As we approach our next public milestone, we will begin to circle back to topics we covered in the blog and talk about the changes we’ve made to the product since the Developer Preview. As we've said often, we read the comments, newsgroup discussions, and reviews that have been written about Windows 8 and track the feedback carefully. We listen to this feedback by taking into account the source of the feedback and factoring in the intended audience for features as well as trying to reconcile conflicting feedback (no matter how many thumbs up votes there might be, we can promise that, for any design worth discussing, there are conflicting and equally valid points of view). Of course, we always consider the engineering feasibility of any changes we make—compatibility, security, performance, and so on.
Ilana Smith, a lead program manager on the Engineering System team, authored this post.
--Steven

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In Windows 8, we have a new experience for selecting the right file when file name collisions are encountered during a copy or move.
L. Brown said:Frequently, the reason two files have the same name is because they’re copies. Making a choice between two identical files is usually pointless – it’s unnecessary for a copy operation, and often unnecessary for a move operation. We looked at several methods of identifying duplicate files and decided that checking the file name, file size and date modified attributes was the most effective approach. They can be used to identify the vast majority of duplicate files quickly, efficiently, and with good backward compatibility compared to other methods like file hashes.
In the beta, we’ve added a new option to the detailed conflict resolution dialog. By checking the box in the bottom left of the dialog, you can filter out all files that match on name, size (down to the byte) and time (down to the granularity of the file system timestamp: 2 seconds for FAT, 100 nanoseconds for NTFS). The system will skip copying or moving these files. This functionality adds no additional time to the operation, works both locally and across networks, and on all types of systems and storage.
This check box is deselected by default (to ensure users opt into the changed behavior), but it persists once you select it.

JL asked:If both sides of the copy operation are on Windows 8 machines, yes, it will be able to take advantage of the increased network throughput on the fly, thanks to advancements in the Server Message Block (SMB) protocol to support multiple channels.
Tobi asked:
Will it be possible to pause the copy operation and resume it after reboot/sleep/hibernate?
In the beta, when a system sleeps or hibernates, the copy operation will automatically pause, and when the machine wakes, you can choose to resume the copy by clicking the depressed pause button. (We decided not to have copies automatically resume on wake, as the system environment may have changed significantly in the interim and we do not want to cause an error.)

gawicks asked:We have two types of user interaction that can occur during a copy job - we break these into two groups, “confirmations” and ”interrupts.” Confirmations like “Are you sure you want to permanently delete this file?” need to be completed before the copy operation can start. Interrupts are issues that the system encounters while copying, things like “File not found,” “File in use,” and file name conflicts.
The system presents all confirmations before it starts to move or copy files. While copying, any interrupt issues are queued and presented once the system has completed all the work it can. In the beta, we’ve made improvements in how confirmations are presented, making sure they don’t get lost amongst existing running copies.

xpclient said(See this Microsoft Answers thread for more information.)
We fixed it! As of the beta, it’s gone.

Raf askedIn Windows 7 and 8, JPEG rotation is lossless when both image dimensions are divisible by 16 (standard image sizes).
Additionally, Explorer now respects EXIF orientation information for JPEG images. If your camera sets this value accurately, you will rarely need to correct orientation. Look for a future blog post where we will discuss this in more detail.

In Windows 8, we continue to prioritize great performance. We pay close attention to milliseconds of lag and look for reductions. In Explorer, we found an opportunity for improvement in delays caused by icon overlays.
In Windows 7, we have a padlock icon overlay to indicate a private file. (You might recall that, due to the increase in shared files, it had superseded the ”palm up” overlay for shared files.) We recently found that checking for these overlays was adding about 120 milliseconds to our Explorer library launch tests. This might not seem like much, but we consider this a big delay.

Overlays have limitations – they can only show a single state, add a lot of visual noise, and can be confusing. The padlock overlay has been removed; this information is conveyed better by the “Sharing status” column.
This column has these advantages:

• Performance: The column is hidden by default, so the delay is incurred only when you opt into showing this information.
• Tri-state: This column has three values: Shared, Not shared, and Private, so you get more detail than you would from the icon overlay.
• Sorting/filtering: You can sort and filter the sharing status property, providing more powerful file management capabilities.

On Marina’s post about the Start screen, Boots112233 said:In the beta, you can now easily pin your favorite folders to Start, and take advantage of the rich customization functionality that we built into it to arrange the folders into groups and into any order you want.
Additionally, just as in Windows 7, you can pin shortcuts to executables to Start directly from Windows Explorer, which can be very useful for applications that don’t add themselves to the Start screen by default.

