the aim of this paper is to show how some measures of noncompactness in the banach space of continuous functions defined on two variables can be applied to the solvability of a general system of functional integral equations . the results obtained generalize and extend several equations . an illustrative example is also presented .

User modelling will extensively be used in future multiservice communication networks. By using its techniques, network operaters and service providers will be able to learn about the user habits and to serve his/her requests more efficiently. In this paper, we describe a correlation-based pseudometric that could be used for creating a model for estimation of the services the user is likely to ...

Fair access of the shared wireless medium among different contending stations is a very important issue, especially when quality of service needs to be provided. In the CSMA/CA-based IEEE 802.11 protocol, carrier sensing (CS), collision avoidance (CA) and contention resolution (CR), the three main components, affect its fairness. While the influences of CA and CR on the fairness have already be...

The tremendous increase of Internet users and the wide ranging need to support both multimedia traffic and other traffic leads to service differentiation schemes. Multimedia applications have uncompromising and strict deadlines and the packets are worthless if they arrive late than their associated deadlines. The aim of the proposed system is to improve the quality of service by increasing the ...

In this paper, we describe a mechanism for adaptive transmission of multimedia data, which is based on real time protocols. The proposed mechanism can be used for multicast multimedia data over heterogeneous networks, like the Internet, and has the capability to adapt the transmission of the multimedia data to network changes. In addition, the adaptive multicast transmission mechanism uses an i...

In this paper, we propose a novel medium access control (MAC) protocol, called SYN-MAC (for SYNchronized MAC), based on a binary countdown approach tailored for wireless networks. SYN-MAC has several attractive features such as simplicity, robustness, high efficiency, fairness, and quality of service capability. We evaluate SYN-MAC in terms of collision probability, system throughput, and packe...

We consider application-level quality of service (QoS) requirements in design of networks that provide delay and loss guarantees. Using this approach, we have designed a novel network architecture that in many aspects is more efficient than ones motivated exclusively by packet QoS. An overview of our work is presented in this paper. The centerpiece of our design is a traffic model that enables ...

A novel communication system named “OR cooperative UWB” is proposed by bringing OR (Opportunistic Relaying) to UWB system. Particularly, the exact and closed-form symbol error rate (SER) expression is derived firstly in this paper. In order to maximize the capacity considering fairness between users, a definition of equivalent mean channel gain is given, and a joint resource allocation algorith...

In this paper we describe a mechanism for redundant multicast transmission of multimedia data supporting adaptive QoS over the Internet and we investigate its behaviour using simulation. There are two major issues that have to be considered when designing and implementing such a mechanism, the fairness, which is the ability to cope with receiver heterogeneity, and the adaptation schemes. The pr...