While 4G devices offer better network coverage and longer battery life than older 2G and 3G devices, provisioning them is typically more difficult. On a 2G or 3G device, basic network registration can always be achieved simply by inserting an active sim card. Internet connectivity can then be established by sending the correct APN details via SMS. However, on 4G devices, network registration and internet connectivity are established simultaneously, so the APN details must be correct before registration can occur. Additionally, the network technology (Cat-M1 / NB-IoT) and bands should be set ensure fast network acquisition. If these are not set, the modem may timeout while scanning the enormous NB-IoT bands, which can take over 20 minutes and waste significant battery power.

Digital Matter's 4G devices can recognize the sim cards of many popular networks, and automatically apply the correct settings to establish initial connectivity. However, some sims will not be automatically recognized, and we always recommend manually setting the APN if possible.

The network settings are configured through the Admin Parameters. If the device is already connecting to the network, the Admin Parameters can be changed (carefully!) on devicemanager.digitalmatter.com. If the device is not yet connecting, the APN details can be configured via a specially prepared SIM card, or the complete 4G Network settings can be configured using the wired Provisioning Tool.

Please take special care when using the website to change the parameters, and always test them on a single device before rolling changes out to multiple devices, as mistakes can only be fixed through physical intervention with the Provisioning Tool.

Set 4G Network Parameters

Components of the 4G Network Settings

The '4G Radio Access Technology' setting only applies to older v1.x firmware. In the default, automatic mode, the device will try registering to the network on both CAT-M1 and NB-IoT, trying CAT-M1 first. If it successfully registers using either technology, it will not try the other technology again until the device fails to register, or a new sim card is inserted. This setting is ignored in newer firmware, but is still available for use when updating older devices. There is no way to control which bands are enabled in older v1.x firmware.

The '4G Network' setting allows you to choose a preset network profile, leaving the Custom Network field blank. This sets the enabled bands, the enabled radio access technologies, and the default APN details. You can still override the APN details using the 'Fixed APN' Admin Parameter tab.

Choosing 'Custom' in the '4G Network' dropdown enables the 'Custom Network' setting. This allows you to specify all aspects of the network profile in a flexible configuration string.

Custom Network Strings

The custom network string is a comma separated list of network options. For example, the string n8+28,x,Aiot chooses NB-IoT on bands 8 and 28, using the PCO message for DNS, with a default APN of iot. Please note that the custom string is case sensitive. If your network isn't available in the dropdown list, and you are not sure how to choose a custom network string, please contact your distributor for help.

Setting The Band Mask

• You can choose use either Cat-M1 only, NB-IoT only, or both technologies, with one prioritized
• If you choose to use both, you can either specify the bands together (i.e., mn1+2+5) or separately (i.e., m1+2+5,n28)
• You shouldn't enable more than 2 or 3 NB-IoT bands simultaneously, as they take 2 or 3 minutes each to scan
• If you enable too many NB-IoT bands, and set a short registration timeout in your System Parameters, you may lose network connectivity intermittently when the scans time out
• If you don't need NB-IoT, you should disable it, as NB-IoT connections can be very slow and may make firmware updates difficult
• The SARA-R4 chipset used in most current 4G products supports bands 1, 2, 3, 4, 5, 8, 12, 13, 18, 19, 20, 26, and 28

Setting The APN Defaults

• You can specify the default APN name, username, and password
• These are used if the 'Fixed APN' tab in the Admin Parameters is left blank
• Any values you don't specify will use a blank value by default
• Many networks accept a blank APN, but we recommend explicitly setting the APN if possible

Circuit Switched Mode

• Most 4G IoT networks don't support SMS, but some Cat-M1 networks do
• Where supported, you generally have to enable Circuit Switched mode to get SMS reception
• However, if you attempt to enable it, and the network doesn't support it, your device won't register
• We recommend leaving it disabled

PCO / ePCO

• The Protocol Configuration Options and Extended Protocol Configuration Options messages are used by the network to establish DNS settings when a device registers
• Most networks use the ePCO, but some still require the non-standard PCO
• If your device registers, but can't connect to servers specified by domain name, you may need to use the PCO
• Selecting the PCO using the 'x' option will only take effect if your device's modem has been updated to the latest internal hardware network profiles
• This can be done with the wired Provisioning Tool, as described in this article

eDRX

• eDRX is a new feature in Cat-M1 and NB-IoT networks, that lowers the idle power consumption of the modem at the expense of increasing its latency
• It is only useful in applications where the modem is powered continuously, and can cause compatibility issues on some networks, so it is disabled by default
• When enabling eDRX, an eDRX interval between 0 and 15 can be supplied, as per 3GPP TS 24.008
• If no number is supplied, the default value is 2, so e and e2 are equivalent
• We recommend leaving it off, even if your network supports it

Hardware Profiles

• The modem has a number of internal hardware network profiles that apply settings similar to those shown here
• When you choose settings using the custom network string or a preset, they are applied on top of a default hardware network profile (hardware profile 100)
• However some networks require settings that can only be achieved using a special hardware profile (for instance the Verizon preset uses hardware profile 3)
• The exact mix of settings in these profiles is known only to the modem manufacturer
• Do not set a hardware profile unless advised to by our support team