Specifications

Cinterion
®
EXS62-W/EXS82-W Hardware Interface Description
3.3 Power Saving
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3.3.3.3 3GPP PSM Configuration
EXSx2-W can be configured to use 3GPP PSM to reduce power consumption. PSM is similar
to power off, while EXSx2-W remains registered with the network. There is no need to re-attach
or re-establish PDN connections. EXSx2-W in PSM is not immediately reachable for mobile ter-
minating services (see also SUSPEND mode in Section 3.3.1.2).
The network accepts and negotiates the use of PSM by providing specific values for periodic
TAU cycles (T3412) as well as an active timer (T3324). Upon expiry of the active timer, or if the
value provided by the network is zero, EXSx2-W may activate PSM.
Note: If EXSx2-W negotiates to enable both PSM (requesting an active timer and possibly a
periodic TAU cycle value) as well as eDRX (requesting a specific extended idle mode DRX
cycle value and possibly a paging time window), it is up to the network to decide whether to:
1. Enable only PSM, i.e. not accept the request for eDRX.
2. Enable only eDRX, i.e. not accept the request for an active timer.
3. Enable both PSM (i.e. negotiate and provide requested PSM timers) and eDRX (i.e. negoti-
ate and provide extended DRX parameters).
Figure 46 shows the module’s eDRX and PSM timings for the third case where module and
network negotiate PSM and eDRX simultaneously (for eDRX see also Section 3.3.3.2). For the
second case the module will reach eDRX SUSPEND mode only as an option, and will continue
with the eDRX paging cycles. For the first case the module will not extend to the eDRX paging
cycles, but will continue with the DRX paging cycles until the active timer (T3324) expires.
Figure 46: eDRX/PSM based paging and power saving in LTE Cat M1 or Cat NB1/2 networks
EXSx2-W monitors paging messages only while the active timer (T3324) has not expired. If the
module has uplink data or signal, it will not change to PSM.
The active timer (T3324) and periodic tracking area update (TAU) timer (T3412) can be nego-
tiated/requested with AT+CPSMS. For more information on this AT command see [1].
Periodic TAU cycle (T3412)
PCL PCL
3GPP PSM mode
(SUSPEND)
Active time (T3324)
PTW
Default
Paging
Cycle
(DRX)
DRX SLEEP mode
eDRX SLEEP mode
(“deep sleep“)
eD RX SLEEP mo de
(“deep sleep“)
Periodic TAU cycle T3412
Active time T3324
PCL Paging Cycle Length eDRX (5.12...10485.76 seconds)
PTW Paging Time Window eDRX (2.56...40.96 seconds)
Default Paging Cycle Paging Cycle DRX (LTE Cat M 1: 0.32...2.56 seconds,
LTE Cat NB 1/2: 1.28...10.24 seconds)
3GPP PSM 3GPP Power Saving Mode
P1 P2 P3 P4
eDRX SUSPEND mode eDRX SUSPEND mode