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When a wireless mesh network accommodates interactive applications with quality of service requirements, schedulebased protocols are more suitable than contention-based protocols. In this paper, the problem of determining an appropriate schedule assignment for multiple group transmissions within a spatial time division multiple access link scheduling network is referred to as an integrated multiple-group...
Authentication is the first line of defense against compromising confidentiality and integrity. Though traditional login/password based schemes are easy to implement, they have been subjected to several attacks. As an alternative, token and biometric based authentication systems were introduced. However, they have not improved substantially to justify the investment. Thus, a variation to the login/password...
As a major result of the rapid population growth around the world, the number of road users, vehicles, drivers, passengers and pedestrians has increased dramatically, resulting in the need for a rapid development in transport systems to deal with everyday challenges to provide a safe, reliable, comfortable and efficient environment. In this paper, we explore the background of V2I, I2V communications...
Almost all deployed implementations of the IEEE802.16 standard (also known as WiMAX) employ the Point to Multipoint (PMP) topology. With such a topology Quality of Service (QoS) can be easily achieved, but the coverage area is limited. The other architectural topology is the Mesh Mode which is able to provide a larger coverage area, but cannot support the QoS required. This paper addresses the issue...
Recently, many authentication mechanisms have been proposed to provide security in WiMAX networks. Accessing information securely from any device, anywhere, anytime is becoming an increasingly important requirement for Human Centric Computing (HCC) environments. High mobility of end-users makes typical authentication procedures a challenging task. A novel EAP-TLS-ECDH-RSA-based authentication protocol...
Vehicular wireless networks have emerged as a promising wireless communication technology in recent years. Vehicular wireless networks collect information on real-time traffic, such as the road situation, the location of a car accident, etc., which must be delivered to its destination before a set deadline in order to be useful for an Intelligent Transportation System (ITS). Target applications are...
These days, a wide variety of wireless interfaces are available to connect to Internet. When coverage area of these different technologies overlap, receiver equipped with multiple interfaces can use them simultaneously to improve the performance of its applications in terms of bandwidth rely on bandwidth aggregation. However, specific conditions such as bottleneck bandwidth and end-to-end delay need...
In this paper, we propose a novel generalized approach to estimate the time-probabilistic characteristics of the cryptographic protocols by means of random graphs. The influence of channel errors on the performance of authentication and encryption protocols is also studied. Our results demonstrate that the usage of cryptographic algorithms influences the throughput in many ways.
Fading is one of the common characters of a wireless channel. Many rate adaptation mechanisms were proposed to enhance the IEEE 802.11 systems, but these may cause multiple rates in a single network. However, IEEE 802.11 DCF faces the performance anomaly in multi-rate network, that is, when the stations with different rates collide, the low-rate station will greatly degrade the high-rate station....
IEEE 802.16 standard defines the broadband wireless access specification for WiMAX, but it did not specify a standard scheme for scheduling algorithms and admission control. As a result, we propose an uplink scheduling scheme called Random Early Detection based Deficit Fair Priority Queue (RED-based DFPQ) for WiMAX. RED-based DFPQ adjusts the deficit counter of rtPS based on the current queue length...
Recent years have witnessed the development of a wide-range of wireless technologies. Next generation communication systems are aimed at integrating existing and emerging wireless systems to enable ubiquitous network access to mobile end-users. The availability of various access networks requires a mobile device to be capable of selecting the best access network with minimum user intervention. We...
The use of wireless networks has spread further than simple data transfer to delay sensitive and loss tolerant multimedia applications. The IEEE 802.11 WLAN has become a dominating technology due to its low cost and ease of implementation. This paper presents across-layer mapping algorithm to improve the quality of transmission of H.264 (a recently-developed video coding standard of the ITU-T video...
In this paper, a novel multi-path FEC control scheme with path interleaving is proposed for improving the quality of video transmission. The proposed scheme adaptively adjusts the FEC block size and sends interleaved data over multiple paths. Our scheme aims at dispersing the burst losses to different FEC blocks and therefore the efficiency of FEC can be improved. Compared to traditional multi-path...
Quality of service (QoS) support in multimedia applications is a crucial requirement. Many researchers focus on the performance enhancement of video transmission and they use simulation tools to evaluate their proposed mechanisms. Most simulation tools only use network-level performance metrics, such as throughput. However in some cases, network-level performance metrics can not evaluate the video...
Use of a variety of multimedia applications in Internet usage has grown up rapidly in recent years. This has stimulated the study of networking mechanisms for providing QoS guarantees. Simulators play an important role when researchers want to validate their proposed networking mechanism. In order to pursue more realistic simulations, some researchers devoted themselves to the improvement of simulators...
In this paper, we propose a novel realistic simulation tool-set known as MyEvalvid-NT for evaluating video delivery over simulated networks. This tool-set integrates Evalvid and NS2. Though PSNR is most often used to measure the perceived quality by an end user, it is time-consuming to calculate PSNR when evaluating a long video sequence. To avoid overhead, in this paper, we used decodable frame rate...
In this paper we used a DiffServ network model for the wired network where the ingress executed enhanced token bucket three color marker system (ETBMS). The framework also describes a video differentiator present in the access point which identifies the video packets and maps it to corresponding IEEE 802.11e prioritized video service queue. Using simulations the proposed concept is examined with QoS...
Multicasting techniques can be applied to facilitate applications such as video conference-calls and multimedia distribution. Multicasting enhances network utilization by containing traffic to network segments that are part of the multicast tree only. This prevents network segments that are not part of the multicast tree to be flooded with unwanted traffic. In addition, multicasting prevents redundancy...
The need for QoS for multimedia traffic arouse from the fact that the current network is a best effort network where all packets are treated equally irrespective of their importance. Moreover when a video packet changes its mode of transport from wired to wireless there arises a need to identify these packets and provide them with prioritized service to achieve end-to-end QoS. In this paper we used...
Layered multicasting is an effective technique in distributing large-scale streaming multimedia content over the standard IP networks -which form the Internet. The major issue is fairness, which is the desire for the multicast traffic not to overwhelm other usual traffic such as standard TCP traffic. The need for speed of UDP and its designed nature of obtaining as much bandwidth as possible is what...
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