Changes between Initial Version and Version 1 of Tutorials/Wireless/Measurement Tool

Timestamp:

May 14, 2019, 6:37:49 PM (6 years ago)

Author:

nilanjan

Comment:

—

Tutorials/Wireless/Measurement Tool

@@ +1 @@
+== Measurement tools ==
+This tutorial will demonstrate data collection method using the OML interface.
+
+== Prerequisites ==
+ 1. Accounts, ssh keys
+ 2. Reservation
+ 3. Familiarity with USRPs.
+
+=== Description ===
+This tutorial utilizes an existing application provided by the UHD driver. The application used is ''rx_multi_sample'' which is a c++ application that configures and reads samples from multiple the USRPs. A c++ based OML-wrapper has been added to this application to store FFTed blocks of samples to an OML database server.
+
+=== Set up ===
+ 1. First ssh into the console that you made a reservation.
+ 2. Use the ''omf stat'' to find all the experiment servers and SDRs that are seen by OMF.
+{{{
+console> omf stat -t all
+ INFO NodeHandler: OMF Experiment Controller 5.4 (git 861d645)
+ INFO NodeHandler: Slice ID: default_slice (default)
+ INFO NodeHandler: Experiment ID: default_slice-2019-05-14t10.58.59.167-04.00
+ INFO NodeHandler: Message authentication is disabled
+ INFO property.resetDelay: resetDelay = 200 (Fixnum)
+ INFO property.resetTries: resetTries = 1 (Fixnum)
+ INFO property.nodes: nodes = "system:topo:all" (String)
+ INFO property.summary: summary = false (FalseClass)
+ INFO Topology: Loaded topology 'system:topo:all'.
+
+Talking to the CMC service, please wait
+-----------------------------------------------
+ Node: mob1.sb1.cosmos-lab.org           State: POWERON
+ Node: mob2.sb1.cosmos-lab.org           State: POWERON
+ Node: mob3.sb1.cosmos-lab.org           State: POWERON
+ Node: sdr1-lg1.sb1.cosmos-lab.org       State: POWERON
+ Node: sdr1-md1.sb1.cosmos-lab.org       State: POWERON
+ Node: sdr2-lg1.sb1.cosmos-lab.org       State: POWERON
+ Node: sdr2-md1.sb1.cosmos-lab.org       State: POWERON
+ Node: srv1-lg1.sb1.cosmos-lab.org       State: POWERON
+ Node: srv2-lg1.sb1.cosmos-lab.org       State: POWERON
+-----------------------------------------------
+
+ INFO EXPERIMENT_DONE: Event triggered. Starting the associated tasks.
+ INFO NodeHandler:
+ INFO NodeHandler: Shutting down experiment, please wait...
+ INFO NodeHandler:
+ INFO run: Experiment default_slice-2019-05-14t10.58.59.167-04.00 finished after 0:5
+}}}
+
+ 3. Load the ''baseline-sdr.ndz'' image onto the experiment server. This image has the UHD driver and other pertinent libraries  pre-installed. For this tutoral we'll use ''srv1-lg1.sb1.cosmos-lab.org'' as the experiment server.
+{{{
+console> omf load -i baseline-sdr.ndz -t srv1-lg1.sb1.cosmos-lab.org
+}}}
+
+ 4. After loading is complete turn on the experiment server. We'll also use the ''sdr1-lg1.sb1.cosmos-lab.org'' which is an N310 USRP. So turn this on as well.
+{{{
+console> omf tell -a on -t srv1-lg1.sb1.cosmos-lab.org,sdr1-lg1.sb1.cosmos-lab.org
+}}}
+
+ 5. Use the ''omf stat'' command again to verify ON/OFF status of the devices.
+{{{
+console> omf stat -t srv1-lg1.sb1.cosmos-lab.org,sdr1-lg1.sb1.cosmos-lab.org
+}}}
+
+
+ 7. Configure interface
+{{{
+ifconfig enp1s0 10.115.1.1 netmask 255.255.0.0 mtu 8000
+}}}
+
+ 6. Next ssh into the experiment server and discover the USRP that we turned on. We'll need the ip address for this USRP; At the command line do a 'host sdr1-lg1.sb1.cosmos-lab.org' to find its ip address. Then run ''uhd_find_devices'' with the --args option to discovery the USRP.
+{{{
+native@localhost:~$ host sdr1-lg1.sb1.cosmos-lab.org
+sdr1-lg1.sb1.cosmos-lab.org has address 10.113.2.1
+
+native@localhost:~$ uhd_find_devices --args="addr=10.113.2.1"
+
+<<some output here>>>
+}}}
+
+=== Explain ''rx_multi_receive'' application and how to use ===
+Navigate to the ~/RX_MULTI_RECEIVE directory - this contains the files that build the ''rx_multi_receive'' application.
+This is a c++ application that can be run on the experiment server to collect a set of continuous samples.
