Mobile access to the services in ambient networks

Abstract

Ambient Networks will enable mobile terminals to communicate in an environments populated by several networks, devices, services and artefacts in a transparent way to the final user. In these scenarios, one way of implementing services uses web service architecture. So it is important to study how these mobile devices will integrate efficiently to access web services. Because of the reduced capabilities of the mobile devices, their access to web services is not easy and might have some performance costs related to show data speeds and processing both HTTP commands and XML. Moreover, sOlne mobile devices could not support web service access and if supported it lacks of web service search engine. In order to allow mobile devices to access web services efficiently, giving a solution to the previous problems, we propose a new architecture based on a peer-to-peer with distributed hash tables network, as a gateway between the mobile device and web service. This architecture is a base software simulator for an Anlbient Network environnlent developed in our research group. Nodes of the peer-topeer network publish services, allow finding them easily and acting as a gateway to the mobile devices for accessing web services more efficiently.

A Reference Architecture for Mobile SOA

“…The following considerations influence the function of mobile devices as service consumers or service providers: Relocation of a service consumer or a service provider can change topology of communication network. Mobility can hinder access to previously available services and facilitate access to other environmental services. Hence, service discovery in a dynamic topology network of a mobile device is not as easy as it is for networks with fixed topologies [Ou et al., ; Reyes et al., ]. Maintaining the availability of a service when a mobile device roams between heterogeneous wireless networks is a key consideration [Autili, Caporuscio, and Issarny, ]. Mobile devices have low processing power that can be variable according to the mobile device being used. Mobile devices have limited memory size that can be variable according to the device being used. Mobile devices have limited bandwidth, variable according to the network being used. Mobile devices generally experience intermittent connectivity, some studies such as Philips, Straeten, and Jonckers [] consider (temporary) network failure as “the rule rather than the exception in nomadic (mobile) networks.” In comparison with desktop computers, mobile devices have smaller keypads. Hence, user interfaces (UIs) designed for desktop computers can be inappropriate for mobile devices. In comparison with desktop computers, mobile devices have smaller screens.…”

“…Pattern f recommends eliminating the SOAP processing cost from mobile consumers by doing interactions on behalf of the user via software agents [Adaçal and Bener, ] or a gateway [Reyes et al., ].…”

“…Pattern o suggests a mediation framework or a mediation element to cope with the resource constraints of mobile devices. The mediator responsibilities involve service invocation on behalf of a mobile service consumer [Reyes et al., ], WS‐Security processing of a mobile service provider [Srirama, Jarke, and Prin, , ; Asif, Majumdar, and Dragnea, ], WS‐Policy processing of a mobile service provider [Asif, Majumdar, and Dragnea, ], using agents to serve as a mobile proxy to continue service interactions regardless of mobile device disconnections [Leong et al., ], and to distribute service invocation tasks with small granularity such as discovery, extraction, selection, installation, invocation, and presentation of a service's output [Duda, Aleksy, and Butter, ].…”

“…In contrast to centralized registries, distributed registries are more scalable; distributed registries are based on protocols of peer‐to‐peer networks common in mobile SOAs. A pastry overlay network has a discovery time in the order of nLogn for n nodes of the overlay network [Reyes et al., ], a layered overlay network [Ou et al., ], and JuXTApose (JXTA) [Srirama, Jarke, and Prin, ] used in the distributed peer‐to‐peer registries of mobile SOAs.…”