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Audio streaming over wireless local area network (WLAN) has an ability to transmit audio data ranging from short messages to music station. A popular application of this is in setting up a community radio, which is in demand, especially in developing countries where frequency spectrum management is still problematic. Audio streaming has to assure high quality of content reception without any packet...
To reduce the session setup delay there have been many methods used widely in traditional 2G networks, as well as the IP Multimedia Subsystem (IMS). However, the existing approaches to solve the problem depend on optimization of Session Initiation Protocol (SIP) message transmitting and signaling flows. The article proposes a novel paralleling session setup mechanism (PSSM) based on the exploration...
This paper describes the principles of QoS communications, analysis the requirements of how voip to provide QoS guarantees, clarify the major problems it's facing now. And proposes the solution to the problem of latency, jitter, packet loss and echo effects, with the same time introduces several of the QoS model that can improve the qos of voip, discusses their respective advantages and shortcomings,...
We propose a modified Transmission Control Protocol (TCP) flow classification method and Round Trip Time (RTT) computation method which is more precise and more dynamic than the traditional fixed timeout method, especially for long, sparse TCP flows and long RTTs. Then we present passive measurement results for TCP RTT and RTT variation in network traffic traces. Analysis shows several interesting...
In this work, we present a systematic study of how the traffic of different transport protocols (UDP, TCP and ICMP) is treated, in three operational Swedish 3G networks. This is done by studying the impact that protocol and packet size have on the one-way-delay (OWD) across the networks. We do this using a special method that allows us to calculate the exact OWD, without having to face the usual clock...
This article presents a study for VoIP technology to elaborate a differentiated VoIP infrastructure with the proposed approach ProxySIP Bridge. This approach enhances the Back-to-Back User Agent With Media (B2BUAWM) approach in order to isolate the voice traffic from the remaining general purpose traffic and to enable direct voice traffic whenever possible. A differentiated VoIP infrastructure with...
With the increase in femtocell deployments and the migration toward all-IP networks Adaptive Multi-Rate (AMR) voice calls are increasingly being transported over Internet Protocol (IP) networks. The default AMR adaptation mechanisms are designed to adapt to radio conditions between the terminal and basestation and do not consider backhaul networks. Although Explicit Congestion Notification (ECN) can...
Recently, there has been significant progress in incorporating using the human sense of touch in the virtual world (Haptics) as well as in transmitting this kind of data. Moreover, all types of networks, including the Internet, have been designed to mainly support only the traditional multi-modal media such as voice and video. Therefore, haptic traffic transmission over these networks will have different...
VoIP systems have to face far tougher security threats than their underlying IP infrastructure. In fact, a security hole in a VoIP infrastructure could bring to a major security failure for the interconnected PSTN network(s), usually regarded as a reliable and secure domain. This is the reason why before connecting a private VoIP network to the carrier infrastructure, a great number of tests have...
This paper addresses the issue of supporting time-sensitive multiplayer games in a single hop ad-hoc network. We first propose an analysis of the gameplay experience in such network. To this end, we conducted several experiments of an FPS (First Person Shooter) game over a real ad-hoc network. The poor performances experienced when the number of players reaches a certain value (11, in our scenario)...
SNMPv2 is the most popular Network Management Protocol for its simplicity, wide support in most of the Operating Systems and network devices. The weakness in SNMPv2 was lack of proper security mechanism which led to the improved version SNMPv3 in 1999 [1]. It required separate PKI infrastructure and lacked support in older network devices so it could not get wide popularity and adaptation. Therefore...
The de facto inter-domain routing protocol, Border Gateway Protocol (BGP), plays a critical role in the Internet routing reliability. Invalid routes generated by mis-configurations or malicious attacks will devastate the Internet routing system. In the near future, deploying a secure BGP in the Internet to completely prevent hijacking is impossible. As a result, lots of hijacking detection systems...
There are many challenges in the QoS controls and traffic handling mechanisms in the deployment of Long Term Evolution (LTE). Simulations are crucial for performance evaluation of end-to-end QoS (Quality of Service) management across LTE network elements over heterogeneous networks. The LTE CoS/QoS Harmonization Emulator presented in this paper will allow the user to determine whether the QoS design...
Vehicular Delay-Tolerant Network (VDTN) is a new opportunistic network approach where vehicles act as the communication infrastructure, furnishing low-cost asynchronous communications, variable delays, and bandwidth limitations. At the edge of the VDTNs, terminal nodes assume the gateway function with other networks, such as the common TPC/IP. In VDTNs, IP packets (datagrams) are aggregated in large...
Distributed Denial-of-Service (DDoS) attacks are one of the major threats the Internet is facing today. The problem of tracing the attackers is particularly difficult since attackers spoof the source addresses. Researchers all over the world have proposed several packet marking based techniques for DDoS attack mitigation using IP Traceback, however even after a decade of active research no commercial...
Handover efficiency in wireless packet switched networks is very crucial in providing QoS guarantees to real time applications. Mobile IPv6 (MIPv6) is a prevalent choice for mobility management in future generations networks. Although MIPv6 benefited from the design knowledge of its predecessor i.e. MIPv4 and is more efficient, it still suffers from high handover delays. The main reason for MIPv6...
Worldwide Interoperability for Microwave Access (WiMAX) deployment is growing at a rapid pace. Since Mobile WiMAX has the key advantage of serving large coverage areas per base station, it has become a popular emerging technology for handling mobile clients. However, serving a large number of Mobile Stations (MS) in practice requires an efficient handover scheme. Currently, mobile WiMAX has a long...
With advances in low-power and low-cost wireless and sensor technologies, using WSNs in eHealthCare system has yielded tremendous efforts in recent years. However, most of previous researches adopt a remote server to process large scale of health sensor data forwarded by gateways that allow for interconnecting WSNs to IP network. In this paper, we present a prototype of a smart 6LoWPAN border router...
Information lookup systems using Distributed Hash Ta-ble (DHT) have been actively studied. In the Chord DHT, nodes are configured as a ring structure and lookup re-quests are forwarded along with the ring. In order to get information efficiently, response time should be short. However, since Chord overlay network is constructed without considering the real network, the efficient lookup cannot be done...
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