Craig

 

I’m sorry that I missed the June meetings there – so please excuse any duplication or overlap below as the topics may have been discussed during the working groups.  Some thoughts on the question of how data formats arise, and the appropriate point within the LRIT Infrastructure follows:

 

As a practical matter many ASPs today support most, if not all, of the satellite providers likely to meet the performance standards for LRIT (and thus be potentially CSPs or support CSPs).  Therefore I would disagree that this aspect is overly burdensome.  Converting data is not, in context, likely to determine the success or failure of an ASP considering all other factors within an ASP’s list of responsibilities (securing customers, maintaining a data center, certification into LRIT). 

 

However; in our view that discussion itself is rendered moot by the bigger question of what is technically feasible for a CSP.

The view here is that CSPs will be unable to convert data to the proposed format (or any other standard format for that matter).

 

Each CSP provides a communications path via a specific satellite network.  However CSPs do not, in most instances, have knowledge of payload interpretation, protocol or format of the data exchanged between the ASP and the Shipboard Equipment.  Such aspects are handled by firmware, scripting or other configuration mechanisms that are specific to each equipment vendor.  Hence the data transmitted via any given CSP may vary from device-to-device and change over time as new software or firmware revisions are made to the onboard equipment.

 

To our knowledge, all potential CSPs provide flexibility in the representation of the LRIT requirements over their networks (e.g. the raw encoding of a position report).  Most potential CSPs also provide several different delivery mechanisms which are proven both technically and commercially.  As the CSP cannot generally control the scripting/firmware/configuration options present on each piece of Shipboard Equipment it becomes technically infeasible to assign any data translation capabilities to the CSP.

                                                                                                                                                                               

Furthermore; even if a CSP did have knowledge of the payload protocol – and thus could translate it – that approach may have unintended consequences.  If would lead to a lowest-common-denominator approach within the data available to ASPs.  Shipboard Equipment and CSPs often make data available in addition to the fields required for LRIT.  We anticipate that ASPs are likely to use this additional data to offer services complementary to LRIT – in terms of their offerings to fleet owners and operators.  Consequently; we do not believe that it is desirable for a CSP to remove all additional data as that would limit the overall utility of the LRIT system to fleet owners and operators.  Such a step would also reduce the commercial opportunities available to ASPs.

 

Our view is that the earliest point in the LRIT infrastructure where sufficient information is available to standardize a format is at the ASP.

Of note the ability to satisfy the Performance Standards arises through the use of two system components in conjunction:

                                                                                                                                                                                          

a) Shipboard equipment; including configuration options (scripts, firmware versions etc)

b) The CSP; including the account configuration and selected delivery formats etc (i.e. VPN, Internet, header formats)

 

There are two additional notes here - to avoid potential misinterpretation of the above:

 

1)       A CSP may also act as an ASP.  In that case the ASP+CSP can take responsibility for the configuration of shipboard equipment – and thus is able interpret the payload data fully within the ASP aspects of its dual role.

 

2)       It may initially appear that Inmarsat-C equipment operating in according to the baseline PDR specifications is an exception – as this is a rare case of a network operating defining a position reporting protocol.  However; it should be noted that most deployed Inmarsat-C equipment extends the Inmarsat-C baseline standards in vendor proprietary ways – and this is specifically allowed within the Inmarsat-C baseline PDR specifications.

 

3)       Finally; any translation to a common format could not be performed once per “physical” satellite network.  The “CSP” for example in Inmarsat could be a Land Earth Station operator, other distribution partner or Virtual Network Operator (i.e. Inmarsat-D+).  The same comment applies to other satellite providers who elect to have distribution partner(s) act as the CSP.  It should be noted that this may be required by the telecommunications regulators in some countries (where a specific legal entity or reseller holds the concession to land traffic from a given network within a defined country).  Consequently, care should be taken here not to equate “CSP” in the LRIT lexicon with “Satellite Network” in the sense of the physical satellite constellations available – there may be many CSPs sharing the same physical satellite network.  Hence the apparent simplicity of the “one-CSP” vs. “many-ASP” argument falls down.  It is actually quite possible that there would be fewer ASPs than CSPs in practice once LRIT is deployed.

 

Best Regards

Jeff Douglas

Director

ABSOLUTE SOFTWARE INC

www.absolutesw.com

 

 

 

You make a fair point... I would suggest other interested parties (such as ASPs wishing to bid on the ASP function for the IDC case) voice their position. If we allow CSPs to send the shipborne data to the ASP based upon any "format" or protocol than the ASP will have to absorb the cost of supporting multiple "formats" and communication protocols. The extra expense, of course, would likely be pushed back to the customers (contracting governments).

