Saša Dešić

Mobile agent based software operation and maintenance

The paper deals with a mobile agent based software operation and maintenance. Remote maintenance shell is described as the protected environment allowing software installation, modification and verification on the remote target system, without suspending its regular operation. It is based on the remote operations performed by mobile agents. Multiagent system with collaborative mobile agents, supporting software maintenance, and its architecture are elaborated. Remote maintenance shell implementation in one maintenance session is included.

Improving software maintenance by using agent-based remote maintenance shell

The paper deals with a method developed for software maintenance called remote maintenance shell. It allows software installation, modification and verification on the remote target system without suspending its regular operation. The method is based on remote operations performed by mobile agents. The role of remote maintenance shell in software maintenance is elaborated, as well as its architecture. A case study on version replacement of an object-oriented application is included.

Communication in machine-to-machine environments

It has been estimated that by the end of 2020 there will be 50 billion connected devices in Machine-to-Machine (M2M) networks. Such projections should encourage us to deal with the corresponding problems in heterogeneous M2M systems. First of all, devices can communicate through different access technologies (e.g. wireline, 2G/3G, WiFi, Bluetooth) and their communication can be classified as direct or indirect, internal or external. In this paper we explain differences between those types of communication and propose a new identification scheme that allows M2M devices to establish communication in every possible way. Secondly, there is a problem of device hardware and software diversity. To over-come this problem, we propose the usage of the Open Service Gateway Initiative (OSGi) framework.

Agents Based Load Balancing with Component Distribution Capability

Distributed processing has become inevitable in many areas today. It can be found in localized systems like multiprocessor computers, in client-server network configurations, in computer clusters or in widely dispersed systems like the Internet. Development of effective techniques for task distribution is considered as one of the biggest issues in parallel and distributed operating environment. Over the past years, a number of load balancing methods has been proposed. This paper describes simulation used for methods comparison. Contrary to the vast of known methods, which are based on client/server technology, a few recent methods are based on mobile agents. This article gives short review of achievements in this area and describes simulation used for agents based load balancing methods comparison. The paper also suggests enhancement in load balancing: mobile agents could include fresh node into the system by installing and starting necessary software components.

Grid Service Management by Using Remote Maintenance Shell

This paper presents a method called Remote Maintenance Shell (RMS) developed for Grid service management. It allows service management and maintenance of several versions without suspending its regular operation. The method is based on the remote operations performed by mobile agents. The RMS prototype implemented as a multi-agent system with stationary and mobile multi-operation agents is elaborated. A case study of monitoring service managing in the Grid system is included.

Distributed positioning: a network-supported method for satellite positioning performance improvement

Recent studies show that basic satellite positioning is reaching its limits in terms of performance improvements. Further enhancements in positioning performance can be based almost entirely on augmentation and procedures supported by other systems. Considering the complexity of the interrelationship with additional systems, intrinsically different solutions are being developed to solve the positioning performance improvement problem. Here we present a new concept in positioning. Dubbed distributed positioning, it merges basic satellite positioning with advanced and assisted positioning procedures. The resulting complex synergy unavoidably includes the use of additional technologies in mobile communications, wireless Internet, and advanced computer systems. The real advantage from the introduction of distributed positioning lies in its capability to provide a significant improvement in overall positioning performance. Latest navigation status and up-to-date local environment models are much easier to apply on rover positioning, compared with classical assisted-GPS positioning procedures. Distributed positioning presents a completely different approach in positioning performance improvement, opening new prospects in research and development not only in the field of the satellite positioning, but also in telecommunications and computer engineering.

Assisted satellite positioning

Although standard satellite positioning provides unbeatable performance, compared with other available positioning methods it still suffers from many environment-related issues. One of them is disruption of continuity of positioning service, usually caused by temporal inability to collect navigation data due to poor satellite visibility. This problem is particularly noticeable in urban areas, where high buildings often considerably decrease the satellite visibility. A number of GPS-based systems and services (among them the location-based services - LBS) rely upon continuous provision of satellite positioning service. In order to decrease as much as possible the time to first fix (TTFF) after temporal unavailability of standard positioning service, auxiliary communications systems deploy the functionality of assistance data provision to satellite positioning receiver. This article examines the content of satellite positioning assistance, the impact of assistance data on position estimate calculation algorithm and the means for assistance data distribution. Special emphasis is given on satellite positioning assistance for LBS, and the mechanisms for assistance data delivery through the mobile communication network are presented. In conclusion, assistance data are identified as the major contributor to satellite positioning performance improvement, with a brief list of related future activities given

Mobile agent-based software management in grid

This paper presents a method called Remote Maintenance Shell (RMS), developed for software management in large distributed environments. It allows software upgrading, testing and maintenance of several versions on a remote target system without suspending its regular operation. The method is based on the remote operations performed by cooperative mobile agents. A case study of software upgrading in the grid system is elaborated.

Satellite Positioning for LBS: A Zagreb Field Positioning Performance Study

Recent studies confirm the importance of satellite positioning in location-based services (LBS) development. A field study was conducted in suburban and rural areas near Zagreb, Croatia in order to examine the real-time data compliance with recently established positioning performance requirements for LBS quality of service (QoS). Data analysis was based on comparison between actual positioning performance and pre-specified positioning parameter values using defined comparative procedures. The results presented here confirm a good correlation between the actual and required positioning performance, even without implementation of any of augmentation or assistance positioning methods.

Designing user interfaces for elderly: A case study in applicability of thin vs. fat clients

One common approach in dealing with increased number of elderly is provisioning of IT based applications that strive to prolong their independent life. However, development of such applications is cumbersome and expensive. In order to simplify and ease the development of such applications, MPOWER framework has been developed. The MPOWER framework provides service based architecture and a set of predefined services that can be assembled into applications for elderly. In this article we give a brief overview of the MPOWER framework and concentrate on the issue of providing usable interfaces for the elderly. Specifically, we compare two versions of an application for the elderly, one using a thin and other a fat client. We demonstrate that although thin clients are simpler to develop, in many situations fat clients should be used as they can provide interfaces that are better accustomed to the elderly.