Jamie Thomson said:We agree, and so we added this as well. It is worth noting that there are sometimes conflicting points of view on whether advanced things should be in the GUI or in PowerShell, and how front and center they should be. We are always balancing the complexity of too many options and too many ways to do things. As you can see, there is no right answer, so we'll continue to balance these complex choices.
These menu items launch the PowerShell console. The PowerShell ISE continues to be available from the Edit command on a PowerShell file.

We had expected the introduction of the ribbon to Explorer to spur conversation, and it is fair to say the voluminous response was in line with our expectations. It’s exciting to work on something that brings so many different perspectives.
There were many reactions, and as we expected, there is a set of people who have an entirely negative reaction to the affordance and have been telling us about it in no uncertain terms. Our view is that we do need to move the user interface forward and accept that a vocal set of customers are just not happy with the direction we're going. When looked at broadly, that is balanced out by a majority of people who are happy and more productive with the changes. We remind folks that there are third-party tools available (likely the tools being used by this set of people), that provide a number of different interface paradigms. We do embrace the notion that third-party tools play an important part in the Windows experience.
That said, we’ve internalized your feedback, experimented with and tested various approaches, and used our co-workers as test subjects, in addition to the formal testing as you would expect. You’ll see three major changes in the ribbon in the beta.
Ribbon minimized by default: With the ribbon maximized in the Developer Preview, we’ve been able to learn a lot about how people interact with it, which has enabled us to tweak and fine-tune it. With the beta, we will be making a major change that brings Explorer in line with our design principles for Windows 8. As in our copy dialogs, Task Manager, and Metro style experiences, we will be reducing distractions and trusting users to discover functionality on their own, by minimizing the ribbon by default.

We’ve tested this change for a while now, and the results have been heartening. This is data from internal usage at Microsoft, which we know not to be representative of broad audiences, but is generally representative of the folks like you that engage in the dialog on the blog.
This data shows that our very tech-savvy users are generally fine with either setting, but that our heavier Explorer users are our ribbon maximizers. For lighter file browsing scenarios, we can provide a UI with reduced distractions, and still trust that users who want to really exercise Explorer functionality will maximize and leverage the ribbon.
Visible hotkeys: Our telemetry data has shown us that for users who actively choose to minimize the ribbon, their strong preference is to use hotkeys. The ribbon provides new ways to access functionality via the keyboard with keytips (those floating cues that pop up when you hit Alt), but traditional shortcut keys like Ctrl+V remain the most efficient method. We love shortcut keys (internally, their usage gets up over 85% of all Explorer commands issued), so we want to help more people discover them.
For the beta release, we’ve added hotkey information to the tooltips of relevant buttons.
User setting roaming: We want to make sure you only need configure your Explorer options once. If you maximize your ribbon, and add Undo and Map Network Drive in your Quick Access Toolbar, we want your Explorer to look like that every time.
For the beta release, we’ve added Explorer settings to the attributes that are roamed to your other Windows 8 PCs. In the “Sync your settings” UI, this shows up under “Other Windows settings.” (For more information about roaming user settings, take a look at Katie’s post.)
We really appreciate all your feedback on our previous posts. We believe it has contributed directly to an improved file management experience for Windows 8.
--Ilana Smith



Source

Recent advances in sensor technology are catalysts for the acceleration and evolution of user experiences on PCs. The ability to react to changes in ambient light, motion, human proximity, and location are becoming common and essential elements of the computing experience. Even something simple—like an ambient light sensor to adjust display brightness in a room with changing light—is potentially a basic scenario for desktop PCs. Of course, we also want to make sure you have full control over the use of these peripherals, since we know that different sensors leave open opportunities for risk or abuse that some folks might not be comfortable with. This post looks at the details of supporting sensors in Windows 8 and was authored by Gavin Gear, a PM on the Device Connectivity team.
--Steven

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The first system feature was automatic display brightness control, or what we call “adaptive brightness.” This was a feature that we first introduced in Windows 7 using ambient light sensors (ALS), and is targeted at mobile form factors like slates, convertibles, and laptops. With today’s display panels supporting brightness levels at approximately twice the intensity of what was common just a few years ago, this feature is more important than ever. By dynamically controlling screen brightness based on changing ambient light conditions, we can optimize the level of reading comfort, and save battery life when the screen is dimmed in darker environments.
You can see here that adaptive brightness helps you see content on the screen more clearly, since the screen automatically gets brighter when the tablet enters a bright environment. And for those of you who use your desktop PCs in a sunny room, you know this same thing can happen at different times of the day in different seasons.