 

This topic affects only ASPs and CSPs wishing to form the communication path to the International Data Centre (not national or regional data centers).

 

Based upon e-mails written on this reflector and the discussion in the Hamburg meeting, the document will be aligned with the "consensus" view.

 

 

 

Regards,

 

Craig Hayley

System Engineer

Canadian Coast Guard

 

From: ccglrit-gcclrit-bounces@lists.ncf.ca [mailto:ccglrit-gcclrit-bounces@lists.ncf.ca] On Behalf Of Brian Mullan
Sent: Friday, June 01, 2007 10:37 AM
To: Hayley, Craig
Cc: ccglrit-gcclrit@lists.ncf.ca
Subject: Re: [Ccglrit-gcclrit] June 12-14 meeting of the Ad hoc Working Group onEngineering Aspects of LRIT, Hamburg Germany

Thanks, Craig

 

Good clarification on the data format from the ships. However, you now infer that CSPs will perhaps be asked to format messages from ships – but not all CSPs have signed up to do this (I know of only one). It is the understanding of many CSPs that the manipulation of the “raw” data from ships starts at the ASP level. Also, the LRIT coordinator has said in the past that coordination (“oversight”) starts at the ASP level. The CSP has largely been seen (until now) as purely the comms pipe that provides the LRIT data from ships to the ASP and to start involving CSPs in manipulating LRIT data would extend the oversight role.

 

Writing in specifications for all CSPs would therefore appear to be premature!

 

Kind regards

 

Hi All,

 

I'm please to see a good discussion has developed around this topic. Hopefully, more discussion on other topics in the documents will be initiated over the coming week before we meet in Hamburg.

 

Given the e-mails on this topic, the text (including wording in the table) should be altered to eliminate any confusion.

 

I agree that the specific data elements (latititude, longitude, year, month, day, hour, minute, unique equipment identifier) that the shipborne equipment transmits is the important information. The "format" of how those elements are displayed is accomplished by land based software (not shipborne equipment software). Essentially, an application piece of software will take those data elements, process them and display them in a given "format". It has been decided that SOAP messages (using XML format) will be the back bone of the LRIT communication system. Thus, the various data elements contained in a given LRIT message will have to be "formatted" as such. The question of whether application software residing at the CSP or ASP (not software on the shipborne equipment) begins to format the data elements into an LRIT message (SOAP using XML) as defined in the communications document is another issue. Currently, the document is written such that the CSP (for the International Data Centre case) begins to build SOAP messages and pass them to the ASP. We have to define an interface between the ASP and the CSP for the International Data Centre case. If we allowed CSPs to transmit information to the ASP using different formats, protocols, etc than it wouldn't be fair to the ASP. This would add an extra cost burden on the ASPs given that they would have to support multiple formats, protocols, etc. Please note that national data centers and regional data centers are free to define and allow different formats, protocols, etc from the CSP to the ASP.

 

The intention of the LRIT communications document shall be to specify the data elements transmitted by the shipborne equipment as stated in Brian's previous e-mail:

 

Shipborne Data Elements:

 

Latitude -> degrees, minutes and decimal minutes to two decimal places  N / S

Longitude ->degrees, minutes and decimal minutes to two decimal places  E / W

 

Unique equipment ID -> number

 

Year -> 4 digit year number

Month -> 2 digit month number

Day ->  2 digit day number

Hour -> 2 digit hour number

Minute -> 2 digit minute number

 

 

 

 

Regards,

 

Craig Hayley

 

From: Brian Mullan [mailto:Brian_Mullan@inmarsat.com]
Sent: Friday, June 01, 2007 6:18 AM
To: Hayley, Craig
Cc: ccglrit-gcclrit@lists.ncf.ca
Subject: RE: [Ccglrit-gcclrit] June 12-14 meeting of the Ad hoc Working Group onEngineering Aspects of LRIT, Hamburg Germany

Hi, Hayley

 

Many thanks for your email. I can agree that the text of the document is clear; but that the wording in the table is not consistent and appears even to contradict the text you quote. My copy of the document shows wording for 1.1.1.1 that is different:

“The intent of this document is to outline the technical specifications for communication within the international Long-Range Identification and Tracking (LRIT) system as stated in the terms of reference of resolution MSC.211(81).”

