User Manual

Table Of Contents
Chapter 4. SPP-over-IP
requires that Access Server is equipped with a working GSM/GPRS compact flash card. See
Appendix D for supported cards.
Figure 4-3. SPP-over-IP over GPRS
Notice when using GPRS:
Data upload rate is around 8-12kbps (depending on GPRS card)
Data download rate is around 32-48kbps (depending on GPRS card)
Data transmission delays can be very high, sometimes even seconds
GPRS connection may be unreliable and break easily. This should be taken account when
designing the system. If GPRS connection breaks, all the TCP and Bluetooth connections will
also be closed.
4.1.4. Opening Connections from Access Server
In the basic SPP-over-IP use case, Access Server is in passive mode and only accepts incom-
ing connections. It is however possible to implement a system where Access Server opens the
Bluetooth connections to the defined static Bluetooth devices or, alternatively, on ad-hoc basis.
In this case, special software must be developed for Access Server, which handles the outgoing
connections and decides where they are opened to. This software can be developed with the
Access Server Software Development Kit (SDK). The software can be written with C, C++ or
standard Linux scripts.
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