Validating connected standby

Enabling the low power consumption and constant connectivity of connected standby is a test and validation challenge for the system integrator. All components in the system—hardware and software—must work together to quickly turn power on and off while maintaining connection to the Internet.

This section describes test and validation best practices for system designers and integrators who are building connected standby PCs. It explains what platform components you should have functionally working before you begin testing power management during connected standby. Also included in this section is information about the built-in power management diagnostics in Windows 8.1, and a description of how to use Windows Performance Analyzer (WPA) to observe specific operations during connected standby. This information applies to Windows 8 and Windows 8.1.

In this section


Introduction to connected standby testing

Testing and validating the operation of a connected standby PC is a critical effort for the system integrator. Connected standby involves all hardware and software components on the system, and requires special attention to the core silicon or System on a Chip (SoC), networking devices (for example, Wi-Fi), and peripheral devices connected to the pins of the SoC chip.

Connected standby testing prerequisites

The SoC platform should meet a set of basic software and hardware requirements before you try to test and validate connected standby operation. These requirements help to ensure that any problems that might arise are quickly identified and easily debugged.

Connected standby SleepStudy

Starting with Windows 8.1, a software tool, SleepStudy, is available as an inbox component in all Windows PCs that implement the connected standby power model. SleepStudy can measure connected standby performance with minimal impact.

Using Windows Performance Analyzer to analyze connected standby issues

The Windows Performance Analyzer (WPA) lets you view traces of system activity displayed in a graphical format. WPA is used for many Windows performance and debugging scenarios, and is the second-level triage tool for connected standby issues that cannot be resolved by using SleepStudy.

Connected standby basic test scenarios

Stabilize basic connected standby functionality before progressing to more advanced test scenarios, such as those that have an active Wi-Fi connection. First, validate entry to and exit from connected standby. Then validate airplane mode and audio playback.

Connected standby Wi-Fi-connected scenarios

The goal of Wi-Fi-connected testing is to identify activities that should not be happening during connected standby and resolve them. The activities might be a result of network activities, real-time notifications, or unexpected hardware interrupts.

Connected standby roaming connectivity

Connected standby is designed to keep the system continuously connected to the right network at the right time. At all times during connected standby, Windows favors the highest performance and lowest-cost network that is available, and seamlessly transitions between wired Ethernet, Wi-Fi, and mobile broadband (MBB), as needed.

Connected standby resume performance

For users, the most noticeable benefit of using a connected standby PC is its ability to instantly resume from sleep. Connected standby resume performance is typically less than 500 milliseconds, as measured from power button press to powering on the display. Significant engineering in Windows, third-party drivers, and system firmware is required to achieve this high level of performance.

Optimizing connected standby

To optimize power savings during connected standby, start by reducing the amount of power that is consumed during the power floor—the state in which all components are idle and inactive and power is dominated by hardware static leakage. After the power floor is optimized, the power consumed by the Wi-Fi and communications devices can be reduced.

Connected standby stress and long-duration validation

System designers should run stress tests and long-duration tests on their connected standby systems to help identify and resolve potential reliability issues.


About connected standby validation

Starting with Windows 8, the connected standby power model enables applications to stay fresh, up-to-date, and reachable whenever a suitable network is available. For more information, see Introduction to Connected Standby.

Windows supports connected standby only on low-power PC platforms that include low-power hardware and meet Windows Certification requirements. Systems that are not specifically designed for connected standby continue to use the traditional PC power model, which is fully supported in Windows 8 and Windows 8.1. This section pertains only to PCs that implement the connected standby power model. It does not provide test guidance for PCs that implement the traditional ACPI Sleep (S3) and Hibernate (S4) system power states.

Before you start to test and validate your connected standby PC, we recommend that you build a close working relationship with your core silicon or SoC provider and with your Wi-Fi device provider. These components and their operation are critical to achieving proper connected standby operation. Comprehensive debugging and testing requires collaboration among the system designer, the platform firmware developer, the SoC provider, and the Wi-Fi device provider.



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