Minor additions

Author: Kari Severinkangas

docs/tutorials/using_apis/mesh/thread_commissioning.md

@@ -44,6 +44,8 @@ To get the MAC address for your end device, connect the node to the Thread netwo
 
 For example, in the **mesh-minimal** application, place this `printf("MAC address = %s\n", mesh.get_mac_address());` after `printf("connected. IP = %s\n", mesh.get_ip_address());`
 
+It is also possible to use mesh-api (ThreadInterface.h) to set values for these parameters.
+
 There are four additional (optional) query parameters you can put into this field:
 
 - `vn`    Vendor name.
@@ -55,6 +57,9 @@ Once you have completed the details, proceed to generate the QR code for your en
 
 #### Using the Thread commissioning application
 
+When building a Thread example application do not change any of the PSKc related parameters (network name, extended PAN ID or PSKc). PSKc has been pre-calculated for the application. The nanostack has no capability to generate PSKc on runtime.
+
+
 You can use the [Thread Android application](https://play.google.com/store/apps/details?id=org.threadgroup.commissioner) for commissioning. Download and install this on your Android device, turn on Wi-Fi and start the app. Then follow these steps after ensuring all the requirements listed above are satisfied:
 
 1. Set up a connection to the Wi-Fi access point to which the Thread border router is connected. When connected, the application lists your Thread border router(s).

docs/tutorials/using_apis/mesh/thread_intro.md

@@ -44,6 +44,7 @@ Nanostack provides a set of C API headers with more functionalities. The [nanost
 - `thread_diagcop_lib.h` for building and parsing the Thread diagnostics protocol TLV messages.
 - `thread_meshcop_lib.h` for building and parsing the Thread mesh commissioning protocol TLV messages.
 - `thread_net_config_api.h` for making neighbour discovery (ND) data requests.
+- `net_polling_api.h` for configuring the Thread node's sleep mode and polling interval.
 
 #### Thread devices you can build on Mbed OS
 
@@ -55,7 +56,7 @@ The Mbed OS Mesh API allows you to define 3 types of devices:
 
 In addition the Nanostack API allows you to define the Full end device (FED) device type.
 
-In most cases, the REED, MED and SED configurations are enough to build a network. In a SED device, the radio is switched off during the sleep times. To take the full advantage of the SED configuration, the application developer must implement the sleep procedures in the device.
+In most cases, the REED, MED and SED configurations are enough to build a network. The SED device can be configured to use sleep mode, in which case the radio is switched off between the polling times. To take the full advantage of the SED configuration, the application developer must implement the sleep procedures in the device.
 
 For an end device or a router example, see [mesh minimal example](https://github.com/ARMmbed/mbed-os-example-mesh-minimal).
 
@@ -122,6 +123,8 @@ The Thread network name and the extended PAN ID are received in the scanning pha
 
 After the authentication phase, the commissioner requests the Thread network leader to petition the commissioner to become an authorized commissioner. Here, the border router works as an arbitrator in the middle.
 
+The PSKc generation is described in the Thread specification.
+
 Now, the Thread network is ready to accept new joiner devices.
 
 1. The commissioner application scans the QR code, which is PSKd (Pre-Shared Key for device) + EUI64, from the device's label and informs the Thread network that this device is accepted to the network.