[ldm-users] Corrupted data with the NOAAport DVB-S2 signal, and thoughts on the new broadcast

I just called the NWS Network Control Facility (NCF). The specific problem
they are encountering is that the data on the new DVB-S2 broadcast is being corrupted. They were testing it this weekend and noticed the issue. They are working to resolve it, but I was advised *NOT* to switch over to the DVB-S2 broadcast (see below), and the dual period of illumination will continue until this issue is resolved.

Of course, did you think that was going to stop me from switching my Novra S-300 receiver to DVB-S2 to check things out? :-) (I have backup
sites to get the NOAAport feed from, so I am not concerned.)

With all the warnings and caveats the NWS warned us about in mind,
I logged into my NOAAport receiver running CentOS 5.6 and the
Novra-supplied CMCS command tool utility for Linux. I did the switchover
using the CMCS tool to ensure I could actually do this remotely.
Surprisingly, it took all of 45 seconds to do the switch.

For those of you who have S-300's and your PID's have been set, here's the commands you'll need to type at the CMCS prompt, after you have logged in:

mode DVB-S2
frequency 1141.85
symbolrate 15.120
isi on
set isi 13

If you haven't set your PID's, then you need to add them. From the cmcs command prompt, type:

add pid 101
add pid 102
add pid 103
add pid 104
add pid 105

Type "reboot" on the CMCS command line to ensure the changes take hold.
And then, when you type "show satellite" on the command line, you should
see something like this (I "x"'d out and changed the IP and MAC addresses
below for security reasons):

CMCS XXX.XXX.XXX.XXX> show satellite
        Satellite Interface Settings:

        Receiver MAC Address:   xx-xx-xx-xx-xx-xx
        Receiver Mode:          DVBS2
        Frequency:              1142.0 MHz
        Symbol Rate:            15.120 Msps
        ModCod:                 Unknown (ANY)
        Gold code:              0
        Input Stream Filter:    On
        Input Stream ID:        13

        Signal Lock:            On
        Data Lock:              On
        Uncorrectable Rate:     0/Second
        Packet Error Rate:      0.0000e+00

        Carrier to Noise C/N:   11.3dB
        Signal Strength:        -45 dBm

Yes, the frequency shows up as 1142.0 MHZ. It is auto-corrected
by the Novra S-300. If you use the full Windows program, you'll see that
PLUS the correction frequency to lock into the NOAAport broadcast. The
S-200 was the same way; it always showed the frequency rounded up or down.

So, what am I seeing? An ldmadmin watch has tons of products flying by. That's good! But in my ldmd.log on my satellite receiver, I see:

Apr 18 14:56:06 noaaport readnoaaport[4617] ERROR: Missing fragment in sequence, last 15/34490810 this 17/34490810 Apr 18 14:56:06 noaaport dvbs_multicast[4613] ERROR: Gap in SBN last 156909021, this 156909023 Apr 18 14:56:07 noaaport dvbs_multicast[4613] ERROR: Gap in SBN last 156909057, this 156909059 Apr 18 14:56:07 noaaport dvbs_multicast[4613] ERROR: Gap in SBN last 156909081, this 156909083 Apr 18 14:56:07 noaaport dvbs_multicast[4611] ERROR: Gap in SBN last 242340760, this 242340762 Apr 18 14:56:07 noaaport readnoaaport[4617] ERROR: Missing fragment in sequence, last 3/34490813 this 5/34490813 Apr 18 14:56:07 noaaport readnoaaport[4617] ERROR: Missing fragment in sequence, last 1/34490816 this 3/34490816 Apr 18 14:56:07 noaaport dvbs_multicast[4613] ERROR: Gap in SBN last 156909145, this 156909147 Apr 18 14:56:08 noaaport dvbs_multicast[4611] ERROR: Gap in SBN last 242340866, this 242340868 Apr 18 14:56:08 noaaport dvbs_multicast[4613] ERROR: Gap in SBN last 156909186, this 156909188

So, as you can see, one packet frequently gets messed up.

Items I noted:

1. I was surprised to see that the signal strength was -45 dBm. I thought
it would be at least several dBm stronger (I was guessing around -40 dBm).
Oh, well...as long as you are between -25 dBm and -65 dBm, you should
lock. BTW, I have dense low-mid level cloud cover over me today, and
that will hurt the signal a tad.

