Before Apple released the first iPhone in 2007, former Microsoft CEO Steve Ballmer infamously said at the USA Today...
CEO Forum that the iPhone wouldn't appeal to business customers because, "it doesn't have a keyboard, which makes it not a very good email machine."
Touchscreen technology, which most mobile devices use today, was unproven at the time, and Ballmer was clearly worried about users' ability to interact with desktop-centric apps such as email. The lack of keyboard hardware did not turn out to be a big barrier to enterprise adoption of mobile devices, but those concerns were not completely unfounded.
Mobile devices have a very different UI than PCs and laptops, which can make it challenging for mobile users to interact with certain business applications on their virtual desktops. As a result, it can be especially hard to deliver mobile VDI access when some applications aren't compatible with some devices.
Challenges of VDI access for mobile devices
In an ideal world, mobile users would be able to interact with virtual desktops using their mobile devices' native UIs. In most cases, the device UI is a touchscreen, as opposed to the keyboard and mouse used with PCs and laptops.
The problem arises with legacy applications and applications with no mobile equivalent. Those applications that aren't designed for a mobile UI can be challenging because users cannot take advantage of the device's native UI -- in many cases, the touchscreen.
Mobile devices, PCs and laptops all need a network connection to access VDIs. PCs rarely move, and users often use Wi-Fi on their laptops, so accessing virtual desktops isn't a huge problem. Users carry mobile devices everywhere they go, however, which means they might not always have an internet connection through which they can access their applications.
VDI offerings for mobile devices
To address the issues around mobile VDI access, vendors such as VMware and Citrix offer products that can simplify virtual desktop delivery.
The VMware Blast Extreme display protocol for VMware Horizon, for example, supports a range of devices and OSes, including Google Android and Apple iOS. Mobile VDI users can access virtual desktops through Blast Extreme and interact with them using the native touchscreen or the VMware Unity Touch toolbar. Blast Extreme uses the H.264 video format for display and allows users to access their virtual desktops without any software installed on their devices.
Citrix's HDX Mobile protocol for mobile access to virtual desktops via Citrix Receiver also supports native interface controls for touchscreens, as well as inertia-sensing controls. Alternatively, Citrix allows IT to redesign business applications that do not have a mobile version with the Citrix Mobile software development kit to improve the apps' mobile interfaces.
Citrix HDX's support of iOS devices is the most robust, including features such as Framehawk, a remote display technology for mobile workers, and Follow-Me Desktop sessions, which allow IT to access and take over remote desktops. Citrix Receiver for Android doesn't include those features, but it does support auto client reconnect and client drive mapping.
Parallels' Remote Application Server offers numerous utilities to help Android and iOS users interact with virtual desktop apps. The Quick Keypad allows users to navigate virtual desktops, and the Swiftpoint GT mouse allows mobile users to input commands, such as left- and double-click.
Microsoft Remote Desktop Services offers the Remote Desktop client for Microsoft Windows, iOS and Android devices. All of these device types can perform text and touch redirection for user input, but some features are device-type exclusive. Only Windows and iOS devices can perform clipboard image redirection, and only Windows and Android devices' Remote Desktop clients support mouse redirection.