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Currently available IEEE 802.11n implementations do not apply aggregate MAC protocol data unit (A-MPDU) aggregation to voice traffic because of its strict end-to-end delay requirements. When multiple nodes contend to send voice and other lower-priority traffic, 802.11n network faces serious performance degradation problems for two major reasons: i) due to the medium access control (MAC) and physical...
According to Forbes collected data, the public cloud services market will rise in 2016 and is expected to grow to $105 billions and, in fact, Virtual Machines (VMs) are one of the most popular tools for building “Cloud” services. But in service delivery such composition of multiple components greatly complicate analysis of product quality, especially if it is about Voice over IP (VoIP) set of services,...
PoC is a group communication service using VoIP technology based on 3G cellular network packet domain carrier. ROHC can complete the header compression in PS domain of 3G network, which can improve the efficiency of wireless transmission. This paper analyzes the working principle and the operation modes of ROHC, designs the processing of the compressor and decompressor. Simultaneity an improved algorithm...
Long Term Evolution (LTE) is the new generation wireless networks that support all IP transmission for multimedia services. One of the major challenges in LTE network is to provide the packet scheduling scheme that can supports the Quality-of-Service (QoS) requirements of multimedia services. In this paper, a Quality-of-Service (QoS) aware packet scheduler for Real Time (RT) downlink communication...
Quality of Service (QoS) is an important network performance parameter having significant impact on real time applications like VoIP, Interactive gaming and Video Streaming. Although IPv6 was designed to improve addressing, security and QoS in IPv4, services like Video Conferencing and VoIP with strong reliance and sensitivity towards delay and jitter pose a daunting challenge in today's packet based...
The Internet has now become such an important infrastructure that is capable of sending information within a very short time and easy to access. It is considered as public networks that provide affordable WAN services to most customers. Applications such as video conferencing, file transfer protocol and VoIP are the example of typical network applications supported by the Internet Protocol. Various...
IP networks are increasingly being used for the provision of real time media services. This raises new challenges for QoS assurance through real time monitoring due to the complexity of distribution and the need for information correlation across a number of protocols. New tools and approaches are being developed. In this paper we report early results on one such tool, DRAI. In particular we show...
One of the major challenges for real-time applications over next-generation heterogeneous access networks is the vertical handoff. Such applications require fast and efficient handover that realize service continuity and seamless mobility preserving the security and the QoS. In this paper we propose a new seamless vertical handover solution performing fast authentication while guaranteeing the QoS...
The IEEE 802.16 standard has defined several QoS scheduling types without detailed implementation of the bandwidth scheduling scheme. Since the DL direction is more likely to be bottleneck than the UL direction, in this paper, we propose an improved framework for downlink real-time traffic, which acquire packet information by cross-layer design and dynamic drops the packets according to the network...
In IPv4 and IPv6 network, there are especially shortages of Application Performance Monitor system, which can help system owners to monitor and diagnostic system performance and provide warning message. In the paper, we have designed and implemented a SIP service monitoring scheme (SSMS) that includes a Service Detection System (SDS) and Real-time Alert System (RAS). The Service Detection System simulates...
With growth of Internet and wireless IP network, multimedia systems can be accessed from any-where and anytime. However, efficient real-time services are open and challenging research problem. To implement real-time services such as VoIP over wireless access network, IP header compression scheme can be used for saving bandwidth. Enhanced compressed RTP (ECRTP) has been used for lossy link and high...
Quality of service (QoS) provisioning is critical to real-time applications such as VOIP and IPTV, but has not been resolved in multihop networks such as mesh and ad hoc networks. For multiple access in ubiquitous networks, energy efficiency is of the single most important design goal, and can be supported through power save and power control techniques. In this paper, we propose a class of MAC protocols...
Voice over IP (VoIP) and high quality video streaming becomes an alternative to conventional telephony and TV service in many locations by way of ongoing deployment of WLAN hotspots. The newly proved IEEE 802.11e QoS enhancement standard will be a proper solution of delay demanding for real-time multimedia applications, while the existing auto rate fallback (ARF) link adaptation scheme, designed to...
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