Information Technology Reference
In-Depth Information
of products on offer as well as stock and pricing information. The Store Agent is
spawned and transferred by the Store Manager to the Marketplace to enter an
auction as required.
Marketplace Manager Agent.
Coordination of the centralized Marketplace is
perhaps the most important factor in enabling the arena in which agents may buy
and sell products. The Marketplace Manager Agent organizes and administers
migration to the marketplace as well as allocating system resources required
in the auctioning process. In practical terms, this means that a public market
list, containing information on exactly what products are sought by whom, is
maintained. This list is monitored by both the Stall Manager agents, which
request to administer individual auctions and by the Store Agents who may
request entrance to a particular auction, should an auction be of interest.
Stall Manager Agent.
This agent is charged with the task of coordinating
the auction process. After acquiring an auction from the market list, the auction
is deemed to be open. A deadline for interestedpartiesaswellasopeningand
closing time values are set. At this point, the type of auction is also made known.
This can be any one of a number of auction protocols - e.g. Dutch or Vickrey [22,
12]. It is important to note at this point that the Stall Manager is what is termed
as an environmental agent. This means that the number of Stall Manager agents
in the system is not fixed and may be adjusted by the Marketplace Manager
agent as required. More Stall Manager Agents might be required at busy times,
for example. The bid, accept and reject messaging of participating auctions is
coordinated before the auction closes, at which point a winner is declared.
4.4
Implementation
The EasiShop (client-side) system is installed on a standard PDA - the iPAQ
3870. Bluetooth is used to determine the user's location. When the user is de-
tected as being in the broadcast range of a particular EasiShop HotSpot (an
area adjacent to a store within which agent communication may take place),
the user's location may be determined to within an accuracy of approximately
twenty meters. From a software perspective, the system components are imple-
mented in Java. Kaffe, a free JVM licensed under the terms of the GNU General
Public License, is used as the runtime environment. The operating system is
Linux. Bluetooth functionality is implemented via a runtime interface to the
Bluez [39] bluetooth protocol stack.
5 Toward Autonomic Wireless Sensor Networks
(AWSNs)
Wireless sensor networks (WSN) are a relatively new concept in distributed
computing and represent the third case study we will consider for ambient intel-
ligence. Former distributed sensing systems were generally comprised of many
Search WWH ::
Custom Search