Deliverable 04 is final: Specification of Service Discovery Platform Architecture
Based on the results of WP2, the concept of the network and service discovery platforms will be developed in the work package 3. The goal is to obtain a system requirement handbooks which specify the needed functionality, the possible protocol extensions needed as well as the development framework. Therefore, this deliverable concentrate on constructing a software demonstration of service discovery and composition.
In the demonstrator of SMONET-NGNI there have been developed mechanisms that show all aspects of how such problems which can be solved. Therefore, the design and implementation were the focus of D04 and in that documentation SMONET-NGNI provided is merely the design document in support of the implementation. The service, in the point-of-view of this document, is that of a meta-service which enables other application services to be discovered (through incomplete, and heterogeneous, network connectivity environments) and composed from service elements, if no requested service instance actually exists. The demonstration software is not a simulator. It is a fully functional system, but operates within very constrained bounds.
This document states explicitly, and attempts to justify, that SMONET-NGNI has assumed TCP/IP is present in the network whatever that network happens to be. Therefore, the state is that GPRS, WLAN, and UMTS support TCP/IP. Regarding WAP and i-mode, WAP 1.1 has being unlikely to survive for much longer and, therefore, was equally unlikely to still be present in the "next generation". However, if a better job was made of the WAP protocol stack to enable TCP (see WAP 2.0) SMONET-NGNI can also support WAP with their implementation. Regarding I-mode the same procedure is possible, but I-mode is an proprietary approach from NTT DoCoMo which will be merge into the WAP 2.0 standard. Regarding WAP, D03 describes the features, constraints, and chances to play an important role for NGN. This deliverable does not give attention about WAP and I-mode, because the approach is independent of the underlying application and service structure.
The results of current developments in both wireless data communications and mobile computers are being combined to facilitate a new trend: nomadic computing. Compared to today's traditional distributed systems, the nomadic computing environment is very different in many respects. Bandwidth, latency, delay, error rate, quality of display and other non-functional parameters may change dramatically when a nomadic end-user moves from one location to another and thus from one computing environment to another, for example, from a wireline LAN to a UMTS network. The variety of mobile workstations, handheld devices and smart phones, which allow nomadic end-users to access Internet services, is increasing rapidly. The capabilities of mobile devices range from very low performance equipment (such as PDAs) up to high performance laptop PCs. All these devices create new demands for adaptability of Internet services. For example, PDAs cannot display properly high quality images and as nomadic end-users may be charged based on the amount of data transmitted over the GPRS-UMTS network, they may have to pay for bits that are totally useless to them.
Confronted with these circumstances, the nomadic end-user would benefit from having the following functionality provided by the infrastructure: information about expected performance, agent monitoring and controlling the transfer operations, and adaptability. It is in situations like these where agent technologies will become very useful. User agents on user's device can discover the network, and locate and communicate with services on the network transparently to the user.
SMONET-NGNI started in this deliverable an investigating in ad-hoc networking services where a general use case illustrates a scenario of ad-hoc service discovery. Also a practical use case has been shown. Although FIPA has started to investigate the area with Nomadic Application Support specification and has started to talk about ad-hoc FIPA, there has been very little work done on ad-hoc agent network discovery. In the following SMONET-NGNI described how ad-hoc networking can be solved using a FIPA agent platform, especially a design and implementation for ad-hoc networking for FIPA-OS is described. Therefore a meta-service has been developed which enables other application services to be discovered (through incomplete, and heterogeneous, network connectivity environments) and composed from service elements.
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