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Today, most of the smart phones are equipped with two network interfaces: Mobile Broadband (MBB) and Wireless Local Area Network (WLAN). Multi-path transport protocols provide increased throughput or reliability, by utilizing these interfaces simultaneously. However, multi-path transmission over networks with very different QoS characteristics is a challenge. In this paper, we studied Multi-Path TCP...
The purpose of our study is to guarantee the required throughput of high-priority (UDP) flows and to achieve the stable throughput for each flow in a wireless LAN in which both high-priority and low-priority (TCP) flows exist. The authors previously proposed a QoS control scheme called Receiving Opportunity Control in MAC Frame (ROC), in which an Access Point (AP) intentionally does not return an...
The technology of flow-based QoS control on wireless LANs is receiving a lot of attention. There are several QoS technologies that can provide bandwidth guarantees by using TCP congestion control (QoS-TCP) and MAC control (QoS-MAC). Unfortunately, since QoS-TCP runs on the end terminal, it is possible that QoS-TCP will attempt to guarantee bandwidth without the permission of the network administrator...
The following topics are dealt with: tree-building algorithms; HCM decision tree; grid authorization system; grid scheduling system; evolutionary algorithm; data allocation problem; read-one-write-all monitoring synchronization transaction system; large block FEC; RED queue; TFRC congestion control; TCP; mobile ad hoc networks; vehicular ad hoc networks; wireless sensor networks; failure route protocol;...
This paper describes an approach to detect Quality of Service degradation due to packet congestion within wireless networks. The proposed approach can assist management systems to detect a degradation based on easy determinable packet metrics. Metrics like interface queue length, round trip times and retry ratio are evaluated regarding thresholds and detection performance. With a combination of metrics,...
This paper presents a Cross-Layer scheme that tries to improve the performance of real-time traffic over TCP in 802.11e wireless networks. It is based on a well-known TCP-friendly, binomial algorithm at the Transport layer, which is jointly configured with the 802.11e protocol at the MAC layer. TCP-friendly schemes have shown to improve the quality of media transfer over wired and wireless networks...
This paper focuses on the quality parameters of Voice over Wireless Local Area Network (VoWLAN) and how they are affected by the addition of end-to-end encryption using Advanced Encryption Standard (AES) of 128-bits and 256-bits block sizes. An experimental setup was made to evaluate mean and maximum delay and jitter, and packet loss. These quality parameters were measured for non-encrypted streams,...
The Internet Protocol Stack provides a set of transport layer protocols. There are two dominant types of transport layer protocol used in the Internet: UDP (User Datagram Protocol) and TCP (Transmission Control Protocol). The transport layer provides end-to-end information transfer across a network with the quality of service needed by the application. In this paper, we provide a performance comparison...
The following topics are dealt with: mobility management; ad hoc networks; routing protocol; resource allocation; cooperative relay MIMO systems; adjacent channel interference cancellation; MANETs; LDPC codes; frequency selective fading channels; mobile services; mobile telemedicine; TCP; public key; time frequency division multiplex; RF front-ends design; asynchronous DS-CDMA; indoor tracking algorithm;...
In beyond 3G networks the user will not be aware of the access network technology used to provide a telecommunications service. Heterogeneous network technologies will be seamlessly integrated in one "common'' access network, enabling users to move around and continuously receive their subscribed services. In a commercial environment, this network evolution requires that a telecommunications...
There has been considerable research into the performance of the enhanced IEEE 802.11e standard in recent years. Majority of the performance analysis has been based on simulations and analytical models, with little testing done in a real-world environment. We investigate the behaviors of the enhanced distributed channel access (EDCA) and legacy distributed coordination function (DCF) based on a testbed...
We propose QoS-aware mesh deterministic access opportunities (MDAOPs) assignment algorithm for the IEEE 802.11s wireless mesh networks (WMNs). The WMNs can benefit from the mesh deterministic access (MDA) in terms of guaranteeing the QoS of the delay bounded traffic, mitigating the exposed node problem, and providing the fairness among best effort traffic flows. However, it is not considered that...
In wireless local area networks (WLANs), the demand of the multimedia applications such as voice telephony and peer-to-peer content distribution has followed the necessity of quality-of-service (QoS) control for uplink flows. However, in uplink WLANs, the hidden-station problem causes difficulties in the QoS control because of unfair collision probability. In this paper, we point out this hidden-station...
Wireless mesh networks are emerging as a promising access network architecture. In this work, we report on an extensive measurement campaign performed over an experimental WiFi-based mesh network, deployed in an office building environment. The measurements are focused on the performance of HTTP traffic. Results demonstrate the existence of an unfairness issue, whereby longer sessions achieve better...
Although a number of investigations have been conducted using IEEE 802.11e enabled networks to stream class differentiated video, very few reports are available based on a real testbed. In our work, we set up a wireless testbed for H.264 video streaming through assigning the partitioned video packets onto the DCF MAC layer and different access classes of the EDCA MAC layer. We investigate three assignment...
The Internet access paradigm is changing and a wide range of overlapping radio access technologies, such as WiMAX, Wi-Fi, 3GPP UMTS/LTE and DVB-H, will soon be available to most users and their multi-access devices. Therefore, novel mechanisms and protocols are needed to provide seamless mobility between different wireless access technologies. This paper presents novel handover procedures, based on...
In this paper we investigate the potential benefits of a selective delayed channel access algorithm (SDCA) for the future IEEE 802.11n based high-throughput networks. The proposed solution aims to resolve the poor channel utilization and the low efficiency that EDCA's high priority stations adhere due to shorter waiting times and consequently to the network's degrading overall end performance. The...
Multimedia applications have been the key driving force in converging fixed, mobile and IP networks. A major hurdle in the realisation of this convergence is obtaining Quality of Service from a heterogeneous, best-effort service network. Interactive voice requires strict bounds on delay, jitter and packet losses, video adds significant bandwidth requirements to the network, while Internet only makes...
In our earlier work, the authors proposed WLAN Manager (or WM) a centralised controller for QoS management of infrastructure WLANs based on the IEEE 802.11 DCF standards. The WM approach is based on queueing and scheduling packets in a device that sits between all traffic flowing between the APs and the wireline LAN, requires no changes to the AP or the STAs, and can be viewed as implementing a ldquoSplit-MACrdquo...
To achieve fully mobile communications, considering different environments and modern service requirements, a multiple-segment architecture is the most suitable to guarantee service continuity with acceptable performance. Handover (HO) procedures can be invoked either out of necessity (if the current network connection is going off) or to improve performance (if different bandwidth or quality of service...
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