Re: [Tinyos-help] cc2420 transmission delay ( backoff times)
i have a question. Why do CC2420 need to wait for hardware ACK for such a log time? It should be very fast. On 5/28/08, Jongkeun Na [EMAIL PROTECTED] wrote: On Wed, May 28, 2008 at 2:06 AM, salvatore galati [EMAIL PROTECTED] wrote: ack wait time of 256 jiffies = 3,84 msec isn't one jiffy 32us? if so, the ack wait time should be 8.192ms. -- Jongkeun ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help -- Renjie Huang Sensorweb Research Laboratory http://sensorweb.vancouver.wsu.edu/ Washington State University ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
Re: [Tinyos-help] cc2420 transmission delay ( backoff times)
I think it's mainly due to software-ACK and the congestion backoff mentioned by Phil. Jun On Fri, Jun 13, 2008 at 12:10 PM, renjie huang [EMAIL PROTECTED] wrote: i have a question. Why do CC2420 need to wait for hardware ACK for such a log time? It should be very fast. On 5/28/08, Jongkeun Na [EMAIL PROTECTED] wrote: On Wed, May 28, 2008 at 2:06 AM, salvatore galati [EMAIL PROTECTED] wrote: ack wait time of 256 jiffies = 3,84 msec isn't one jiffy 32us? if so, the ack wait time should be 8.192ms. -- Jongkeun ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help -- Renjie Huang Sensorweb Research Laboratory http://sensorweb.vancouver.wsu.edu/ Washington State University ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help -- -- Mailto: [EMAIL PROTECTED] ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
Re: [Tinyos-help] cc2420 transmission delay ( backoff times)
There are no backoffs when transmitting an acknowledgment. Even if the ack is transmitted instantaneously to the receiver, it still takes time to download and process the acknowledgment from the RXFIFO. The ack wait period was chosen experimentally in an environment with multiple transmitters. The more transmitters, the more likely the ack reception will be delayed by some significant amount. -David _ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Jun Sent: Friday, June 13, 2008 1:41 PM To: renjie huang Cc: tinyos-help@millennium.berkeley.edu Subject: Re: [Tinyos-help] cc2420 transmission delay ( backoff times) I think it's mainly due to software-ACK and the congestion backoff mentioned by Phil. Jun On Fri, Jun 13, 2008 at 12:10 PM, renjie huang [EMAIL PROTECTED] wrote: i have a question. Why do CC2420 need to wait for hardware ACK for such a log time? It should be very fast. On 5/28/08, Jongkeun Na [EMAIL PROTECTED] wrote: On Wed, May 28, 2008 at 2:06 AM, salvatore galati [EMAIL PROTECTED] wrote: ack wait time of 256 jiffies = 3,84 msec isn't one jiffy 32us? if so, the ack wait time should be 8.192ms. -- Jongkeun ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help -- Renjie Huang Sensorweb Research Laboratory http://sensorweb.vancouver.wsu.edu/ Washington State University ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help -- -- Mailto: [EMAIL PROTECTED] ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
Re: [Tinyos-help] cc2420 transmission delay ( backoff times)
On Wed, May 28, 2008 at 2:06 AM, salvatore galati [EMAIL PROTECTED] wrote: ack wait time of 256 jiffies = 3,84 msec isn't one jiffy 32us? if so, the ack wait time should be 8.192ms. -- Jongkeun ___ Tinyos-help mailing list Tinyos-help@millennium.berkeley.edu https://www.millennium.berkeley.edu/cgi-bin/mailman/listinfo/tinyos-help
