sahana-nz team mailing list archive

[Gavin Treadgold <gt@xxxxxxxxxxxxx>]

On 2009-10-01, at 12:03 , Steve Davis wrote:
> I can't recall what the issue was, but either the providers here  
> can't do it, or it would cost to set it up.
>
> This has lots of advantages, its more efficient, doesn't require  
> subscription to a list, and can target specific geographic areas by  
> targeting specific cell sites.
>
> Anyone know any more about this?

Yep :)

The telco's said it was pretty expensive to set up broadcast  
facilities and there weren't many non-emergency applications that they  
could try and recovered some of the costs from. The only way this was  
going to happen? If Government stepped in and funded the capability.

It came up quite a bit whilst we were doing the CAENZ report that I  
was involved in.

From the key findings:
> 7.	For mobile networks, SMS with geo- location was identified as the  
> most optimal mechanism currently available to deliver localised  
> alerts. While Cell Broadcasting is a technically superior mobile  
> network technology as it is less vulnerable to congestion compared  
> to SMS, it will require significant investment to be deployed in New  
> Zealand.

Interesting comment on Japen:
> Japan is planning to use normal ‘Cell Broad- cast’ for warning and  
> informing the public for emergencies, but is also investigating a  
> special, additional signal in the ‘Paging Channel’ for earthquake  
> and tsunami warnings. Japan’s tsunami risk necessitates messages to  
> be sent very rapidly. The paging channel can sound a special alert  
> tone to all customers within 20 seconds to indicate an imminent  
> tsunami. In contrast, cell broadcasting will take between 20 seconds  
> and 2 minutes.

There is a lot on Cell Broadcasting (types 1 and 2) in the report  
starting at page 22.

> Telecommunication networks are optimised for “peak hour, peak  
> period” load factors, and not for public alerting traffic during  
> CDEM emergencies. Consequently, sufficient capacity may need to be  
> held in reserve or be capable of being deployed rapidly during an  
> emergency event to ensure an adequate performance level for  
> alerting. An alternative to in-place reserve capacity may be traffic  
> prioritisation mechanisms. These performance measures, will however,  
> require significant investment.

> Type 2 cell broadcasting is preferable to SMS as a mobile alerting  
> tool due to its ability to operate in a congested network.

Anyway, I'd really recommend reading the CAENZ report, as it will give  
a lot of background in this area.

<http://www.civildefence.govt.nz/memwebsite.nsf/Files/Public-alerting/$file/CAENZ-Report.pdf 
>

One of the more interesting techniques I came across during the report  
was the discovery of a proposal to embed an alerting channel in GPS,  
and create a global system. I'm not sure if this has gone any further  
yet.

Cheers Gavin