GNSS stop to work

Hi, I have a problem with the GNSS module - can’t obtain a lock GNSSSEV:3,2 or GNSSSEV:3,3.

My settings:

ATI9
HL7800-M.2.5.6
BHL78xx.2.5.6.1.RK_02_01_01_00_41.20190412
2019/04/12 16:08:23
IMEI-SV: 3594160905626304
Legato RTOS: 18.09.2.ALT1250.rc5 2019/04/04 14:02:47
atSwi: 13.01
UBOOT: 01.03
Apps: RKAPP_02_01_01_00_37__76cc94b4672ac9bde0f08de3724a5c20b28bc2ba
MAC: ALT1250_02_01_01_00_38_FW
PHY: 12.50.209178
PMP: 209236
SBUB: 0
SBFW: 0
RPuK:
FPuK:
RBUB: 0
RBFW: 0


I need to open TCP connection for sending/receiving data and periodically check if GPS is received a position event.
The problems:

  1. GNSSSTART=0
    +GNSSEV: 1,1 it says GNSS is started successfully, but if I send
    AT+GNSSNMEA=04, I receive CONNECT status, but no “$GP” messages during 10 seconds.
    Command ends by sending “+++”.
    If I retry again with restarting of GNSS - it helps and I start to receive “$GP” messages.
  2. After AT+KTCPCLOSE=1 - I send AT+GNSSNMEA=04 - but receive nothing, need to restart again GNSS by sending the GNSSSTART=0 command. For example, “$GPRMC,000008.00,V,060180,N,*56”.
  3. Sending/receiving data, “+KTCP_NOTIF: 1,4” - stop GNSS, need again restart GNSS.

Additional data - init of GNSS module - all Sierra defaults - only “AT+GNSSSTOP”, “AT+GNSSSTART=0”, “AT+GNSSNMEA=04”, “+++”

Previously I tried also to configure GNSS, but the result was the same - “AT+GNSSLOC?” receive “+GNSSLOC: FIX NOT AVAILABLE”:

AT+GNSSSTOP
AT+GNSSCONF=10,1
AT+GNSSNMEA=0,1000,0,1FF
AT+GNSSSTART=0
AT+GNSSNMEA=04
+++

I receive the following messages:
$GPGGA,001004.00,0,00,*4D
$GPGSV,1,1,03,05,29,15,25,29,24,*7A
$GPGNS,001004.00,NN,00,*66
$GPRMC,001004.00,V,060180,N,*5B
$GPGST,001004.00,*7C
$GPGGA,001005.00,0,00,*4C
$GPGSV,1,1,03,05,28,15,24,29,23,*7D
$GPGNS,001005.00,NN,00,*67
$GPRMC,001005.00,V,060180,N,*5A
$GPGST,001005.00,*7D

What I do wrong? Why the "$GP " data is stopped to arrive?

Additional about TCP connection:
+++
[31-10 13:30:56 TRACE] GSM-FIN_3: AT
ERROR
[31-10 13:30:56 TRACE] GSM-FIN_3: AT
OK
[31-10 13:30:57 TRACE] GSM-FIN_3: ATE0
OK
[31-10 13:30:57 TRACE] GSM-FIN_3: AT+CCID
+CCID: 89332401000013998519

OK
[31-10 13:30:58 TRACE] GSM-FIN_3: AT+CNUM
OK
[31-10 13:30:58 INFO ] GSM-FIN_3: My phone number:<>
[31-10 13:30:58 TRACE] GSM-FIN_3: AT+CNMI=1,0,0,0
OK
[31-10 13:30:59 TRACE] GSM-FIN_3: AT+CSQ
+CSQ: 16,7

OK
[31-10 13:30:59 TRACE] GSM-FIN_3: AT+CCLK?
+CCLK: “19/10/31,13:34:53-16”

OK
[31-10 13:31:00 TRACE] GSM-FIN_3: AT+CGDCONT=1,“IP”,“internet.swir”,0,0,0,
OK
[31-10 13:31:01 TRACE] GSM-FIN_3: AT+CREG?
+CREG: 2,5,“6202”,“0103CE07”,7

