The Experts below are selected from a list of 2532 Experts worldwide ranked by ideXlab platform

Yves Lemieux - One of the best experts on this subject based on the ideXlab platform.

  • umts to ip qos mapping for voice and video Telephony services
    IEEE Network, 2005
    Co-Authors: Samuel Pierre, Yves Lemieux
    Abstract:

    Quality of service mapping between UMTS services and IP transport is crucial for maintaining a suitable end-to-end delay for emerging UMTS Multimedia Telephony. However, due to incompatibilities in QoS classifications within these two technologies, straightforward mapping is impossible and current proposals within the 3GPP could lead to unpredictable and undesirable behavior for certain services. In this article we focus on two very important UMTS services, voice and video Telephony, and establish the QoS issues that exist for these services. We then propose a refined QoS mapping that differentiates between the transmission of voice and video-Telephony and a weighted fair queuing scheduler to schedule the transmissions. Through a simulation study, we show the effect on the queuing delays of both traffic types when their WFQ weights vary and then derive an optimal weight that provides the best overall delays for Multimedia Telephony services.

  • diffserv qos performance evaluation of Multimedia Telephony
    Canadian Conference on Electrical and Computer Engineering, 2004
    Co-Authors: Racha Ben Ali, Samuel Pierre, Yves Lemieux
    Abstract:

    The Differentiated Services architecture (DiffServ) is a scalable and economic solution which provides relative QoS to different kind of services. Due to the critical QoS constraints of conversational Multimedia services (including voice and video-Telephony), a QoS mapping between those services and DiffServ classes must be well defined. Voice and video-Telephony services are always mapped within the same EF Premium class to provide them with the best service. However, voice and video have divergent stochastic characteristics. Consequently, this standard mapping leads to heterogeneous traffic multiplexing within the same queues in the aggregating routers, which may deteriorate the best service always provided to voice. Thus, we have proposed a refined mapping which differentiates them. In order to carry out a performance study of voice/video packet scheduling, we have considered two different traffic models for voice and video. Simulation results show that WFQ scheduling with a well chosen weight performs better than FIFO and PQ. In our case, a weight of 0.25 for the voice class gives the optimal overall delay performance for Multimedia Telephony.

Samuel Pierre - One of the best experts on this subject based on the ideXlab platform.

  • umts to ip qos mapping for voice and video Telephony services
    IEEE Network, 2005
    Co-Authors: Samuel Pierre, Yves Lemieux
    Abstract:

    Quality of service mapping between UMTS services and IP transport is crucial for maintaining a suitable end-to-end delay for emerging UMTS Multimedia Telephony. However, due to incompatibilities in QoS classifications within these two technologies, straightforward mapping is impossible and current proposals within the 3GPP could lead to unpredictable and undesirable behavior for certain services. In this article we focus on two very important UMTS services, voice and video Telephony, and establish the QoS issues that exist for these services. We then propose a refined QoS mapping that differentiates between the transmission of voice and video-Telephony and a weighted fair queuing scheduler to schedule the transmissions. Through a simulation study, we show the effect on the queuing delays of both traffic types when their WFQ weights vary and then derive an optimal weight that provides the best overall delays for Multimedia Telephony services.

  • diffserv qos performance evaluation of Multimedia Telephony
    Canadian Conference on Electrical and Computer Engineering, 2004
    Co-Authors: Racha Ben Ali, Samuel Pierre, Yves Lemieux
    Abstract:

    The Differentiated Services architecture (DiffServ) is a scalable and economic solution which provides relative QoS to different kind of services. Due to the critical QoS constraints of conversational Multimedia services (including voice and video-Telephony), a QoS mapping between those services and DiffServ classes must be well defined. Voice and video-Telephony services are always mapped within the same EF Premium class to provide them with the best service. However, voice and video have divergent stochastic characteristics. Consequently, this standard mapping leads to heterogeneous traffic multiplexing within the same queues in the aggregating routers, which may deteriorate the best service always provided to voice. Thus, we have proposed a refined mapping which differentiates them. In order to carry out a performance study of voice/video packet scheduling, we have considered two different traffic models for voice and video. Simulation results show that WFQ scheduling with a well chosen weight performs better than FIFO and PQ. In our case, a weight of 0.25 for the voice class gives the optimal overall delay performance for Multimedia Telephony.

Miguelangel Garcamartn - One of the best experts on this subject based on the ideXlab platform.

  • the 3g ip Multimedia subsystem ims merging the internet and the cellular worlds
    2004
    Co-Authors: Gonzalo Camarillo, Miguelangel Garcamartn
    Abstract:

    Third edition of this best-selling guide to IMS: fully revised, and updated with brand new material The IMS (IP Multimedia Subsystem) is the technology that merges the Internet with the cellular world. It makes Internet technologies such as the web, email, instant messaging, presence, and videoconferencing available nearly everywhere at any time. The third edition of this bestselling book is fully updated and provides comprehensively expanded content, including new chapters on emergency calls and on Voice Call Continuity (VCC). As well as this, The 3G IP Multimedia Subsystem (IMS) presents updated material including a comprehensive picture of Session Initiation Protocol (SIP) as well as its applicability to IMS. As most of the protocols have been designed in the IETF, this book explains how the IETF developed these protocols and describes how these protocols are used in the IMS architecture. This is an indispensable guide for engineers, programmers, business managers, marketing representatives and technically aware users who want to understand how the IMS works and explore the business model behind it. New chapters on emergency calls, Voice Call Continuity (VCC), service configuration (XCAP, XDM), and conferencing Fully updated throughout, including Policy and Charging Control (PCC), QoS, Presence, Instant Messaging, Multimedia Telephony Services, and Push-to-talk over Cellular (PoC) Describes the IP Multimedia Subsystem from two different perspectives: from the IETF perspective, and from the 3GPP perspective. Provides details on the latest policy technology and security architecture Written by experienced professionals in the field.

