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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...
This paper analyzes the possibility to introduce a WiFi type of secondary network containing multiple secondary access points (SAPs) in TV bands. In particular, the analysis investigates the limitations of TV whitespace (TVWS) usage imposed by the aggregate interference of the secondary users towards the primary and secondary system, assuming different levels of penetration of the TVWS-operating technology...
Medium Access Control (MAC) protocols for Wireless Local Area Networks (WLANs) as well as Wireless Personal Area Networks (WPANs) like Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) are known to provide stable distributed channel access for multiple users. The wide acceptance of wireless systems operating in licensed-exempt frequencies demands for efficient spectrum usage of the...
Low-powered and light-weight sensor nodes will be deployed for e-health services in wireless body area networks (WBANs). Recently, the Institute of Electrical and Electronic Engineering (IEEE) introduced a new standard, IEEE 802.15.6 for wireless body area communications. The goal of this standard is to specify several physical layers (PHY) and medium access control (MAC) layer protocols for variety...
The design of a cooperative spectrum sensing strategy has to take two aspects into consideration: from the physical layer perspective, a number of secondary users cooperatively measuring the channels to improve the detection performance, and from the MAC layer perspective, the users efficiently reporting their measurement results to a decision entity. Both operations are time critical and required...
This paper discusses the IVC (Inter Vehicle Communication) system for ITS. DS-SS (Direct Sequence Spread Spectrum) is used for the IVC because it has CDMA (Code Division Multiple Access) capability. However, efficient PN code allocation scheme is a problem to solve because the vehicles communication directly without base stations. In this paper, the location oriented PN code allocation scheme is adopted...
The fundamental basis of QoS differentiation in IEEE 802.11e EDCA is to differentiate durations of several channel access parameters for initiating and pursuing contention over the shared channel. More precisely, EDCA specifies the durations of those parameters in such a way that they remain inverse-proportional to the corresponding priorities of the contending packets. As such, the higher priority...
Present years showed increasingly active competition on the mobile market. Considering rapid technology development and its business implications, operators need to steer the market trend and take faster response than competitors in order to survive and to keep growing. Rich spectrum of alternative 3G network upgrade directions opens a debate on the applicable and convenient evolution strategy providing...
This paper presents an original development methodology for the use of SystemC to compare two different networks at the system level. A single cluster of a single channel network based on CSMA and multi-channel network cluster based on non-overlapping channels available for each node have been developed. In both network configurations a noiseless (error-free) channels are used, since the focus in...
The recent study (Lopez2007game) on fountain-based protocol (FBP) suggested that TCP nodes have incentive to switch to FBP approach in order to gain higher throughput with the trade-off of redundant packets. Moreover, it is reported that a network of FBP nodes only and sending at maximum speed will not degrade the overall throughput, as compared to the typical network of all TCP nodes. However, we...
The hidden terminal problem in wireless sensor network (WSN) is one of the main causes of collision. Even though RTS/CTS handshaking has been implemented in CSMA/CA standard to alleviate the problem, it does not solve the collision completely. Moreover, it induces an issue called false blocking problem. Unaware of a busy status of a hidden receiver, adjacent nodes which can be potential senders will...
This paper addresses the design of an innovative scheduling algorithm which optimizes the performance of Multimedia Broadcast Multicast Service (MBMS) in High Speed Packet Access (HSPA) networks. The proposed policy is based on the subgrouping approach which splits multicast members into subgroups and applies a subgroup-based Adaptive Modulation and Coding mechanism. The optimal number of multicast...
In this paper, we evaluate performance of time synchronized multi-channel MAC protocol called DSME for wireless sensor networks. DSME MAC enhances IEEE 802.15.4 MAC specification, which provides backward compatibility and adds new features such as multichannel extension to the current single channel based superframe structure; enhancing peer-to-peer communications. Our numerical results show that...
The Payload Dropping CSMA/CA is a cross-layer modified version of the CSMA/CA protocol that can serve as an alternative to the carrier-sense threshold approach for improving throughput in multi-cell networks when the number of co-channel, interference-limited cells is small. The basic idea behind it is a qualification of each signal during the entire preamble and header stages of its reception, and...
We propose an architecture of FL-net over Ethernet for a networked control system. FL-net over Ethernet is ease of broadcast which makes nodes exchange information easily and precisely. The proposed timed token passes among control units and determines which control unit has the data transmission right. Due to the token is unique in FL-net, only one control unit can send packets at time. This makes...
In this paper, we propose a new backoff algorithm for wireless local area networks (WLANs). The proposed algorithm develops by using mathematical optimization function theory on Carrier Sensing Multiple Accesses with Collision Avoidance and Request-to-Send Clear-to-Send protocol (CSMA/CA RTS CTS). A new backoff algorithm is named Contending Stations Backoff Algorithm (CSBA). The performance of CSBA...
The objective of this paper is to study the latest mobile technologies such as HSDPA (High Speed Downlink Packet Access) or 3.5G, and an approach to its successor LTE (Long Term Evolution) or 4G using network simulator called NS-2. First 2G technology came into existence which enabled mobile users with the technologies such as GSM, TDMA and CDMA. It also provided SMS services. After 2G many advanced...
We present a large-scale cell based measurement analysis of the user behavior in a live operational HSDPA network. The motivations are: first, to understand the statistical properties of users in cells for refining network planning procedures; and second, to provide realistic traffic models for simulations of cellular packet-oriented networks. We provide an analysis of mean cell load over daytime,...
In this paper, an anti-collision protocol called code division cooperative identification protocol (CDCIP) is proposed in order to tackle the reader collision problem in smart RFID systems. CDCIP allocates orthogonal sequences to each reader and composes a RFID network. Consequently, it strives to let more than one reader work at the same time and at the same frequency. Eventually, comparing with...
CSMA/CA is an important MAC protocol for wireless LAN that uses short RTS/CTS control messages for the avoidance of collision. Although it has certain advantages for accessing of contended medium, it blocks some other nodes unnecessarily, especially the nodes that reside in the opposite sides of the communication between the source and the destination pair, thereby reducing network throughput. Also...
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