Insys GPRS 5.0 serial 11-02-01-03-10.014 Manuale Utente

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11-02-01-03-10.014
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INSYS GPRS 5.0 serial 
 
Information Regarding GPRS 
 
Mai 06 
            63 
 
 
1 TS 
2 TS 
3 TS 
4 TS 
CS1 8 
16  24  32 
CS2 
12 24 36 48 
CS3 14.4 28.8 43.2 57.6 
CS4 
20 40 60 80 
Data rates of PC data only (without GPRS control data) 
 
Note: The above mentioned values represent the theoretically maximum possible val-
ues. 
 
In practice, the following applies: 
GPRS will not provide guaranteed data rates or bandwidths for the application. The val-
ues allocated by the network provider (using coding schemes and time slots) can change 
dynamically during a connection and, among other things, depend on the current 
amount of connections in the GSM cell. 
In the device class B, the INSYS GPRS 5.0 serial supports the GSM services GPRS, CSD and 
voice. However, only one service can be executed at a time. 
8.6 
Quality of Service (QoS) 
The above mentioned characteristic data rates (in the form of values such as “data 
amount per hour” and maximum data amount) and delay times are a part of the Quality 
of Services, among others. 
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 perform-
ance improvement, as the providers always supply "Best Effort” as QoS, i.e. the best val-
ues according to the current network load during the moment of the connection setup. 
8.7 
Delay Times 
Usually, there will be marginally higher delays than with a "normal" connection via GSM.  
The delays will mostly be below one second. 
 
The average delay times are stated with 700 ms, for GSM values of 500 ms are assumed. 
In rare cases, delays of several seconds are possible; the applications at the GPRS end de-
vices should therefore be set to maximum delay times.