[BC] Another iBiquity goof

[WFIFeng@aol.com]

In a message dated 10/01/2005 09:15:44 PM Eastern Daylight Time, 
richwood at pobox.com writes:

> Over the air 
>  upgrades are dangerous. How many receivers will be in bad signal 
>  areas and switch to analog in the middle of the process?

Not if the thing is properly designed with more than double the total amount 
of memory needed for the firmware. The software update is downloaded to RAM. 
It's sent as packets with very robust error detection/correction interleaved 
with the data packets. Each packet is checked for proper checksum and CRC, etc. 
If the packet is NG, it's discarded. The software program waits for a 
subsequent re-feed, and then "fills in the blanks" while also double-checking the 
already existing good packets. Only when the entire firmware upgrade has been 
successfully downloaded, verified and confirmed, will the system commit it to the 
FLASH Memory as a legitimate firmware update.

It's a similar system to what is used by the Unity 4000 receivers by Wegener. 
They have sent a number of firmware upgrades through the system since it's 
implementation in 2000, and to my knowledge, all have funtioned perfectly. (Only 
some very rare situations resulted in receivers NOT getting the upgrade. I 
don't know of any that were corrupted.)

So, over-the-air updates to IBUZ are not impossible, technically. It seems, 
though, that the firmware was written into PROM chips, so now it can't be 
changed without changing the physical chip. That's a very unlikely scenario.

Willie...