[Cesg-all] Result of CESG poll closing 8 August 2011

[Enrico.Vassallo at esa.int]

Dear Tom,

please find attached the RFM WG response to the issues raised. Looking 
forward to advancing to the next step quickly.

Thanks to all CESG members who took the time to review this document.

Regards, Enrico


Barkley-1 

No problem to remove CCSDS. The rationale here was the distinction between 
SNIP and CCSDS transponders but since the standard is only dealing with 
CCSDS, we can do a global search and replace (with care).

Barkley-2 

This is a legitimate requirement for the station supporting CDMA and PN 
ranging.  Maybe it should be added to 414.1-B-1 at the next 5-years 
review.

Barkley-3 

The section needs to remain there to indicate the functional requirement. 
The performance requirement is mission specific and does not belong here. 
See also similar comment Scott-3.

Scott-1 

The problem with figure 2-2 is due to the revision marks showing the 
changes following RID dispositions. If the changes are accepted, the 
picture does appear correctly. 

Scott-2 

The reason is to follow the signal path: the transponder first receives 
(to lock to the CDMA code) and then transmits. 

Scott-3 

The comment is the same as Barkley-3. The ranging calibration error is 
mission specific. 
An analogy is that we specify the modulation and data format of a receive 
system at a ground station but if the antenna size is too small for a 
mission with high data rate, the link will not work.  We still specify the 
modulation and date format but we do not specify the antenna size.  The 
User decides if the station fits his needs.  The same can be said for the 
range calibration accuracy available.
Incidentally, also the European (ECSS) 'conventional' ranging standard 
does the same.





From:
CCSDS Secretariat <tomg at aiaa.org>
To:
<cesg-all at mailman.ccsds.org>
Date:
09/08/2011 16:19
Subject:
[Cesg-all] Result of CESG poll closing 8 August 2011
Sent by:
cesg-all-bounces at mailman.ccsds.org



CESG E-Poll Identifier:  CESG-P-2011-07-002 Approval to publish CCSDS 
415.1-B-1,  Data Transmission and PN Ranging for 2 GHz CDMA Link via 
Data Relay Satellite (Blue Book, Issue 1)
Results of CESG poll beginning 25 July 2011 and ending 8 August 2011:

                  Abstain:  1 (16.67%) (Taylor)
  Approve Unconditionally:  3 (50%) (Peccia, Calzolari, Moury)
  Approve with Conditions:  2 (33.33%) (Barkley, Scott)
  Disapprove with Comment:  0 (0%)

CONDITIONS/COMMENTS:

      Erik Barkley (Approve with Conditions):  This appears to be 
very close to being a blue book.  I believe there are a few 
conditions that need to be addressed:

1) The document makes numerous reference to a "CCSDS transponder" or 
"CCSDS transponder/transceiver".  It is unclear what is meant as 
CCSDS is not in the business of specifying hardware nor are there any 
normative references indicated to identify what a "CCSDS transponder" 
is.   It appears that this is a construct used to help with 
specifying behavior at a spacelink endpoint.  I would therefore 
request either a) the term "CCSDS transponder/transceiver" be somehow 
defined so that it is clear that this used to generally indicate an 
interface end-point, rather than give the impression of some standard 
CCSDS hardware component, or b) revise all instances of the term   -- 
e.g 7.5.3,  reads "Both long and short return link codes shall be 
generated in the CCSDS
transponder/transceiver in accordance with section 5." This could be 
changed to  "Both long and short return link codes shall be generated 
by the transponder in accordance with section 5." Also, section 7.3.3 
refers to just the transponder, where as 7.3.4 refers to the CCSDS 
transponder.  (If there is a difference this needs to be clearly 
indicated.)

2) Section/sentence 3.4 should be removed. The Rationale is to keep 
the recommendation focused; ie., the requirement to report on range 
and Doppler information is irrelevant to the specification of the 
CDMA spacelink. It may also be noted that these types of requirements 
do not appear in 414.1-B-1 (PN Ranging Systems).  Without further 
detailed format specification it is not possible to use this 
requirement in achieving interoperability. This could be indicated as 
a best practice (maybe section 2).

3) Section 6.4 should either be removed.  The rationale is that the 
behavior of the network element in performing its calibration 
activities is irrelevant to the specification/behavior of the CDMA 
spacelink itself.  Without further detailed format specification it 
is not possible to use this requirement in achieving 
interoperability.  This could be indicated as best practice.

      Keith Scott (Approve with Conditions):  These are comments that 
do not require formal resolution in order to proceed with the document.

Section 2.1
Figure 2-2 the two drawings seem to overlap.

Is there an explicit reason for reversing the order of the 
transmitter and receiver in figure 2-2 with respect to the order in 2-1?


Section 6.4.1
The spec states that if the system employs PN ranging then the 
network element shall be capable of measuring the delay between 
transmitted and received range codes.  Is there somewhere a 
requirement on the accuracy / precision of the RTT 
measurement?  Section 7.6 seems to be imposing requirements on the 
turn-around system itself, but is that enough?  Without some measure 
of performance the requirement in 6.4.1 to measure the delay seems weak?

Total Respondents:  6

No response was received from the following Area(s):

      SEA

SECRETARIAT INTERPRETATION OF RESULTS:  Approved with Conditions
PROPOSED SECRETARIAT ACTION:            Generate CMC poll after 
conditions have been addressed

* * * * * * * * * * * * * * * * * * * * * * * *


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