| |
|
|
|
|
|
People Projects Contacts Technical Reports
reports  |
 ESPERANTO Click Here to view the POSTER presented at DOA 05 ESPERANTO is a middleware infrastructure for mobile/nomadic environments. Traditional middleware technologies aimed to provide a flexible support to transparency (of distribution and heterogeneity), in order to ease the development of enterprise distributed systems. However, some characteristics of mobile environments, such as resource constraints, the different performance of wireless and wired networks (in terms of stability, reliability, bandwidth and latency), and the mobility factor itself, make the traditional middleware solutions not suitable for supporting modern nomadic applications. We believe that the success of a mobile computing middleware will depend on the following three main factors: 1) management of device resources: each device, such as pda, smartphone, desktop PC, and laptop, require a specific resource management strategy tailored to its own characteristics; 2) optimization of network resources: wireless network infrastructures are characterized by limited bandwidth, frequent disconnections, high costs, and high bit error rate. The middleware layer should take these characteristics into account; 3) network node mobility: network topology frequently changes during a nomadic system's life-time; the middleware layer should allow users to interact with new services and other users during their movements; 4) interoperability: as one size does not fit all, diversity is the trend in the nomadic computing scenario. The effectiveness of a nomadic computing middleware depends on the openness of the architecture, and on its interoperability with existing solutions. In order to face these factors, a mobile middleware infrastructure should satisfy the following requirements. The infrastructure should not be too "intrusive" with respect to user devices: middleware platforms like CORBA are too complex for personal mobile devices. Approaches like minimumCORBA are useful, even though they do not satisfy other crucial requirements. Moreover, the number of active applications and devices in a mobile computing environment might be huge; for instance, in an UMTS environment, an international network consists of a lot of devices. Hence, scalability of both the hardware and software infrastructures is a crucial requirement to address. Traditional communication paradigms, such as the Remote Procedure Call, rely on fixed dependable connections; moreover, they assume the counterpart is always available. In mobile environments, disconnections and unavailability are the rule, not the exception; thus, the middleware infrastructure should provide primitives for decoupled interaction. As devices move while interacting with the nomadic computing system, they need a transparent mechanism to manage movements, disconnections, and migrations. The above mentioned requirements represent a sub-set of all the requirements of modern nomadic systems. These systems also need dynamic reconfiguration, reflection, adaptability, context-awareness, and spontaneous interworking between heterogeneous legacy solutions. The ESPERANTO middleware ambitiously aims to achieve the foregoing requirements. To download it please refer to to Protypes page.
|
2009
|
|
|
|||
|
|||
|
|
