The following is excerpted from the Alabama Broadcasters Association's weekly e-newsletter, Monday Morning Coffee and Technical Notes. Thanks to Larry Wilkins, who puts together the content and has shared it with Radio magazine readers. To subscribe to the newsletter, send an email to firstname.lastname@example.org, and he will add you to the database.
Last Friday afternoon, Sept. 28 all stations received IPAWS “offline” messages. Alfred Kenyon, IPAWS customer support branch chief reported “that the IPAWS EAS Atom Feed lost connectivity into and out of one of the data centers on an intermittent basis that was not detected by the Akamai external load balancer.”
“The EAS Atom Feed traffic was directed to the other data center. We anticipate running this way until Monday (today) when we hope to be able to get core connectivity issue resolved.”
As a reminder the National EAS test is scheduled to run this coming Wednesday Oct. 3 at 2:20 p.m. (EDT). All EAS participants should make sure that your EAS decoders have the most current "security certificate" installed. Contact your equipment vendor to make sure you are current.
Attention Alabama Broadcast and Cable operators: If you have any problems with the National test (receiving, relaying or quality of audio) please send an email describing the trouble to the Alabama SECC.
FEMA will also test the WEA (Wide Area Alerting) system via wireless carriers at 2:18 p.m. (EDT).
CAN YOU HEAR ME NOW?
Most radio stations are streaming their audio with various systems. Streaming inevitably means codecs - people are not listening to your WAV file over the air, they are hearing an AAC or Ogg Vorbis reproduction. These files don't behave as nicely as the audio in your air chain. Codecs struggle to handle hot audio, which leads to distortion in the stream not present in the over the air program.
The space between the samples is where trouble lies; in these gaps the analogue waveform continues smoothly, so in some cases the reconstructed waveform can be higher than the sample measurements either side. This is known as an 'inter-sample peak', and it results in distortion as the waveform is incorrectly reconstructed.
Set some guides lines in your facility, especially in the production room to ensure the proper amount of headroom is available to minimize peak over shoots. You might want to use a true peak limiter to monitor and control these peaks and avoid inter-sample peaks.
ACRONYMS ARE US: MPLS?
MPLS is short for Multiprotocol Label Switching.
MPLS is an initiative that integrates layer 2 information about network links (e.g. bandwidth, latency, utilization) into Layer 3 (IP) within a particular autonomous system, or ISP, in order to simplify and improve IP package exchange. MPLS gives network operators a great deal of flexibility to divert and route traffic around link failures, congestion, and bottlenecks.
From a quality of service QoS standpoint, ISPs will better be able to manage different kinds of data streams based on priority and service plan. For instance, those who receive/transmit a lot of streaming media or high-bandwidth content can see minimal latency and packet loss.
C-BAND DISH REGISTRATION
Don't forget to register your stations C-band satellite dish before Oct. 17. The FCC needs to be made aware of much this spectrum (3.7 GHz-4.2 GHz) is being used so that they can make an accurate decision concerning the requested sharing of the band with broadband users.
If you have not registered contact SES at their website www.ses.com for directions.
MINIMUM OPERATING SCHEDULE
Section 73.1740 of the FCC's rules requires stations to adhere to minimum operating requirements and, under Section 73.1740(a)(4), Notification must be sent to the FCC in Washington, D.C., not later than the tenth day of limited or discontinued operation.
Also if a station is unable to operate in compliance with its license for more than 30 days, it must request authority from the FCC to remain silent. Notwithstanding the grant of such authority, if a station fails to transmit broadcast signals for any consecutive 12-month period, the station's license expires at the end of that period pursuant to Section 213(g) of the Communications Act.
The FCC stated that stations that resume operations for a short time in between long periods of silence only to avoid license termination is counter to the policy against allowing extended periods of silence, which aims to "ensure that scarce broadcast spectrum does not lie fallow and unavailable to others."