Emergency alert system methods and apparatus

1. A method for providing emergency alert messages, comprising:

receiving, at a network switching device located at a hub site, coupled to a plurality of customer premise devices, a first emergency alert control message indicating that an emergency alert is in effect;

accessing, at said hub site a program channel map table, said program channel map table including for each of a first plurality of individual program channels corresponding emergency alert content stream identification information, emergency alert content stream identification information corresponding to an individual program channel in the first plurality of program channels indicating an emergency alert content stream to be output in place of the corresponding individual program channel content when an emergency alert is in effect; and

switching, on a per program channel basis, at said network switching device, when the emergency alert is in effect, from outputting program content to customer premise devices on the program channel being switched, to outputting on the program channel being switched, emergency alert message content communicated by the emergency alert content stream indicated by said program channel map table to correspond to the individual program channel being switched, said switching including switching each of the first plurality of individual program channels.

2. The method of claim 1 , wherein said program channel map table includes, for each of a second plurality of individual program channels, information indicating that a switch to an emergency alert stream is not to be made when the emergency alert is in effect; and

wherein said first emergency alert control message is received from an emergency alert server.

3. The method of claim 1 , wherein

the method further comprises delivering the emergency alert message content to a customer premise device on one of said first plurality of program channels using the same frequency and modulation technique which was previously being used to deliver program content on said one of said first plurality of program channels.

4. The method of claim 3 , further comprising:

receiving said program channel map table prior to an emergency alert going into effect; and

storing the program channel map table in memory at said hub distribution site, said table including information identifying program channels and corresponding emergency alert message source information in addition to descriptions of program channels listed in said program channel map table and corresponding multicast source IP addresses indicating multicast addresses used to supply regular program content.

5. The method of claim 1 ,

wherein said network switching device does not output program content, from said one or more content sources used to provide regular program content, on a first plurality of outputs when outputting said emergency alert message content on said first plurality of outputs.

6. The method of claim 1 , further comprising:

receiving, at the network switching device, a second emergency alert control message instructing that said emergency alert is not in effect; and

switching, in response to the received second emergency alert control message, said first plurality of program channels back to outputting program content from one or more content sources from which content was being output prior to said alert being in effect.

7. The method of claim 1 , further comprising:

receiving at said hub site said program channel map table from an emergency alert server prior to receiving said first emergency alert control message; and

wherein the method further comprises operating the emergency alert server to generate and send said first emergency alert control message to said hub site after said program channel map table is stored in said hub site.

8. The method of claim 7 , wherein said emergency alert content stream to be output in place of the corresponding individual program channel is an emergency alert audio content stream.

9. The method of claim 7 , further comprising:

identifying from said program channel map table which of a second plurality of program channels are to be switched to a second emergency alert content source providing second emergency alert message content; and

switching, in response to the received first emergency alert control message, to outputting said second emergency alert message content on the identified second plurality of program channels.

10. The method of claim 9 , wherein said second emergency content includes audio and video content including emergency alert message information.

11. The method of claim 9 , the method further comprising:

switching, in response to the received first emergency alert control message, to outputting test information on a third plurality of program channels.

12. The method of claim 1 , wherein said network switching device supplies content to a single Federal Information Processing Standard (FIPS) region, the method further comprising:

receiving said source mapping information prior to receiving said first emergency alert control message.

13. The method of claim 1 , further comprising:

receiving, at the hubsite including said network switching device, said program channel map table via a control communications channel, said control communications channel being a different communications channel from a content channel used to supply said emergency alert content stream.

14. The method of claim 1 , further comprising:

operating an emergency alert server to perform the steps of:

receiving a first emergency alert message;

generating first emergency alert message content based on at least some information included in said first emergency alert message; and

transmitting said first emergency alert message content to said network switching device via an emergency alert content stream identified in said program channel map table.

15. The method of claim 14 , wherein said emergency alert content stream includes audio content.

16. The method of claim 14 ,

wherein said emergency alert content stream includes video content.

17. A system for providing emergency alert messages, comprising:

a network switching device located at a hub site, the network switching device including an interface configured to receive a first emergency alert control message indicating that an emergency alert is in effect;

an identification module configured to access, at said hub site a program channel map table, said program channel map table including for each of a first plurality of individual program channels corresponding emergency alert content stream identification information, emergency alert content stream identification information corresponding to an individual program channel in the first plurality of program channels indicating an emergency alert content stream to be output in place of the corresponding individual program channel content when an emergency alert is in effect; and

a switching control module configured to control said network switching device, to switch, on a per program channel basis, at said network switching device, when the emergency alert is in effect, from outputting program content to customer premise devices on the program channel being switched, to outputting on the program channel being switched, emergency alert message content communicated by the emergency alert content stream indicated by said program channel map table to correspond to the individual program channel being switched, said switching including switching each of the first plurality of individual program channels.

18. The system of claim 17 , further comprising:

a QAM modulator device configured to modulate the emergency alert message content output by said network switching device onto a first frequency band for delivery to one or more customer premise devices on at least one program channel used to supply content prior to said switch being controlled to switch from outputting program content to outputting said emergency alert message content.

19. The system of claim 17 ,

wherein said network switching device does not output program content on program channels which have been switched to outputting said emergency alert message content while an emergency alert is in effect.

20. A non-transitory computer readable medium for use in a system for providing emergency alert messages, said non-transitory computer readable medium comprising instructions which when executed by a processor control a network switching device located at a hub site, coupled to a plurality of customer premise devices, to:

receive, at said network switching device, a first emergency alert control message indicating that an emergency alert is in effect;

access, at said hub site a program channel map table, said program channel map table including for each of a first plurality of individual program channels corresponding emergency alert content stream identification information, emergency alert content stream identification information corresponding to an individual program channel in the first plurality of program channels indicating an emergency alert content stream to be output in place of the corresponding individual program channel content when an emergency alert is in effect; and

switch, on a per program channel basis at said network switching device, when the emergency alert is in effect, from outputting program content to customer premise devices on the program channel being switched, to outputting on the program channel being switched, emergency alert message content communicated by the emergency alert content stream indicated by said program channel map table to correspond to the individual program channel being switched, said switching including switching each of the first plurality of individual program channels.