+
+Use the --help option to display all the variables ''rx_multi_receive'' accepts.
+{{{
+root@node20-1:~/RX_MULTI_RECEIVE# ./rx_multi_receive --help
+linux; GNU C++ version 4.8.4; Boost_105400; UHD_003.010.001.001-0-unknown
+
+UHD RX Multi Receive Allowed options:
+  --help                        help message
+  --args arg                    single uhd device address args
+  --secs arg (=1.5)             number of seconds in the future to receive
+  --nsamps arg (=10000)         total number of samples to receive
+  --freq arg (=900000000)       RF center frequency in Hz for all channels
+  --rate arg (=6250000)         rate of incoming samples for all channels
+  --gain arg (=0)               gain for the RF chain for all channels
+  --ant arg                     rx antenna selection for all channels
+  --prefix arg                  enables file output with filename prefix
+  --addr arg                    udp address: 10.10.0.10
+  --port arg (=1337)            udp port: 1337
+  --sync arg (=now)             synchronization method: now, pps, mimo
+  --subdev arg                  subdev spec (homogeneous across motherboards)
+  --dilv                        specify to disable inner-loop verbose
+  --int-n                       tune USRP with integer-N tuning
+  --channels arg (=0)           which channel(s) to use (specify "0", "1",
+                                "0,1", etc)
+  --oml-id arg                  OML sender ID - pass the hostname here
+  --oml-domain arg (=omlcli)    file name for OML database
+  --oml-collect arg (=oml:3003) Storage options:
+                                 network: <server:port>
+                                 local text file: <file:my_file_name>
+}}}
+
+To use ''rx_multi_receive'' standalone on an experiment server we can using the following options
+{{{
+root@node20-1:~/RX_MULTI_RECEIVE# ~/RX_MULTI_RECEIVE/rx_multi_receive --args="addr0=10.10.23.5" --freq 2440e6 --rate 20e6 --gain 3
+ --nsamps 1024000 --channels "0" --dilv
+}}}
+
+ --args="addr0=10.10.23.5" specifies the SDR's IP address.
+ --freq 2440e6             sets the center freq
+ --rate 20e6               sets sampling rate
+ --gain 3                  sets receive path gain
+ --nsamps 1024000          number of samples to collect
+
+Executing the application with only the above options will only configure the USRP's radio parameters and read in the specified nu
+mber of samples. However the samples will be lost once the application exits. You should see output similar to the following.
+{{{
+
+linux; GNU C++ version 4.8.4; Boost_105400; UHD_003.010.001.001-0-unknown
+
+
+Creating the usrp device with: addr0=10.10.23.5...
+-- X300 initialization sequence...
+-- Determining maximum frame size... 7972 bytes.
+-- Setup basic communication...
+-- Loading values from EEPROM...
+-- Setup RF frontend clocking...
+-- Radio 1x clock:200
+
+:
+:
+:
+
+Using Device: Single USRP:
+  Device: X-Series Device
+  Mboard 0: X310
+  RX Channel: 0
+    RX DSP: 0
+    RX Dboard: A
+    RX Subdev: UBX RX
+  TX Channel: 0
+    TX DSP: 0
+    TX Dboard: A
+    TX Subdev: UBX TX
+  TX Channel: 1
+    TX DSP: 0
+    TX Dboard: B
+    TX Subdev: UBX TX
+
+Number mboards        = 1
+Number of rx channels = 1
+Setting RX Rate: 20.000000 Msps...
+Actual RX Rate: 20.000000 Msps...
+
+Setting RX Freq: 2440.000000 MHz...
+Actual RX Freq: 2440.000000 MHz...
+
+Setting RX Gain: 3.000000 dB...
+Actual RX Gain: 3.000000 dB...
+
+Setting device timestamp to 0...
+channel_nums.size() = 1
+
+UHD Warning:
+    For this connection, UHD recommends a send frame size of at least 8000 for best
+    performance, but your system's MTU will only allow 7972.
+    This will negatively impact your maximum achievable sample rate.
+
+UHD Warning:
+    For this connection, UHD recommends a receive frame size of at least 8000 for best
+    performance, but your system's MTU will only allow 7972.
+    This will negatively impact your maximum achievable sample rate.
