Mobile Multimodal Virtual Reality for Personal Teleservices
by Petri Pulli
Augmented reality merging real and
virtual environments to provide totally new services and interfaces to
mobile observers is the basis of the mobile multimodal virtual reality
system for personal teleservices, developed in the PIHVI (Picocellular
based personal virtual products and services) project at VTT Electronics
and University of Oulu Infotech Research Center. The research focuses on
the characteristics and components of wearable personal virtual reality
systems with augmented reality display systems, tracking systems, wireless
communications and wearable computing. The backbone of the mobile virtual
reality is a wireless picocellular personal surrounding network (PSN).
Currently, experiments are carried out with a multimodal personal augmented
reality user interface for Nokia 9000 Communicator product, which is a
small-sized combination of a notepad computer and a cellular phone.
Two major approaches to extend the use of computing resources beyond
a single workstation can be recognized: ubiquitous computing and augmented
reality. Ubiquitous computing is a term coined by Mark Weiser to mean a
situation, where small computational devices are embedded into our everyday
environment in a way that they can be operated seamlessly and transparently.
Augmented reality is a research approach that attempts to integrate some
form of computer media with the real world.
The core idea of our approach is that by using a very short distance
radio communication network it is possible to mix these two approaches.
Thus we suggest ubiquitous computing in the form where different devices
are computationally active. But instead of a multitude of different displays
and interaction devices we suggest that the interaction with all these
devices would take place in an 'augmented reality', for example by using
a head-mounted see-through display and a mobile phone/remote controller.
Essential requirements for augmented reality display systems are a stereoscopic
see-through head-mounted display and haptic displays providing touch and
force feedback for artificial surfaces. Tracking systems are needed for
head movement to synchronize and overlay virtual world with real world;
eye viewing direction for context sensitive viewing; hand and finger position
tracking for gesture recognition; I/O device tracking for data and command
entry and object tracking for synchronizing real and virtual worlds.
An essential requirement for personal augmented reality is that they
should work wireless, otherwise the human user is tied with cables and
the freedom of movement is lost. Wireless communication is needed between
components of the system and also between personal augmented reality system
and networks services, such as world models and other users or avatars.
Wearable computing means that the computing equipment is attached to the
user's body or clothes.
The backbone of mobile virtual reality is a wireless picocellular personal
surrounding network (PSN). The PSN network connects user's personal mobile
terminals like a head-mounted-display or a pen-shaped input device and
provides mobile access to other mobile and fixed networks.
The benefits of using very small cells in mobile virtual reality are
obvious. The smaller the cell size, the higher the throughput, because
there are fewer users in each cell and higher transmission frequencies
can be used. The diameter of a PSN cell in our system is going to be some
three meters, which enables the construction of small very low-powered
hand held terminals still capable of transmitting high bandwidth multimedia
data required by virtual reality applications.
Adjacent PSNs can change information directly without using a fixed
base station. This does not only enable wireless communication between
user's personal terminals but also makes it possible for two users to transmit
data to each other directly. In this way the number of expensive base stations
can be greatly reduced. To decrease the amount of computation power needed
by a PSN most of the heavy processes should be distributed across the fixed
network and executed in different network nodes.
The main components of the system are a fixed base station providing
access to fixed networks and their services, Personal mobile terminals
including virtual reality devices and a mobile base station providing connections
between mobile terminals and a fixed network.
Although we have experimented mainly with small electronics and tele-communication
products, we believe that our approach has a wide utilisation reserve.
The PIHVI project is co-funded by Technology Development Centre of Finland
(TEKES), CCC Software Professionals, Elektrobit, Nokia Mobile Phones, Polar
Electro, and Telecom Finland. We are interested in co-operation with other
ERCIM members, eventually in joint EU projects.
Please contact:
Petri Pulli - VTT Electronics
Tel: +358 8 551 2111
E-mail: Petri.Pulli@vtt.fi
Tino Pyssysalo - University of Oulu
Tel: +358 8 5531011
E-mail: tino@tks.oulu.fi
