Welcome to Windows Phone 8.1 GDR2!

This release includes several improvements and new features from Microsoft.

To build a Windows Phone 8.1 GDR2 phone, follow the Windows Phone Partner Documentation except where it is contradicted, modified, or expanded by the material included in this section of the documentation.

Software changes

Customization and runtime configuration changes

These customization and runtime configuration changes are new for Windows Phone 8.1 GDR2.

New or updated feature Description
Video over LTE Customize specific settings and behavior for Video over LTE to meet mobile operator requirements including:

  • Showing or hiding the LTE video calling switch
  • Setting the default value for the switch
  • Customizing the name/label of the switch and the description
  • Specifying the timeout, in milliseconds, for the phone to remain in video transition state
  • Enabling video conferencing
  • Specifying the amount of time before a video call is downgraded to a voice call due to low video quality
  • Hiding the video charges dialog that is displayed when the user turns on the LTE video calling switch
Restore Start tile layout Append the OEM-defined Start screen layout to the bottom of the user's backed up Start screen layout when the user restores their device from a backup.
More phone languages Include support for these additional phone languages:

  • Bangla (Bangladesh)
  • Khmer
  • Kiswahili
  • Lao
Remove the trailing MSISDN digits on a SIM card Use to remove the trailing MSISDN digits that are appended to the service provider name (SPN) in the phone UI.
Use voice domain for emergency call branding Use to enable the voice domain to decide whether to use Emergency calls only or No service in the phone UI branding.
SimbldIccidTable.xml Create a SimbldIccidTable.xml to allow certain SIMs to disable one or more languages. For more information, see the Use SIMBLD to disable languages per ICCID section in Variant selection during runtime.
Key handling and ProvXML ordering improvements For more information, see the Selecting the variant section in Variant selection during runtime.


Provisioning and device management updates

These provisioning and device management features are new for Windows Phone 8.1 GDR2.

New or updated feature Description
PolicyManager configuration service provider Added the following new policies:

  • Connectivity/AllowManualVPNConfiguration
  • Connectivity/CellularAppDownloadMBLimit
  • Connectivity/WLANScanMode
  • Experiences/AllowTaskSwitcher
  • Security/AntiTheftMode
  • DataProtection/RequireProtectionUnderLockConfig
  • DataProtection/EnterpriseProtectedDomainNames
VPN configuration service provider Changes:

  • New AlwaysOn value in ConnectionType.
  • New Policies/AppIdleTimeout setting in the CSP.


Manufacturing changes

These manufacturing changes are new for Windows Phone 8.1 GDR2.

New or updated feature Description
MMOS image definition You can enable TShell in MMOS.


Testing changes

These software tracing changes are new for Windows Phone 8.1 GDR2.

New or updated feature Description
Use Field Medic from a command prompt New parameters were added to FieldMedicHelper.
LBS test API New location-based services (LBS) test library API.
Gathering custom Qualcomm modem logs with Field Medic Use to add custom modem logging profiles to Field Medic.
SSM firewall plug-in for Qualcomm modem logging in Field Medic Use to create an SSM firewall plug-in for Qualcomm modem logging.
Source: https://dev.windowsphone.com/en-US/O...Phone_8.1_GDR2