Update file TS-0019-Abstract_Test_Suite_&_implementation_eXtra_Information_for_Test.md

TS-0019-Abstract_Test_Suite_&_implementation_eXtra_Information_for_Test.md

@@ -217,7 +217,7 @@ APTs used by the oneM2M test suite are described in figure 5.1-1. The test syste
 **Figure 5.1-1: Abstract protocol testers - oneM2M**
 
 
-As figure 5.1-1 illustrates, the corresponding ATS needs to use lower layers to establish a proper connection to the implementation under test (SUT) over a physical link (Lower layers link). Four different lower layers have been specified corresponding to the binding protocols considered in oneM2M: HTTP, CoAP, WebSocket and MQTT.
+As figure 5.1-1 illustrates, the corresponding ATS needs to use lower layers to establish a proper connection to the implementations under test (SUT) over a physical link (Lower layers link). Four different lower layers have been specified corresponding to the binding protocols considered in oneM2M: HTTP, CoAP, WebSocket and MQTT.
 
 
 ## 5.2 Test Configuration