-The development of the ALOHA system packet broadcasting network at the University of Hawaii illustrates a number of general principles about the relationship between information theory and the design of real information systems. An anecdotal account is given of the development of the ALOHA system, emphasizing the interaction of the theory and the design of the experimental network. In addition...

In Underwater Acoustic Sensor Networks (UASN) designing Medium Access Control (MAC) protocol is a challenging issue. This is due to low bandwidth and high propagation delay in UASN. This paper proposes a MAC protocol for UASN called Aloha with Virtual Back off Algorithm (AlohaV). The VBA approach is the collision avoidance mechanism for wireless networks. In this proposed work we use VBA with n...

In this paper we present an exact finite-length analysis of frameless ALOHA that is obtained through a dynamical programming approach. Monte Carlo simulations are performed in order to verify the analysis. Two examples are provided that illustrate how the analysis can be used to optimize the parameters of frameless ALOHA. To the best of the knowledge of the authors, this is the first contributi...

In this report we describe the background and the properties of Aloha, which is a tool for learning structured programming. The learning approach in Aloha is based on understanding the program structures instead of the detailed syntax of the programming language. The implementation of Aloha supports both visual and active learning styles. The feedback from students encourages us to develop inte...

A fundamental part of a wireless system is the MAC protocol, whose main goal is to let the users quickly and orderly gain access to the needed bandwidth to transmit their information. The main problem in wireless communications is to overcome the disadvantage of the hostile characteristics presented by the radio channel. This paper deals with the proposal of a Retransmission Algorithm based on ...

We present the design, implementation, and experimental results of our soft real time (SRT) system for multimedia applications in a general purpose UNIX environment. The SRT system supports several service classes for the real time processes based on their processor usage time pattern: periodic constant processing time(PCPT) class, aperiodic constant processing time(ACPT) class, variable proces...

osting by E Abstract It is expected that many networks will be providing services at a time in near future and those will also produce different interfering signals for the current Slotted ALOHA based systems. A random packet destruction Denial of Service (DoS) attacking signal can shut down the Slotted ALOHA based networks easily. Therefore, to keep up the services of Slotted ALOHA based syste...

The concept and model of Spread Spectrum ALOHA (SS-ALOHA), as an important subject to develop dual-purpose satellite system in China, are described in this paper. The new synchronous code format and method for capturing the SS-ALOHA signals are presented and the process of correlation with surface-audio wave (SAW) is shown. The diagram of fast acquisition system and the results of experiment ar...

We address the problem of fair medium access control in multi-hop Aloha networks, with the objective of achieving proportionally fair rates. We consider a general multi-hop wireless network, and show how the attempt probabilities/attempt rates in Aloha protocols should be set so that the achieved rates are globally proportionally fair. For both slotted and unslotted Aloha, we argue that it is p...

Multimedia presentations can convey information not only by the sequence of events but by their timing. The correctness of such presentations thus depends on the timing of events as well as their sequence and content. This paper introduces a formal speci cation language for playback of real-time presentations. The main contribution of this language is a quality of service (QOS) speci cation tha...