Information Technology Reference
In-Depth Information
mobile host. Therefore, by considering the computing resource of the mobile
player, MiMAR adopts the centralized repository approach to design its
server system. In addition, the implementation of the centralized repository
can be broadly classified into three techniques including the file repository,
the repository in server memory, and the virtual repository [21]. Due to the
latency of the instability of the wireless signal, the transmission overhead
induced by the server on the mobile host has to be minimized. Hence, the
method of repository in server memory is implemented to achieve prompt
message exchange between the desktop players and the mobile players.
The use case diagram of UML illustrates the MiMRA architecture
(Figure 6.1). The MiMAR architecture can be roughly divided between the
server side and the client side. The server side contains the login server and
the game server; whereas the client side includes the login agent, a 3-D vir-
tual space scene file, and the application agent. The user has to register a user
name with a password to the login server before being allowed to join the
3-D virtual space. After successful registration, the login server will validate
the user information whenever a player wants to enter the 3-D virtual space.
The game server is responsible for exchanging dynamic shared states and
events between the desktop and the mobile players. On the client side, the
login agent provides an interface for the user to register and login to the 3-D
virtual space. For each registered player of the 3-D virtual space, the login
server will return a validation key to the login agent. This key will then
activate the application agent to enter the 3-D virtual space. The application
agent then takes over all the interactions until the player leaves the 3-D vir-
tual space.
To reduce the transmission delay between the server host and the client host,
the message pushing methodology is realized on the game server. There are
two known technologies (i.e., push and pull [22-23]) to implement a message
passing mechanism between the server and the client. The pull approach
demands the client to specifically request a message from the server; while
the push method allows the server periodically and automatically to send a
Client side
Server side
Login agent
Network
Login server
Desktop player
3-D Campus
User profile
3-D Browser
Network
Game server
Application agent
Mobile player
Figure 6.1
The use case diagram of the MiMAR system.
