Outdoor spectrum usage and allocation

Description

Demonstrate outdoor spectrum usage and record measurements to Influx DB.

This example is split into two parts. First part will focus on outdoor spectrum usage and running a simple sdr application for data transfer on shared / non-federal frequency band. Second part will show how to record measured data and visualize statistics using Influx database and Graffinni.

Prerequisites

In order to access the test bed, create a reservation and have it approved by the reservation service. Access to the resources is granted after the reservation is confirmed. Please follow the process shown on the COSMOS getting started page to get started.

Resources utilized

• This example will use two x310 SDR on bed.cosmos-lab.org
  • sdr2-s3-lg1.bed.cosmos-lab.org as the transmitting SDR
  • sdr2-s2-lg1.bed.cosmos-lab.org as the receiving SDR
• baseline-uhd.ndz : operating system to load onto above resources.

• [RF control service] to configure the [RF front end's TX chain] on the transmitting SDR.

• ​Influx database - time series database supporting SQL-like queries.
• ​Grafana - a front end visualization and analytic tool for Influx database.

Steps

1. Sign up for a ​COSMOS account
2. Create a resource reservation on bed.cosmos-lab.org
3. Login to your reserved domain.
4. Load baseline-uhd.ndz on your resource. - this is done via OMF

First make sure the resources are turned off

user@console:~$ omf tell -a offh -t sdr2-s2-lg1.bed.cosmos-lab.org,sdr2-s3-lg1.bed.cosmos-lab.org

Load the resources with the image

user@console:~$ omf load -i baseline-uhd.ndz -t sdr2-s2-lg1.bed.cosmos-lab.org,sdr2-s3-lg1.bed.cosmos-lab.org

Turn on the resources

user@console:~$ omf tell -a on -t sdr2-s2-lg1.bed.cosmos-lab.org,sdr2-s3-lg1.bed.cosmos-lab.org

5. Download the application source code from the attachment section below.

   user@console:~$ UPDATE wget https://wiki.cosmos-lab.org/raw-attachment/wiki/tutorials/basic_usage/spectrum_view.tar.gz
   user@console:~$ UPDATE tar -zxvf spectrum_view.tar.gz
   user@console:~$ UPDATE cd SPECTRUM_VIEW
   

Configure transmitter and receive SDRs

Most of this part is scripted via the Makefile. This is to simplify the download and installation of the required libraries onto the resources so we don't have to go back and forth between the console and the resource node.

6. Set up the transmit side.
   Open a terminal and equate the enviroment variable (NODE) to specify the transmitting SDR.

   user@console:~$ export NODE=sdr2-s3-lg1.bed.cosmos-lab.org
   

Next the following make commands are run on the above NODE. This should install all the dependencies to make the sdr application: sdrapp

user@console:~$ make remote-install-deps
user@console:~$ make remote-install-websocket
user@console:~$ make remote-make

Now ssh into the NODE and run sdrapp

user@console:~$ ssh root@$NODE
root@sdr2-s3-lg1:~# cd SDRAPP/build/
root@sdr2-s3-lg1:~/SDRAPP/build# ./sdrapp --cmd "make resource=rio0"

7. Set up the receiving side.
   This is exactly the same as the above step but the environment variable NODE points to a different resource.

Open a terminal again and equate the environment variable (NODE) to specify the receiving SDR.

user@console:~$ export NODE=sdr2-s2-lg1.bed.cosmos-lab.org

Next the following make commands are run on the above NODE. This should install all the dependencies to make the sdr application: sdrapp

user@console:~$ make remote-install-deps
user@console:~$ make remote-install-websocket
user@console:~$ make remote-make

Now ssh into the NODE and run sdrapp

user@console:~$ ssh root@$NODE
root@sdr2-s3-lg1:~# cd SDRAPP/build/
root@sdr2-s3-lg1:~/SDRAPP/build# ./sdrapp --cmd "make resource=rio0"

Note: Keep track of these two terminals.

8. Configure the transmit antenna using the RF Control service. Please check here for more details on the service.

Open another terminal - this is the 3rd terminal. First we'll configure the TX path, power amplifier and frequency ranges for the transmitting side.

