In this paper, we consider an integrated voice and data system over CDMA Slotted-ALOHA (CDMA SALOHA). We investigate its performance when multi-code CDMA (MC-CDMA) is applied as a multi-rate scheme to support users which require transmission with different bit rates. Two different classes of data users are transmitted together with voice. Performance measurement is obtained in respect of throug...

Ad hoc networks provide data communication services without being bound to an existing infrastructure. An exciting application of highly dynamic ad hoc networks is the exchange of data between running vehicles. For air-interfaces based on a slotted Time Division Multiple Access (TDMA) scheme, slot synchronization is required among the rapidly moving vehicles. In this paper a scheme for complete...

We propose a new packet reservation multiple access (PRMA) scheme for the joint transmission of voice and data traffics in a microcellular medium. The collision resolution protocol within the system is based on a modification of the window random access algorithm, which has superior properties compared to the conventional slotted Aloha. The proposed algorithm, which we call packet reservation w...

In this paper, we propose and present a new access persistence control mechanism for packet cellular networks, such as General Packet Radio Service (GPRS) system, in order to improve the MAC layer performance. The MAC layer in GPRS make use of slotted ALOHA protocol combined with a specific retransmission mechanism to establish the physical connection. The main object of the new mechanism is to...

Traditionally, random access protocols have been designed and studied by assuming simple models for the physical layer. We introduce a reception model that incorporates the channel states of the transmitting users and allows for multiple simultaneous successes. We assume that each user has access to his channel state and propose a variant of the Slotted ALOHA protocol for medium access where th...

In cases where machines having bursty data are equally likely to transmit to one another, code-division multipleaccess (CDMA) ALOHA which allows for an individual “virtual channel” for each receiving station may he a better multipleaccess protocol than simple ALOHA. With the use of “receiverbased code” multiple-access protocol, it is also possible for a station to listen to the channel of the i...

This paper deals with a two-way relay network (TWRN) based on a slotted ALOHA protocol which utilizes network coding to exchange the packets. We proposed an analytical approach to study the behavior of such networks and the effects of network coding on the throughput, power, and queueing delay of the relay node. In addition, when end nodes are not saturated, our approach enables us to achieve t...

In this paper, we study Radio Frequency IDentification (RFID) tag identification problems using Framed Slotted ALOHA (FSA) protocol. Each tag will be assumed to participate in the contention with a certain probability. Then, the frame size and the probability will be dynamically controlled by the reader in every reading round so that all the tags can be detected in a short period of time. Moreo...

The QoS over shared media LANs has three major elements: improving the current LANs for QoS, developing QoS aware LANs for future purposes, and utilizing the capabilities of QoS aware LANs optimally. Following the categorization, this paper discusses how TCP/IP is currently carried over the most popular shared media LAN, Ethernet, and how it is developed. An introduction to different LAN and pa...

In this paper, we consider a slotted ALOHA protocol with capture, in a mobile communication environment, in the presence of Rayleigh fading and log-normal shadowing. The capture probabilities are computed, along with their limit as the number of colliding packets tends to innnity. Some suucient conditions for this limit to be positive, and therefore for the system to achieve a positive stable t...