User Manual

TOBY-L2 and MPCI-L2 series - System Integration Manual
UBX-13004618 - R08 Early Production Information System description
Page 65 of 158
TOBY-L2 series modules, acting as an SAP client, can be connected to an SAP server by a completely wired
connection, as shown in Figure 27.
Device including TOBY-L2
LTE/3G/2G
Interface
Local SIM
(optional)
TOBY-L2
SAP Client
Application
Processor
Device including SIM
SAP
Serial Interface
Remote SIM
Mobile
Equipment
SAP Server
SAP
Serial Interface
(SAP channel over
USB or UART)
Figure 27: Remote SIM access via completely wired connection
As stated in the SIM Access Profile Interoperability Specification [20], the SAP client can be connected to the SAP
server by means of a Bluetooth wireless link, using additional Bluetooth transceivers. In this case, the application
processor wired to TOBY-L2 series module establishes and controls the Bluetooth connection using the SAP
profile, and routes data received over a serial interface channel to data transferred over a Bluetooth interface
and vice versa, as shown in Figure 28.
Device including TOBY-L2
SAP
Serial Interface
(SAP channel over
USB or UART)
LTE/3G/2G
Interface
Local SIM
(optional)
TOBY-L2
SAP Client
Application
Processor
SAP
Bluetooth
Interface
Bluetooth
Transceiver
Device including SIM
Remote SIM
Mobile
Equipment
SAP Server
Bluetooth
Transceiver
Figure 28: Remote SIM access via Bluetooth and wired connection
The application processor can start an SAP connection negotiation between TOBY-L2 series module SAP client
and an SAP server using custom AT command (for more details see u-blox AT Commands Manual [3]).
While the connection with the SAP server is not fully established, the TOBY-L2 series module continues to
operate with the attached (local) SIM, if present. Once the connection is established and negotiated, the module
performs a detach operation from the local SIM followed by an attach operation to the remote one. Then the
remotely attached SIM is used for any LTE/3G/2G network operation.
URC indications are provided to inform the user about the state of both the local and remote SIM. The insertion
and the removal of the local SIM card are notified if a proper card presence detection circuit using the GPIO5 of
TOBY-L2 series modules is implemented as shown in section 2.5, and if the related “SIM card detection” and
“SIM hot insertion/removal” functions described in section 1.8.2 are enabled by AT commands (for more details
see u-blox AT Commands Manual [3]).
Upon SAP deactivation, the TOBY-L2 series modules perform a detach operation from the remote SIM followed
by an attach operation to the local one, if present.