[Title 47 CFR 11.51]
[Code of Federal Regulations (annual edition) - October 1, 2004 Edition]
[Title 47 - TELECOMMUNICATION]
[Chapter I - FEDERAL COMMUNICATIONS COMMISSION]
[Subchapter A - GENERAL]
[Part 11 - EMERGENCY ALERT SYSTEM (EAS)]
[Subpart D - Emergency Operations]
[Sec. 11.51 - EAS code and Attention Signal Transmission requirements.]
[From the U.S. Government Printing Office]


47TELECOMMUNICATION12004-10-012004-10-01falseEAS code and Attention Signal Transmission requirements.11.51Sec. 11.51TELECOMMUNICATIONFEDERAL COMMUNICATIONS COMMISSIONGENERALEMERGENCY ALERT SYSTEM (EAS)Emergency Operations
Sec. 11.51  EAS code and Attention Signal Transmission requirements.

    (a) Broadcast stations must transmit, either automatically or 
manually, national level EAS messages and required tests by sending the 
EAS header codes, Attention Signal, emergency message and End of Message 
(EOM) using the EAS Protocol. The Attention Signal must precede any 
emergency audio message. After January 1, 1998, the shortened Attention 
Signal may only be used as an audio alert signal and the EAS codes will 
become the minimum signalling requirement for National level messages 
and tests.
    (b) When relaying EAS messages, broadcast stations and cable systems 
and wireless cable systems may transmit only the EAS header codes and 
the EOM code without the Attention Signal and emergency message for 
State and local emergencies. Television stations, cable systems and 
wireless cable systems should ensure that pauses in video programming 
before EAS message transmission do not cause television receivers to 
mute EAS audio messages. No Attention Signal is required for EAS 
messages that do not contain audio programming, such as a Required 
Weekly Test.
    (c) Effective January 1, 1997, all radio and television stations 
shall transmit EAS messages in the main audio channel.
    (d) By the above date, television stations shall transmit a visual 
message containing the Originator, Event, Location and the valid time 
period of an EAS message. If the message is a video crawl, it shall be 
displayed at the top of the television screen or where it will not 
interfere with other visual messages.
    (e) Class D non-commercial educational FM stations as defined in 
Sec. 73.506 of this chapter, Low Power FM (LPFM) stations as defined in 
Sec. Sec. 73.811 and 73.853 of this chapter, and low power TV (LPTV) 
stations as defined in Sec. 74.701(f) of this chapter are not required 
to have equipment capable of generating the EAS codes and Attention 
Signal specified in Sec. 11.31.
    (f) Broadcast station equipment generating the EAS codes and the 
Attention Signal shall modulate a broadcast station transmitter so that 
the signal broadcast to other broadcast stations and cable systems and 
wireless cable systems alerts them that the EAS is being activated or 
tested at the National, State or Local Area level. The minimum level of 
modulation for EAS codes, measured at peak modulation levels using the 
internal calibration output required in Sec. 11.32(a)(4), shall 
modulate the transmitter at the maximum possible level, but in no case 
less than 50% of full channel modulation limits. Measured at peak 
modulation levels, each of the Attention Signal tones shall be 
calibrated separately to modulate the transmitter at no less than 40%. 
These two calibrated modulation levels shall have values that are within 
1 dB of each other.
    (g) Effective October 1, 2002, cable systems with fewer than 5,000 
subscribers per headend and wireless cable

[[Page 735]]

