Rachid El Azouzi

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This paper studies distributed choice of retransmission probabilities in slotted ALOHA. Both the cooperative team problem as well as the noncooperative game problem are considered. Unlike some previous work, we assume that mobiles do not know the number of backlogged packets at other nodes. A Markov chain analysis is used to obtain optimal and equilibrium(More)
We investigate connectivity in the ad hoc network formed between vehicles that move on a typical highway. We use the common model in vehicular traffic theory in which a fixed point on the highway sees cars passing it separated by times with exponentially distributed duration. We obtain the distribution of the distances between cars, which allows us to use(More)
TCP performance degrades when end-to-end connections extend over wireless connections — links which are characterized by high bit error rate and intermittent connectivity. Such link characteristics can significantly degrade TCP performance as the TCP sender assumes wireless losses to be congestion losses resulting in unnecessary congestion control actions.(More)
Connectivity in vehicular ad hoc networks may degrade dramatically in sparse traffic and also high speed highways. In this paper we study a way to improve the connectivity by adding some extra nodes with higher transmission range which we call mobile base-stations. These nodes can also offer commercial services (e.g. advertisement, video, audio, etc.) to(More)
In this survey, we summarize different modeling and solution concepts of networking games, as well as a number of different applications in telecommunications that make use of or can make use of networking games. We identify some of the mathematical challenges and methodologies that are involved in these problems. We include here work that has relevance to(More)
We present a competitive model that describes the interaction between several competing telecommunications service providers (SPs), their subscribers, and a network owner. Competition between the service providers is assumed to take place in their pricing decisions as well as in terms of the quality of service (QoS) they offer. In turn, the subscribers’(More)
We consider the situation where N nodes share a common access point. With each node i there is an associated buffer and channel state that change in time. Node i dynamically chooses both the power and the admission control to be adopted so as to maximize the expected throughput, which depends on the actions and states of all the players, given its power and(More)
We study noncooperative routing in which each user is faced with a multicriterion optimization problem, formulated as the minimization of one criterion subject to constraints on others. We address the questions of existence and uniqueness of equilibrium. We show that equilibria indeed exist but uniqueness may be destroyed due to the multicriteria nature of(More)
Multimedia data transmission over wireless networks often suffers from delay, jitter and packet loss. The main problem to implement a wireless network is the high and variable bit error rate in the radio link, making it necessary to use an additional error control mechanism. The traditional techniques for error control are ARQ (Automatic Repeat Request) and(More)
The goal of this paper is to study the behaviour of viewcount in YouTube. We first propose several bio-inspired models for the evolution of the viewcount of YouTube videos. We show, using a large set of empirical data, that the viewcount for 90% of videos in YouTube can indeed be associated to at least one of these models, with a Mean Error which does not(More)