Re: [Discuss-gnuradio] how to get wireless carrier signal in GNU Radio
Hi Zenghao, Thank you for your reply. I have few more queries regarding the carrier sense module in probe_avg_mag_sqrd_c.cc file. It looks like to find the presence of carrier in air, there is a variable d_unmuted, which is being checked. This variable is set whenever pre_output_iir variable is more than d_threshold value. I have two doubts about it. First, How can d_threshold be compared with d_iir.prev_output variable? It seems that d_ threshold is the ratio of Signal to Noise. Does it mean, d_iir.prev_output is also ratio os signal ro noise? Second, is there any way to define the threshold signal strength? Or does the packet initiation detection not depended on carrier's strength and rather dependent on S/N ratio? Hoping for the kind reply again. - Sachin Zenny Zhang wrote: Sachin, Sure, here is the related code I use: # get a probe alpha = 0.001 thresh = 30 self.probe = gr.probe_avg_mag_sqrd_c(thresh,alpha) # connect usrp to the probe self._fg.connect(self.u, self.probe) # wait until the medium is free while objDemod1.probe.level() threshold: time.sleep(0.0001) Zhenghao On Thu, Oct 23, 2008 at 4:59 PM, Shirve [EMAIL PROTECTED] wrote: Hi Zhenghao, Thank you for your valuable reply. I appreciate it. As per your supplied information, I will start looking for CSMA code in tunnel.py, though if you can send me your code, it will be quite helpful too. I hope that using tunnel.py code and help from you I will be able to get the carrier sense capability for my application. Thanks -Sachin Zenny Zhang wrote: Sachin, I don't know if this is helpful, just sharing my experience. 1. You may want to check tunnel.py, in which there is a CSMA scheme -- Eric told me this a couple of weeks ago. 2. It is possible to do some carrier sensing by ourself. You can just read the signal from the USRP and compare the signal strength level with a threshold. Of course a filter is needed. I tried this last week and it is working, although the threshold may need some tuning. If you need I can send you the code written in python. Zhenghao On Wed, Oct 22, 2008 at 6:19 PM, Shirve [EMAIL PROTECTED] wrote: Hi, As per the current status of GNU Radio, I got to know that there is no MAC (CSMA) implementation. Therefore I am not sure if I can get the signal from signal processing blocks of GNU Radio about the carrier sensed by USRP receiver. Please help me in this regard. Till now I am able to locate the message queue mechanism to get the received packets from the other USRP transmitter, which is in gr_msg_que.cc in runtime library of GNUradio-core. But this mechanism just indicates the received packets (correct or corrupted), while the signal sensing (packet start) starts much earlier than the complete packet reception. Is it possible to get the information about the wireless carrier signal in the vicinity of USRP receiver from the current GNU Radio framework? I am using GNU Radio 3.1.1 version. Your help will greatly help me in my goal. Thanks in advance and expecting your kind reply. - Sachin -- View this message in context: http://www.nabble.com/how-to-get-wireless-carrier-signal-in-GNU-Radio-tp20120856p20120856.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- View this message in context: http://www.nabble.com/how-to-get-wireless-carrier-signal-in-GNU-Radio-tp20120856p20139200.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- View this message in context: http://www.nabble.com/how-to-get-wireless-carrier-signal-in-GNU-Radio-tp20120856p20169595.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] how to get wireless carrier signal in GNU Radio
Sachin, Sure, here is the related code I use: # get a probe alpha = 0.001 thresh = 30 self.probe = gr.probe_avg_mag_sqrd_c(thresh,alpha) # connect usrp to the probe self._fg.connect(self.u, self.probe) # wait until the medium is free while objDemod1.probe.level() threshold: time.sleep(0.0001) Zhenghao On Thu, Oct 23, 2008 at 4:59 PM, Shirve [EMAIL PROTECTED] wrote: Hi Zhenghao, Thank you for your valuable reply. I appreciate it. As per your supplied information, I will start looking for CSMA code in tunnel.py, though if you can send me your code, it will be quite helpful too. I hope that using tunnel.py code and help from you I will be able to get the carrier sense capability for my application. Thanks -Sachin Zenny Zhang wrote: Sachin, I don't know if this is helpful, just sharing my experience. 1. You may want to check tunnel.py, in which there is a CSMA scheme -- Eric told me this a couple of weeks ago. 2. It is possible to do some carrier sensing by ourself. You can just read the signal from the USRP and compare the signal strength level with a threshold. Of course a filter is needed. I tried this last week and it is working, although the threshold may need some tuning. If you need I can send you the code written in python. Zhenghao On Wed, Oct 22, 2008 at 6:19 PM, Shirve [EMAIL PROTECTED] wrote: Hi, As per the current status of GNU Radio, I got to know that there is no MAC (CSMA) implementation. Therefore I am not sure if I can get the signal from signal processing blocks of GNU Radio about the carrier sensed by USRP receiver. Please help me in this regard. Till now I am able to locate the message queue mechanism to get the received packets from the other USRP transmitter, which is in gr_msg_que.cc in runtime library of GNUradio-core. But this mechanism just indicates the received packets (correct or corrupted), while the signal sensing (packet start) starts much earlier than the complete packet reception. Is it possible to get the information about the wireless carrier signal in the vicinity of USRP receiver from the current GNU Radio framework? I am using GNU Radio 3.1.1 version. Your help will greatly help me in my goal. Thanks in advance and expecting your kind reply. - Sachin -- View this message in context: http://www.nabble.com/how-to-get-wireless-carrier-signal-in-GNU-Radio-tp20120856p20120856.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- View this message in context: http://www.nabble.com/how-to-get-wireless-carrier-signal-in-GNU-Radio-tp20120856p20139200.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] how to get wireless carrier signal in GNU Radio
