IP Session Research Articles

Performance analysis of a context aware cross layer scheme for fast handoff in IMS based integrated WiFi–WiMax networks

Providing fast and seamless handoff in a pervasive computing environment is one of the recent research issues. The delay incurred due to IP Multimedia subsystem (IMS) re-registration and session re-setup process during vertical handoff (VHO) is still a major bottleneck for Voice Over IP (VoIP) and interactive multimedia services. In the conventional Session initiation Protocol (SIP), handoff performance is very poor due to high handoff delay and packet loss. In this paper, we propose two SIP based schemes, a Context Awareness (CA)-based Pre-registration approach to reduce the IMS Re-registration delay and a novel scheme called Prior-SIP (P-SIP) with a cross layer scheme utilizing Media Independent Handover (MIH) services to reduce the IMS session re-setup delay in a WiFi/WiMax heterogeneous environment by defining new SIP messages. We have simulated these scenarios using NS2 and the performance characteristics are studied. We have also analyzed the IMS pre-registration delay and IMS session re-setup delay based on Queuing theory. The simulation and analytical results show that, the proposed solution shows an improvement of 44% in terms of handoff delay and packet loss when compared with previous approaches and was able to maintain 90% throughput during handoff and suits well for supporting real-time applications to mobile users.

Soft Phone Support Voice and Video Calling Using Sip And Rtp Protocol

Soft Phone is a VoIP soft phone that uses the Session Initiation Protocol. It is a powerful and unique SIP software telephone that lets users make phone and video calls using single software application using any Voice over IP (VoIP) telephony provider. As a fully featured SIP client, Soft Phone is designed from the ground up to work with current and future IP-based. Soft phone can be used in the place where we need establish the voice and video phone calls in the IP network. This can be installed at any personal computer. It uses the SIP protocol to establish the IP session and using RTP, RTCP and RTSP for media transmission. Using Soft phone they make call to any Soft Phone and Physical hardware SIP phone which can understand the SIP protocol.In computing, a soft phone is a software program for making telephone calls over the Internet using a general purpose computer, rather than using dedicated hardware. A soft phone is usually used with a headset connected to the sound card of the PC. To communicate, both end-points must have the same communication protocol and at least one common audio code. Many service providers use the Session Initiation Protocol (SIP) standardized by the Internet Engineering Task Force (IETF)

Intelligent connection manager for seamless interworking of multi-technology mobile devices

As wireless service providers ramp up their Long Term Evolution (LTE) installations, and telecommunications and cable operators continue to expand Wi-Fi coverage, 100 percent wireless coverage with overlapping areas of 3G, 4G, and Wi-Fi access is becoming a reality. Ensuring that a multi-mode device can roam across different radio access technologies while maintaining seamless session and service continuity across virtual private network (VPN), Voice over Internet Protocol (VoIP), and streaming video applications is critical. Differences in 3GPP, 3GPP2, and WiMAX standards led to the absence of uniform interworking solutions. Specific interworking standards per access technology pair define the behavior and interfaces for common core network components including the IP anchor, AAA, and HSS, as well as the IP Multimedia Subsystem (IMS). This paper discusses the Intelligent Wireless Connection Manager (IWCM), a critical component of a mobile device platform that enables seamless and transparent inter technology mobility for user applications through IP session continuity, make-before-break handoff algorithms, and uniform quality of service (QoS) and policy management APIs.

A Cross-Layering Design for IPv6 Fast Handover Support in an IEEE 802.16e Wireless MAN

Broadband wireless access networks, such as the IEEE 802.16 standard for wireless metropolitan area networks (WMANs), aim to provide high bandwidth, low-cost, scalable solutions that extend multimedia services from backbone networks to wireless users. Because of a larger coverage area, portability and mobility have become significant issues for providing high quality mobile services, as it is crucial to minimize handover latency and maintain IP session continuity. As a result, such issues were addressed by the IEEE 802.16e task group on the mobile WMAN. However, the scope of the IEEE 802.16e standard did not include cross-layering approaches for the enhancement of upper layer handover performance. This article proposes a new cross-layering design for fast IPv6 handover support over IEEE 802.16e. First, we describe the IEEE 802.16 deployment architectures, as well as the link layer, handover procedures in IEEE 802.16e. Next, we describe the operation of fast IPv6 handover and point out the need for interaction between the network layer and the link layer for proper performance. Then, we propose a new cross-layering design to achieve a proper behavior of the fast IPv6 handover over IEEE 802.16e. Finally, we present handover scenarios for the proposed techniques and discuss the major factors that contribute to the handover latency.

A Real-Time Network Analysis Tool to Aid in Characterizing VoIP System Performance

This paper details the development of an educational and research tool, the Network Performance Application (NPA), which provides real-time network performance measurement through a simulated voice over IP session using live real-time data transmission over packet networks. This application, written in Visual C++ for MS Windows environments, is used to collect Quality of Service (QoS) statistics such as packet loss, end-to-end delay, inter-arrival delay jitter, and out-of-order packet delivery. The paper also demonstrates a practical application using a government standard for VoIP transmissions.

User-aware object-based video transmission over the next generation Internet

In this paper, we present a new user-aware adaptive object-based video transmission approach to heterogeneous users over the next generation Internet. Firstly, we describe a new transport framework for complex multimedia applications over the next generation Internet, which provides differentiation functionality within one IP session as well as among different IP sessions. It includes application-aware intelligent resource control at the edge of the network, fast transcoding and signaling in the network. Secondly, we propose a new bitstream classification , prioritization and packetization scheme in which different types of data such as shape, motion and texture are reassembled, assigned to different priority classes, and packetized separately based on their priorities. Thirdly, we present a simple but effective mechanism of object-based dynamic rate control and adaptation by selectively dropping packets in conjunction with differentiated services (Diffserv) to minimize the end-to-end quality distortion. Finally, we perform the queuing analysis for our mechanism and explore how to extend our approach to the multicast case. Experimental results demonstrate effectiveness of our proposed approach.