Connect Azure Percept DK over 5G or LTE by using a Quectel RM500-GL 5G modem

This article discusses how to connect Azure Percept DK over 5G or LTE by using a Quectel RM500-GL 5G modem.

For more information about this 5G modem dev kit, contact your Quectel local sales team:

  • For North American customers: northamerica-sales@quectel.com
  • For global customers: sales@quectel.com

Note

About USB cables for 5G modems:
5G modems require more power than LTE modems, and the wrong USB cable can be a bottleneck to realizing the best possible 5G data rates. To supply sufficient, consistent power to a 5G modem, make sure that the USB cable meets the following standards:
Power:

  • Max amperage should be equal to or greater than 3 amperes.
  • The cable length should be less than 1 meter.
  • When you use a 5G modem, only one USB A port on Azure Percept DK should be active.

Throughput:

  • USB 3.1 Gen2
  • USB-IF certified

Prepare to connect Azure Percept DK

To learn how to prepare Azure Percept DK, go to Connect Azure Percept DK over 5G or LTE networks by using a USB modem. Be sure to note the comments about the USB cables that should be used.

Prepare the modem

Before you begin, your modem must be in Mobile Broadband Interface Model (MBIM) mode. An undocumented but standard Quectel Attention (AT) command can be used for this: AT+QCFG="usbnet".

The usbnet property can be set to four different values, from 0 to 3:

  • 0 for NDIS / PPP / QMI mode (supported by qmi_wwan driver, enabled with CONFIG_USB_NET_QMI_WWAN=y|m)
  • 1 for CDC Ethernet mode (supported in Linux when CONFIG_USB_NET_CDCETHER=y|m)
  • 2 for MBIM mode (supported in Linux when CONFIG_USB_NET_CDC_MBIM=y|m)
  • 3 for RNDIS mode

The easiest way to configure the mode is to connect the Quectel 5G modem to a PC and use terminal software, such as TeraTerm, or Quectel's own PC software, such as QCOM. You can use Windows Device Manager to see which USB port is assigned for the modem. The COM port settings should be:

  • Baud rate: 115200
  • Stop bits: 1
  • Parity: None
  • Byte size: 8
  • Flow control: No control flow

Here are the AT commands:

To check to see which USB mode Quectel device is currently running, use:

AT+QCFG="usbnet"

To change to mode 2, use:

AT+QCFG="usbnet",2

If you check again by using the first AT command, you should get:

+QCFG: "usbnet",2`

After you've set the correct USB mode, issue a hardware reset by using:

AT+CFUN=1,1

At this point, the modem should disconnect and later reconnect to the USB port.

Use the modem to connect

  1. Put a SIM card in the Quectel modem.

  2. Plug the Quectel modem into the Azure Percept DK USB port. Be sure to use a proper USB cable.

  3. Power up Azure Percept DK.

  4. Ensure that ModemManager is running.

    systemctl status ModemManager
    

    If you're successful, you'll get a result that's similar to the following:

    * ModemManager.service - Modem Manager
       Loaded: loaded (/lib/systemd/system/ModemManager.service; enabled; vendor pre set: enabled)
       Active: active (running) since Mon 2021-08-09 20:52:03 UTC; 23s ago
    [...]
    

    If you're unsuccessful, make sure that you've flashed the correct image to Azure Percept DK (5G enabled).

  5. List the active modems.

    When you list the modems, you'll see that the Quectel modem has been recognized and is now handled by ModemManager.

    mmcli --list-modems
    

    You should get a result that's similar to the following:

    /org/freedesktop/ModemManager1/Modem/0 [Quectel] RM500Q-GL
    

    The modem ID here is 0, which is used in the following commands to address it (that is, --modem 0).

  6. Get the modem details.

    By default, the modem is disabled (Status -> state: disabled). To view the status, run:

    mmcli --modem 0
    

    You should get a result that's similar to the following:

