> 5.12.3 | Data Rates on RS-232 API

> For details about the software platform and interfaces refer to Chapter 4, "Software Platform". This section summarises limitations and preconditions for performance when using the interface CommConnection from package com.siemens.mp.io (refer to [3]).
> The data rate on RS232 depends on the size of the buffer used for reading from and writing to the serial interface. It is recommended that method read (byte[ ] b) be used for reading from the serial interface. The recommended buffer size is 2kbyte. To achieve error free data transmission the flow control on CommConnection must be switched on: <autorts> and <autocts>, the same for the connected device.
> Different use cases are listed to give an idea of the attainable data rates. All applications for measurement use only one thread and no additional activities other than those described were carried out in parallel.

> 5.12.3.1 | Plain Serial Interface

> Scenario: A device is connected to ASC0 (refer to Section 4.2.4). The Java application must handle data input and output streams. A simple Java application (with only one thread) which loops incoming data directly to output, reaches data rates up to 180kbit/s. Test conditions: hardware flow control enabled (<autorts> and <autocts>), 8N1, and baud rate on ASC0 set to 230kbaud (→ theoretical maximum: 184kbit/s net data rate).
> Figure 15: Scenario for testing data rates on ASC1

> 5.12.3.2 | Voice Call in Parallel

> Same scenario as in Section 5.12.3.1, but with a voice call added. The application reflects incoming data directly to output and, additionally, handles an incoming voice call. The data rates are also up to 180kbit/s. Test conditions: same as in Section 5.12.3.1.
> Figure 16: Scenario for testing data rates on ASC1 with a voice call in parallel

> 5.12.3.3 | Scenarios with GPRS/EGDE Connection

> The biggest challenges to the module performance are setting up a GPRS/EDGE connection, receiving data on javax.microedition.io interfaces and sending or receiving the data on the RS232 API with the help of a Java application.

> 5.12.3.4 | Upload

> The ME supports up to four uplink time slots for GPRS and up to two for EGDE. The Java application receives data over RS232 API and sends them over GPRS to a server.

> Table 1: | GPRS upload data rate with different number of timeslots, CS2

> Upload data rate with x timeslots Coding scheme 2 [kbit/s]
> 1 time-slot | theor. Value1 | % from theor. Value | 2 time-slots | theor. Value1 | % from theor. Value | 3 time-slots | theor. Value1 | % from theor. Value | 4 time-slots | theor. Value1 | % from theor. Value
> 9 | 12 | 75% | 15 | 24 | 63% | 20 | 36 | 55% | 16 | 48 | 33%

> 1
> net transmission rates for LLC layer

> Table 2: | GPRS upload data rate with different number of timeslots, CS4

> Upload data rate with x timeslots Coding scheme 4 [kbit/s]
> 1 time-slot | theor. Value1 | % from theor. Value | 2 time-slots | theor. Value1 | % from theor. value | 3 time-slots | theor. Value1 | % from theor. value | 4 time-slots | theor. Value1 | % from theor. value
> 13 | 20 | 65% | 22 | 40 | 55% | 20 | 60 | 33% | 13 | 80 | 16%

> 1
> net transmission rates for LLC layer

> Table 3: | EDGE upload data rate with two timeslots, CS5

> Upload data rate with x timeslots Coding scheme 5 [kbit/s]
> 2 timeslots | theor. Value1 | % from theor. Value
> 33 | 44 | 73%

> 1
> net transmission rates for LLC layer

> Table 4: | EDGE upload data rate with two timeslots, CS9

> Upload data rate with x timeslots Coding scheme 9 [kbit/s]
> 2 timeslots | theor. Value1 | % from theor. Value
> 72 | 118 | 61%

> 1
> net transmission rates for LLC layer
> Figure 17: Scenario for testing data rates on ASC1 with GPRS data upload

> 5.12.3.5 | Download

> The data rate for downloading data over GPRS/EDGE depends on the number of assigned timeslots and the coding schemes given by the net. The ME supports up to four downlink time slots. For the measurements, the Java application receives data from the server over GPRS and sends them over RS232 to an external device.
> Figure 18: Scenario for testing data rates on ASC1 with GPRS data download
> The tables below show the download data rates that can be achieved if hardware flow control is enabled on the CommConnection interface and the port speed is set to 460800.

> Table 5: | GPRS Download data rate with different number of timeslots, CS2

> Download data rate with x timeslots Coding scheme 2 [kbit/s]
> 1 time-slot | theor. Value1 | % from theor. Value | 2 time-slots | theor. Value1 | % from theor. Value | 3 time-slots | theor. Value1 | % from theor. Value | 4 time-slots | theor. Value1 | % from theor. Value
> 11 | 12 | 91% | 21 | 24 | 87% | 29 | 36 | 81% | 35 | 48 | 73%

> 1
> net transmission rates for LLC layer

> Table 6: | GPRS Download data rate with different number of timeslots, CS4

> Download data rate with x timeslots Coding scheme 4 [kbit/s]
> 1 time-slot | theor. Value1 | % from theor. Value | 2 time-slots | theor. Value1 | % from theor. value | 3 time-slots | theor. Value1 | % from theor. value | 4 time-slots | theor. Value1 | % from theor. value
> 17 | 20 | 85% | 31 | 40 | 78% | 35 | 60 | 58% | 38 | 80 | 48%

> 1
> net transmission rates for LLC layer

> Table 7: | EDGE Download data rate with different number of timeslots, CS5

> Download data rate with x timeslots Coding scheme 5 [kbit/s]
> 1 time-slot | theor. Value1 | % from theor. Value | 4 time-slots | theor. Value1 | % from theor. Value
> 20 | 22 | 91% | 78 | 89 | 87%

> 1
> net transmission rates for LLC layer

> Table 8: | EDGE Download data rate with different number of timeslots, CS9

> Download data rate with x timeslots Coding scheme 9 [kbit/s]
> 1 time-slot | theor. Value1 | % from theor. Value | 4 time-slots | theor. Value1 | % from theor. value
> 50 | 59 | 85% | 184 | 236 | 77%

> 1
> net transmission rates for LLC layer