The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The performance of wireless LANs is greatly affected by path loss, RF interference and other sources of signal attenuation in addition to network congestion. The primary factors involved in effective real-time communication, namely delay and loss, must be within certain controlled limits in such a scenario. In this paper, we analyze the various factors driving IEEE 802.11b access points through extensive...
An efficient low rate Speech Codec can get well utilized to solve the problem of network congestion under the circumstance of current network. To the speech characteristic analysed, the voice activity detection (VAD)algorithm that is much fewer operational quantity and very effective is designed based on conjugate structure algebraic code excited linear prediction (CS-ACELP),the Speech Codec in this...
In the end-to-end voice communication networks, the packet losses caused by network congestion and wireless channel errors reduce the efficiency of the forward error correction (FEC) scheme. Especially for mobile VoIP, network congestion and wireless channel status changed very fast. This paper presents an adaptive FEC that can adaptive adjust and predict the FEC block according to the network status.
IP Television (IPTV) is a new service that is growing up very quick in recent years. Its implementation is performed as a Triple-Play service, being the integration of voice, high-speed data and television. Moreover, the network traffic has been increased due to the use of VoIP, video or P2P. It is also creating congestion problems to the network provider and has high impact on the quality of IPTV...
Switching a communication path from one access point (AP) to another in inter-domain WLANs is a critical challenge for delay-sensitive applications such as voice over IP (VoIP) because communication quality during handoff (HO) is more likely to be deteriorated. To maintain VoIP quality during HO, we need to solve many problems. In particular, in bi-directional communication such as VoIP, an AP becomes...
It is well known that packet loss is an indication of network congestion. Thus, numerous applications including adaptive control in VoIP detects packet loss and responds to reduce the congestion. However, detecting packet loss provides very limited information about the state of the network. In this paper, we attempt to use observations of the delay and loss correlation to characterize congestive...
With the availability of large bandwidth and high data rates the transmission of data, voice and video over the Internet is gaining popularity. Voice-over-IP (VoIP) uses packetized transmission of speech over the Internet (IP network). However, at the receiving end; packets are missing due to network delay, network congestion (jitter) and network errors. This packet loss degrades the quality of speech...
The fundamental characteristics of VoIP are constant rate, delay sensitivity, and loss tolerance. VoIP over packet-switched networks including the Internet poses problems because the network service is not guaranteed to meet such requirements, i.e. the available bandwidth as well as the delay and loss bounds. Adaptive rate VoIP is a solution that can mitigate the problem. Adaptive rate VoIP has the...
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...
The Internet low bit-rate coder (iLBC) is now widely used for voice over Internet protocol (VoIP) applications. Unlike speech coders such as those based on code excited linear prediction (CELP), the iLBC achieves superior robustness to packet loss by avoiding inter-frame coding dependencies. While robustness to packet loss is essential, a VoIP codec should also possess the flexibility to change its...
The large diffusion of VoIP is an essential key for the success of emerging Internet service providers. These ISPs conflict with the interests of historical and predominant network maintainers which often control the network infrastructure and telephone services. To win this competition, emerging ISPs have to adopt strategic QoS solutions which will capture the attention of network users and phone...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.