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MB NITZ support

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Overview

Starting in Windows 10, version 1903, Windows supports Network Identity and Time Zone (NITZ) at the OS level for mobile broadband (MBB) devices. In previous versions of Windows, the only network time available at the OS level was Network Time Protocol (NTP), even though NITZ was supported at the modem level by all 3GPP-compliant modems. With NITZ support, Windows is able to receive unsolicited NITZ notifications from modems and publish necessary events to notify consumers of the NITZ timestamps.

For MBIM functions, no additional NITZ-related setup and provisioning is required. As long as a data connection is established over a cellular bearer, a modem can notify the OS any time it has received a NITZ timestamp from the network. Modems can receive NITZ notifications from the network infrastructure based on the mobile operator's own defined cadence and schedule, within the 3GPP specifications. NITZ notifications are unsolicited. Upon receiving the NITZ notification, the OS publishes the notification that NITZ data is available.

NDIS interface extension

The following OID has been defined to support NITZ.

MBIM service and CID values

Service name UUID UUID value
Microsoft Voice Extensions UUID_VOICEEXTENSIONS 8d8b9eba-37be-449b-8f1e-61cb034a702e

The following table specifies the UUID and command code for each CID, as well as whether the CID supports Set, Query, or Event (notification) requests. See each CID’s individual Section within this topic for more info about its parameters, data structures, and notifications.

CID UUID Command code Set Query Notify
MBIM_CID_NITZ UUID_VOICEEXTENSIONS 10 N Y Y

MBIM_CID_NITZ

Parameters

Operation Set Query Notification
Command Not applicable Not applicable Not applicable
Response Not applicable MBIM_NITZ_INFO MBIM_NITZ_INFO

Query

Queries the current network time. The InformationBuffer of MBIM_COMMAND_MSG is not used. The following MBIM_NITZ_INFO structure is used in the InformationBuffer of MBIM_COMMAND_DONE.

MBIM_NITZ_INFO

Offset Size Field Type Description
0 4 Year UINT32 The year as an integer. For example, 2014.
4 4 Month UINT32 The month (1..12), where January == 1.
8 4 Day UINT32 The day of the month, (1..31).
12 4 Hour UINT32 The hour, (0..23).
16 4 Minute UINT32 The minute, (0..59).
20 4 Second UINT32 The second, (0..59).
24 4 TimeZoneOffsetMinutes UINT32 The time zone offset, in minutes, from UTC. This value includes any adjustment for the current state of daylight saving time. This value should be set to 0xFFFFFFFF when time zone info is not available.
28 4 DaylightSavingTimeOffsetMinutes UINT32 The offset for daylight saving time, in minutes. This value should be set to 0xFFFFFFFF when daylight saving time is not available.
32 4 DataClasses UINT32 Data classes supported by this network. If this information is not available, this field should be set to MBIMDataClassNone.

Set

Not applicable.

Response

The InformationBuffer in MBIM_COMMAND_DONE contains an MBIM_NITZ_INFO structure.

Unsolicited Events

This unsolicited event provides the current network time and time zone information.

Status Codes

This CID only uses generic status codes defined in Section 9.4.5 of the MBIM specification revision 1.0.

OID Definitions

Hardware Lab Kit (HLK) Tests

See Steps for installing HLK.

In HLK Studio connect to hte device Cellular modem driver and run the test: TestNitzInfo - GSM.

Manual Tests

[NITZ] Time update while roaming on Cellular

  1. Place the Cobalt device in an RF cage with Cellular disabled.
  2. Enable Airplane mode.
  3. Disable Ethernet and all other connections.
  4. Set the time mode to manual.
  5. Set the time to 11:15AM 10/15/2016 UTC.
  6. Verify that the time is set to the value given in the system tray.
  7. Set the time mode to automatic.
  8. Turn on Cellular.
  9. Wait for the device to receive the NITZ information from the simulated cellular base station.
  10. Verify that the time is set to the value sent by the simulated base station.