  • the 3g ip Multimedia subsystem merging the internet and the cellular worlds
    2004
    Co-Authors: Gonzalo Camarillo, Miguelangel Garcamartn
    Abstract:

    Third edition of this best-selling guide to IMS: fully revised, and updated with brand new material The IMS (IP Multimedia Subsystem) is the technology that merges the Internet with the cellular world. It makes Internet technologies such as the web, email, instant messaging, presence, and videoconferencing available nearly everywhere at any time. The third edition of this bestselling book is fully updated and provides comprehensively expanded content, including new chapters on emergency calls and on Voice Call Continuity (VCC). As well as this, The 3G IP Multimedia Subsystem (IMS) presents updated material including a comprehensive picture of Session Initiation Protocol (SIP) as well as its applicability to IMS. As most of the protocols have been designed in the IETF, this book explains how the IETF developed these protocols and describes how these protocols are used in the IMS architecture. This is an indispensable guide for engineers, programmers, business managers, marketing representatives and technically aware users who want to understand how the IMS works and explore the business model behind it. New chapters on emergency calls, Voice Call Continuity (VCC), service configuration (XCAP, XDM), and conferencing Fully updated throughout, including Policy and Charging Control (PCC), QoS, Presence, Instant Messaging, Multimedia Telephony Services, and Push-to-talk over Cellular (PoC) Describes the IP Multimedia Subsystem from two different perspectives: from the IETF perspective, and from the 3GPP perspective. Provides details on the latest policy technology and security architecture Written by experienced professionals in the field.

Gonzalo Camarillo - One of the best experts on this subject based on the ideXlab platform.

  • the 3g ip Multimedia subsystem ims merging the internet and the cellular worlds
    2004
    Co-Authors: Gonzalo Camarillo, Miguelangel Garcamartn
    Abstract:

    Third edition of this best-selling guide to IMS: fully revised, and updated with brand new material The IMS (IP Multimedia Subsystem) is the technology that merges the Internet with the cellular world. It makes Internet technologies such as the web, email, instant messaging, presence, and videoconferencing available nearly everywhere at any time. The third edition of this bestselling book is fully updated and provides comprehensively expanded content, including new chapters on emergency calls and on Voice Call Continuity (VCC). As well as this, The 3G IP Multimedia Subsystem (IMS) presents updated material including a comprehensive picture of Session Initiation Protocol (SIP) as well as its applicability to IMS. As most of the protocols have been designed in the IETF, this book explains how the IETF developed these protocols and describes how these protocols are used in the IMS architecture. This is an indispensable guide for engineers, programmers, business managers, marketing representatives and technically aware users who want to understand how the IMS works and explore the business model behind it. New chapters on emergency calls, Voice Call Continuity (VCC), service configuration (XCAP, XDM), and conferencing Fully updated throughout, including Policy and Charging Control (PCC), QoS, Presence, Instant Messaging, Multimedia Telephony Services, and Push-to-talk over Cellular (PoC) Describes the IP Multimedia Subsystem from two different perspectives: from the IETF perspective, and from the 3GPP perspective. Provides details on the latest policy technology and security architecture Written by experienced professionals in the field.

  • the 3g ip Multimedia subsystem merging the internet and the cellular worlds
    2004
    Co-Authors: Gonzalo Camarillo, Miguelangel Garcamartn
    Abstract:

    Third edition of this best-selling guide to IMS: fully revised, and updated with brand new material The IMS (IP Multimedia Subsystem) is the technology that merges the Internet with the cellular world. It makes Internet technologies such as the web, email, instant messaging, presence, and videoconferencing available nearly everywhere at any time. The third edition of this bestselling book is fully updated and provides comprehensively expanded content, including new chapters on emergency calls and on Voice Call Continuity (VCC). As well as this, The 3G IP Multimedia Subsystem (IMS) presents updated material including a comprehensive picture of Session Initiation Protocol (SIP) as well as its applicability to IMS. As most of the protocols have been designed in the IETF, this book explains how the IETF developed these protocols and describes how these protocols are used in the IMS architecture. This is an indispensable guide for engineers, programmers, business managers, marketing representatives and technically aware users who want to understand how the IMS works and explore the business model behind it. New chapters on emergency calls, Voice Call Continuity (VCC), service configuration (XCAP, XDM), and conferencing Fully updated throughout, including Policy and Charging Control (PCC), QoS, Presence, Instant Messaging, Multimedia Telephony Services, and Push-to-talk over Cellular (PoC) Describes the IP Multimedia Subsystem from two different perspectives: from the IETF perspective, and from the 3GPP perspective. Provides details on the latest policy technology and security architecture Written by experienced professionals in the field.

Ben F Shatwan - One of the best experts on this subject based on the ideXlab platform.

  • performance evaluation of ims Multimedia Telephony over wireless lans
    2007 International Conference on IP Multimedia Subsystem Architecture and Applications, 2007
    Co-Authors: Asma Elmangosh, Majdi Ashibani, Ben F Shatwan
    Abstract:

    Multimedia Telephony over IP is a standardized IP Multimedia subsystem (IMS) Telephony service in release 7 of the third generation partnership project (3GPP), which is build on the IMS capabilities already provided in 3GPP Releases 5 and 6. In this paper we investigate the performance of IMS Multimedia Telephony service over WLAN access networks by the means of simulation using NS-2. The objective of this study is to evaluate the performance of Multimedia Telephony with IPSec tunnel in 3G-WLAN interworking architecture, and the maximum number of possible connections in a single 802.11 access point (AP) without degrading the required level of quality of service (QoS) for the Multimedia traffic.