Hi Zhenghao, Thank you for your valuable reply. I appreciate it. As per your supplied information, I will start looking for CSMA code in tunnel.py, though if you can send me your code, it will be quite helpful too. I hope that using tunnel.py code and help from you I will be able to get the carrier sense capability for my application. Thanks -Sachin Zenny Zhang wrote: Sachin, I don't know if this is helpful, just sharing my experience. 1. You may want to check tunnel.py, in which there is a CSMA scheme -- Eric told me this a couple of weeks ago. 2. It is possible to do some carrier sensing by ourself. You can just read the signal from the USRP and compare the signal strength level with a threshold. Of course a filter is needed. I tried this last week and it is working, although the threshold may need some tuning. If you need I can send you the code written in python. Zhenghao On Wed, Oct 22, 2008 at 6:19 PM, Shirve [EMAIL PROTECTED] wrote: Hi, As per the current status of GNU Radio, I got to know that there is no MAC (CSMA) implementation. Therefore I am not sure if I can get the signal from signal processing blocks of GNU Radio about the carrier sensed by USRP receiver. Please help me in this regard. Till now I am able to locate the message queue mechanism to get the received packets from the other USRP transmitter, which is in gr_msg_que.cc in runtime library of GNUradio-core. But this mechanism just indicates the received packets (correct or corrupted), while the signal sensing (packet start) starts much earlier than the complete packet reception. Is it possible to get the information about the wireless carrier signal in the vicinity of USRP receiver from the current GNU Radio framework? I am using GNU Radio 3.1.1 version. Your help will greatly help me in my goal. Thanks in advance and expecting your kind reply. - Sachin -- View this message in context: http://www.nabble.com/how-to-get-wireless-carrier-signal-in-GNU-Radio-tp20120856p20120856.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio -- View this message in context: http://www.nabble.com/how-to-get-wireless-carrier-signal-in-GNU-Radio-tp20120856p20139200.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] how to get wireless carrier signal in GNU Radio
Hi, As per the current status of GNU Radio, I got to know that there is no MAC (CSMA) implementation. Therefore I am not sure if I can get the signal from signal processing blocks of GNU Radio about the carrier sensed by USRP receiver. Please help me in this regard. Till now I am able to locate the message queue mechanism to get the received packets from the other USRP transmitter, which is in gr_msg_que.cc in runtime library of GNUradio-core. But this mechanism just indicates the received packets (correct or corrupted), while the signal sensing (packet start) starts much earlier than the complete packet reception. Is it possible to get the information about the wireless carrier signal in the vicinity of USRP receiver from the current GNU Radio framework? I am using GNU Radio 3.1.1 version. Your help will greatly help me in my goal. Thanks in advance and expecting your kind reply. - Sachin -- View this message in context: http://www.nabble.com/how-to-get-wireless-carrier-signal-in-GNU-Radio-tp20120856p20120856.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] how to get wireless carrier signal in GNU Radio
Sachin, I don't know if this is helpful, just sharing my experience. 1. You may want to check tunnel.py, in which there is a CSMA scheme -- Eric told me this a couple of weeks ago. 2. It is possible to do some carrier sensing by ourself. You can just read the signal from the USRP and compare the signal strength level with a threshold. Of course a filter is needed. I tried this last week and it is working, although the threshold may need some tuning. If you need I can send you the code written in python. Zhenghao On Wed, Oct 22, 2008 at 6:19 PM, Shirve [EMAIL PROTECTED] wrote: Hi, As per the current status of GNU Radio, I got to know that there is no MAC (CSMA) implementation. Therefore I am not sure if I can get the signal from signal processing blocks of GNU Radio about the carrier sensed by USRP receiver. Please help me in this regard. Till now I am able to locate the message queue mechanism to get the received packets from the other USRP transmitter, which is in gr_msg_que.cc in runtime library of GNUradio-core. But this mechanism just indicates the received packets (correct or corrupted), while the signal sensing (packet start) starts much earlier than the complete packet reception. Is it possible to get the information about the wireless carrier signal in the vicinity of USRP receiver from the current GNU Radio framework? I am using GNU Radio 3.1.1 version. Your help will greatly help me in my goal. Thanks in advance and expecting your kind reply. - Sachin -- View this message in context: http://www.nabble.com/how-to-get-wireless-carrier-signal-in-GNU-Radio-tp20120856p20120856.html Sent from the GnuRadio mailing list archive at Nabble.com. ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
