Cinterion
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MV31-W Hardware Interface Description
3.2 Characteristics
75
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MV31-W_HID_v01.009a
2022-04-27
Public / Preliminary
Page 30 of 76
3.2.4
WWAN/WiFi Coexistence Control
The signals COEX_RXD, COEX_TXD, LAA_n79_Tx_EN and WLAN_Tx_EN are provided to
allow the implementation of wireless coexistence solutions between the radio(s) on the M.2
Data Card and other off-card radio(s). These other radios can be located on another M.2 Card
located in the same host platform or as alternate radio implementations.
The signals COEX_RXD, COEX_TXD are reserved for future use.
3.2.5
Dynamic Power Reduction
The optional DPR signals are used by M.2 Data Card to assist in meeting regulatory SAR (Spe-
cific Absorption Rate) requirements for RF exposure. The signal is provided by a host system
proximity sensors to the M.2 Data Card to provide an input trigger causing a reduction in the
radio transmit output power.
The required value of the power reduction will vary between different host systems and is left
to the host platform OEM and card vendor to determine, along with the specific implementation
details. The assertion and de-assertion of DPR is asynchronous to any system clock. All tran-
sients resulting from the proximity sensor need to be de-bounced by system circuitry.
DPR_1 can be implemented for 3G/4G/5G ANT Tx. DPR_2 can be implemented for 5G FR1
ANT Tx only in case DPR_1 is for 3G/4G ANT Tx.
It is recommended to control DPR_1 and DPR_2 lines with an open collector transistor or an
open drain field-effect transistor.
Table 6:
Coexistence Control between LAA and n79 with WiFi 5GHZ
Signal
Direction
Description
LAA_n79_Tx_EN
MV31-W to WLAN
Avoid n79 Tx impact 5GHz Wi-Fi Rx
(While n79/LAA is in Tx mode, the WiFi 5G
Rx mode is not working.)
WLAN_Tx_EN
WLAN to MV31-W
Avoid WLAN Tx impact n79/LAA Rx
(While WiFi 5G is in Tx mode, the n79/LAA
Rx mode is not working.)
Table 7:
Dynamic Power Reduction States
Signal
Signal State
Definition
DPR_1
Low
Enable the SAR power back off
High
Disable the SAR power back off
DPR_2
Low
Reserved for EN-DC multiple Tx requirement
High