Many smartphones and other mobile devices have established the expectation that when you rotate the device, the graphic display will also rotate and adapt to the new orientation (including adapting to aspect ratio changes). Data from an accelerometer allows the device to determine its basic orientation. By automatically rotating the screen, people can use their devices (primarily slates and convertibles) in a more natural and intuitive way, without needing to manually rotate the screen with software controls or hardware buttons.

Beyond figuring out the basics for how a Windows 8 system might use sensors, we also needed to think about how apps might use sensors. We looked at a variety of examples of sensor-enabled apps including games, commercial applications, tools, and utilities, to help us determine which scenarios to support.
First on the list was the ability for apps to understand motion and screen rotation. This requires an accelerometer – a device that can be used to measure the force due to gravity, and the motion of the device itself. But most scenarios require more than just an understanding of motion and gravity. Orientation is also an important requirement for many applications. To enable a PC to understand orientation we needed to integrate the functionality of a compass.
Supporting a compass would at minimum require a 3D accelerometer (which measures acceleration on three axes) and a 3D magnetometer (which measures magnetic field strengths on 3 axes). This combination of sensors is called a 6-axis motion and orientation sensing system, and can support a basic tilt-compensated compass, screen rotation, and certain casual game apps like a labyrinth style game. However, in our testing and prototyping, we found the 6-axis motion sensing system has two key drawbacks: sporadic compass inaccuracy, and a lack of the responsiveness required by 3D interactive games.
Recently, a new type of sensor has started to emerge on phone platforms – the gyro sensor. Gyro sensors measure angular speed, typically along 3 axes. You can also use the data from gyro sensors to increase the responsiveness and accuracy of 3D motion-sensing systems. A gyro sensor is very sensitive, but it lacks any form of orientation reference (such as gravity or north heading).
This diagram shows how gyro data is represented as a set of three rotations along the three primary axes for the device:

Initially, some thought that the need for such sensors was scoped to very few apps, such as specialized games. But the more we examined the 3D motion and orientation sensing problem, the more we realized that applications are much more immersive and attractive if they react to the kind of motion humans can easily understand, such as shakes, twists, and rotations in multiple dimensions. With these kinds of sensors it would certainly be possible to build very immersive 3D games, but it would also enable lots of other apps to more naturally respond to input from a variety of motions, including mapping and navigation applications, measuring utilities, interactive (between two machines) applications, and simple apps like casual games.

We started our exploration into motion apps by prototyping some 3D experiences. The first challenge was to map the physical orientation of the device directly to a virtual 3D environment in the app. We decided to model a simple augmented reality experience by emulating a tablet as a window into a virtual world. The concept was fairly simple: when you move the device while looking at the screen, the virtual environment (the inside of a room) would appear to stay stationary.
Initially, we tried an experiment using the accelerometer to map up and down movement of the device to up and down movement of the 3D environment in response. When you hold the device still, the scene should remain stable. When you tilt the device, the view should tilt up or down. Right away we encountered an issue: “noise” in the data from the accelerometer sensor was causing jittery movement of the 3D environment even when the device was held stationary. We were able to see this noise clearly by capturing accelerometer data and charting it.

Without noise, the lines on the chart would be straight, with no vertical deviation. The conventional way to remove such noise is to apply a low-pass filter to the raw data stream. When we implemented this mitigation in our prototype, the resultant motion was smooth and stable (jitter-free). But the low-pass filter introduced another problem: the app lost responsiveness and felt sluggish when responding to motion. We needed a way to compensate for this jitter without reducing responsiveness.
The next experiment was to provide the ability to “look left” and “look right” in our virtual 3D environment app. We used a 6-axis compass solution (3D accelerometer + 3D magnetometer) to support this type of movement. Although this kind of worked, the movement was not consistent due to the general instability of the 6-axis compass. It was also challenging to blend the up-and-down movement with the left-and-right movement.
From these experiments it was clear that this combination of sensors could not provide the fluid and responsive experience we wanted. The accelerometer sensor was not providing clean data, and could not be used alone to determine device orientation. The magnetometer was slow to update and was susceptible to electromagnetic interference (think of a compass needle that sticks in one position occasionally). We had yet to experiment with the gyro sensors, but because gyros could only determine rotational speed, it wasn’t clear how they could help.

