testSuite.xml

<!DOCTYPE suite SYSTEM "http://testng.org/testng-1.0.dtd" >

<suite name="AndroidTestSuite" verbose="1" parallel="tests" thread-count="2">

    <test name="Test on device 1">
        <parameter name="udid" value="localhost:12345"/>
        <parameter name="systemPort" value="8200"/>
        <classes>
            <class name="ParallelTests" />
        </classes>
    </test>
    <test name="Test on device 2">
        <parameter name="udid" value="localhost:12346"/>
        <parameter name="systemPort" value="8201"/>
        <classes>
            <class name="ParallelTests" />
        </classes>
    </test>

</suite>