Information Technology Reference
In-Depth Information
augmented reality allows 3-D graphics to be overlapped with real images
while the user is navigating inside of the real world. Among the researches of
mobile augmented reality, MARS [18] and ARQuake [19] are two well-known
systems. Those two systems allow users to interact in an environment with a
“pervasive” graphical user interface. That is, the user can see a 3-D object on
top of, say, any wall within his FOV, without actually installing a screen on
that wall. This capability promotes the augmented reality to a more friendly
and daily application. However, one drawback of mobile augmented reality
is that it still isolates the user from each other. The user can only interact
with the environment alone and unknown to the existence of other players.
That is, it lacks the interoperability among users of mobile augmented real-
ity system. With such capability, users of mobile augmented reality systems
can perform social interaction such as playing a team game or performing a
work collaboration [20].
6.4 The Concept of Multiplayer Mobile Augmented
Reality (MiMAR)
MiMAR is designed to enable the player of the mobile augmented reality
system to join the conventional network virtual environment. To achieve this
goal, the MiMAR architecture is composed of two types of servers. One is
the multiuser server, called the game server, and the other is the mobile sup-
port server (MSS). The MiMAR is the study of adding multiplayer capability
to MAR. The basic idea of MiMAR is integrating NVE with MAR to enable
the distant users of MAR systems to interoperate with each other.
6.4.1 The Server architecture
Similar to the design goal of CVE [21], the MiMAR environment aims to pro-
vide an illusion to the distributed users that they all observe the same things
and interact with each other within the virtual space. This goal implies that
each player has to share his status and event with others within the virtual
space and for them to realize his existence by a graphic rendering engine.
This dynamic state sharing is achieved by message exchange among play-
ers of the virtual world. There are three general approaches to implement
this message exchange mechanism among hosts of a network virtual envi-
ronment. They are centralized repository, frequent state regeneration, and
dead reckoning [21]. Due to the instability of the wireless signal, the fre-
quent state regeneration approach can easily flood the wireless bandwidth
on the mobile host. Further, the instability of the wireless signal may also
cause the dead reckoning method to produce jittering remote avatars on the
