The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The IEEE 802.11 Distributed Coordination Function (DCF) does not require the presence of a central controller or access point. It is therefore, the standard protocol used for resolving medium access contention in mobile ad hoc networks. IEEE 802.11 DCF is based on carrier sense multiple access with collision avoidance and Binary Exponential Back off Algorithm (BEBA). BEBA can improve the system throughput...
Traditionally in routing approaches, each node allows a maximum load through the selected route. The existing routing approaches in cognitive radio networks (CRN) do not take into account spectrum trading as well as spectrum competition among licensed users (PUs). This paper introduces a novel routing algorithm that is based on spectrum trading and spectrum competition for cognitive radio networks...
We present some recent results on a scheme, named Coded Slotted Aloha, where the theory of codes on graphs is used to obtain a random access protocol that does not require retransmissions. The scheme is based on the use of erasure correcting codes for the recovery of packet segments that are lost in collisions, and on successive interference subtraction for resolving collisions. The proposed protocol...
Efforts are underway in improving power conservation in WLAN devices and thus increasing the duration between recharging the battery. In order to evaluate the performance of new energy saving methods, there is a need for analytical tools. This paper proposes a simple analytical model that provides the average power consumption of a WLAN device. The proposed model is based on Markov models that provide...
Abstract-QoS parameter mapping is a key technology with respect to guaranteeing QoS of business in heterogeneous networks dynamically. This paper studies a method for guarante necessary End-to-End QoS for user satisfaction, focusing on the problem of quality of service (QoS) mapping between layers in a cascade. Due to the dynamic mapping of parameters, the consistency between user and netweork is...
In Wireless Local-Area Networks (WLANs), most of the wireless Access Points (APs) work at the full power level. So, the conflicting channels may have a significant and inevitable impact on throughput and transmission delay when the density of the APs is increasing. This paper proposes a power control algorithm, Dynamic Power Control called DPC based on NetFlow. DPC applies a fine tuning idea to get...
Based on game theory, a general and compatible modeling process, named by GGMP/CSMA (General Game Modeling Process for CSMA/CA), is proposed. With τ (the probability that a node transmits packet in a slot time) as mixed-strategy of game, and M networks performance parameters as payoff functions of game, GGMP/CSMA constitute M rounds of n-players non-cooperative mixed-strategy game. After playing M...
High performance networking interfaces, such as 10-Gigabit Ethernet (10GE), are now widely deployed in commercial Cloud computing environments. Virtualization is a standard technique for these environments, one of whose key challenges is to achieve highly efficient and scalable I/O virtualization. Single Root I/O Virtualization (SR-IOV) eliminates the overhead of redundant data copies and the virtual...
In the cognitive radio networks (CRNs), primary user (PU) has higher priority to access the spectrum band over the secondary user (SU). In this paper, new multichannel priority based cognitive radio (CR) architecture is presented for medium access control (MAC). This multichannel CRN architecture is designed with pre-emptive, non-pre-emptive resume, and pooling priority based systems. Main objective...
Heterogeneous deployment is a promising solution to enhance both system capacity and coverage, where the planned macro cell is overlaid with pico cells. However, higher transmit power of macro eNB (MeNB) results in small coverage for pico cell, which causes insufficient offloading from macro cell to pico cell and inefficient cell splitting gain exploration. Cell range expansion (CRE) is one of alternative...
In this paper, we evaluate the effect of energy constraints on the performance of a simple network comprised of wireless nodes with energy harvesting capability. In this scenario, wireless nodes contend with each other based on slotted Aloha protocol in order to transmit a packet. Packet transmission occurs provided that enough energy exists in the energy buffer. We propose an analytical model based...
To achieve highly efficient and flexible spectrum sharing in cognitive radio networks, we proposed a queuing method in combined channel aggregation and fragmentation (CAF) strategy for dynamic spectrum access (DSA). We derived the balance equation and evaluated various system performance metrics including blocking probability, dropping probability, spectrum utilization, throughput and mean queuing...
In cognitive radio systems, the sparse assigned frequency bands are opened to secondary users. We consider the sensing of the frequency spectrum for cognitive radios, based on energy detection. It has been shown that the sensing reliability can be improved in the presence of fading by using several cooperating cognitive radios that exchange their individual sensing information to a coordinator node...
In this paper we investigate the impact of asymmetric traffic patterns on the energy consumption and throughput in a wireless multi hop network. Network coding is a novel technique for communication systems and a viable solution for wireless multi hop networks. State of the art research is mainly focusing on ideal scenarios with symmetric traffic patterns that are not realistic in a real life scenario...
In this paper we present a novel approach to throughput analysis of synchronous dataflow (SDF) graphs. Our approach is based on describing the evolution of actor firing times as a linear time-invariant system in max-plus algebra. Experimental results indicate that our approach is faster than state-of-the-art approaches to throughput analysis of SDF graphs. The efficiency of our approach is due to...
Though, Wireless Sensor Networks have many successful applications in military, smart building, habitat monitoring, etc. it just begun to show its superiority in the medical domain in recent years. Deployment of WSNs in medical domain exert many more stringent requirements on the capability of sensing and in-networking processing, due to the nature of high accessibility and the privacy sensitive requirement...
Inspired by clustered photolithography tools in semiconductor wafer manufacturing, we study flow lines with deterministic process times subject to random state dependent setups. For tractability, we assume that the setup probability is constant and independent from customer to customer; the setup duration is constant. We show that the internal state of such a flow line can be modeled as a Markov chain...
In this paper we study the interactions of TCP and IEEE 802.11 MAC in Wireless Mesh Networks (WMNs). We use a Markov chain to capture the behavior of TCP sessions, particularly the impact on network throughput performance due to the effect of queue utilization and packet relaying. A closed form solution is derived to numerically determine the throughput. Based on the developed model, we propose a...
Energy-based sensing (EBS) has been a topic of strong research in the last years due to its importance to Cognitive Radios (CRs). While EBS has been used in several works, different parameterizations have been adopted. In this work we compare different parameterization criteria to determine the decision threshold to the energy detector. We compare their performance through simulations by characterizing...
IEEE-802.11-based WLAN MAC performance evaluation is of great importance, especially under non-saturated conditions. A new load equation, respect to the non-saturation, is proposed for analysis of the MAC mechanism in this paper. The load equation together with a backoff equation and a transmission equation are sufficient to analyze the MAC performance under non-saturated conditions. In the new load...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.