2. Even though I can't say I was amused by a command line tool to do this,
I've learned that CMCS isn't complicated, the instructions are easy,
and major changes can literally be done in seconds. I was pleasantly
and happily surprised.

3. Just like the DVB-S broadcast, the DVB-S2 broadcast is very "bursty"
with data. Instead of a constant stream, you get quick bursts of lots of
products. In other words, situation normal.

OK, enough for now...check out the official NWS update announcement below.
I'm going to stick with the DVB-S2 broadcast for now unless it goes down
entirely...or unless we get severe weather here, which could happen later
this week. I want to watch to see the performance and other
characteristics of this new broadcast.

Any questions...feel free to ask. Oh, the CMCS tool is available via Novra support at support@xxxxxxxxxx

-------------------------------------------------------------------------

NOXX01 KWBC 181358
WHAT - SBN/NOAAPORT EXPANSION AND HARDWARE UPGRADE
DATE - APRIL 18, 2011
NOTICE - 007

--------------------------------------------
SBN ACTIVATION INFORMATION - APRIL 18 2011
--------------------------------------------
THE NEW -SBN/NOAAPORT- SIGNAL WAS ACTIVATED
AS OF 04/18/11 - 1300Z.

--------------------------------------------
NOTICE-NOTICE-NOTICE-NOTICE-NOTICE-NOTICE
--------------------------------------------
DUE TO UNEXPECTED INTERNAL PROCESSING PROBLEMS
ENCOUNTERED OVER THE WEEKEND, THE OPERATIONAL
DEPLOYMENT HAS BEEN PLACED ON HOLD BY THE NWS
TILL FURTHER NOTICE.  THE DUAL ILLUMINATION
WILL CONTINUE AT THIS TIME, BUT WE ARE
ENCOURAGING OUR CUSTOMERS TO ONLY USE THE
DVB-S2 SIGNAL FOR TESTING PURPOSES TILL A
RESOLUTION FOR THE PROBLEMS ENCOUNTERED THIS
WEEKEND HAVE BEEN ADDRESSED. IF YOU ENCOUNTER
PROBLEMS OR HAVE QUESTIONS, PLEASE REPORT THE
PROBLEM TO THE NOAAPORT SUPPORT TEAM /SEE EMAIL
ADDRESS BELOW/.

--------------------------------------------
PLANNING DATES
1. DUAL ILLUMINATION DATES - APR 18 TO MAY 17
2. DECOMMISSION OLD DVB-S DOWNLINK - MAY 17
--------------------------------------------

ALL TECHNICAL SPECIFICATIONS AS WELL AS UPDATES
FOR THIS UPGRADE CAN BE FOUND ON THE FOLLOWING
WEB PAGE

------------------------------------------
WWW.NWS.NOAA.GOV/NOAAPORT/HTML/NOAAPORT.SHTML
------------------------------------------

A EXTENSIVE WINDOW OF DUAL ILLUMINATION IS PLANNED
TO ALLOW NWS SITES AND NOAAPORT CUSTOMERS TIME TO
COMPLETE THE TRANSITION. DURING THIS PERIOD, THE
FULL -SBN/NOAAPORT- FEED WILL BE DISSEMINATED IN
BOTH DVB-S AND DVB-S2.  AFTER THE COMPLETION OF
THE DUAL ILLUMINATION, THE ONLY SIGNAL DISSEMINATED
OVER THE -SBN/NOAAPORT- WILL BE IN DVB-S2.

THIS NEW AND INCREASED -SBN/NOAAPORT- BANDWIDTH
WHICH WILL HELP TO ENABLE DISSEMINATION OF THE NEW
PRODUCTS THAT ARE ON THE HORIZON FOR OUR CUSTOMERS
WILL MAKE THIS A VERY EXCITING CHANGE FOR EVERYONE.

IF YOU HAVE ANY QUESTIONS, WE ENCOURAGE YOU TO
CONTACT US VIA EMAIL AT THE FOLLOWING ADDRESS

NWS.NOAAPORT -AT- NOAA.GOV