But further experimentation demonstrated that using all three sensors together could solve the problem. It turns out that an accelerometer, magnetometer, and a gyro can complement each-other’s weaknesses, effectively filling in gaps in data and data responsiveness. Using a combination of these sensors it is possible to create a better, more responsive, and more fluid experience than the sensors can provide individually. Combining the input of multiple sensors to produce better overall results is a process we call sensor fusion.
Essentially, sensor fusion is a case where the whole is greater than the sum of the parts. A typical sensor fusion system uses a 3D accelerometer, a 3D magnetometer, and a 3D gyro to create a combined “9-axis sensor fusion” system. To understand how this system works, let’s take a look at the inputs and outputs.
This diagram shows two types of outputs: pass-through outputs in which the sensor data is passed directly to an application, and sensor fusion outputs in which the sensor data is synthesized into more powerful data types.
Some applications can use pass-through sensor data directly. This data can be used at “face value” for a variety of scenarios. One such scenario is an app that implements a pedometer to count your steps as you walk. The graph below shows the output of the accelerometer for a person walking with a tablet PC. This graph clearly shows it is possible to detect every step the person took.


But, as our experiments revealed, many applications can’t effectively use the raw sensor data. Some of these applications include:

• Compass apps
• Enhanced navigation and augmented reality apps
• Casual games
• 3D gaming apps

Here’s a screenshot from a 3D game sample:

These applications need to use sensor fusion data in order to support the features they implement. The “magic” of sensor fusion is to mathematically combine the data from all three sensors to produce more sophisticated outputs, including a tilt-compensated compass, an inclinometer (exposing yaw, pitch, and roll), and more advanced representations of device orientation. With this kind of data, more sophisticated apps can produce fast, fluid, and responsive reactions to natural motions.
By integrating a sensor fusion solution, Windows 8 provides a complete solution for the full range of applications. Sensor fusion in Windows solves the problems of jittery movement and jerky transitions, reduces data integrity issues, and provides data that allows a seamless representation of full device motion in 3D space (without any awkward transitions).

While designing a sensor fusion solution for Windows, we also needed to help hardware designers to take advantage of this solution by partnering with them early. Designing a sensor fusion system is relatively easy if you’re designing a single device. But Windows runs on many kinds of PCs in many form factors, using hardware components from many different manufacturers. We needed to provide a solution that enabled the entire ecosystem of Windows hardware partners to participate.
The first step was to provide a baseline of performance for sensor packages that would work with Windows’ sensor fusion solution. Using Windows certification guidelines, we provided specifications for sensor performance. To help hardware companies verify that their solutions were compatible with Windows, we built a number of tests, which we provide with the Windows Certification kit.
Reducing the cost of developing and supporting drivers was another challenge. In order to make it simpler for sensor hardware manufacturers and PC makers, we wrote a single Microsoft-supplied driver that would work with all Windows-compatible sensor packages connected over USB and even lower power busses like I2C. This sensor class driver enables hardware companies to innovate with sensor hardware while ensuring that their hardware can be supported easily with drivers that ship with the Windows operating system.
To help speed adoption of the class driver, Microsoft worked with industry partners to introduce the specification into public standards. In July 2011 the standard for sensors was introduced in the HID (Human Interface Device) specification of the USB-IF (HID spec version 1.12, introduced with review request #39). This standardization enables any sensor company to build a sensor package that is compatible with Windows 8 by following the public standard USB-IF specifications for compliant device firmware. This reduces the time and cost required to integrate sensor hardware with Windows 8 PCs. Other benefits include a lower support cost and more consistent hardware capabilities for Windows 8 PCs that are equipped with sensors.
But beyond standardizing the class driver, we also wanted to optimize the performance of the sensor fusion solution, and minimize its impact on battery life. Each active sensor on a system draws power, and sending data up the stack consumes both memory and CPU time. We helped minimize the power and performance impact for sensor fusion systems running on Windows 8 in two major ways:
1. We architected the sensor fusion interfaces in Windows 8 to enable much of the processing of sensor fusion data to happen at the hardware level. This hardware-level sensor fusion capability means that computationally expensive algorithms don’t have to run on the main CPU, saving power and CPU cycles.
2. We implemented powerful filtering mechanisms that we tied directly to the needs of sensor apps running at any given point in time. This pay-for-play data and event model means that sensor data is only sent up the stack at the rate that apps need that data, and no faster. This results in greatly reduced CPU utilization for sensor data throughput.

