Re: [Discuss-gnuradio] Packet Header Generator and Stream CRC32

Hi Martin,

Thank you.

1.Why the packet length should be larger than 32 bits?Can you explain it?

2.For example,I'm using the OFDM example in gnuradio.If i want to have a working CRC,I must set the length>=4?Is 4 OK?

3.Is the packet length means that the original length(for example len=a) or the length of data pass through CRC(len+4)?

Best regards,

zswx  

At 2015-07-11 07:40:38, "Martin Braun" <martin.braun@ettus.com> wrote:

On 10 Jul 2015 01:38, "zs" <zswx_890@126.com> wrote:
> If I want to have a working CRC,what is the number of packet length at least?

32 bits.

> If someone don't want to use the Stream CRC32 block,Packet Header Generator still will add the crc at bit 24-31.Is it right?I suggest the code should add a function to judge before add the crc at bit 24-31.

We don't want to overload this generator with options. The idea is you subclass the generator to tailor to your needs. See also the other generators.

> 3.For example,the OFDM example.If the transmitter don't add the crc32 block,whether the receiver will display the warning "Detected an invalid packet at item %1%"?

No, that's precisely why we have it. However, the payload also has a crc.

Cheers,
M