Pallapa Venkataram

Applications of agent technology in communications: a review

The rapid growth in the Internet users and diverse services have made the researches and practitioners to think of intelligent tools that can assist the users and applications in delivering the required quality of services. In this context, software agent technology is expected to become the tool for development of future softwares in distributed environments such as mobile computing, E-commerce, telecommunication network management, etc. Agent technology can be classified as single- and multi-agent systems (distributed static and mobile agents). In this paper, we review the software agent technology applications in communications with more emphasis on mobile agents since it is an emerging agent technology. The popularity of the agent technology is due to its support to: component based software engineering, flexible operations, easy software maintainability, adaptability to the real world, and extensibility of the softwares.

Performance of a wireless access protocol on correlated Rayleigh-fading channels with capture

The throughput performance of a wireless media access protocol taking into account the effect of correlated channel fading, capture, and propagation delay is analyzed. For efficient access on the uplink (mobile-to-base-station link), the protocol makes use of the uplink channel status information which is conveyed to the mobiles through a busy/idle flag broadcast on the downlink (base-station-to-mobile link). A first-order Markov model is used to describe the correlation in the packet success/failure process on a Rayleigh-fading channel. The analytical results obtained through the first-order Markov approximation of the channel are compared to those obtained from an independent and identically distributed (i.i.d.) channel model. The Markovian-fading channel model is shown to provide better performance results than the i.i.d. channel model. Simulations show that a first-order Markov approximation of the Rayleigh-fading process is quite accurate. An enhanced version of the access protocol to take advantage of the memory in the fading channel behavior is proposed and analyzed. The effect of retransmission of erroneous data packets and propagation delay on the throughput is also analyzed. It is shown that the access protocol with an error detect (ED) feature is efficient in slow fading (e.g., pedestrian user speeds), whereas a retransmission protocol is more efficient in fast fading (e.g., vehicular user speeds).

A Dynamic Authentication Scheme for Mobile Transactions

Most of the existing authentication schemes for mobile communication are static in nature, and principally dependent on strength of authenticating identifiers for users identity. The acceptance of all the transactions of a user under a single authentication level is vulnerable. We propose a novel transaction based authentication scheme (TBAS) for mobile communication using cognitive agents. The proposed approach provides range of authentication based on mobile transaction sensitivity, and users behaviors. The TBAS uses mobile agents to gather user behaviors, and static agents for detecting transaction sensitivity, user history analysis, and for choosing appropriate authentication actions. The method has been simulated using the agent factory framework for cognitive agents generation, and their communication. The performance analysis, and the simulation of the proposed system shows that, there is a considerable reduction in the security cost compared to regular session based authentication schemes. By combining transaction based authentication with behavior analysis the authentication attacks can be effectively identified.

Review: Artificial intelligence approaches to network management: recent advances and a survey

With increased number of new services and users being added to the communication network, management of such networks becomes crucial to provide assured quality of service. Finding skilled managers is often a problem. To alleviate this problem and also to provide assistance to the available network managers, network management has to be automated. Many attempts have been made in this direction and it is a promising area of interest to researchers in both academia and industry. In this paper, a review of the management complexities in present day networks and artificial intelligence approaches to network management are presented.

Neural network based optimal routing algorithm for communication networks

This paper presents the capability of the neural networks as a computational tool for solving constrained optimization problem, arising in routing algorithms for the present day communication networks. The application of neural networks in the optimum routing problem, in case of packet switched computer networks, where the goal is to minimize the average delays in the communication have been addressed. The effectiveness of neural network is shown by the results of simulation of a neural design to solve the shortest path problem. Simulation model of neural network is shown to be utilized in an optimum routing algorithm known asflow deviation algorithm. It is also shown that the model will enable the routing algorithm to be implemented in real time and also to be adaptive to changes in link costs and network topology.

Energy efficient scheduling in 4G smart phones for Mobile Hotspot application

With higher data rates becoming reality, there are quite a few Internet sharing applications that are increasingly becoming popular on present day smart phones. These applications are very useful and are widely popular by names such as Mobile Hotspot, Tethering, and MiFi etc. Using these applications, multiple users (such as friends, family members and colleagues in a limited area) can share Internet from a single high speed wireless network link. Typically in this method, a mobile device (smart phone or dongle) connects to backbone network using communication networks such as 4G/HSPA+ etc. which provides high speed data link and mobile phone in turn acts as a local Internet access point for other devices using communication technologies like Wi-Fi/Bluetooth. Wi-Fi access points were originally designed to be operated as standalone devices connected with a power supply and hence no specific care was taken to save power of base stations. Though subsequent enhancements were made in specifications to incorporate power saving mode in Wi-Fi Technology to optimize power consumption of the clients, Mobile Hotspot applications does not come under the purview of such enhancements. Due to this, present day Mobile phones which run on battery and host these applications for acting as Wi-Fi Hotspot, demonstrate very poor battery life. We have performed few experiments with commercially available products, which show that technologies like LTE (Long Term Evolution) which act as the backbone for these mobile hotspot applications consume very high power. Together LTE & Wi-Fi are draining Mobile Station current at alarming rate. Effort of this work is to strike a balance between maximum achievable QOS (Quality of Service) for end users and increased battery life of mobile phone which is acting as WiFi access point. This can be achieved by efficiently coordinating power saving techniques provided by LTE/3G wireless communication specifications and those provided by Wi-Fi specifications.