+
+Begin streaming 1024000 samples, 1.500000 seconds in the future...
+samps_per_buff = 1024
+num_buff_ptrs = 1000
+mdbp_idx = 1000
+
+Done!
+
+}}}
+
+To save the samples for post processing, specify the following OML arguments
+ --oml-id `hostname`          this identifies the source of the data being store.
+ --oml-domain rx_samples     file name for the OML database
+ --oml-collect oml:3003       network storage located on oml:3003
+
+
+Rerun the application with these and we'll see a few additional lines of output at the end indicating a connection to the OML database server.
+
+{{{
+
+Writing FFT blocks into rx_samples.sq3 @ oml:3003
+May 13 21:36:18 INFO    OML Client V2.10.1rc [Protocol V4] Copyright 2007-2013, NICTA
+INFO    OmlNetOutStream: attempting to connect to server at tcp://oml:3003
+INFO    tcp:oml:3003: Waiting for buffered queue thread to drain...
+
+}}}
+
+
+=== Instrumenting ''rx_multi_receive'' application with OML ===
+The source file for this application is in ~/RX_MULTI_RECEIVE/main.cpp. Without going into the details off c++ and the enitire contents of the source file, we'll make note of the following blocks of code:
+
+ 1. Lines xxx creates a handle to the USRP at the specified IP address. This handle is used thoughout the source to make reference to the radio.
+ 2. Lines xxx uses the handle to configure the radio paramters passed in from the command line.
+ 3. The read loop on lines xxx to xxx. This block reads out the complex floating samples into a buffer that is used for post processi
+ng samples.
+ 4. Lines xxx to xxx are OML additions made to send the FFTed sample data to the OML server for storage.
+
+ In side this block, we create an object that performs 1024pt FFTs.
+{{{
+   std::vector<std::complex<float> > time_buff( samps_per_buff );
+   std::vector<std::complex<float> > freq_buff( samps_per_buff );
+   std::vector<float>                signal_mag_instant( samps_per_buff );
+
+   fftwf_plan fft_p = fftwf_plan_dft_1d( samps_per_buff,
+                                         (fftwf_complex*)&time_buff.front(),
+                                         (fftwf_complex*)&freq_buff.front(),
+                                         FFTW_FORWARD,
+                                         FFTW_ESTIMATE);
+}}}
+
+ We also contruct an object for writing data to an OML server. Initialized the OML object with the OML options described above.
+{{{
+      // OML object for sending data
+      CWriteOml oml;
+      oml.init(oml_id, oml_domain, oml_collect );
+}}}
+
+ Create keyed-values that will be sent for storage. Here we specify a string label with an OML type. After all the keyed-value pairs have been defined, we start a connection with the OML service.
+ {{{
+       std::vector< std::pair<std::string, OmlValueT> > _omlKeys;
+      //                                 string label        OML type
+      _omlKeys.push_back( std::make_pair("mboard_id",        OML_STRING_VALUE));
+      _omlKeys.push_back( std::make_pair("mboard_serial",    OML_STRING_VALUE));
+      _omlKeys.push_back( std::make_pair("mboard_name",      OML_STRING_VALUE));
+      _omlKeys.push_back( std::make_pair("rx_id",            OML_STRING_VALUE));
+      _omlKeys.push_back( std::make_pair("rx_subdev_name",   OML_STRING_VALUE));
+      _omlKeys.push_back( std::make_pair("rx_subdev_spec",   OML_STRING_VALUE));
+      _omlKeys.push_back( std::make_pair("rx_ant",           OML_STRING_VALUE));
+
+      _omlKeys.push_back( std::make_pair("channel",          OML_UINT32_VALUE));
+      _omlKeys.push_back( std::make_pair("total_samps",      OML_UINT32_VALUE));
+      _omlKeys.push_back( std::make_pair("sample_size",      OML_UINT32_VALUE));
+
+      _omlKeys.push_back( std::make_pair("rx_freq",          OML_DOUBLE_VALUE));
+      _omlKeys.push_back( std::make_pair("rx_rate",          OML_DOUBLE_VALUE));
+      _omlKeys.push_back( std::make_pair("rx_gain",          OML_DOUBLE_VALUE));
+      _omlKeys.push_back( std::make_pair("SizeFFT",          OML_UINT32_VALUE));