    General  |                    path: /org/freedesktop/ModemManager1/Modem/0
             |               device id: 8e3fb84e3755524d25dfa6f3f1943dc568958a2b
    -----------------------------------
    Hardware |            manufacturer: Quectel
             |                   model: RM500Q-GL
             |       firmware revision: RM500QGLABR11A04M4G
             |          carrier config: CDMAless-Verizon
             | carrier config revision: 0A010126
             |            h/w revision: RM500Q-GL
             |               supported: gsm-umts, lte, 5gnr
             |                 current: gsm-umts, lte, 5gnr
             |            equipment id: xxxx
    -----------------------------------
    System   |                  device: /sys/devices/platform/soc@0/38200000.usb/xhci-hcd.1.auto/usb4/4-1/4-1.1
             |                 drivers: option, cdc_mbim
             |                  plugin: quectel
             |            primary port: cdc-wdm0
             |                   ports: cdc-wdm0 (mbim), ttyUSB0 (qcdm), ttyUSB1 (gps),
             |                          ttyUSB2 (at), ttyUSB3 (at), wwan0 (net)
    -----------------------------------
    Numbers  |                     own: +1xxxx
    -----------------------------------
    Status   |          unlock retries: sim-pin2 (3)
             |                   state: disabled
             |             power state: on
             |          signal quality: 0% (cached)
    -----------------------------------
    Modes    |               supported: allowed: 3g; preferred: none
             |                          allowed: 4g; preferred: none
             |                          allowed: 3g, 4g; preferred: 4g
             |                          allowed: 3g, 4g; preferred: 3g
             |                          allowed: 5g; preferred: none
             |                          allowed: 3g, 5g; preferred: 5g
             |                          allowed: 3g, 5g; preferred: 3g
             |                          allowed: 4g, 5g; preferred: 5g
             |                          allowed: 4g, 5g; preferred: 4g
             |                          allowed: 3g, 4g, 5g; preferred: 5g
             |                          allowed: 3g, 4g, 5g; preferred: 4g
             |                          allowed: 3g, 4g, 5g; preferred: 3g
             |                 current: allowed: 3g, 4g, 5g; preferred: 5g
    -----------------------------------
    Bands    |               supported: utran-1, utran-3, utran-4, utran-6, utran-5, utran-8,
             |                          utran-2, eutran-1, eutran-2, eutran-3, eutran-4, eutran-5, eutran-7,
             |                          eutran-8, eutran-12, eutran-13, eutran-14, eutran-17, eutran-18,
             |                          eutran-19, eutran-20, eutran-25, eutran-26, eutran-28, eutran-29,
             |                          eutran-30, eutran-32, eutran-34, eutran-38, eutran-39, eutran-40,
             |                          eutran-41, eutran-42, eutran-43, eutran-46, eutran-48, eutran-66,
             |                          eutran-71, utran-19
             |                 current: utran-1, utran-3, utran-4, utran-6, utran-5, utran-8,
             |                          utran-2, eutran-1, eutran-2, eutran-3, eutran-4, eutran-5, eutran-7,
             |                          eutran-8, eutran-12, eutran-13, eutran-14, eutran-17, eutran-18,
             |                          eutran-19, eutran-20, eutran-25, eutran-26, eutran-28, eutran-29,
             |                          eutran-30, eutran-32, eutran-34, eutran-38, eutran-39, eutran-40,
             |                          eutran-41, eutran-42, eutran-43, eutran-46, eutran-48, eutran-66,
             |                          eutran-71, utran-19
    -----------------------------------
    IP       |               supported: ipv4, ipv6, ipv4v6
    -----------------------------------
    3GPP     |                    imei: xxxxxxxxxxxxxxx
             |           enabled locks: fixed-dialing
    -----------------------------------
    3GPP EPS |    ue mode of operation: csps-1
             |      initial bearer apn: ims
             |  initial bearer ip type: ipv4v6
    -----------------------------------
    SIM      |        primary sim path: /org/freedesktop/ModemManager1/SIM/0
    
  7. Enable the modem.

    Prior to establishing a connection, turn on the modem's radio or radios by running:

    mmcli --modem 0 --enable
    

    You should get a response that's similar to the following:

    successfully enabled the modem
    

    After some time, the modem should be registered to a cell tower, and you should see a modem status of Status -> state: registered after you run the following code:

    mmcli --modem 0
    
  8. Connect by using the access point name (APN) information.

    Usually, modems provide the APN to use (see 3GPP EPS -> initial bearer APN information), so you can use it to establish a connection. If the modem doesn't provide an APN, consult with your cell phone provider for the APN to use.

