MeiG_SLM156_Hardware Design Manual
MeiG Smart Technology Co., Ltd
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3.5.2 Power Saving Mode (PSM)
SLM156 can lower its power consumption through entering PSM mode. PSM is similar to power off, but
the module is still registered online. After PSM is waken up, the module does not need reattach and
rebuild PDN connection. Thus, when the module enters into PSM, it cannot respond to user’s request
immediately.
When the module uses PSM, it will ask an activity period during each attach and TAU process. If
network supports PSM and accepts the use of PSM, network confirms use of PSM through allocating
activity time for modules. If the module wants to change activity time, such as change of conditions, the
module will ask needed time during TAU process.
If network supports PSM, it can send AT+CPSMS=1 command to realize PSM function.
The module can be waken up from PSM state in the following ways:
Pulling PWRKEY pin to low level can wake up the module;
When the waitable timer boils, the module is waken up automatically.
3.5.3 Extent Idle Mode Discontinuous Receiving
SLM156 can use e-I-DRX to lower its power consumption. The power consumption of e-I-DRX is higher
than PSM; but compared with PSM, it improve the accessibility of download communication to a large
extent. Module and core network negotiate e-I-DRX related parameter through attach and TAU process.
Please refer to chapter 3.5.3 for detail information.
If the module decides to ask e-I-DRX, the module will carry ask-for-use e-I-DRX parameter in attach
request or TAU information, including DRX -related parameters.
Core network decides whether accept the request of activating e-I-DRX.
If core network accept the request, the core network can provide e-I-DRE parameter, which is
different from the request, in the meantime, it will provide the length of paging time window for the
module; then the module should use e-I-DRX in accordance with the received length of e-I-DRX
and paging time window.
If the n
etwork rejects the module’s request or doesn’t support e-I-DRX, the received information of
attach/TAU doesn’t appear e-I-DRX parameter, the module uses normal DRX system.
If network supports e-I-DRX, this function can be realized through AT+CEDRXS=1 command.
