Device to Cloud General Info Low Power Features
Cellular-based iot can have a very low power footprint, expecially if the low power modes are exploited correctly. As explained in section “here link to mobile network information”, these low power modes can greatly reduce the power consumption.
Cellular-based iot can have a very low power footprint, expecially if the low power modes are exploited correctly.
As explained in section “here link to mobile network information”, these low power modes can greatly reduce the power consumption.
PSM
The PSM (power saving mode) is the deepest power mode that allows to achieve the lowest power consumption.
The PSM needs the configuration of two timers: the activity timer (T3324) and the periodic TAU timer (T3412). These timers are often called in similar ways, please refer to the timer name (TXXXX) to avoid confusion.
The first timer configures how long the modem will stay active and connected to the network, while the second defines the wholetime of a psm cycle. The sleep time will then be T3412 - T3324.
🚧 PSM availability in countries
The iotcreators (Deutsche Telekom) network natively supports PSM, however when using iotcreators sim cards in roaming, the PSM needs to be supported by the local network as well in order to be enabled.
Please check the “Support over networks” section for details.
eDRX
The eDRX (Extended Discontinuous Reception) is the low power mode that allows to save power while mantaining the modem as reachable from the network as intended. This mode is indicated if the end device needs to be reachable for downlinks from the network.
The is done by extending the time between the modem availability window. For LTE, this value is fixed at 2,56 seconds but, for NB-IOT and LTE-M, this value can be brought up to about 40 minutes, thus relaxing the power consumption spent being active.
In the eDRX mode, usually the modem only allows to configure the eDRX cycle duration, the PTW (Paging time window) is provided and fixed by the network.
The eDRX can be used in conjuction with the PSM, indeed the activity timer defines the time that the eDRX will be working.
🚧 eDRX availability in countries
The iotcreators (Deutsche Telekom) network natively supports eDRX, however when using iotcreators sim cards in roaming, the eDRX needs to be supported by the local network as well in order to be enabled.
Please check the “Support over networks” section for details.
NON-IP data delivery (NIDD)
This is not actually a low power mode, but allows the least overhead to be used and thus is very indicated for low power mode. This data delivery mode is only available with a dedicated network, and iotcreators provides such dedicated network.
🚧 NIDD apn
You cannot use noip under public network, because it requires a dedicated infrastructure to work. Please only use the dedicated noip apn provided by iotcreators: nonip.iot.t-mobile.nl
To send data over non-ip, set the apn for non-ip, which is “nonip.iot.t-mobile.nl” and the modem in non-ip mode with:
AT+CGDCONT=0,"NONIP","nonip.iot.t-mobile.nl"
this command could be slightly different for your modem.
Then, to send data, just issue:
AT+CSODCP=0,4,"45726963"
or
AT+CSODCP=0,5,"Hello"
Where 4 or 5 in the example is the length in bytes and data can be in ascii or hex format.
👍 NIDD support
Noip data delivery is a standardized 3gpp feature. It is supported by all modems stated below, with the same command!
Non-ip has limited support currently on local networks.
Support over networks
You can find supported functionalities in the different countries here (this excel file only covers coverage for sim cards provided by iotcreators starting with 894xxx):
👍 NB-IOT and LTE-M coverage and low power modes availability
🚧 NB-IOT and LTE-M coverage and low power modes availability
These low power features are in general much better supported, currently, under nb-iot rather than lte-m.
👍 Network information
PSM timers calculator
You can calculate the PSM timers value with this useful tool here
👍 PSM timers calculator