    Here is the ModemManager command for connecting by using, for example, the Verizon APN APN=vzwinternet.

    mmcli --modem 0 --simple-connect="apn=vzwinternet"
    

    Again, you should get a response that's similar to the following:

    successfully connected the modem
    
  9. Get the modem status.

    You should now see a status of Status -> state: connected and a new Bearer category at the end of the status message.

    mmcli -m 0
    
    -----------------------------------
    General  |                    path: /org/freedesktop/ModemManager1/Modem/0
             |               device id: 8e3fb84e3755524d25dfa6f3f1943dc568958a2b
    -----------------------------------
    Hardware |            manufacturer: Quectel
             |                   model: RM500Q-GL
             |       firmware revision: RM500QGLABR11A04M4G
             |          carrier config: CDMAless-Verizon
             | carrier config revision: 0A010126
             |            h/w revision: RM500Q-GL
             |               supported: gsm-umts, lte, 5gnr
             |                 current: gsm-umts, lte, 5gnr
             |            equipment id: xxx
    -----------------------------------
    System   |                  device: /sys/devices/platform/soc@0/38200000.usb/xhci-hcd.1.auto/usb4/4-1/4-1.1
             |                 drivers: option, cdc_mbim
             |                  plugin: quectel
             |            primary port: cdc-wdm0
             |                   ports: cdc-wdm0 (mbim), ttyUSB0 (qcdm), ttyUSB1 (gps),
             |                          ttyUSB2 (at), ttyUSB3 (at), wwan0 (net)
    -----------------------------------
    Numbers  |                     own: +1xxxx
    -----------------------------------
    Status   |          unlock retries: sim-pin2 (3)
             |                   state: connected
             |             power state: on
             |             access tech: lte
             |          signal quality: 12% (recent)
    -----------------------------------
    Modes    |               supported: allowed: 3g; preferred: none
             |                          allowed: 4g; preferred: none
             |                          allowed: 3g, 4g; preferred: 4g
             |                          allowed: 3g, 4g; preferred: 3g
             |                          allowed: 5g; preferred: none
             |                          allowed: 3g, 5g; preferred: 5g
             |                          allowed: 3g, 5g; preferred: 3g
             |                          allowed: 4g, 5g; preferred: 5g
             |                          allowed: 4g, 5g; preferred: 4g
             |                          allowed: 3g, 4g, 5g; preferred: 5g
             |                          allowed: 3g, 4g, 5g; preferred: 4g
             |                          allowed: 3g, 4g, 5g; preferred: 3g
             |                 current: allowed: 3g, 4g, 5g; preferred: 5g
    -----------------------------------
    Bands    |               supported: utran-1, utran-3, utran-4, utran-6, utran-5, utran-8,
             |                          utran-2, eutran-1, eutran-2, eutran-3, eutran-4, eutran-5, eutran-7,
             |                          eutran-8, eutran-12, eutran-13, eutran-14, eutran-17, eutran-18,
             |                          eutran-19, eutran-20, eutran-25, eutran-26, eutran-28, eutran-29,
             |                          eutran-30, eutran-32, eutran-34, eutran-38, eutran-39, eutran-40,
             |                          eutran-41, eutran-42, eutran-43, eutran-46, eutran-48, eutran-66,
             |                          eutran-71, utran-19
             |                 current: utran-1, utran-3, utran-4, utran-6, utran-5, utran-8,
             |                          utran-2, eutran-1, eutran-2, eutran-3, eutran-4, eutran-5, eutran-7,
             |                          eutran-8, eutran-12, eutran-13, eutran-14, eutran-17, eutran-18,
             |                          eutran-19, eutran-20, eutran-25, eutran-26, eutran-28, eutran-29,
             |                          eutran-30, eutran-32, eutran-34, eutran-38, eutran-39, eutran-40,
             |                          eutran-41, eutran-42, eutran-43, eutran-46, eutran-48, eutran-66,
             |                          eutran-71, utran-19
    -----------------------------------
    IP       |               supported: ipv4, ipv6, ipv4v6
    -----------------------------------
    3GPP     |                    imei: xxxxxxxxxxxxxxx
             |           enabled locks: fixed-dialing
             |             operator id: 311480
             |           operator name: Verizon
             |            registration: home
             |                     pco: 0: (partial) '27058000FF0100'
    
    -----------------------------------
    3GPP EPS |    ue mode of operation: csps-1
             |     initial bearer path: /org/freedesktop/ModemManager1/Bearer/0
             |      initial bearer apn: ims
             |  initial bearer ip type: ipv4v6
    -----------------------------------
    SIM      |        primary sim path: /org/freedesktop/ModemManager1/SIM/0
    -----------------------------------
    Bearer   |                   paths: /org/freedesktop/ModemManager1/Bearer/1
    
    
  10. Get the bearer details.

    The bearer resulting from the preceding step, --simple-connect, is at path /org/freedesktop/ModemManager1/Bearer/1.

