Follow

Steered Vs. Non-Steered

Non-steered (No PLMN)

· On start up the module will scan all available networks, check the LOCI file & attempt to connect to that operator if one is populated that is visible. If this is the first time the SIM has been activated (LOCI is empty) the SIM allows the module (automatic roaming logic) or application (customer influenced intelligent network selection) to drive the network section process. The network is selected based on module / Application configuration (random available network above a threshold value (set in module – 3GPP states this should be -85Db RSSI level 14) or best signal strength). Some module suppliers will select a random operator above a define threshold not always thr strongest RSSI, check with supplier.

· For subsequent connections the module uses the LOCI file to select the last known good network to speed up the connection.

· The SIM will stay on the selected network unless the signal quality drops below a configured threshold (module/application controlled) or becomes unavailable.

· If the LOCI file selected network is not available the module will run the automatic roaming or application process to select an alternative available network. The SIM doesn’t drive the connection back to a preferred operator after each PDP session/connection or defined time period (usually 30 minutes with operators that use this function with a PLMN).

Steered (MNO driven PLMN)

· On start up the module will scan all available networks, check the LOCI file & attempt to connect to that operator if one is populated that is visible. If this is the first time the SIM has been activated (LOCI is empty) the PLMN list will take priority if the preferred network is available.

· If the preferred network is not available an alternative available network will be selected by the module / application configuration (random available network above a threshold value (set in module – 3GPP states this should be -85Db RSSI level 14) or best signal strength).

· For subsequent connections the module uses the LOCI file to select the last known good network to speed up the connection. The PLMN list will take priority if the preferred network is available.

· If the chosen network at start-up is not the preferred operator (unavailable) the SIM will check for the preferred operator every 30 minutes (Default*) & move the connection if the preferred operator becomes available. If it is not available it will remain on the current selected network.

* The preferred PLMN (and HPLMN) search period on TCXN SIMs is set to 30 min (default), if used. This can be altered in a customized SIM spec to any multiple of 6 minutes (with a minimum of 1 x 6 minutes = 6 minutes).

Below is a table of RSSI values and where bearer services will be functional:

Level

Indication

Equal or less than 4

Unusable

Equal or greater than 5

SMS and Registration

Equal or greater than 7

Context could be open with high heterogeneous properties

Equal or greater than 12

Context could be open with medium heterogeneous properties

Equal or greater than 14

Context could be open with low heterogeneous properties

Equal or greater than 17

Context could be open with homogeneous properties

RSSI

% RSSI

Signal (dBm)

2G

3G

Network Property

0

0

-113

Unusable

Unusable

None

1

3

-111

Unusable

Unusable

2

6

-109

Unusable

Unusable

3

10

-107

Unusable

Unusable

4

13

-105

SMS Only

Unusable

5

16

-103

SMS Only

Unusable

6

19

-101

SMS Only

Unusable

7

23

-99

Poor

Poor

Heterogeneous

8

26

-97

Poor

Poor

9

29

-95

Poor

Poor

10

32

-93

Poor

Poor

11

35

-91

Poor

Poor

12

39

-89

OK

OK

13

42

-87

OK

OK

14

45

-85

OK+

OK

15

48

-83

OK+

OK+

16

52

-81

OK+

OK+

17

55

-79

OK+

Best

Homogeneous

18

58

-77

Best

Best

19

61

-75

Best

Best

20

65

-73

Best

Best

21

68

-71

Best

Best

22

71

-69

Best

Best

23

74

-67

Best

Best

24

77

-65

Best

Best

25

81

-63

Best

Best

26

84

-61

Best

Best

27

87

-59

Best

Best

28

90

-57

Best

Best

29

94

-55

Best

Best

30

97

-53

Best

Best

31

100

-51 <

Was this article helpful?
1 out of 1 found this helpful
Have more questions? Submit a request

Comments