SARA-G3 and SARA-U2 series - System Integration Manual
UBX-13000995 - R26
System description
Page 95 of 217
1.13.22
SIM Access Profile (SAP)
Not supported by SARA-G3 modules.
SIM access profile (SAP) feature allows SARA-U2 modules to access and use a remote (U)SIM card instead of the
local SIM card directly connected to the module (U)SIM interface.
SARA-U2 modules provide a dedicated USB SAP channel and dedicated multiplexer SAP channel over UART for
communication with the remote (U)SIM card.
The communication between SARA-U2 modules and the remote SIM is conformed to client-server paradigm: the
SARA-U2 module is the SAP client establishing a connection and performing data exchange to an SAP server
directly connected to the remote SIM that is used by SARA-U2 module for GSM/UMTS network operations. The
SAP communication protocol is based on the
SIM Access Profile Interoperability Specification
SARA-U2 modules do not support SAP server role: the module acts as SAP client only.
A typical application using the SAP feature is the scenario where a device such as an embedded car-phone with
an integrated SARA-U2 module uses a remote SIM included in an external user device (e.g. a simple SIM card
reader or a portable phone), which is brought into the car. The car-phone accesses the GSM/UMTS network
using the remote SIM in the external device.
SARA-U2 modules, acting as an SAP client, can be connected to an SAP server by a completely wired
connection, as shown in Figure 38.
Device including SARA-U2
GSM/UMTS
interface
SAP
Serial interface
(SAP channel over
USB or UART)
Local SIM
(optional)
SARA-U2
SAP client
Application
processor
Device including SIM
SAP
Serial interface
Remote SIM
Mobile
Equipment
SAP Server
Figure 38: Remote SIM access via completely wired connection
As stated in the
SIM Access Profile Interoperability Specification
[30], 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 SARA-U2 modules 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 39.