Get current configuration

user@console:~$ curl "am1.cosmos-lab.org:5054/rf_control/get_tx_path?node=sdr2-s3-lg1.bed.cosmos-lab.org"

<response status="OK">
  <nodes>
    <node name="sdr2-s3-lg1.bed.cosmos-lab.org">
      <rf_port number="0" antenna="1" connected="true" power_amp="OFF" f_lower="2350" f_upper="2800"/>
      <rf_port number="1" antenna="3" connected="true" power_amp="OFF" f_lower="2350" f_upper="2800"/>
    </node>
  </nodes>
</response>

Turn on the power amplifier and set frequency appropriately. Check the Outdoor frequency allocation table for acceptable frequency bands. In this example a center frequency of 2600MHz is used.

user@console:~$ curl "am1.cosmos-lab.org:5054/rf_control/set_tx_path?node=sdr2-s3-lg1.bed.cosmos-lab.org&rf_port=0&power_amp=on&f_lower=2500&f_upper=2680"

9. Execute the run script to configure and stream both SDRs for receiving and transmitting bursts of packet data.

View the run_data_script.sh script

user@console:~$ cat run_data_script.sh

user@console:~$ sh run_data_script.sh

The script configures sdr application with radio paramenters and begins streaming packets for a few seconds. As long as everything is working fine the script will exit out but the sdr applications will continue to stream packets for a few seconds.

On the transmit side the output should have rows of INFO statements similar to the following.

:
[INFO] [tx_data_link_0]   [sent]   seq_num: 62  pkt_len: 29
[INFO] [tx_data_link_0]   [sent]   seq_num: 63  pkt_len: 8
[INFO] [tx_data_link_0]   [sent]   seq_num: 64  pkt_len: 49
[INFO] [tx_data_link_0]   [sent]   seq_num: 65  pkt_len: 42
[INFO] [tx_data_link_0]   [sent]   seq_num: 66  pkt_len: 63
[INFO] [tx_data_link_0]   [sent]   seq_num: 67  pkt_len: 34
[INFO] [tx_data_link_0]   [sent]   seq_num: 68  pkt_len: 2
:
[INFO] [tx_data_link_0] Transmit complete - summary:
[INFO] [tx_data_link_0] --raw packets:   80 / 21760 bytes
[INFO] [tx_data_link_0] Exitting
:

On the receive side a similar output is expected

:
[INFO] [rx_data_link_0]   [rcvd]  pkt: OK  seq_num: 55  pkt_len: 18  corr_strength: 18131.3
[INFO] [rx_data_link_0]   [rcvd]  pkt: OK  seq_num: 56  pkt_len: 15  corr_strength: 18124.4
[INFO] [rx_data_link_0]   [rcvd]  pkt: OK  seq_num: 57  pkt_len: 3  corr_strength: 18132.9
[INFO] [rx_data_link_0]   [rcvd]  pkt: OK  seq_num: 58  pkt_len: 53  corr_strength: 18148.1
[INFO] [rx_data_link_0]   [rcvd]  pkt: OK  seq_num: 59  pkt_len: 2  corr_strength: 18128.3
[INFO] [rx_data_link_0]   [rcvd]  pkt: OK  seq_num: 60  pkt_len: 34  corr_strength: 18161.1
[INFO] [rx_data_link_0]   [rcvd]  pkt: OK  seq_num: 61  pkt_len: 62  corr_strength: 18135.7
[INFO] [rx_data_link_0]   [rcvd]  pkt: OK  seq_num: 62  pkt_len: 29  corr_strength: 18164.7
:
[INFO] [rx_data_link_0] Receive complete - summary:
[INFO] [rx_data_link_0] --raw packets:   79 / 21488 bytes
[INFO] [rx_data_link_0] Avg correlation threshold of successful detections: 18148.4
[INFO] [rx_data_link_0] Exitting
:

10. Lastly turn off the RF frontend with the following command.

    user@console:~$ curl "am1.cosmos-lab.org:5054/rf_control/set_tx_path?node=sdr2-s3-lg1.bed.cosmos-lab.org&rf_port=0&power_amp=off"
    

11. Execute the run script again and verify that no packets are being received.

In the [next part of this tutorial] we'll add onto the receiving sdr application and recording measured data into Influx Db.