+      _omlKeys.push_back( std::make_pair("Bins",             OML_BLOB_VALUE));
+
+      oml.start( _omlKeys );
+ }}}
+
+ After the OML start has been issued we can set the keyed-value pairs with updated values from sensors. In this section the FFT is
+ performed on chunk of 1024 comoplex samples and the magnitude is computed. These get stored in the OML as binary data (oml_blob).
+ Once all the keyed-valued pairs are updated with set_key(), they are sented over to the OML server by issuing the insert command.
+ This is done repeatedly until the entire buffer has been processed.
+ {{{
+        oml.set_key("rx_id",            (void*)usrp_info["rx_id"].c_str() );
+        oml.set_key("rx_subdev_name",   (void*)usrp_info["rx_subdev_name"].c_str() );
+        oml.set_key("rx_subdev_spec",   (void*)usrp_info["rx_subdev_spec"].c_str() );
+        oml.set_key("rx_ant",           (void*)usrp_info["rx_ant"].c_str() );
+
+        d64 = (double)(usrp->get_rx_freq() / 1e6);
+        oml.set_key("rx_freq", (void*)&d64);
+
+        unsigned int nfftBlocks = MultiDeviceBuffer.at(ch).size() / samps_per_buff;
+        for (unsigned int j = 0; j < nfftBlocks; j++)
+        {
+          // copy samples into time_buff for FFT
+          memcpy((void*)time_buff.data(),
+                 (void*)(MultiDeviceBuffer.at(ch).data() + j*samps_per_buff ),
+                 samps_per_buff * sizeof(std::complex<float>) );
+
+          // Execute FFT. This performs fft on time_buff samples and store results in freq_buff.
+          fftwf_execute(fft_p); // FWD FFT is NOT normalized so div by N.
+
+          // compute magnitude
+          for(unsigned int z = 0; z < signal_mag_instant.size(); z++)
+            signal_mag_instant.at(z) = abs(freq_buff.at(z));
+
+          // save the magnitude values as an OML blob
+          oml.set_key_blob("Bins",(void*)&signal_mag_instant.front(),
+                           (unsigned int)signal_mag_instant.size() * sizeof(float) );
+
+          // Send OML measurement to OML server
+          oml.insert();
+        }
+
+        //oml.stop();  // Don't need this since it is called in the destructor.
+ }}}
+
+ Once this block completes the connection to the OML server is taken down and no more data can be stored into the database.
+
+
+=== View results from OML database ===
+
+The database  is store in /var/lib/oml2 of the console. Use the command line front-end tool (sqlite3) to query the database direct
+ly especially for binary data. For a detailed overview on sqlite3 CLI please refer ​http://www.sqlite.org/cli.html.
+
+An application has been made to parse this database. This application is very specific to this tutorial. If the format of the data
+base table changes, the application may no longer be able to parse the database file.
+Display all the tables in the database.
+{{{
+console> ./db_parse --file /var/lib/oml2/rx_multi_samples.sq3 --showtables
+
+name = _senders
+
+name = _experiment_metadata
+
+name = _mp__rx_multi_samples
+
+Use following command to retrieve contents of table.
+./db_parse --file /var/lib/oml2/rx_multi_samples.sq3 --exec "SELECT * FROM <table>"
+
+To retrieve contents of the blob:
+./db_parse --file /var/lib/oml2/rx_multi_samples.sq3 --blob2bin ch0_data.bin --ch 0 --table  _mp__rx_multi_samples --key Bins
+
+}}}
+
+
+We can recover the contents of the FFT data for each channel and save them into a binary file for viewing in octave.
+{{{
+console> ./db_parse --file /var/lib/oml2/rx_multi_samples.sq3 --blob2bin ch0_data.bin --ch 0 --table  _mp__rx_multi_samples --key
+Bins
+
+Executing query statement
+select LENGTH(Bins),Bins from _mp__rx_multi_samples where channel=0
+}}}
+
+In the console we should have a binary file by the name ch0_data.bin. This can be loaded and viewed in ocatve.
+{{{
+octave> mag0 = fReadBinaryFile('ch0_data.bin','single');
+octave> mag0 = reshape(mag0, 1024, length(mag0)/1024);
+octave> image(mag0*1000)
+}}}
+
+Upload image of mag0...
+