To pull all of this together, our final challenge was to make the power and promise of sensor fusion available to those writing Metro style apps. To enable this, we designed a sensor API as part of the new WinRT. Through these APIs, developers can access the power of sensor fusion from any Metro style app. These APIs are clean and simple, and at the same time give developers access to the data needed to support everything from casual games to virtual reality applications. Of course these capabilities are all available as Win32 APIs for game developers or other uses in desktop applications.
The following JavaScript code snippet shows how easy it is to get access to an accelerometer and subscribe to events using the Windows Runtime:For more information about support for sensors in the Windows Runtime, please see this //build/ session on using location & sensors in your app.
You may be wondering at this point how you can try out sensor fusion on Windows 8, or even write some apps that use these new capabilities. Developers who attended the //build/ conference in 2011 received the Samsung Windows 8 Developer Preview slate PC, which included a full package of sensors. There were only about 4,000 of those given out, so of course, not everyone had the opportunity to get one. The good news is that the same 9-axis sensor fusion system that was built into the Windows Developer Preview device is now available online for purchase from ST Microelectronics. The “ST Microelectronics eMotion Development Board for Windows 8” (model # STEVAL-MKI119V1) attaches via USB, and works with the HID sensor class driver that’s included in Windows 8. If you’ve downloaded the Developer Preview version of Windows 8 and are itching to try out the sensor experience you should consider getting one of these devices.
Now let’s take a look at sensor fusion in action!
-- Gavin



Source

In this post, we dig into the details of how we have re-engineered the wireless networking stack to optimize it for both mobile broadband and Wi-Fi networks. We’ve done a ton of work to enable mobile broadband providers to make it easy for you to use 3G and 4G connectivity along with Wi-Fi in Windows 8. In addition to this architectural work, we’ve worked on keeping Windows connected to a network even when in a low-power state (when the screen is off, for example) when running on supporting architectures/PCs. You can learn more about this in the //build/ sessions on connected standby. Billy Anders, a group program manager on our devices and networking team, authored this post.
--Steven

We knew that if we were to give you true mobility, that Wi-Fi alone would not be enough. Therefore, for Windows 8, we fully developed and integrated mobile broadband (MB) as a first-class connectivity experience within Windows – right alongside Wi-Fi.
We first included mobile broadband in Windows 7, but if you were a mobile broadband user, you likely had a number of hurdles to overcome before connecting with mobile broadband. Yes, you needed the requisite mobile broadband hardware (e.g., mobile broadband dongle or embedded module and SIM) and data plan, but you also needed to locate and install third-party device drivers, and in some cases software, before ever getting your first connection. If the drivers for your device and software from your mobile operator were not available locally, you had to find another connection type (perhaps Wi-Fi) to the Internet to search for software on the websites of the PC maker or mobile operator. This placed a sizable hurdle in front of users trying to connect with mobile broadband, right when they most needed that connection.
We wanted to eliminate the guesswork in locating and installing device drivers for mobile broadband. We did this by working with our mobile operator and mobile broadband hardware partners across the industry, designing a hardware specification that device makers can incorporate into their device hardware. In Windows 8, we developed an in-box mobile broadband class driver that works with all of these devices and eliminates your need for additional device driver software. You just plug in the device and connect. The driver stays up to date via Windows Update, ensuring you have a reliable mobile broadband experience.
The USB Implementers Forum (USB-IF) recently approved the Mobile Broadband Interface Model (MBIM) specification as a standard, and major device makers have already begun adopting this standard into their device designs, including some designed for other operating systems. For more information on the specification, see the USB-IF press release.

Typically, mobile broadband devices come with radio and connection management software. Device manufacturers, PC manufacturers, and mobile operators all develop, distribute, and support these applications for you to connect to their networks, turn radios on and off, configure connection settings, and get contact information for help and support. Prior to Windows 8, you needed these applications to compensate for functionality not provided natively in Windows. This additional software confused and frustrated users by conflicting with the Windows connection manager, showing different networks, network status, and a separate user interface. Windows 8 eliminates this confusion by providing simple, intuitive, and fully integrated radio and connection management.
The new Windows 8 network settings allow you to turn individual radios on and off (Wi-Fi, mobile broadband, or Bluetooth), as well as disable all radios at once with the new “airplane mode.” Windows 8 provides native radio management to eliminate the conflicts and confusion, and to provide a consistent experience for controlling your radios without the need to install additional software. This is new for PCs even though it has obviously long been available on today’s mobile phones (or Windows Mobile phones, going way back).

