[Sis-csi] RF aspects of Cislunar

[Scott,Keith L.]

I think Dave's right.  We certainly need to be considerate of link
characteristics such as bandwidth constraints and simplex or half-duplex
channels, but there's a space link services area within CCSDS that deals
with link-specific stuff.

		--keith

>-----Original Message-----
>From: sis-csi-bounces at mailman.ccsds.org 
>[mailto:sis-csi-bounces at mailman.ccsds.org] On Behalf Of Dave Israel
>Sent: Thursday, June 02, 2005 8:39 AM
>To: James L. Rash
>Cc: sis-csi at mailman.ccsds.org
>Subject: Re: [Sis-csi] RF aspects of Cislunar
>
>All,
>
>There is a new IP-over-CCSDS BoF in formulation that will 
>address how IP is to
>be transmitted over CCSDS lower layers.  I believe that will 
>be the place for
>these discussions about the lower layers.  This Cislunar 
>working group should
>be focused more on IP and above.
>
>Dave
>
>Quoting "James L. Rash" <James.L.Rash at nasa.gov>:
>
>> All,
>>
>> This group will define a number of communication scenarios.  These
>> scenarios would imply certain requirements on the lower layers.
>> Could we determine or at least characterize those requirements?
>>
>> Jim
>>
>>
>> At 12:59 AM -0400 6/2/05, Keith Hogie wrote:
>> >All,
>> >
>> >   As we are drawing diagrams of all these communication scenarios,
>> >I was wondering if the group plans on addressing lower layer issues
>> >like frequencies, modulation, coding, and framing.  By following
>> >a layered approach, lots of work can be done at upper layers while
>> >ignoring details of the lower layers.  But, at some point we need
>> >lower layer radios and RF technologies that can support all sorts of
>> >dynamic links between all our CEVs, rovers, astronauts, relay
>> >satellites, ISS, ground, etc.
>> >
>> >   Today's space communication systems tend to treat lots of
>> >satellite communication as 2 one-way links with different solutions
>> >in each direction (telemetry down, commands up).  That's fine for
>> >a spacecraft that always talks to ground stations but it doesn't
>> >work when you try to have any node communicate with any other node.
>> >
>> >   I was just wondering if this group should be looking at low level
>> >RF link solutions as well as upper layers.
>> >
>> 
>>----------------------------------------------------------------------
>> >   Keith Hogie                   e-mail: 
>hogie at ipinspace.gsfc.nasa.gov
>> >   Computer Sciences Corp.       office: 301-794-2999  fax: 
>301-794-9480
>> >   7700 Hubble Dr.
>> >   Lanham-Seabrook, MD 20706  USA        301-286-3203 @ NASA/Goddard
>> 
>>----------------------------------------------------------------------
>> >
>> >_______________________________________________
>> >Sis-CSI mailing list
>> >Sis-CSI at mailman.ccsds.org
>> >http://mailman.ccsds.org/cgi-bin/mailman/listinfo/sis-csi
>>
>>
>> --
>>
>> James L. Rash
>> Building 23, Room E403
>> Code 588 -- Advanced Architectures and Automation Branch
>> NASA Goddard Space Flight Center
>> Greenbelt, MD  20771
>> 301-286-5246 (voice)     301-286-1768 (fax)
>>
>>
>> _______________________________________________
>> Sis-CSI mailing list
>> Sis-CSI at mailman.ccsds.org
>> http://mailman.ccsds.org/cgi-bin/mailman/listinfo/sis-csi
>>
>
>
>______________________________________________________________
>Dave Israel
>Leader, Advanced Technology Development Group
>Microwave & Communication Systems Branch
>NASA Goddard Space Flight Center  Code 567.3
>Greenbelt, MD 20771
>Phone: (301) 286-5294      Fax:   (301) 286-1769
>E-mail: david.j.israel at nasa.gov
>
>"Without deviation from the norm, progress is not possible."  
>-Frank Zappa
>
>_______________________________________________
>Sis-CSI mailing list
>Sis-CSI at mailman.ccsds.org
>http://mailman.ccsds.org/cgi-bin/mailman/listinfo/sis-csi
>