INSYS EDGE 5.0 Series, Manual

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GSM, GPRS, and EDGE General INSYS GPRS/EDGE 5.0 serial
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In the device class B, the INSYS GPRS/EDGE 5.0 serial supports the GSM services
EDGE (optional), GPRS, CSD and voice. However, only one service can be executed
at a time.
8.6 Quality of Service (QoS)
The above mentioned characteristics data rates (in the form of values such as
“data amount per hour” and maximum data amount) and delay times are, among
others, a part of the Quality of Services.
Theoretically, there is a possibility for requesting a certain QoS profile from the
provider during the connection setup via
AT
commands (
AT+CGQREQ
) or to define
a minimum profile (
AT+CGQMIN
) which must exceeded by the QoS offered by the
provider, in order to enable the device to establish the connection.
Experience has shown that these settings will not show any success regarding
performance improvement, as the providers always supply "Best Effort” as QoS,
i.e. the best values according to the current network load during the moment of
the connection setup.
8.7 Delay Times
The data delays in the GSM radio network are longer than in wire-based net-
works.
Typical ping times (disconnect time for 1 short request and answer) are:

GSM / CSD: 500 ms

GPRS: 700 ms

EDGE: 350 ms
The applications at the GPRS/EDGE end terminals should therefore be configured
to maximum delay times if possible.