WiFi Indoor Location Device (WILD) software
Contents
Overview
The Wi-Fi location technology is based on a protocol specified in 802.11mc-FTM (IEEE 802.11mc-2016 technical Specification) which defines the Fine-Timing-Measurement (FTM) procedure between a mobile device (FTM initiator) and a network infrastructure device (FTM responder / FTMR)
The protocol allows:
- Initiator to exchange FTM packets without the need to be associated with a Wi-Fi Access Point.
- Co-existance of SoftAP functionality and FTM ranging in both initiator and responder.
Hardware platform
WILD is based on Compulab fitlet2 with Intel AC8260 WiFi module
Getting started
Deployment
CopmpuLab provides a raw image that can be deployed onto the following bootable media.
- SD-Card
- USB flash disk
- Internal SATA SSD / HDD (not covered by this man page)
- Internal eMMC (not covered by this man page)
CompuLab installation procedure must be invoked in order to deploy the image onto a removable media.
- Download the latest WILD image - see WILD revision notes and consult associated readme.
- To deploy on a desktop PC:
| OS | How To |
|---|---|
|
Linux |
udevadm monitor --subsystem-match=block --kernel
udevadm monitor --subsystem-match=block monitor will print the received events for: UDEV - the event which udev sends out after rule processing KERNEL - the kernel uevent KERNEL[37893.873104] add /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/host3/target3:0:0/3:0:0:0/block/sdc (block) KERNEL[37893.873136] add /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/host3/target3:0:0/3:0:0:0/block/sdc/sdc1 (block) KERNEL[37893.873161] add /devices/pci0000:00/0000:00:14.0/usb3/3-3/3-3:1.0/host3/target3:0:0/3:0:0:0/block/sdc/sdc2 (block)
Important: xz -dc /path/to/4G-wild.img.xz | sudo dd of=/dev/sdc bs=1M status=progress Important: |
|
Windows |
Make use of Rufus. Refer to the vendor site for details: https://rufus.akeo.ie/ |
Boot
- Allow the device to boot from the bootable FTM media.
- Login with one of the default users:
| User Name | Password | |
|---|---|---|
|
compulab |
compulab |
- To acquire root credentials:
sudo -i
ftm-services
- Intro
ftm-services is a set of the CompuLab scripts for managing FTM devices.
- History
| WILD Version | Description | |
|---|---|---|
|
< 0.70 |
Delivered as a set of services installed onto the rootfs, but w/out being registered as a deb package in the Debian package manager. |
|
|
>= 0.70 |
Starting from the 0.70 version these services come as a deb package with the same name. |
- Install/Update procedure
cd /tmp wget https://www.fit-iot.com/files/download/wild/0.7.2/ftm-services_0.7.2.deb sudo dpkg -i /tmp/ftm-services_0.7.2.deb
Commands
wild
This is an FTM management command. Refer to the command man page for details. wild command is available in WILD version 0.7 and later.
man wild
Get WILD version
wild -v
Set WILD to initiator mode
wild -mi
Set WILD to responder mode
wild -mr
Set WILD to off mode
wild -mo
Neither initiator or responder commands are available in this mode.
ftm-role (depreciated)
ftm-options
When in client mode, scan responders and enable / disable specific responders for ranging requests
ftm-options
ftm-show
- Client: show the results of ranging request.
- Responder: show the FTM requests statistics.
ftm-show
FTMR (FTM Responder)
Configuration files
hostapd configuration file
- /etc/hostapd.conf
Used for setting FTMR properties e.g.
- SSID - to brodcast when in responder mode
- Channel and bandwidth
Change channel bandwidth
| 80MHz | 40MHz | 20MHz |
|---|---|---|
|
ieee80211ac=1 |
ieee80211ac=0 |
ieee80211ac=0 |
Change band
| 2.4GHz | 5.0GHz |
|---|---|
|
hw_mode=g |
hw_mode=a |
For more information about the hostapd.conf parameters refer to: https://w1.fi/cgit/hostap/plain/hostapd/hostapd.conf
Configuration Manual
For more information refer to: FTMr configuration
FTMR Network Configuration
- Interfaces
The device network configuration described by /etc/network/interfaces
Below is an configuration example that configures the br0 at the boot time.
