Specifications

CINTERION

BGS12 Hardware Interface Description

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BGS12 HID_V00.915

Confidential / Released

2019

3.4.5 Timing of the CTS Signal in CYCLIC SLEEP Modes

The CTS signal is enabled in synchrony with the module’s paging cycle. It goes active low each

time when the module starts listening to a paging message block from the base station. The

timing of the paging cycle varies with the base station. The duration of a paging interval can be

calculated from the following formula:

4.616 ms (TDMA frame duration) * 51 (number of frames) * DRX value.

DRX (Discontinuous Reception) is a value from 2 to 9, resulting in paging intervals from 0.47

to 2.12 seconds. The DRX value of the base station is assigned by the network operator.

Each listening period causes the CTS signal to go active low: If DRX is 2, the CTS signal is

activated every 0.47 seconds, if DRX is 3, the CTS signal is activated every 0.71 seconds and

if DRX is 9, the CTS signal is activated every 2.1 seconds.

The CTS signal is active low for 5ms. This is followed by another 5ms UART activity. If the start

bit of a received character is detected within these 10ms, CTS will be activated and the pro-

per reception of the character will be guaranteed. CTS will also be activated if any character is

to be sent.

After the last character was sent or received the interface will remain active for

•

another 2 seconds, if AT+CFUN=7

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or for an individual time defined with AT^SCFG, if AT+CFUN=9. Assertion of RTS has the

same effect.

In the pauses between listening to paging messages, while CTS is high, the module resumes

power saving and the AT interface is not accessible. See Figure 10 and Figure 11.

Figure 10: Timing of CTS signal (example for a 2.12 s paging cycle)

Figure 11 illustrates the CFUN=7 modes, which reset the CTS signal 2 seconds after the last

character was sent or received.