T he integration of the Internet with telecommunication networks promises a distributed computing infrastructure that provides globally available services. The Internet's diffusion permits an almost ubiquitous availability of attachment points, allowing users access to its information services irrespective of their location. In addition, advances in cellular telecommunications and device miniaturization let increasing numbers of portable devices connect to the Internet. Several forms of mobility emerge in this scenario. User mobility requires providing users with a uniform view of their preferred working environments-user preferences and subscribed services-independent of their current positions in the network. 2 Terminal mobility allows devices to transparently move and connect to different points of attachment. Mobile access is an emerging issue that involves the dynamic adaptation of mobile-aware resources and services that mobile users and terminals can automatically retrieve regardless of their current location. Mobile computing requires an advanced infrastructure that integrates suitable support protocols, mechanisms, and tools. This mobility middleware should dynamically reallocate and trace mobile users and terminals and permit communication and coordination of mobile entities. In addition, open and untrusted environments must overcome system heterogeneity and grant the appropriate security level. Solutions to these issues require compliance with standards to interoperate with different systems and legacy components and a reliable security infrastructure based on standard cryptographic mechanisms and tools. Many proposals suggest using mobile agent technology middleware to address these issues. 4-6 A mobile agent (MA) moves entities in execution together with code and achieved state, making it possible to upgrade distributed computing environments without suspending service. We propose three mobile computing services: user virtual environment (UVE), mobile virtual terminal (MVT), and virtual resource management (VRM). UVE provides users with a uniform view of their working environments independent of current locations and specific terminals. MVT extends traditional terminal mobility by preserving the terminal execution state for restoration at new locations, including active processes and subscribed services. VRM permits mobile users and terminals to maintain access to resources and services by automatically requalifying the bindings and moving specific resources or services to permit load balancing and replication. Mobile computing benefits from the asynchronicity between user requests and terminal operations and their execution. For example, wireless connections impose strict constraints on available bandwidth and communication reliability minimizing connection time for wireless device support. The MA paradigm does not need continuous network connectivity because connections last only long enough to inject agents from mobile terminals into the fixed network. With autonomous agents, users can access services even if the terminal disconnects because the agents deliver the results upon reconnection. [4][5][6] Mobility middleware's location awareness facilitates service-specific optimization and allows users to adapt to
In the previous study REF , mobile agent is designed into a middleware for it does not need continuous network connectivity while performing tasks.
Mobile Agent Middleware for Mobile Computing
IEEE Computer
Computer Science