An agent based synchronization scheme for multimedia applications

Synchronization of multimedia streams is one of the important issue in multimedia communications. In this paper, we propose an adaptive synchronization agency for synchronization of streams by using an agent based approach. The synchronization agency triggers one of the three synchronization mechanisms, point synchronization or real-time continuous or adaptive synchronization in order to adapt to the run-time and life-time presentation requirements of an application. The scheme or agency employs static and mobile agents for the following purpose: to estimate the network delays in real-time based on sustainable stream loss, to compute the skew, to monitor the loss and estimate the playout times of the presentation units. We have experimentally evaluated the scheme by using IBM Aglets and verified its functioning in terms of synchronization loss and mean buffering delays. The benefits of this agent based scheme are: asynchronous and autonomous delay estimation, flexibility, adaptability, software re-usability and maintainability.

An intelligent product-information presentation in E-commerce

Electronic commerce (E-commerce) web-sites must be equipped with multimedia presentations for effective marketing of their products. Providing required product-information to a genuine buyer is a complex task in the present day web-based service environments. In this paper, we propose a distributed proxy based electronic shopping model, which is intelligent enough to study the customer behavior and plan the presentations accordingly by using a flexible multimedia synchronization model. The multimedia synchronization model is located at the proxy. The model triggers one of the three synchronization mechanisms, point, real-time continuous or adaptive synchronization based on the customer buying probability. The synchronization scheme employs a set of static and mobile agents: to estimate the network delays, to compute the skew, to monitor the loss and estimate the playout times of the presentation units of product-information. We simulated the electronic shopping model and the synchronization model to evaluate their operation effectiveness in several network scenarios. The benefits of scheme are: intelligent planning of product-information presentations, asynchronous delay estimation, flexibility and adaptability.

Agent-based subsystem for multimedia communications

There are several issues in multimedia communications, such as resource allocation, quality-of-service (QoS) routing, synchronisation, playout compensation and so on, which affect the continuous and smooth running of a multimedia application. The Internet demands the design of flexible and adaptable multimedia services so as to offer better quality presentations to the user. In this context, agent technology is emerging as a promising solution to provide flexible and adaptable services in distributed environments. The authors propose a subsystem called Protocol Engineering and Technology unit – Agent-based Subsystem for Multimedia Communications (PET-ASMAC) at the client side, which is an intelligent multimedia communication assistant to facilitate multimedia presentation to Internet users. The PETASMAC comprises a set of static and mobile agents, which perform certain autonomous tasks (QoS routing, resource allocation, synchronisation and playout) that satisfy the full-service requirements of an application, and coordinate with each other to provide smooth and continuous multimedia presentations. PET-ASMAC is simulated in several network scenarios to evaluate its effectiveness. The subsystem considers presentations from a single server to a client. However, it can be easily extended for multipoint-to-point communication. The results are encouraging and the observed benefits of the agent technology in multimedia communications are flexibility, adaptability, customisability, maintainability, re-usability and support to component-based software engineering.

An agent based adaptive bandwidth allocation scheme for multimedia applications

Bandwidth allocation for multimedia applications in case of network congestion and failure poses technical challenges due to bursty and delay sensitive nature of the applications. The growth of multimedia services on Internet and the development of agent technology have made us to investigate new techniques for resolving the bandwidth issues in multimedia communications. Agent technology is emerging as a flexible promising solution for network resource management and QoS (Quality of Service) control in a distributed environment. In this paper, we propose an adaptive bandwidth allocation scheme for multimedia applications by deploying the static and mobile agents. It is a run-time allocation scheme that functions at the network nodes. This technique adaptively finds an alternate patchup route for every congested/failed link and reallocates the bandwidth for the affected multimedia applications. The designed method has been tested (analytical and simulation) with various network sizes and conditions. The results are presented to assess the performance and effectiveness of the approach. This work also demonstrates some of the benefits of the agent based schemes in providing flexibility, adaptability, software reusability, and maintainability.