The new wireless network settings in Windows 8 allow you to see and connect to all available MB and Wi-Fi networks from one convenient user interface. We made sure that this interface is consistent and allows you to think less about which network you want to connect. Windows does this by starting with the right default behaviors, and then it gets smarter by learning your network preferences over time.
One of those default behaviors is to prioritize Wi-Fi networks over broadband whenever one of your preferred Wi-Fi networks is available. Wi-Fi networks are typically faster, with lower latency, and have higher data caps (if they are not free). When you connect to a Wi-Fi network, we automatically disconnect you from your mobile broadband network and, when appropriate, power down the mobile broadband device, which also increases battery life. If no preferred Wi-Fi network is available, we automatically reconnect you to your preferred mobile broadband network.
To make sure we connect to the right network when multiple networks are available, Windows maintains an ordered list of your preferred networks based on your explicit connect and disconnect actions, as well as the network type. For example, if you manually disconnect from a network, Windows will no longer automatically connect to that network. If, while connected to one network, you decide to connect to a different network, Windows will move the new network higher in your preferred networks list. Windows automatically learns your preferences in order to manage this list for you.
When you resume from standby, Windows can also reconnect you faster to your preferred Wi-Fi networks by optimizing operations in the networking stack, and providing your network list, connection information, and hints to your Wi-Fi adapter. Now when your PC resumes from standby, your Wi-Fi adapter already has all the information it needs to connect to your preferred Wi-Fi networks. This means you can reconnect your PC to a Wi-Fi network from standby in about a second –oftentimes before your display is even ready. You do not have to do anything special for this – Windows just learns which networks you prefer and manages everything for you. This work was a major part of the architectural work we did in the networking stack and with our hardware partners.

Even with its broad availability, Wi-Fi by itself does not enable the ubiquitous Internet access that users increasingly want. True mobility requires mobile broadband, which provides connectivity over cellular networks (the same networks as your smartphone). However, just including mobile broadband in Windows 8 was not enough. We also wanted to remove any hurdles to getting you connected to mobile broadband, making it simpler, more intuitive, and more like Wi-Fi.
We made things simpler and more intuitive by fully integrating mobile broadband into Windows 8. When you’re ready to connect to a mobile broadband network, you simply insert your mobile broadband device or SIM card into your Windows 8 PC and we take care of the setup.
If you have a carrier-unlocked mobile broadband device that supports carrier switching (this includes most mobile broadband users outside the US), Windows 8 has native support that allows you to select and connect to any supported carrier from within the Windows UI.

We’ve already talked about how we removed the need to install a driver, or a radio and connection manager. We also automatically identify which mobile operator is associated with your device (or SIM card), brand it in the Windows connection manager with the mobile operator’s logo, configure the PC for connecting to the mobile operator’s network, and download the operator’s mobile broadband app (if they have one) from the Windows Store.
If you purchased and activated a data plan along with your SIM or mobile broadband device, all you need to do is connect to the network and we get out of the way, allowing you to do what you want to do.
If you don’t already have a data plan and would like to purchase one, then simply click the “Connect” button for the mobile operator you want, and we automatically direct you to their mobile broadband app or website, where you can select a data plan (for example, a time-based, limit-based, or subscription-based plan). 
After you’ve purchased your plan, your mobile operator provisions your PC over the air for their network, including information about your data plan details and Wi-Fi hotspots.

Behind the scenes, Windows identifies the mobile broadband subscriber information, looks up the mobile operator in the new Access Point Name (APN) database, and pre-provisions the system to connect to the operator’s network. Meanwhile, your core connection experience stays the same.
The operator’s mobile broadband app is available via the “View my account” link, or from the app’s tile on the Start screen. Here, you can see how much data you’ve used, pay your bill, manage your account, and get customer support.

