BWG

99 dBW at 20 kW

34m HEF

79 dBW at 250 W


106 dBW at 20 kW



110 dBW at 20 kW


116 dBW at 20 kW

Refer to Table 5-1

Polarizations Supported

No RCP/LCP simultaneity

Modulation Types

BPSK on subcarrier for uplink rate ≤ 4 kbps
BPSK directly on carrier for uplink rate 4 kbps to 256 kbps[2]

Modulation Formats

NRZ: L, M, S
Bi-phase L or Manchester, M, S

Modulation Index Range

Sinewave subcarrier:       0.1 – 1.52 radians

Squarewave subcarrier:   0.1 – 1.40 radians

No subcarrier:                  0.1 – 1.57 radians

Carrier/Subcarrier Waveform

Residual carrier: sine wave
Subcarrier:  8 or 16 kHz

Uplink Acquisition Types

CCSDS Physical Link Operations Procedure-2 (PLOP-2)

Uplink Data Rate

Maximum 256 kbps
Minimum 7.8 bps

Channel Coding

Provided by mission user

Data from MOC to DSN

Stream of CLTUs over a TCP/IP interface
File of CLTUs

Data from DSN To Spacecraft

CLTU per CCSDS TC Space Link Protocol (ref. CCSDS 232.0-B-1)

Data Unit Size

Maximum CLTU size: 32,752 bits
Minimum: 16 bits
A series of CLTUs can be contiguously radiated.

Data Retention Period

No data retention other than buffer staging for radiation

Data Delivery Methods from MOC to DSN

CCSDS Space Link Extension (SLE) Forward CLTU (ref. CCSDS 912.1-B-2), on-line delivery mode
CCSDS SLE Enhanced Forward CLTU (ref. CCSDS 912.11-O-1), on-line delivery mode (being implemented, available in 2017)
AMMOS Space Command Message File (SCMF) Interface, on-line or off-line delivery mode

Radiation Latency

≤ 125 milliseconds per CLTU

Service Operating Mode


Service Availability

Nominal 95%
Mission critical event 98%

Data Quality†

Bit error rate: 10-7
CLTU error rate: 10-4

Accountability Reporting

SLE command radiation status report

Ground Communication Interface Methods

Refer to Section 3.8

DSN Interface Specifications

DSN documents 810-005; 810-007[3]; 820-013 0163-Telecomm, 0191-Telecomm, 0197-Telecomm, 0198-Telecomm

-----Telemetry Service Table Example---



Frequency Bands Supported

Near-Earth S, X, Ka[4]
Deep space S, X, Ka

G/T @ 45 Degree Elevation, diplexed (refer to Table 5.1)


G/T (dB)

34m BWG


34m HEF





G/T (dB)

34m BWG


34m HEF





G/T (dB)

34m BWG (deep space, 32 GHz)


34m BWG (near Earth, 26 GHz)


Polarizations Supported

RCP/LCP simultaneity at some stations for S-, X-and deep space Ka-band.

Modulation Types

PSK on residual carrier (with or without subcarrier)
BPSK on suppressed carrier (no ranging)
QPSK, OQPSK* (no ranging)

Modulation Formats

NRZ: L, M, S;
Bi-phase L or Manchester, M, S

Carrier/Subcarrier Waveform

Residual carrier: sine or square wave

Downlink Data Rate
(Information and redundancy)

Maximum:  150 Mbps for near Earth Ka-band
                     10 Mbps for other frequencies
Minimum:  10 bps (> 40 bps recommended for timely acquisition)

Downlink Symbol Rate

Maximum:  300 Msps for near Earth Ka-band (with ½ code)
                     20 Msps for other frequencies (with ½ code)
Minimum:  20 sps (with ½ code)

Forward Error Correction

Convolutional codes: (k=7, r=1/2), without punctured code option
Reed-Solomon (RS) interleave = 1 to 8
Reed-Solomon (RS) without convolutional code
Reed-Solomon (outer) concatenated with convolutional (inner) code
Turbo codes: 1/2, 1/3, and 1/4 (1.6 Mbps max); not available for near-Earth Ka-band
Turbo code: 1/6 (1 Mbps max); not available for near-Earth Ka-band
Low Density Parity Code (LDPC): ½, 2/3, 4/5, 7/8 (10 Msps, max); not available for near-Earth Ka-band.[5]

Data Format, from Spacecraft to the DSN

CCSDS TM Synchronization and Channel Coding (ref. CCSDS 131.0-B-1)
Transfer frame format conforming to CCSDS TM Space Data Link Protocol (ref. CCSDS 132.0-B-1)
VCDUs conforming to CCSDS AOS Space Data Link Protocol (ref. CCSDS 732.0-B-2)

Data Format, from DSN to MOC

Stream of frames or VCDUs

Data Unit Size (information bits only)

TM frame or VDCU:  8920 bits (nominal), 1760 bits (safing and critical events), 16 kbits (maximum)

Maximum Number Of Virtual Channels Supported

64 (16 virtual channels can be processed at a given time)

Data Retention Period at the DSN

Nominal 14 days after acquisition[6].

Data Delivery Methods from the DSN to the MOC

CCSDS Space Link Extension (SLE) RAF/RCF (ref. CCSDS 911.1-B-2 and 911.2-B-2)
On-line timely
On-line complete

Data Delivery Latency (DSN to MOC)

Engineering telemetry:  Typically on-line timely (seconds) and on-line complete (hours)
Science telemetry:  Typically off-line (hours to 24 hours).
Note: Latency commitment limited by bandwidth from DSN to project MOS

Service Operating Mode


Service Availability

Nominal:  95%
Mission critical event:  98%

Data Quality†

Frame rejection rate: 10-4 to 10-5 typical

Time Tagging Accuracy

10-50 microseconds in Earth Receive Time (ERT) relative to UTC, depending on downlink data rate

Accountability Reporting

SLE RAF/RCF status report
Frame accountability report
0199-Telecomm, 0206-Telecomm-SLE

Ground Communication Interface Methods

Refer to Section 3.8


[1] S-band uplink at Madrid excludes the use of 2110-2120 MHz frequency band, per agreement between NASA and Secretaria de Estado de Telecomunicaciones para la Sociedad de la Informacion (SETSI), January 2001.

[2] It is recommended to use large CLTU size (32 kb) for high command data rate (e.g., 256 kbps) to minimize the transaction rate.
[3] DSN Mission Interface Design Handbook, Document No. 810-007, Rev. E, Jet Propulsion Laboratory, Pasadena, California.

[4] Near-Earth Ka-band can be concurrently received with S-band, but not X-band

[5] LDPC code will be available in 2018, with a firm commitment on code rate ½ to support Human Space Flight mission.  Availability of other code rates (2/3, 4/5, 7/8) may extend beyond 2018.

[6] Longer retention period due to mission-specific need could be negotiated, subject to data volume constraint.
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