Installation guide

LMU Users Guide

V1.0.6 December 10 2009

- 51 - CalAmp Proprietary & Confidential

If the LMU is set to Require a given network it must connect to that network before a data

session will be established. If the data session is already established and the modem roams

off the Required network, the LMU will automatically drop the data session and attempt to

reconnect to the Required network.

Lastly, if the LMU is set to Exclude a given network, the LMU will only allow data session to

be established or maintained if the LMU is register to a network that is not on the Exclude

list.

The LMU can be set for either one Preferred network or one Required network and up to 4

Excluded networks. For each definition, three values are required, the network selection

criteria (Prefer, Require or Exclude), the ID of the network in question and the network ID

type.

The network selection condition is controlled by Parameter 1537 and contains 4 indexes.

Index 0 can be used for the Prefer, Require or Exclude criteria. Indexes 1 – 3 are only used

for Exclude values. The value of this register may be set as follows:

• 0=Ignore / Not Used

• 1=Require

• 2=Prefer

• 3=Exclude

The network ID type is always set to 1 if the Index is to be used and 0 if it is off. The

network ID type is controlled by Parameter 1536. This Parameter also has 4 Indexes which

are associated with the Indexes of Parameter 1537. Again, the values for this Parameter may

be:

• 0=Do not use network selection

• 1=Select on SID (CDMA) or MNC (GPRS)

The network ID value is stored in Parameter 1538. Again, this Parameter contains 4 Indexes,

which are associated with the Indices of parameter 1537 and 1536. The value of this

Parameter may range from 0 to 65535. For CDMA networks, this should be the SID

(System ID) of the network in question. For GPRS networks the ID should be the MNC

(Mobile Network Code) of the network in question. Please note that GPRS networks will

automatically use the MCC (Mobile Country Code) as defined by the IMSI. If your SIMs

IMSI does not match the MCC of the network you are using, DO NOT enable the network

selection feature.

Keep in mind that most devices already have some measure of network preference built in.

It is best to talk to your wireless network carrier on what roaming features / pitfalls exist

before using the LMU’s network selection capabilities.