Mobile Computing

Synchronization ensures that any changes that are made to offline files and folders are propagated back to the network and that any changes that have occurred on the network are propagated to the user's computer. A general overview of synchronization options is presented earlier in this book. (See Managing Files, Folders and Search Methods.) This section discusses synchronization features and options that relate specifically to portable computers.

Configuring Synchronization for Battery-Powered Computers

In order for synchronization to occur, the hard disk on a user's portable computer must be powered up so that files can be copied from the network to the local cache and files in the local cache can be copied to the network. This might not be an optimum use of power for a portable computer when it is running on battery power. Fortunately, there are configuration options that allow you to control whether synchronization occurs when a computer is running on battery power.

Enabling Synchronization During Idle

By default, offline files are not synchronized when a computer is in an idle state and it is using battery power. This is because portable computers rely on a low-power idle state to conserve battery power and you might not want to waste battery power synchronizing files. You can change this so that synchronization occurs when the computer is on idle even when the computer is running on battery power.

To enable synchronization during idle when running on battery power

  1. From the Start menu, point to Programs point to Accessories , and then click Synchronize .

  2. In the Items to Synchronize dialog box, click Setup .

  3. In the Synchronization Settings dialog box, click the On Idle tab, and then click Advanced .

  4. In the Idle Settings dialog box, click the Prevent synchronization when my computer is running on battery power check box to clear it.

Preventing Scheduled Synchronization

You can also schedule synchronization for specific days and times. Because a scheduled synchronization is often a low-priority task that consumes power, Windows 2000 allows you to prevent scheduled synchronization from running when a computer is operating under battery power.

To prevent scheduled synchronization when the computer is running on battery power

  1. From the Start menu, point to Programs and then Accessories , and then click Synchronize .

  2. In the Items to Synchronize dialog box, click Setup .

  3. In the Synchronization Settings dialog box, click the Scheduled tab.

  4. Click a scheduled task, and then click Edit .

  5. On the Settings tab, under Power Management , click the Don't start the task if the computer is running on batteries check box.

If a scheduled synchronization is in progress and a portable computer is shifted from alternating current power to battery power, you can have Windows 2000 cancel synchronization. This might occur if scheduled synchronization starts on a docked portable computer that is using a wireless network connection and the user performs a hot-undock.

To stop scheduled synchronization when the computer is running on battery power

  1. From the Start menu, point to Programs and then Accessories , and then click Synchronize .

  2. In the Items to Synchronize dialog box, click Setup .

  3. In the Synchronization Settings dialog box, click the Scheduled tab.

  4. Click a scheduled task, and then click Edit .

  5. On the Settings tab, under Power Management , click the Stop the task if battery mode begins check box.

Enabling Automatic Connection During Scheduled Synchronization

If a computer is not connected to a network when scheduled synchronization occurs, you can configure Windows 2000 to connect so that synchronization can occur. This might not be desirable for portable computer users, especially if they frequently use the portable computer while it is disconnected from the network. In this case, Windows 2000 attempts to connect to the designated network, detects that the computer is not connected to the network, and then informs the user that the network is not available. By default, Windows 2000 does not connect if there is no network connection at the time of synchronization.

To enable automatic connection for scheduled synchronization

  1. From the Start menu, point to Programs point to Accessories , and then click Synchronize .

  2. In the Items to Synchronize dialog box, click Setup .

  3. In the Synchronization Settings dialog box, click the Scheduled tab.

  4. Under Current synchronization tasks , click a scheduled task, and then click Edit .

  5. On the Synchronization Items tab, click the If my computer is not connected when this scheduled synchronization begins, automatically connect for me check box.

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Note

You can also enable automatic connection during scheduled synchronization when you first schedule the synchronization.

Windows 2000 does not provide a system-wide definition or threshold for a slow link; rather, Windows 2000 allows every system component to define a slow link in terms of its own capabilities and requirements. For example, one component might define a slow link as 28.8 kilobits per second (Kbps), while another might define it as 56 Kbps. For Offline Files and synchronization, a slow link is defined as any connection that operates at 64 Kbps or slower, which is the speed of a single-channel Integrated Services Digital Network (ISDN) connection. Therefore, most modem connections through telephone lines are considered slow link connections with regard to offline files synchronization. This is important because synchronization behaves differently depending on whether the network connection is considered a slow link or not.

A slow link connection affects synchronization two ways: it prevents the automatic transition of shared network folders to an online state, and it prevents newly added files from being pulled from the network share to the user's computer during synchronization. This behavior is not configurable, but it is important to know how the behavior affects portable computer users.

Transitioning from an Offline State to an Online State

After a network share has been offline to a user (for example, a server goes offline and is then brought back online, or a user undocks their portable computer and then docks it), it becomes available online for the user if three conditions are met:

  • No offline files from that network share are open on the user's computer.

  • None of the offline files from that network share have changes that need to be synchronized.

  • The network connection is not considered a slow link.

When all of these conditions are satisfied and a user opens a file on the network share, the user is working online on that network share. Any changes that the user makes are saved to the file on the network share as well as to the file that is stored in the Offline Files folder. When any one of these conditions is not met and a user opens a file on the network share, the user is still working offline, even though the network share is available. Any changes that the user makes are saved only to the offline version of the file.

When a user first connects to a network over a slow link connection, the user also is working offline on any shared network folders, even though the folders are available. To start working online with a shared network folder, the user must synchronize the shared network folder. Synchronization shifts the folder to an online state and pushes any offline files that have changed to the shared network folder. It does not pull files on the shared network folder to the Offline Files folder. To do this, the user must perform a second synchronization, which pulls files that have changed from the network share to the Offline Files folder.

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Note

When you are using a slow link connection, a second synchronization does not pull newly created files from the network share to the Offline Files folder. To make new files on the network share available offline during a slow link connection you must manually pin the files.

Making Network Shares Available Without Synchronization

As discussed in the previous section, slow link connections can prevent a network share from coming online even though the network share is available. Although you can bring the network share online by synchronizing it, this method might not be ideal — for example, when a user's portable computer is disconnected from the network and the user requires access to a file on a shared network folder that has been made available offline, a file to which the user has made several changes offline but is not ready to synchronize with the network share. Another example is when a user is in a hurry and does not want to take the time to synchronize files — the user wants only to connect to the network, get the new file from the network share, and then log off. Windows 2000 provides a way of doing this.

To make a folder available online without synchronizing offline files

  1. In the System Tray, click the Offline Files icon to open the Offline Files Status dialog box.

  2. Click the Work online without synchronizing changes check box.

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Note

The Offline Files icon appears in the System Tray when users are working offline.