systems with fewer than 5,000 subscribers shall transmit EAS audio 
messages in the same order specified in paragraph (a) of this section on 
at least one channel. The Attention Signal may be produced from a 
storage device. Additionally, cable systems and wireless cable systems 
must:
    (1) Install, operate, and maintain equipment capable of generating 
the EAS codes. The modulation levels for the EAS codes and Attention 
Signal shall comply with the aural signal requirements in Sec. 76.605 
of this chapter,
    (2) Provide a video interruption and an audio alert message on all 
channels. The audio alert message must state which channel is carrying 
the EAS video and audio message,
    (3) Cable systems and wireless cable systems shall transmit a visual 
EAS message on at least one channel. The message shall contain the 
Originator, Event, Location, and the valid time period of the EAS 
message. If the visual message is a video crawl, it shall be displayed 
at the top of the subscriber's television screen or where it will not 
interfere with other visual messages.
    (4) Cable systems and wireless cable systems may elect not to 
interrupt EAS messages from broadcast stations based upon a written 
agreement between all concerned. Further, cable systems and wireless 
cable systems may elect not to interrupt the programming of a broadcast 
station carrying news or weather related emergency information with 
state and local EAS messages based on a written agreement between all 
parties.
    (h) Effective December 31, 1998, cable systems with 10,000 or more 
subscribers; and, effective October 1, 2002, cable systems serving 5,000 
or more, but less than 10,000 subscribers per headend and wireless cable 
systems with 5,000 or more subscribers; shall transmit EAS audio 
messages in the same order specified in paragraph (a) of this section. 
The Attention Signal may be produced from a storage device. 
Additionally, after the dates indicated, these cable systems and 
wireless cable systems must:
    (1) Install, operate, and maintain equipment capable of generating 
the EAS codes. The modulation levels for the EAS codes and Attention 
Signal for cable systems shall comply with the aural signal requirements 
in Sec. 76.605 of this chapter. This will provide sufficient signal 
levels to operate cable subscriber television and radio receivers 
equipped with EAS decoders and to audibly alert subscribers. Wireless 
cable systems shall also provide sufficient signal levels to operate 
subscriber television and radio receivers equipped with EAS decoders and 
to audibly alert subscribers.
    (2) The cable systems and wireless cable systems in this paragraph 
(h) shall transmit the EAS audio message required in paragraph (a) of 
this section on all downstream channels.
    (3) The cable systems and wireless cable systems in this paragraph 
(h) shall transmit the EAS visual message on all downstream channels. 
The visual message shall contain the Originator, Event, Location and the 
valid time period of the EAS message. These are elements of the EAS 
header code and are described in Sec. 11.31. If the visual message is a 
video crawl, it shall be displayed at the top of the subscriber's 
television screen or where it will not interfere with other visual 
messages.
    (4) Cable systems and wireless cable systems may elect not to 
interrupt EAS messages from broadcast stations based upon a written 
agreement between all concerned. Further, cable systems and wireless 
cable systems may elect not to interrupt the programming of a broadcast 
station carrying news or weather related emergency information with 
state and local EAS messages based on a written agreement between all 
parties.
    (i) If manual interrupt is used as authorized in paragraph (k) of 
this section, EAS Encoders must be located so that broadcast station, 
cable system or wireless cable system staff, at normal duty locations, 
can initiate the EAS code and Attention Signal transmission.
    (j) Broadcast stations, and cable systems and wireless cable systems 
that are co-owned and co-located with a combined studio or control 
facility, (such as an AM and FM licensed to the same entity and at the 
same location or a cable headend serving more than one system) may 
provide the EAS transmitting requirements contained

[[Page 736]]

in this section for the combined stations or cable systems or wireless 
cable systems with one EAS Encoder. The requirements of Sec. 11.32 must 
be met by the combined facility.
    (k) Broadcast stations and cable systems and wireless cable systems 
are required to transmit all received EAS messages in which the header 
code contains the Event codes for Emergency Action Notification (EAN), 
Emergency Action Termination (EAT), and Required Monthly Test (RMT), and 
when the accompanying location codes include their State or State/
county. These EAS messages shall be retransmitted unchanged except for 
the LLLLLLLL-code which identifies the broadcast station, cable system, 
wireless cable system, or other entity retransmitting the message. See 
Sec. 11.31(c). If an EAS source originates an EAS message with the 
Event codes in this paragraph, it must include the location codes for 
the State and counties in its service area. When transmitting the 
required weekly test, broadcast stations and cable systems and wireless 
cable systems shall use the event code RWT. The location codes are the 
state and county for the broadcast station city of license or cable 
system or wireless cable system community or city. Other location codes 
may be included upon approval of broadcast station, cable system or 
wireless cable system management. EAS messages may be transmitted 
automatically or manually.
    (1) Automatic interrupt of programming and transmission of EAS 
messages are required when facilities are unattended. Automatic 
transmissions must include a permanent record that contains at a minimum 
the following information: Originator, Event, Location and valid time 
period of the message. The decoder performs the functions necessary to 
determine which EAS messages are automatically transmitted by the 
encoder.
    (2) Manual interrupt of programming and transmission of EAS messages 
may be used. EAS messages with the EAN Event code must be transmitted 
immediately and Monthly EAS test messages within 60 minutes. All actions 
must be logged and include the minimum information required for EAS 
video messages.
    (l) Broadcast stations and cable systems and wireless cable systems 
may employ a minimum delay feature, not to exceed 15 minutes, for 
automatic interruption of EAS codes. However, this may not be used for 
the EAN event which must be transmitted immediately. The delay time for 
an RMT message may not exceed 60 minutes.
    (m) Either manual or automatic operation of EAS equipment may be 
used at broadcast stations and cable systems and wireless cable systems 
that use remote control. If manual operation is used, an EAS decoder 
must be located at the remote control location and it must directly 
monitor the signals of the two assigned EAS sources. If direct 
monitoring of the assigned EAS sources is not possible at the remote 
location, automatic operation is required. If automatic operation is 
used, the remote control location may be used to override the 
transmission of an EAS alert. Broadcast stations and cable systems and 
wireless cable systems may change back and forth between automatic and 
manual operation.

[59 FR 67092, Dec. 28, 1994, as amended at 60 FR 56000, Nov. 6, 1995; 63 
FR 29664, June 1, 1998; 65 FR 7639, Feb. 15, 2000; 67 FR 18510, Apr. 16, 
2002]