Wireless Future - Telenor

Even when the user does not have an active session
going on, he might still be registered at a
device. This is specified so that any incoming
service requests will be delivered to this device.
If the user wants to change which device to
receive a possible service request on, he may
communicate this to the Virtual Terminal, which
will consider the new device as where to reach
the user. This situation is shown in Figure 19.
It should also be possible for the Virtual Terminal
to automatically change which devices to be
registered at according to the user profile and
depending on for example time of day and the
location of the user. In this case the user will not
have to tell specifically which device to use as
long as he has already configured his profile correctly.
6.3.3.2 Changing the Input and Output
If the user wants to change only some parts of
the input or output streams, the Virtual Terminal
should allow him to do so. These changes will
be relevant to the user in cases where he arrives
at places where more appropriate devices are
located or if his services are changing and hence
require different output or input quality.
The user should be able to tell the Virtual Terminal
through his active device which devices he
wants services to be delivered to at any time as
shown in Figure 20. He should be able to switch
back and forth as many times as he likes and to
any available devices he has access to.
The Virtual Terminal should always know what
type of devices the user wants to use. The user
can either specify this whenever he switches
to a new device, or if it is a previously known
device, this information can be contained in the
profile within the Virtual Terminal so that it
already knows what type it is, i.e. voice, video
or data, and whether it is offering output or input
capabilities, etc.
6.3.4 Adding and Releasing new Devices
Since each device often has a limited user interface,
the combination of several devices will
offer the user better user interfaces and hence
better services. During a service session a user
may want to add one or more elementary devices
with just input or output functionality, e.g. a big
screen display, speakers, microphone etc. or
more smart devices like PC, smart phone, etc. to
the session. We may consider the cases where
the new device is trusted or known by the Virtual
Terminal and where it is not.
6.3.4.1 Adding known Devices to a Session
In the case where the new devices are trusted or
known to the Virtual Terminal, e.g. devices at
Telektronikk 1.2001
the user’s home or office, the Virtual Terminal
already knows which services those devices can
offer and how they can work in combination
with the main active device. One can include
those devices in the user service profile on the
Virtual Terminal in advance, and with a few
simple key presses on the active device one can
request the Virtual Terminal to add or release
one or several of these devices to or from the
service.
This requires that the new devices have network
connection and the Virtual Terminal is responsible
for the rerouting and if required, for the splitting
of the stream. It means that the stream
should go via the Virtual Terminal. In the cases
when new devices do not have network connection,
Bluetooth may be used to add new devices
to the service, but then the Virtual Terminal does
not need to be involved in the adding process.
6.3.4.2 Adding unknown Devices to a
Session
If the new devices are unknown, the establishment
of a multi-device session is more complicated.
If a new device is unknown to the Virtual
Terminal, the IP address and the identity of the
device as well as information about which kind
of services the device can offer must be found
out. This can either be done manually by the
user or automatically by the active device. To
do this manually is often not preferred since it
requires user involvement. Another problem is
that unknown devices are also un-trusted by
each other, so some kind of mutual authentication
and access control has to be performed.
With an automatic process one is faced with
general problems like:
• Automatic discovery of devices. Both networked
and not networked devices;
• Ability of device to announce its presence to
the network;
• Ability to describe its capability as well as
query/understand the capabilities of other
devices;
• Seamless interoperability with each other and
self-configuration without administrative
intervention;
• Security issues.
Some new technologies like Universal Plug and
Play [13], Salutation [14], Bluetooth [2], Jini,
etc. [15,16,17] may be used to solve these problems.
When the identity and other characteristics
of the new devices are known, it is possible to
add them to the ongoing service session.
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