Databases Reference
In-Depth Information
example, in the accessing of DBs in which transactions can take a
long time.
Autonomous communications. The agents may make some decisions
on behalf of the user when representing the MUs. This may be inter-
esting, for example, when in the accessing of a DB some transactions
fail; in such a case, the agent can make the decision of retrying the
transaction or not, trying another one, and so on, considering the
knowledge that it has about the MU.
·
Remote communications. The agents can make use of remote facilities
or resources such as memory, CPU, and so forth. This may be inter-
esting when, for example, an MU does not have enough capacity
to develop a task; in such a case, an agent can realize the task in a
remote computer and, once the task is finished, return the results to
the mobile computer.
·
Recently there has been a great research effort with respect to the mobility
feature of agents. A mobile agent is not bound to the system where it begins
execution; it has the unique ability to move from one system in a network to
another. The ability to travel lets a mobile agent move to a system that con-
tains an object with which the agent wants to interact and take advantage of
being in the same host or network as the object. When an agent travels, it
transports its state and the code with it. Mobile agent technology, apart from
the previously mentioned advantages, allows us to migrate processes among
different machines.
10.8
Mobile Computer Design Features for Accessing Data
Services
The number of people who use or work with mobile computers is continu-
ously increasing. Although the performance features of those kinds of com-
puters in disconnected mode (e.g., laptops) are equivalent to those offered by
fixed computers, when they are connected to a wireless network, the same
performance does not hold. The intrinsic features of wireless commu-
nicationspoor quality, limited bandwidth, continuous disconnec-
tionsmake working connected to a wireless network more difficult.
However, one important wish of mobile users is to have the possibility of
working connected to a wireless network in the same way as working