# interfaces(5) file used by ifup(8) and ifdown(8) # Include files from /etc/network/interfaces.d: source-directory /etc/network/interfaces.d auto lo iface lo inet loopback # closest to the edge # a spare network interface (can be disconnected) # Roles: # 1: a generic network interface auto enp2s0 allow-hotplug enp2s0 iface enp2s0 inet manual # closest to the power plug # Roles: # 1: a part of bridge # 2: a generic network interface auto enp3s0 allow-hotplug enp3s0 iface enp3s0 inet dhcp auto wlan0 allow-hotplug wlan0 iface wlan0 inet manual # Bridge Setup # This is a bridge interface # gets turned on when device is a responder # auto br0 iface br0 inet dhcp bridge_ports wlan0 enp3s0
- Bridge configuration
Make use of the brctl for details.
brctl show
bridge name bridge id STP enabled interfaces
br0 8000.0001c01fd60c no enp3s0
wlan0
FTMR Backhaul
All FTM device has two wired interfaces.
Important:
The wired interfaces configured as auto & dhcp must be connected to the LAN at the boot time.
Otherwise the device will experience a boot delay.
FTMR SoftAP
Intel 8260 can work as an FTMR & a SoftAP simultaneously.
SoftAP services
There are two services that must be configured & run in order to provide the SoftAP functionality:
- bridge
FTM bridge service is in charge of configuring a bridge between wlp1s0 (i8260) and enp3s0 interfaces.
It allows all wireless interface requests to get forwarded to the enp3s0.
The enp3s0 interface must be connected to the LAN.
FTM bridge service starts automatically while in responder mode. In order to control it manually: start/stop/status/disable, issue:
systemctl start/stop/status/disable ftm-br
- hostapd
The hostapd daemon turns the device into a SoftAP while in a responder mode.
How to get connected to the SoftAP wireless network:
- Scan wireless networks;
- Try to get connected to a network with name COMPULAB_WILD password indoorlocation.
- In case that the bridge service is up and running the wireless clients will get connected to the LAN.
SoftAP know issues:
- The backhaul interface enp3s0 is down. Wireless clients can't get connected to the SoftAP. The client software reports on Connecting state.
- ftm-br service is stopped. Wireless clients can't get connected to the SoftAP. The client software reports on Connecting state.
FTMI (FTM Initiator)
FTM services configuration file (initiator/client mode)
- /opt/compulab/service/ftm-common
| Field | Description |
|---|---|
|
FTM_SSID |
List of the AP SSIDs to scan & send range requests when in client mode. Match condition 'FTM_SSID[x] ~ discovered_ssid'. For instance the hostapd.conf file SSID="COMPULAB-"+serial_number, then the FTM_SSID must be FTM_SSID="COMPULAB-". The match condition turns 'true' and client takes this responder into account. |
|
BW=80; TOF="bw=${BW} cf=5240 cf1=5210 spb=2 asap" |
Template of a TOF string. The ftm-range service makes use of this when in client mode. BW=80 works for both 40 MHz & 80 MHz bandwidth modes. BW=40 does not work at all. The client receives empty replies from the responders if BW=40. |
Transmit from FTMI list of scanned FTMRs and ranging results
- Configuration file: /opt/compulab/service/ftm-common
Contains the SERVERS list to send the scan results file :/opt/compulab/www/results.all
SERVERS=(http://localhost/cpl/curl.php http://wild-server/hard/curl.php)
- FTM ranged service: /opt/compulab/service/ftm-range.main
The service walks through the SERVERSs' list and send the scan results to each one:
for SERVER in ${SERVERS[@]};do
curl -d @${iw_scan}/results.all ${SERVER} &>/dev/null
done