    This is the bearer that we're querying for modem information about the active connection. The initial bearer isn't attached to an active connection and, therefore, holds no IP information.

    mmcli --bearer 1
    
    --------------------------------
    General            |       path: /org/freedesktop/ModemManager1/Bearer/1
                         |       type: default
    --------------------------------
    Status             |  connected: yes
                         |  suspended: no
                         |  interface: wwan0
                         | ip timeout: 20
    --------------------------------
    Properties         |        apn: fast.t-mobile.com
                         |    roaming: allowed
    --------------------------------
    IPv4 configuration |     method: static
                         |    address: 25.21.113.165
                         |     prefix: 30
                         |    gateway: 25.21.113.166
                         |        dns: 10.177.0.34, 10.177.0.210
                         |        mtu: 1500
    --------------------------------
    Statistics         |   attempts: 1
    

    Here are descriptions of some key details:

    • Status -> interface: wwan0: Lists which Linux network interface matches this modem.
    • IPv4 configuration: Provides the IP configuration for the preceding interface to set for it to be usable.
  11. Check the status of the modem network interface.

    By default, the network interface displays DOWN.

    ip link show dev wwan0
    

    You should get a result that's similar to the following:

    4: wwan0: <BROADCAST,MULTICAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
       link/ether ce:92:c2:b8:1e:f2 brd ff:ff:ff:ff:ff:ff
    
  12. Bring up the interface.

    sudo ip link set dev wwan0 up
    
  13. Check the IP information.

    By default, the interface displays UP,LOWER_UP, with no IP information.

    sudo ip address show dev wwan0
    
    4: wwan0: <BROADCAST,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
       link/ether ce:92:c2:b8:1e:f2 brd ff:ff:ff:ff:ff:ff
       inet6 fe80::cc92:c2ff:feb8:1ef2/64 scope link 
          valid_lft forever preferred_lft forever
    
  14. Issue a DHCP request.

    This feature is specific to, but not limited to, the Quectel module. The IP information is usually to be set manually to the interface or through a network manager daemon that supports ModemManager (for example, NetworkManager), but here you can simply use the dhclient on the Quectel modem:

    sudo dhclient wwan0
    
  15. Check the IP information.

    The IP configuration for this interface should match the ModemManager bearer details.

    sudo ip address show dev wwan0
    

    You should get a result that's similar to the following:

    4: wwan0: <BROADCAST,MULTICAST,NOARP,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN group default qlen 1000
       link/ether ce:92:c2:b8:1e:f2 brd ff:ff:ff:ff:ff:ff
       inet 25.21.113.165/30 brd 25.21.113.167 scope global wwan0
          valid_lft forever preferred_lft forever
       inet6 fe80::cc92:c2ff:feb8:1ef2/64 scope link 
          valid_lft forever preferred_lft forever
    
  16. Check the interface routes.

    Notice that the DHCP client also set a default route for packets to go through the wwan0 interface.

    ip route show dev wwan0
    

    You should get a result that's similar to the following:

    default via 25.21.113.166 
    25.21.113.164/30 proto kernel scope link src 25.21.113.165
    

    You've now established a connection to Azure Percept DK by using the Quectel modem!

  17. Test connectivity.

    Execute a ping request through the wwan0 interface.

    ping -I wwan0 8.8.8.8
    

    You should get a result that's similar to the following:

    PING 8.8.8.8 (8.8.8.8) from 25.21.113.165 wwan0: 56(84) bytes of data.
    64 bytes from 8.8.8.8: icmp_seq=1 ttl=114 time=137 ms
    64 bytes from 8.8.8.8: icmp_seq=2 ttl=114 time=114 ms
    ^C
    --- 8.8.8.8 ping statistics ---
    2 packets transmitted, 2 received, 0% packet loss, time 2ms
    rtt min/avg/max/mdev = 113.899/125.530/137.162/11.636 ms
    

Debugging

For general information about debugging, see Connect by using a USB modem.

Next steps

Depending on the cellular device you have access to, you can connect in one of two ways: