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from what is referred to as the "use your own device" or "bring your own
device" operation model. Devices owned by the end‐user are handled more
carefully, have a longer service life, the users are more satisfied and need
less support because they identify with the product. The chapter on the
economic factors looks at this topic in more detail. The disadvantages of this
solution are clearly in the field of security. Enterprise data is stored on
devices over which the enterprise has only indirect influence. The user using
their own private device to access company data is unlikely to be approved
by the company to manage encryption, firewall, anti‐virus protection and
such like. Based on this consideration, the market for a “client hypervisor”
started to grow. Thanks to this virtualisation solution, the user's terminal
device (e.g. smartphone, laptop, etc.) can support parallel operation of two
or more instances of operating system or application. This means that the
hardware can run a private instance and an enterprise managed instance of
an Operating System or application at the same time. As an example of PC
or laptop products in this area, consider Citrix XenClient or VMware View;
VMware has also already implemented virtualisation for Android
smartphones.
Network connections
Cloud services are provided online, either on an internal network, e.g. LAN
or WLAN, VPN or over the Internet. For this reason an adequate and stable
(
low latency) network connection is the major, technical prerequisite for the
use of a Cloud service. Network connections are mainly defined by two
parameters: the available bandwidth (that is the volume of data that can be
transported per unit of time) and the latency. The latency measures how
quickly the users can expect a response to an action that they started.
Latencies have a major influence on the user experience, especially when
using remote desktop systems such as Microsoft RDS, Citrix
XenDesktop/XenApp or VMware View. The latency is normally directly
proportional to the distance to the sender, and this means that Cloud
services hosted on servers (using the above mentioned technologies) in
America or Asia are typically not very useful in Europe. The bandwidth
requirements for Cloud services depends, to a great extent, on the data to
be handled. For the majority of older legacy applications, provided via
Remote Desktop Services the bandwidth requirement is typically very low.
But it increases when video, audio and printing enter the field. Full HD video
conferencing which becomes common in UC applications requires, typically
a bandwidth of 1 Mb per second for each terminal device involved. This may
not be too high a value considering the bandwidth available in the consumer
field today, but in the case of an enterprise network where the subsidiaries
