Policy-Based QoS Management for Multimedia Communication

World Applied Sciences …, 2009

This paper examines the state-of-the-art in the development of resource and admission control architectures for Next Generation Networks (NGN). The approach taken is, initially, to present some basic concepts for understanding and discussing quality of service in the context of NGN. Following this, we consider current research activities in international standardization organizations and then a detailed discussion on Resource and Admission Control Functions (RACF) architecture proposed by ITU-T. After this survey, we introduce some SIP-based call flows for call set-up and termination in NGN considering the role of RACF and QoS signaling in the call flows. Various scenarios are presented regarding different concepts such as single/two-phase schemes and single/multi-domain networks. We clarify the difference between these scenarios according to their call flows. This results in a more accurate understanding of resource control models, architectures and protocols that have been introduced up to now.

Journal of Network and Systems Management, 2008

The IP Multimedia Subsystem (IMS) adopted in the core of Next Generation Networks (NGNs) promises to make network management easier by separating the control and the transport planes. Therefore, an interface between applications and the underlying transport network has been defined that offers a dynamic and efficient management of network resources based on a policy-based resource control engine. The resulting resource management framework enables the delivery of both the existing carrier grade existing and the next generation Quality of Service (QoS) sensitive services across operator-controlled networks using heterogeneous transport technologies. This review sheds some light into the policy control layer concept and the extended nomenclature introduced by current standardization works. The approaches of international standards development organizations, such as the Third Generation Partnership Project (3GPP), the International Telecommunication Union (ITU), the European Telecommunications Standards Institute (ETSI), the WiMAX Forum, and CableLabs are reviewed and compared with each other revealing the common architectural trend. Challenges and works in progress of NGN resource management towards Fixed and Mobile Convergence (FMC) are discussed as well.

Bell Labs Technical Journal, 2004

With the increasing demand for wireless packet data services, 3G wireless carriers today are faced with the challenge of offering multimedia applications with QoS requirements while at the same time effectively utilizing precious wireless bandwidth. According to the IP Multimedia Subsystem (IMS) framework, end-to-end QoS support requires signaling, traffic regulation and resource allocation capabilities. QoS signaling is used to provision and enforce QoS parameters between endpoints and is conducted in the application layer, network layer and link layer. SIP is used as the application level signaling protocol to establish sessions where SDP parameters that are carried as part of the SIP payload contain session specific information. We discuss how QoS parameters are negotiated between endpoints running SIP user agents through the SIP proxy and AAA server. The Policy Decision Point (PDP) is collocated with the SIP proxy to determine the allowed QoS parameters based on SIP negotiation and local policy of the network. We present how session specific QoS parameters are exchanged via SDP or SIP header fields. We discuss how QoS parameters are enforced using the Policy Enforcement Point (PEP) as part of PDSN in CDMA2000. We report a prototype implementation of the QoS control in IMS including implementation of SIP related to QoS negotiation including SIP user agents, SIP proxy, SIP registrar, and an implementation of PEP in Linux to conduct traffic regulation.

Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering, 2009

The 3GPP are currently finalizing their Evolved Packet System (EPS) with the Evolved Packet Core (EPC) central to this framework. The EPC is a simplified, flat, all IP-based architecture that supports mobility between heterogeneous access networks and incorporates an evolved QoS concept based on the 3GPP Policy Control and Charging (PCC) framework. The IP Multimedia Subsystem (IMS) is an IP service element within the EPS, introduced for the rapid provisioning of innovative multimedia services. The evolved PCC framework extends the scope of operation and defines new interactions-in particular the S9 reference point is introduced to facilitate inter-domain PCC communication. This paper proposes an enhancement to the IMS/PCC framework that uses SIP routing information to discover signaling and media paths. This mechanism uses standardized IMS/PCC operations and allows applications to effectively issue resource requests from their home domain enabling QoS-connectivity across multiple domains. Because the mechanism operates at the service control layer it does not require any significant transport layer modifications or the sharing of potentially sensitive internal topology information. The evolved PCC architecture and inter-domain route discovery mechanisms were implemented in an evaluation testbed and performed favorably without adversely effecting end user experience.

2009 5th International Conference on Testbeds and Research Infrastructures for the Development of Networks & Communities and Workshops, 2009

Abstract-Policy Based Resource Management will form the cornerstone of service differentiation that will drive IMS service deployment. While the IMS specifications are largely finalized, the policy based QoS provisioning architecture still faces many deployment challenges ...

