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Both of Quality of Service (QoS) and Quality of Experience (QoE) are defined to specify the degree of service quality. Although they are dealt with in different layers in multi-layered models, collaboration of these is necessary to improve the user satisfaction for telecommunication services. In this paper, after sorting out the concepts and specification of QoS and QoE, a service quality coordination...
In hierarchical networks, nodes are separated to play different roles such as CHs and cluster members. Each CH collects data from the cluster members within its cluster, aggregates the data and then transmits the data to the sink. Each algorithm that is used for packet routing in quality of service (QoS) based applications should be able to establish a tradeoffs between end to end delay parameter...
In recent years, IEEE 802.11 Wireless Local Area Networks (WLANs) have emerged as one of the prevailing technologies for the broadband wireless access. Although IEEE802.16 wireless network has become a newer generation of wireless network, it will be used as wireless metropolitan area network in the beginning because of its price. IEEE 802.11 network will continue to be the most important wireless...
A recent trend in routing research is to avoid inefficiencies in network level routing by allowing hosts to either choose routes themselves (e.g., source routing) or use overlay routing networks. Such end-to-end route selection schemes are selfish by nature, in that they allow end users to greedily select routes to optimize their own performance without considering the system-wide criteria. Recent...
In this present work, we propose a scheduling approch for heterougeneous traffic over network. The proposed scheduling not only satiesfies the QoS requirements of the real time flows (class-1) but also continues providing best effort service to non real time flows (class-2). Many scheduling techniques have been proposed to respond to the temporal requirements of real-time jobs (flows). The technique...
The most popular Differentiated Services composed of two key components: traffic conditioning and PHB (Per Hop Behavior). This paper addresses the affects of a packet handling mechanism LLQ (Low Latency Queuing) and several dropping schemes to quality of service in term of delay, jitter and packet loss. These schemes include RED (Random Early Detection), WRED (Weighted Random Early Detection) and...
One of the most desirable features of next generation wireless networks is the ability to move seamlessly over different access networks regardless of the underlying infrastructure. Handovers between dissimilar networks may be facilitated by the use of an efficient vertical handover algorithm. This paper explores ongoing research on the development of vertical handover decision methods and their effectiveness...
In this paper we investigate the network lifetime maximization problem in a delay-tolerant wireless sensor network with a mobile sink by exploiting a nontrivial tradeoff between the network lifetime and the data delivery delay. We formulate the problem as a joint optimization problem that consists of finding a trajectory for the mobile sink and designing an energy-efficient routing protocol to route...
Energy consumption in wireless sensor networks (WSN) was always a basic constraint to respect. But, with the appearance of Wireless Multimedia Sensor Networks (WMSN), another basic constraint comes from added, which is the traffic performance in terms of delay, throughput, and Packet Delivery Rate (PDR). The choice of channel access method can help us to better respond the two constraints in WMSN...
In today's world telecommunication plays an important role and to support it, QoS (Quality of Service) has to be given the maximum priority. As a third generation (3G) technology UMTS (Universal Mobile Telecommunication Systems) needs improved QoS because it has to provide QoS both for voice and data. In UMTS network Forward Access Channel (FACH) is one of the downlink transport channel that carries...
Nowadays users have a multitude of ways to connect with other users or applications servers to send and receive data. One of the most used is WIFI and UMTS (3G) networks. These technologies must satisfy users' requirements especially those related to real time applications such as IP telephony or video streaming. Therefore WIFI and UMTS must implement QoS techniques to reach this satisfaction. Both...
In this continuous fast world of mobile devices there is always a growing demand of high rate services. So a call has to be continuous with same data rates during a handoff. This paper deals with a novel approach DBA-CAC to reduce the call dropping probability while ensuring QoS demands are met in LTE wireless networks. The reduction is based on Adaptive Call Admission Control (Ad-CAC) scheme which...
In this paper, we investigate a cross layer design for routing in mobile ad hoc networks. The goal is to improve the performance of the existing Ad-hoc On Demand Distance Vector (AODV) routing protocol. The design allows the physical layer sharing the received signal strength (RSS), and the medium access control (MAC) layer sharing the remaining energy, as well as the remaining queue length information...
As Internet Protocol version 4 (IPv4) addresses deplete, Internet Protocol version 6 (IPv6) is introduced to alleviate the depletion with introduction of much needed functionality in security and so much more. Quality of Service (QoS) has been one of the aspects taken into consideration for improving network performance such as Packet Delivery Fraction (PDF), average End-to-end Delay and throughput...
This paper studies QoE (Quality of Experience) in Multi-View Video and Audio (MVV-A) transmission over IP networks where the users change the viewpoint by request. It jointly analyzes the effects of user interfaces for viewpoint change and contents in conjunction with network performance in a multidimensional way. In order to assess the QoE, we perform a subjective experiment which employs two user...
Worldwide Interoperability for Microwave Access or better known as WiMAX is a technology based on IEEE 802.16 standard with guaranteed QoS which provides high speed data rates. In this paper, we analyze the performance of VoIP over the commercial WiMAX networks through traffic measurements. The measurements focused on two QoS elements, jitter and latency that greatly affect the quality of the network...
Quality of service (QoS) is an important issue in the deployment IEEE 802.16 networks with real-time and non-real-time traffic integration. IEEE 802.16j is an extension of IEEE 802.16 to support relay transmission. In this paper, we propose a dynamic hybrid distributed scheduling mechanism (DHSM) for IEEE 802.16j networks with non-transparent relay stations. First, we define a suitable priority for...
Handover events are a source of instability in a mobile environment, but they are unavoidable. In particular, a significant cause of quality degradation is handovers to congested access points. These cause packet drops, longer RTT, and less available bandwidth for the flow being handed over. Such performance degradation may not be acceptable with respect to the transport protocols. Through simulations,...
Next Generation Wireless Networks (NGWNs) are expected to provide high data rate and optimized quality of service to multimedia and real-time applications over the Internet Protocol (IP) networks. To achieve these goals, handover plays a very critical role in maintaining the seamless connectivity when mobile terminals move across different cells or networks. In this paper, we propose a novel scheme...
The use of end-to-end communication systems as a medium of delivery for electronic healthcare (eHealth) services is considered to be uncertain, with respect to its reliability leading to hesitation in acceptance of such services. There exist different influential dimensions that pose stringent requirements on end-to-end communication systems, influence user perception and might hinder user acceptance...
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