| A very usual architecture is one consisting of a set of POS (Point Of Sales terminal), built on top of PC's, interconnected in a Local Area Network environment. Following the Client-Server model, a POS usually acts as a client, which eventually interacts with the server. This model does not work in the case of a server failure, and, even if the server is robust, the system can be easily collapsed when the number of clients increases and their demands are intense (i.e. multimedia traffic). Using the Client-Server model in such scenario leads to deficient service and slow response. Given a platform of a set of POS interconnected with an ethernet hub, the problem is how to distribute multimedia data fast and efficiently. We propose MCDP-LAN (Multimedia Content Distribution Protocol over LAN), a protocol that solves this problem.; To overcome the partial visibility problem that Mobile Ad-Hoc Networks (MANET) exhibit data link-level (level 2 OSI) routing protocols must be considered. Examples of protocols in use are the Ad Hoc On-Demand Distance Vector (AODV) routing protocol -reactive- and the Destination-Sequenced Distance Vector (DSDV) routing protocol -proactive-. A common feature these and similar protocols share is its complexity. Another consideration is that LAN are massively deployed and its protocols and applications are robust and well-known, therefore the idea of keeping them seems reasonable. An Ethernet LAN characteristic is the total visibility issue, that is, a broadcast frame reaches all members of the LAN, however, IEEE 802.11x MANETs do not have it. The proposed W2LAN protocol is a link-level layer protocol that transforms for the higher layers a 802.11x MANET into an Ethernet LAN, maintaining compatibility with other proven and well-established protocols. The benefit of using W2LAN is that a set of N nodes will have total visibility, eliminating the inherent problem of partial visibility that MANET networks present, without routing and position information. To evaluate the protocol, a SDL (Specification and Description Language) model with N nodes has been constructed, and a simulator instance automatically derived from it. The Cost/Benefit analysis consists of finding out the cost in number of frames being used by the W2LAN protocol in comparison with a conventional LAN under different set of parameters. |
