LBS -System Clock Synchronisation Overview

LBS -System Clock Synchronisation OverviewThis topic describes how LBS synchronises the system clock with -time data received as part of the GPS signal. -

Introduction

The GPS signal contains accurate time -data. LBS can use this data to synchronise the system clock with GPS. The -system clock is synchronised with GPS at regular intervals if the difference -between GPS time and the system clock time exceeds a threshold time difference.

Key concepts

System clock: The mobile device clock that keeps system time.
Set clock plug-in DLL: An optional licensee ECom plug-in DLL used by LBS to set the system -clock. Symbian provides a default class that sets the system clock by calling User::SetUTCTime().

It -is only necessary to implement a set clock plug-in DLL if a licensee requires -to set the system clock by some means other than by calling User::SetUTCTime().

Whether -LBS uses a plug-in DLL or the Symbian default class is configured through -the LBS administration -service.
UTC: Co-ordinated Universal Time. A worldwide time standard. UTC is derived -from the GPS signal and is the time standard used to set the system clock.

API Summary

There are two separate APIs involved -with LBS system clock adjustment:

The LBS Set Clock Plug-in -Interface

Licensees can derive from the interface to create an implementation -class. The class is packaged as an ECom plug-in DLL which is loaded at startup -and used to set the system clock.
Automatic clock synchronisation

The LBS Set Clock Plug-in Interface

LBS defines -an interface class that is used to create a set clock plug-in DLL.

The -interface CGPSSetClockBase is shown in figure 2.

- Figure 2. CGPSSetClockBase is the interface for LBS set -clock plug-in classes. - -

To create a set clock plug-in, licensees create a class that derives -from CGPSSetClockBase and package it as an ECom DLL.

See How to implement a LBS set -clock plug-in DLL for more information.

Automatic clock synchronisation

LBS can perform -automatic synchronisation of the system clock. LBS administration settings -configure automatic clock synchronisation. The settings define the frequency -of automatic clock synchronisation and by how much the system clock and UTC -can differ before the clock is synchronised.

LBS system clock settings

LBS -administration describes how to configure LBS system clock synchronisation -settings using either the LBS Administration API or a repository initialisation -file.

-How to Implement -an LBS Set Clock Plug-in DLL -LBS Administration - + + + + + +LBS +System Clock Synchronisation OverviewThis topic describes how LBS synchronises the system clock with +time data received as part of the GPS signal. +

Introduction

The GPS signal contains accurate time +data. LBS can use this data to synchronise the system clock with GPS. The +system clock is synchronised with GPS at regular intervals if the difference +between GPS time and the system clock time exceeds a threshold time difference.

Key concepts

System clock: The mobile device clock that keeps system time.
Set clock plug-in DLL: An optional licensee ECom plug-in DLL used by LBS to set the system +clock. Symbian provides a default class that sets the system clock by calling User::SetUTCTime().

It +is only necessary to implement a set clock plug-in DLL if a licensee requires +to set the system clock by some means other than by calling User::SetUTCTime().

Whether +LBS uses a plug-in DLL or the Symbian default class is configured through +the LBS administration +service.
UTC: Co-ordinated Universal Time. A worldwide time standard. UTC is derived +from the GPS signal and is the time standard used to set the system clock.

API Summary

There are two separate APIs involved +with LBS system clock adjustment:

The LBS Set Clock Plug-in +Interface

Licensees can derive from the interface to create an implementation +class. The class is packaged as an ECom plug-in DLL which is loaded at startup +and used to set the system clock.
Automatic clock synchronisation

The LBS Set Clock Plug-in Interface

LBS defines +an interface class that is used to create a set clock plug-in DLL.

The +interface CGPSSetClockBase is shown in figure 2.

+ Figure 2. CGPSSetClockBase is the interface for LBS set +clock plug-in classes. + +

To create a set clock plug-in, licensees create a class that derives +from CGPSSetClockBase and package it as an ECom DLL.

See How to implement a LBS set +clock plug-in DLL for more information.

Automatic clock synchronisation

LBS can perform +automatic synchronisation of the system clock. LBS administration settings +configure automatic clock synchronisation. The settings define the frequency +of automatic clock synchronisation and by how much the system clock and UTC +can differ before the clock is synchronised.

LBS system clock settings

LBS +administration describes how to configure LBS system clock synchronisation +settings using either the LBS Administration API or a repository initialisation +file.

+How to Implement +an LBS Set Clock Plug-in DLL +LBS Administration +

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