Int'l J. of Communications, Network and System Sciences, 2009

The study of Quality of Service (QoS) has become of great importance since the Internet is used to support a wide variety of new services and applications with its legacy structure. Current Internet architecture is based on the Best Effort (BE) model, which attempts to deliver all traffic as soon as possible within the limits of its abilities, but without any guarantee about throughput, delay, packet loss, etc. We develop a three-layer policy based architecture which can be deployed to control network resources intelligently and support QoS sensitive applications such as real-time voice and video streams along with standard applications in the Internet. In order to achieve selected QoS parameter values (e.g. loss, delay and PDV) within the bounds set through SLAs for high priority voice traffic in the Internet, we used traffic engineering techniques and policy based routing supported by Border Gateway Protocol (BGP). Use of prototype and simulations validates functionality of our architecture.

IST Mobile …, 2004

In order to provide end-to-end QoS in B3G systems, based on the UMTS architecture, the DiffServ framework can be used in the data plane of the IP core network of the mobile access network. Among the different schemes proposed for the control plane of DiffServ, the Internet2 bandwidth broker approach has been chosen for its centralized management nature, which is needed to coordinate QoS between the different entities of the heterogeneous access network: the core network, the radio, external bearer services and the user. It will be shown that policy-based service negotiation is an important component of the bandwidth broker and of the control plane, in order to provide a flexible end-to-end QoS management in B3G systems. Furthermore, the following issues regarding the proposed policy-based architecture are identified: the need for a policy decision point at the radio bearer service entity, the interaction of service negotiation and mobility management protocols, and the impact of WLAN coupling.

Next Generation Mobile …, 2007

IP Multimedia Subsystem (IMS) originating from the 3GPP is pivotal on the road to next generation all-IP networks. Multimedia applications are potential drivers for the adoption of next generation IP multimedia subsystem (IMS) and could be a decisive factor in its deployment. Innovative multimedia services are expected to generate revenue to the operators and justify their investment in IMS. And, for multimedia services to be widely accepted by the end users, guaranteed and adaptable quality of service provision across heterogeneous access networks and heterogeneous device types is mandatory. In this paper, a generic, adaptive, controlled service delivery framework implementation for multimedia applications on IMS architecture is proposed. The framework is designed to be user-centric, adaptable to terminal mobility and session mobility with minimum session disruption enabling a better end-to-end QoS. It is at the session-level, completely user-driven and does not account for the network-level QoS. It employs the Session initiation protocol (SIP), which is the signaling protocol for the 3GPP specified IMS. The purpose behind the framework is to evaluate the provisioning of quality-adaptive multimedia services on IMS network and analyze the performance with respect to delay induced by quality adaptation procedures during session and terminal mobility which might contribute towards the end-to-end quality of service delivered to the users.

This paper introduces a concept for the selection of QoS (Quality of Service) monitoring points in SIP-based NGN (Session Initiation Protocol; Next Generation Networks). It is assumed that the majority of effects influencing the QoS of a single media session (such as a VoIP session (Voice over IP)) also has an effect on the QoS experienced by coexistent media sessions held by other subscribers under similar conditions (such as if subscribers share the same access network, and comparable access and session parameters). An Artificial Neural Network is intended to be used for determining the comparability of sessions, and hence, of user terminals, regarding their QoS conditions. User terminals affected by comparable QoS conditions are dynamically assigned to virtual groups, each representing the QoS conditions effective for its respective members. Hence, from monitoring network performance parameters at one terminal associated with a particular group, conclusions can be drawn on the QoS experienced by other group members. In order to minimise the network traffic resulting from both the querying for and the communication of QoS conditions experienced by user terminals the concept does not only consider the time already elapsed of a session to be potentially monitored but also the mean duration of sessions held by the subscriber associated with a potential monitoring point.

Current Internet architecture is based on the Best Effort (BE) model, where packets can be dropped indiscriminately in the event of congestion. Though such a model works well for certain traditional applications such as FTP, E-mail and less QoS constrained applications, it can be intolerable for newly emerged real-time, multimedia applications such as Internet Telephony, Video-Conferencing and Video on-Demand. Such applications have a strict demand for high bandwidth, low delay and low jitter. Current research is focused towards providing better than BE services over the Internet thereby providing a better Internet architecture which is scalable and will enable end-to-end QoS. This paper is based on the ongoing research activities being carried out by various researchers in the area of QoS and proposes a Policy Based Network (PBN) for the next generation Internet.