4G/5G 模块测试与调试

1. 常见AT 指令

AT 指令分为两种，通用指令，和厂商自定义的指令，通用指令一般以C 开头，每个modem 厂商基本都遵循这个规范。
下来我们看下常见的一些AT 指令

1.1 查看注册状态: AT+COPS?

AT+COPS?
+COPS: {mode}[,{format},{oper}[,{ AcT}]]

mode	note
0	自动注册; Default value
1	manual ( field shall be present, and optionally)
2	deregister from network
3	set only (for read command +COPS?), do not attempt registration/deregistration ( and fields are ignored); this value is not applicable in read command response
4	manual/automatic ( field shall be present); if manual selection fails, automatic mode (=0) is entered

format	note
0	long format alphanumeric ; Default value
1	short format alphanumeric
2	numeric

oper: 运营商字符串

AcT	access technology selected
0	GSM 2G
1	GSM Compact
2	UTRAN 3G
3	GSM w/EGPRS
4	UTRAN w/HSDPA
5	UTRAN w/HSUPA
6	UTRAN w/HSDPA and HSUPA
7	E-UTRAN 4G
8	EC-GSM-IoT (A/Gb mode)
9	E-UTRAN (NB-S1 mode)
10	E-UTRA connected to a 5GCN (see NOTE 5)
11	NR connected to a 5GCN (see NOTE 5) 5G
12	NG-RAN 5G
13	E-UTRA-NR dual connectivity (see NOTE 6)

通过以上命令就知道该模块的注册方式，以及当前注册的网络信号是3g, 4g 还是5g。

1.2 查询网络信号质量

对于4G 网络使用该命令查询：

AT+CSQ?
+CSQ: rssi, ber
rssi: integer type
0 -113 dBm or less
1 -111 dBm
2…30 -109… -53 dBm
31 -51 dBm or greater
99 not known or not detectable
ber: integer type; channel bit error rate (in percent)
0…7 as RXQUAL values in the table in 3GPP TS 45.008 subclause 8.2.4
99 not known or not detectable

对于5G 网络使用以下信号：

AT+CESQ
rxlev, ber, rscp,ecno,rsrq,rsrp,ss_rsr
q,ss_rsrp, ss_sinr

我们这里只看rxlev 返回值：

rxlev	range
0	rssi< -110 dBm
1	-110 dBm ≤ rssi < -109 dBm
2	-109 dBm ≤ rssi < -108 dBm
:	: : :
61	-50 dBm ≤ rssi < -49 dBm
62	-49 dBm ≤ rssi < -48 dBm
63	-48 dBm ≤ rssi
99	not known or not detectable

更加广泛和通用的信息参考AT+GTCCINFO指令。

1.3 网络拨号:AT+GTRNDIS=1,1

确认到模块已经注册到网络后，就可以进行拨号了

AT+GTRNDIS=1，1
OK
AT+GTPING=0，"182.61.200.6"
+GTPING: 1
OK

表示拨号成功了。

1.4 切换无线网络: AT+WS46

AT+WS46=[<n>]
OK

n的取值范围为：
22 UTRAN only
28 E-UTRAN only
31 UTRAN and E-UTRAN
36 NG-RAN only
37 NG-RAN and E-UTRAN
38 NG-RAN, E-UTRAN and UTRAN
40 NG-RAN and UTRAN

2. ModemManager debug

mmcli --scan-modems
<< successfully requested to scan devices

To list detected cellular devices use command:
mmcli --list-modems
<< /org/freedesktop/ModemManager1/Modem/0 [Sierra Wireless, Incorporated] MC7455

To acquire more device information and status use the --modem command and identifier value.
mmcli --modem=0

https://techship.com/faq/how-to-guide-control-and-set-up-a-data-connection-in-linux-using-modemmanager-as-connection-manager/
https://wiki.archlinux.org/title/Mobile_broadband_modem