Hi All, What the maximum period a device can negotiate for PSM mode ? For example could a device stay connected for 5 days in PSM mode, and still get the fast connection? thanks
Thank you for the question. I've consulted with a Telstra Wireless Networks SME and there response is as follows:
The good news is you could request the device stay connected in PSM mode for 5 days and it should work.
The key thing to understand with PSM is that you can't nominate any random time value and expect it to work. The timers associated with PSM can only be set to values defined by the 3GPP technical standards. To understand what values you can use, grab yourself a copy of the 3GPP Technical Standard TS 27.007 and specifically look at the command used to configure PSM. That is, AT+CPSMS. It costs nothing to download this standard from the 3GPP and the latest version is available from here. https://www.3gpp.org/ftp//Specs/archive/27_series/27.007/27007-h00.zip
Upon reading that standard you'll see the values are administered by selecting a measurement unit and a multiplier. In your example of 5 days, you could select 10 hours as the unit and use a muliplier of 12. With the largest unit size of 320 hours and a muliplier of 31, this means the maximum value you could set is approximately 413 days.
Does this means Telstra's implemenation of the 3GPP standard, will on the Telstra NBIOT network allow a device to be in PSM Mode for 365 days? I know this seems far fetched, if the use case exists, i'd like to understand if this is feasible on the Telstra network.
The example of the above being a remote sensor, which is waiting for a flood ( protracted hybernation), and once the flood hits, is sends an repeated status messages of flood levels.
Hi Cameron,
Thank you for the question. I've consulted with a Telstra Wireless Networks SME and there response is as follows:
The good news is you could request the device stay connected in PSM mode for 5 days and it should work.
The key thing to understand with PSM is that you can't nominate any random time value and expect it to work. The timers associated with PSM can only be set to values defined by the 3GPP technical standards. To understand what values you can use, grab yourself a copy of the 3GPP Technical Standard TS 27.007 and specifically look at the command used to configure PSM. That is, AT+CPSMS. It costs nothing to download this standard from the 3GPP and the latest version is available from here. https://www.3gpp.org/ftp//Specs/archive/27_series/27.007/27007-h00.zip
Upon reading that standard you'll see the values are administered by selecting a measurement unit and a multiplier. In your example of 5 days, you could select 10 hours as the unit and use a muliplier of 12. With the largest unit size of 320 hours and a muliplier of 31, this means the maximum value you could set is approximately 413 days.
Hope this helps.
Regards
TelstraDev team
Does this means Telstra's implemenation of the 3GPP standard, will on the Telstra NBIOT network allow a device to be in PSM Mode for 365 days? I know this seems far fetched, if the use case exists, i'd like to understand if this is feasible on the Telstra network.
The example of the above being a remote sensor, which is waiting for a flood ( protracted hybernation), and once the flood hits, is sends an repeated status messages of flood levels.
Hi Cameron,
The maximum time you can negotiate for PSM is 413 days so 5 days is fine.
Regards
Wayne