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A wireless backhaul network is used to interconnect intermediate nodes to gateway nodes. As it is designed to serve a large population of broadband users, failure sustainability becomes an essential requirement to ensure uninterrupted telecommunication services even in the presence of occasional node or link failures. In this paper, the performance of a failure sustainable wireless backhaul, based...
In this paper, the mainly used packet scheduling algorithms in wireless communication system will be introduced. The 3rd Generation partnership long term evolution (3GPP LTE) will provide QoS guaranteed multimedia services which demand much higher downlink packet rate and lower HOL packet delay. So, a suitable packet scheduling algorithm is becoming more and more important in 3GPP LTE system. The...
Ultra wideband (UWB) communication was evaluated within a closed space, with a view to partly replacing onboard data buses with wireless connections. Spatial distributions of UWB propagation in frequency (from 3.1 to 10.6 GHz), time domains and throughput with use of a radio absorber were derived from measured. It was also found that delay spreads can be suppressed by partially panelling a radio absorber...
A three element patch antenna array is designed for a 2×3 802.11n wireless home media server application for high-definition video streaming at 2.4GHz. An efficiency comparison shows that the use of the RT/Duroid substrate results in a 3dB improvement in performance over the cheaper FR4 substrate. The RT/Duroid patches are characterised in terms of input responses, full (3D) radiation patterns and...
This paper investigates the performance enhancement of IEEE 802.11 used in a radio-over-fiber architecture. It is shown that data throughput can be improved by modifying the ACK timeout value and the slottime parameter value defined in IEEE 802.11. In this study, both UDP and TCP packet transmission were taken into account.
Multicast support is critical and a desirable feature of multi-radio wireless mesh networks. However, the nature of wireless network, i.e. broadcasting and interference, makes it a challenge to efficiently support multicast services. In this paper, we study how to build a multicast structure with maximum average throughput in terms of minimum transmission time and channel interference in a multi-radio...
One of the most critical problems in multihop wireless networks is the fair allocation of bandwidth among different nodes. Although there are significant researches on the fairness issues in single-hop wireless networks, research on multihop fairness rarely found in the literature. A user in multi-hop network, besides the contention with other nodes to obtain the channel in physical layer, must find...
IEEE 802.11 (Wi-Fi) is a standard feature on smart phones and an alternative to cellular networks for connectivity. Users can surf the Web, make VoIP calls and more from home Wi-Fi networks or public hotspots. At present this type of connectivity is intermittently available with limited mobility support. It is unclear if today's Wi-Fi scales for large number of users. We consider the challenges in...
With the development of the wireless communications technology and the multimedia technology, the wireless internet multimedia transport of real-time becomes an important applications field. We will meet a problem that the distinguish of the status of package loss is not very good which will affect the QoS when we transport multimedia data in wireless internet. Based on this problem the article comes...
Wireless backhaul has received much attention as an enabler of future broadband mobile communication systems because it can reduce deployment cost of pico-cells, an essential part of high capacity system. A high throughput with a minimum delay network is highly appreciated to sustain the increasing proliferation in multimedia transmissions. In this research, we propose a backhaul network using the...
By theoretical analysis, we discuss the performance of random access protocol by network coding in wireless relay networks. We present a novel method to increase the opportunity of network coding in relay node. By using this method, the performance of random access protocol in wireless networks can be improved especially in low traffic load. We compare the performance of this method with network coding...
This paper explores the possible effects on the performance of IEEE 802.11 when high-rate real-time applications such as video streaming are transmitted simultaneously with data over the network. While most of the studies conducted have been limited to 802.11b and 802.11g; this study focuses on the newer 802.11n. It considers the effect on performance parameters like throughput, jitter and packets...
Wireless mesh networks (WMNs) have emerged as a key technology for next generation wireless networks showing rapid progress and inspiring numerous applications. The persistence driving force in the development of WMNs comes from their envisioned advantages including extended coverage, robustness, self-configuration, easy maintenance, and low cost. However, to support real-time applications, WMNs must...
Popular wireless network standards, such as IEEE 802.11/15/16, are increasingly adopted in real-time control systems. However, they are not designed for real-time applications. Therefore, the performance of such wireless networks needs to be carefully evaluated before the systems are implemented and deployed. While efforts have been made to model general wireless networks with completely random traffic...
As an advanced train control system, communication-based train control (CBTC) system can improve the utilization of railway network infrastructure and enhance the level of safety and service offered to customers. In this paper, we propose a seamless handoff scheme for CBTC systems based on Stream Control Transmission Protocol (SCTP) and IEEE 802.11p. The focus of our work is in the handoff decision...
In wireless multihop ad hoc networks, the hidden terminal problem severely degrades the overall performance. On the other hand, most existing solutions cause larger blocking areas and hence a more severe exposed-terminal problem. In this paper, we present a new Enhanced Busy-tone Multiple Access (EBTMA) medium access control (MAC) protocol. The proposed protocol minimizes the negative impact of both...
Currently, Transmission Control Protocol (TCP) is the dominant protocol used in the Internet. It is the transport protocol that is responsible for the transmission of around 90% of the Internet traffic. TCP was originally designed for wired network where packet loss due to congestion dominates. Mobile Ad Hoc Network (MANET), one of the wireless networks, has special characteristics which cause several...
Next generation wireless schedulers should exploit multi-user diversity not only by managing bandwidth among users experiencing different channel quality but also by exploiting traffic knowledge. A Traffic Profile and Priority-based Wireless Fair Queuing (TPP-WFQ) scheduling approach is proposed, which utilizes available bandwidth in the system to allow sessions experiencing poor channel quality to...
The general TCP protocol doesn't show good performance in ad hoc network due to nodes mobility and higher vulnerability of the wireless link. This paper proposes a simple end to end approach; in this the hop count of the path and the size of delayed window at receiver end is utilize and also the of CWL with the RTT variation to control the size of the bursts. As the number of hop increases chance...
In this paper, we analysis and simulate the AODV and OLSR routing protocols for both Wireless Ad-hoc Network and Wireless Mesh Network. An Ad-hoc network is a collection of wireless mobile nodes dynamically forming a temporary network without the use of any existing network infrastructure or centralized administration. Wireless Mesh Networks (WMNs) have recently gained a lot of popularity due to their...
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