 

Your reference is new text in 2.2.2.4 in the copy that I received (15-02-2007 LRIT ad hoc WG)

 

In Table 2, the heading indicates “Parameter provided by LRIT Shipborne Equipment” and then describes the various elements, including specifying the format. It is clear to me and others that this method of presenting the information in the table means that the information transmitted by the shipborne equipment *must* follow the format written in the table. This is where the difficulty lies – the wording is over-prescriptive and does not accord with the wording in 2.2.2.4. My original email showed how, in Inmarsat C position reporting at least, the way the information is transmitted. Other shipborne systems probably will have their own format for presenting data to the ASP.

 

May I suggest, please, that we stick to requiring that the specific data elements (unique identifier, latitude/longitude and date/time of the position) are transmitted from the ship and then only start to prescribe the format for onward transmission from the ASP? In other words, as long as the shipborne equipment transmits, as a minimum, the required elements, any format is acceptable. This allows for all approved shipborne LRIT systems to be offered, no matter in which order or format the data is presented. This approach will also allow the table to be in accord with the new wording in 2.2.2.4

 

I hope that this is clear. Your hard work is very much appreciated and it is clearly understood that the document remains a “work in progress”. Please don’t take my input as criticism – it is not! All I seek is clarity of the wording for all.

 

With best wishes

 

Hi Brian,

 

Thanks for the e-mail. I hope more people will take the time to read the documents and provide comments. I assume you are referring to the LRIT communication document.

 

Please note the following text in the LRIT communications document: 

1.1.1.1          The parameters added by the LRIT shipborne equipment include the latitude, longitude, Time Stamp when the position was generated, and the shipborne equipment identifier. The “Format” of these parameters as outlined in table 2 indicates how the parameters shall be formatted while the information is contained within the LRIT message and does not specify the format of how the shipborne equipment transmits the information.

 

Regarding your concerns with the format of the date/time... The only difference that I can detect between the date/time you state and what is in Table 2 of the LRIT communications document is the separators ("-" versus ":") for the year, month, day, hour and minute. The separator used to separate the year, month, etc in the date stated in table 2 is not important and in no way linked to the format coming out of the shipborne equipment. The format is with respect to SOAP messages communicated along the various LRIT communication segments. CSPs for the IDC shall have to "build" SOAP messages complying with table 2 in the communications document using the format from the ship borne equipment. The important thing with the time stamp is that seconds are not transmitted.

 

Regarding your concerns with the format for latitude... We had a discussion on your e-mail and the intention was to implement your recommendation. I can't recall why the "seconds" component of the latitude didn't change to decimal minutes with a precision of 2 decimal places. The most likely reason is that I forgot to incorporate this change in the document due to the numerous requests. My apologies on this topic. I will make the change for latitude to decimal minutes unless someone raises a compelling reason not to change. Any body from the Communications group recall if there was a specific reason why we didn't make the change (Jilian, Guy, etc.)???

 

I would like to high light to everyone that these documents are in constant flux as a result of many requests from different inputs at the Ad Hoc meeting. Thus, it is important to fully read the documents that come out of each meeting to ensure that any particular topic of interest is addressed in a satisfactory manner.

 

Thanks,

 

Craig Hayley

System Engineer

Canadian Coast Guard

709-772-7740

 

From: ccglrit-gcclrit-bounces@lists.ncf.ca [mailto:ccglrit-gcclrit-bounces@lists.ncf.ca] On Behalf Of Brian Mullan
Sent: Thursday, May 31, 2007 12:35 PM
To: ccglrit-gcclrit@lists.ncf.ca
Subject: Re: [Ccglrit-gcclrit] June 12-14 meeting of the Ad hoc Working Group onEngineering Aspects of LRIT, Hamburg Germany

This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify the system manager. In accordance with Inmarsat Information Security Policy and Guidelines on Computer use, emails sent or received may be monitored. Inmarsat plc, Registered No 4886072 and Inmarsat Global Limited, Registered No. 3675885. Both Registered in England and Wales with Registered Office at 99 City Road, London EC1Y 1AX.

_____________________________________________________________________
This e-mail has been scanned for viruses by Verizon Business Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.verizonbusiness.com/uk

_____________________________________________________________________
This e-mail has been scanned for viruses by Verizon Business Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.verizonbusiness.com/uk

_____________________________________________________________________
This e-mail has been scanned for viruses by Verizon Business Internet Managed Scanning Services - powered by MessageLabs. For further information visit http://www.verizonbusiness.com/uk