Many of us have read headlines about people receiving surprisingly expensive bills from their mobile operators. The industry has termed this bill shock, and the problem has received enough attention that some governments have begun taking regulatory steps that ask mobile operators to alert their customers when their data usage reaches a certain threshold. Today, mobile operators all have different ways of responding when subscribers exceed their data usage allotment. An operator may block your Internet access, throttle (slow down) your data speed, or simply begin charging you per kilobyte or megabyte. If you are unaware that you are over your data usage limit, you will likely continue using your data plan and rack up additional charges, resulting in shock when you receive your bill.
Prior to Windows 8, we maintained consistent behavior on all types of networks relative to bandwidth usage. With Windows 8, we now take the cost of the network into consideration: we assume that mobile broadband networks have restrictive data caps with higher overage costs (vs. Wi-Fi), and adjust networking behavior with these metered networks accordingly.
As mentioned earlier, we automatically disconnect from mobile broadband and connect you to your preferred Wi-Fi networks whenever they’re available. This reduces your data usage on mobile broadband when possible.
Because many of us use public Wi-Fi, Windows 8 includes support for popular Wi-Fi hotspot authentication types, including WISPr (Wireless Internet Services Provider roaming), EAP-SIM/AKA/AKA Prime (SIM-based authentication), and EAP-TTLS (popular on university campuses). Windows manages the authentication for you when you come within range of a Wi-Fi network that uses one of these methods, so you won’t have to re-authenticate each time (for instance, by going to a web page). This means you get the same automatic behavior at a public Wi-Fi hotspot as you would at home or the office.
On a PC that has both mobile broadband and Wi-Fi, we’ll move you from MB to the less costly Wi-Fi network automatically whenever Wi-Fi is available, again reducing your mobile broadband usage and your potential for bill shock.
Another way we optimize your bandwidth usage is by changing the Windows Update download behavior. For a majority of users, who have turned on automatic updating, Windows Update will defer the background download of all updates until you connect to a non-metered network, such as your home broadband connection. There is one exception, as noted in our earlier post on Windows Update, and that is in the case of a critical security update to fix a worm-like vulnerability (e.g., a Blaster worm). In that case, Windows Update will download the update regardless of the network type. You can always override the deferred download by launching Windows Update and manually initiating the download of updates at a time more convenient to you. Again, you are in full control of your device.
We recognize that most fixed-line broadband plans also have data caps and overage fees. Those data caps are typically much higher than mobile broadband, and therefore we do not change the behavior for these connections. You are always in control and can always mark any wireless network as metered or unmetered by selecting “reduce data usage” in the right-click (or tap and hold) menu for that network.
We also want Windows applications to behave well on metered networks, so we’ve provided a new set of developer APIs within the ConnectionCost class of the Windows.Networking.Connectivity namespace. If you are an application developer, we encourage you to leverage these APIs and adapt the behavior of your app, such as allowing a low-definition vs. high-definition video stream, or a header-only vs. full-sync of email, depending on the network type. We believe that this adaptive behavior is critical, as it results in actual cost savings for end users. All Metro style apps in the Windows Store must implement these APIs if they use the network.
Even with Windows and other applications behaving smartly on the network, you still may to want to know how much data you have consumed. Windows 8 provides local data usage counters right within the network settings. These counters provide real time local data usage estimates for Wi-Fi and mobile broadband network connections.
The local counters keep track of the amount of data used on each individual network type so you don’t have to. You can reset the counter whenever you want, which may be useful if you want to monitor your usage month-to-month or even within a session. Although you should think of the local data counters as a quick way to determine your usage, they are not a substitute for what mobile operators report as their usage, which may vary slightly, and should be available in the operator’s app.
Another way we help you manage your mobile broadband data usage is by allowing mobile operators to alert you as you approach your bandwidth cap. Some countries have already begun to mandate that operators send messages to subscribers as they approach their bandwidth cap, or once they begin roaming to a different network. The mobile operator sends you an SMS or USSD alert as you approach your bandwidth cap (e.g., 70% used, 85% used, etc.), and the MB operator’s app notifies you and updates its Start screen tile. The following screen shots show what is already available in the Windows Developer Preview (and on the Samsung Preview PC that had an AT&T SIM and plan).
The Windows 8 task manager provides more granular information if you want to know how much data a particular app has consumed on the network. Here, you can see the approximate active and historical data consumption of any process over metered and non-metered networks. With this information, you can take control by identifying which apps are consuming the most bandwidth and taking action if needed.
Here’s a short video that demonstrates some of the new wireless networking features and enhancements in Windows 8.
We designed Windows 8 with you—and mobility—in mind. We set out to simplify your experience with getting and staying connected across mobile broadband and Wi-Fi networks, removing hurdles and whenever possible, doing the right things automatically for you.
-- Billy Anders



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