OK
[31-10 13:31:01 TRACE] GSM-FIN_3: AT+KCNXCFG=1,“GPRS”,“internet.swir”,"","",“IPV4”,“0.0.0.0”,"0.0.0.0
OK
[31-10 13:31:02 TRACE] GSM-FIN_3: AT+KTCPCFG=1,0,“wd.bdlogix.com”,2020
+KTCPCFG: 1

OK
[31-10 13:31:02 TRACE] GSM-FIN_3: AT+KTCPCNX=1
OK

+KCNX_IND: 1,1,0
[31-10 13:31:03 TRACE] GSM-FIN_3: AT+KCGPADDR
+KCGPADDR: 1,“100.71.124.11”

OK
[31-10 13:31:03 TRACE] GSM-FIN_3: GSM_COMMAND_MODE state
[31-10 13:31:10 TRACE] GSM-FIN_3: GPS_INIT state
[31-10 13:31:10 TRACE] GSM-FIN_3: AT
+KTCP_IND: 1,1

OK
[31-10 13:31:11 TRACE] GSM-FIN_3: AT+GNSSSTOP
+CME ERROR: 3
[31-10 13:31:13 TRACE] GSM-FIN_3: AT+GNSSSTART=0
[31-10 13:31:13 TRACE] GSM-FIN_3: Conn request
[31-10 13:31:13 TRACE] GSM-FIN_3: Conn request started
[31-10 13:31:15 TRACE] GSM-FIN_3:
OK

+GNSSEV: 0,1

+GNSSEV: 1,1
[31-10 13:31:15 TRACE] GSM-FIN_3: AT
OK
[31-10 13:31:15 TRACE] GSM-FIN_3: AT+GNSSSTART=0
OK

+GNSSEV: 1,0
[31-10 13:31:18 TRACE] GSM-FIN_3: AT
OK
[31-10 13:31:19 TRACE] GSM-FIN_3: AT+KTCPSTART=1
CONNECT

Hi,

On altair 1250 platform HL7800, the GNSS share the same RF Rx chain with cellular (2G/LTE-M). Because cellular reception has an higher priority, GNSS should be allowed to work only when LTE modem is:

Switched-off (AT+CFUN=0)
In flight-mode (AT+CFUN=4)
In PSM sleep mode
In Idle-DRX/eDRXmode

To obtain a lock GNSSSEV:3,2 or GNSSSEV:3,3. Please make sure your HL7800 is attached to a GPS atten and a GPS signal environments such as an open sky or repeater GPS in a building.
Here is result on my module
ATI3
18:18:26.355 on 08-Nov-2019>
18:18:26.355 on 08-Nov-2019> BHL7800:E0.3.7.2.3.20191030
18:18:26.355 on 08-Nov-2019>
18:18:26.355 on 08-Nov-2019> OK
18:18:34.219 on 08-Nov-2019> AT+CFUN=0
18:18:37.210 on 08-Nov-2019>
18:18:37.230 on 08-Nov-2019> OK
18:18:37.230 on 08-Nov-2019>
18:18:37.230 on 08-Nov-2019> +CEREG: 0
18:18:37.230 on 08-Nov-2019> AT+GNSSSTART=0
18:20:06.195 on 08-Nov-2019>
18:20:06.195 on 08-Nov-2019> OK
18:20:06.195 on 08-Nov-2019>
18:20:06.195 on 08-Nov-2019> +GNSSEV: 0,1
18:20:06.195 on 08-Nov-2019>
18:20:06.466 on 08-Nov-2019> +GNSSEV: 1,1
18:20:06.466 on 08-Nov-2019>
18:20:09.270 on 08-Nov-2019> +GNSSEV: 3,0
18:20:09.270 on 08-Nov-2019>
18:20:59.504 on 08-Nov-2019> +GNSSEV: 3,3