Network Midleware for Mobile and Pervasive Large Scale Augmented Reality Games
Authors
Abstract
Mark Weiser theorized about a new kind of computing, called ubiquitous or pervasive computing, wherespecialized elements of hardware and software would be so ubiquitous no one would notice their
presence. According to Mark Weiser the technology required for ubiquitous computing would come in
three parts: cheap, low power computers including equally convenient displays, software for ubiquitous
applications and a network that ties them all together.
In the current decade we will see the merger of telecommunications and IT worlds. The Internet
Protocol (IP) is the network layer protocol in the 3GPP specifications, and the current trend in
developing new telecommunications networks is to utilize internet protocols. So, the network that ties
all things together is now possible. But there are many issues under study in the internet community.
These are mobility, quality of service, security, management of networks and services, discovery, ad -
hoc networking and dynamic configuration, and geospatial location.
A significant requirement of pervasive applications is fast service development and deployment, which
implies the introduction of various service and application frameworks and platforms. For this,
middleware is a common solution. The benefits of middleware utilization are the improved
programming model, and the hiding of many implementation details, which make middleware based
application development much faster.
It is now becoming quite clear that entertainment, and more specifically mobile gaming, will be one of
the killer applications of future wireless networks, however, mobile gaming applications face issues that
are different from fixed network applications. These issues include fluctuating connectivity, quality of
service and host mobility. Another issue is how to manage game state consistency with a dynamic
mobile networked environment in which devices may be physically close but topologically distant.
Further yet, there is the issue of how to manage multiple wireless network connections such as, for
example, GPRS and IEEE 802.11 at the same time.
Augmented reality extends reality with virtual elements while keeping the computer in an assistive,
unobtrusive role. It is possible to create games that place the user in the physical world through
geographically aware applications. The latest mobile phones are being equipped with GPS receivers and
there are software and hardware tendencies from the largest manufacturers to equip mobile phones
with more advanced context - aware technology. All the latest mobile phones are equipped with
cameras and some of the latest ones are coming with some form of 3D rendering technology. Bluetooth
technology and increasing miniaturization makes possible, in the near future, specialized pervasive
equipment for augmented reality. The opportunity for some cheap augmented reality is here.
To our knowledge, there was no specialized network middleware solution for large-scale mobile and
pervasive augmented reality games.
The main objective of this PhD was the creation of a network middleware for mobile communications
that will enable integrated large-scale augmented reality applications to be built around it.
The middleware that was created evolved from previous work from the candidate in the area of
interactive distributed multimedia, more specifically in state transmission for a collaborative virtual
environment middleware platform, the Status Transmission Framework (STF). This platform extended
ARMS - Augmented Reliable corba Multicast System - with capabilities for the handling of state
transmission for distributed collaborative virtual environments.
In this context mechanisms were studied, proposed and evaluated to deal with issues ranging from
Internet issues to architectural issues.
The internet issues are: Mobility (such as fluctuating connectivity, host mobility and handling of multiple
simultaneous network connections), Quality of Service (QoS - such as minimizing delay and jitter, and
reliability), security (such as authentication and prevention of cheating), management of networks and
services, discovery, ad-hoc networking and dynamic configuration, geospatial location and orientation.
The architectural issues are: scalability; consistency; multimedia data heterogeneity; data distribution
and replication.
The main contribution of this thesis was the creation of a network middleware for mobile and pervasive
large scale augmented reality games, based in Java.
As sub contributions, we have the development of the total architecture of the system, the
development of the SENSACT API, a API for sensors and actuators in a PAN based on Bluetooth network
and Java CLDC, in connection with the STF PAN API. We also have the development of the Sixrm Reliable
Multicast protocol (part of the STF Server API). As for QoS we developed the QoS API, for the distributed
servers (part of the STF Server API) and for the clients (part of the STF PAN API), and for security we
developed the Security Architecture for the whole system. We also have proven system scalability.