The Internet has burgeoned into a worldwide information infrastructure during the past few years, bringing about significant changes in the telecommunications arena. One of the new applications that has thrived is Voice over IP (VoIP), also known as Internet or IP telephony. Since its inception, huge strides have been made in quality and usability and now VoIP enjoys widespread popularity as an...

This research paper has analyzed the mobile VoIP technology from the business point of view, focusing mostly on the consumer sector. Through the identification of relevant technologies in implementing mobile VoIP services the paper has constructed a classification of major players in the business. First, there are incumbent operators, who might leverage on the combination of cellular and emergi...

Lost audio packet steganography (LACK) is a steganography technique established on the VoIP network. LACK provides a high-capacity covert channel over VoIP network by artificially delaying and dropping a number of packets in use to convey stegnogram. However, the increasing loss of packets will hurt the quality of the VoIP service. The quality deterioration will not only affect the legitimate V...

The Internet has burgeoned into a worldwide information superhighway during the past few years, giving rise to a host of new applications and services. Among them, Voice over IP (VoIP) is the most prominent one. Beginning more as a frolic among computer enthusiasts, VoIP has set off a feeding frenzy in both the industrial and scientific communities and has the potential to radically change tele...

Voice over Internet Protocol (VoIP) over a wireless local area network (WLAN) is already an important Internet application. The data rate required for each VoIP stream depends on the used codec and the TCP/IP protocol overhead that typically add 98 bytes in the codec payload. As the G.726 codec has 80-byte payload (32 kb/s), the overhead represents 55% of the total packet size (178 bytes). This...

As cellular networks are evolving into high data rate systems, cdma2000 1x EV-DO (HDR) has been highlighted and deployed for data-only wireless service. For wide applications, it is expected to serve some real-time traffic including VoIP. To meet the loss requirement and to ensure the delay bound of VoIP packets, we consider two scheduling algorithms that are channel-aware and flexible in the f...

In this paper, we study the inherent limitations of the 802.11 (a/b) distributed coordination function (DCF) in supporting VoIP calls over a wireless LAN. Specifically, we evaluate the upper bound on the number of simultaneous VoIP calls that can be placed in a single cell of an 802.11(a/b) network. Making one additional VoIP call in that cell would degrade the quality of all VoIP calls. The up...

Today, wireless LAN (IEEE802.11g/n) has been the dominant wireless network that can provide high data rates in a limited coverage area. While emerging mobile WiMAX (IEEE802.16e) can provide a wireless broadband access to mobile users in a wide coverage area. These two different technolgies will co-exist while complementing each other in some regions, hence, a mobile node (MN) with dual interfac...