Alexandros Kaloxylos

Charging, accounting and billing management schemes in mobile telecommunication networks and the internet

The current technological advances in mobile telecommunication networks and the Internet are about to alter existing business models. These different worlds converge and create an open market, where a large number of independent application/service providers will offer their services to users through a limited number of network providers. At the same time, the evolution of existing network technologies and the specification of new concepts requires new advanced and holistic solutions in several technical areas. One such area is related to the design and management of new sophisticated functions and protocols to support innovative, flexible, and efficient charging, accounting, and billing mechanisms. This survey article considers the key concepts of such mechanisms, and the requirements they impose upon the network infrastructure. The article presents the latest efforts undertaken by standardization bodies in the mobile telecommunication industry as well as by Internet Working Groups to meet these requirements.

An efficient RSVP-mobile IP interworking scheme

During the past years, several attempts have been made to develop functionality for mobility management support and QoS provision in the realm of the IP networks. Since IP was not designed to support such functionality, new protocols have been specified and implemented to tackle these issues. Mobile IP is currently the dominant protocol that allows users to retain connectivity while roaming in IP networks. RSVP (Resource reSerVation Protocol) is a well established protocol for reserving network resources to support QoS requirements. These protocols, when deployed separately, can work quite efficiently. However, if their functionality is combined, several inefficiencies arise in terms of QoS deterioration and misuse of the network resources. To minimize these inefficiencies, we propose a new approach that limits mobility and QoS related network modifications inside the domain, in which a user moves. The deployment of our scheme enhances the network resource usage efficiency, while minimizing the duration of the QoS deterioration experienced after a terminal movement. To quantify the advantages of our proposal, we have developed an analytical and a simulation model that we also present in this paper.

A platform for charging, billing, and accounting in future mobile networks

Current technological advances enable the modification of existing mobile telecommunications business models. In future mobile networks, mobile users will be able to choose from multiple network operators and service providers. This capability requires the extension of the existing charging collection information mechanisms and billing systems to assist the oncoming mass service offering by independent service providers. In this paper, we present a platform that extends the existing systems to provide for advanced and flexible charging mechanisms and pricing policies.

Charging, accounting and billing as a sophisticated and reconfigurable discrete service for next generation mobile networks

The evolution of the Universal Mobile Telecommunication System (UMTS) creates an open market; where a large number of independent application/service providers will offer their services to the users through a limited number of network providers. Moreover, the convergence of the UMTS with the Internet world is about to alter the existing business models. The support of advanced business models is a chance but also implies new requirements. Among the important issues that are to be resolved in order to facilitate the establishment of these advanced models, is the support of innovative, flexible and efficient charging, accounting and billing mechanisms. We propose the complexity involved in all these issues to be handled by an intelligent and integrated platform that will be responsible for coordinating the charging, accounting and billing process allowing all the involved players to affect dynamically these processes. Moreover, the generation of a single, itemised bill for delivered services, which is required from the user perspective, is well accommodated in the proposed platform.

An efficient micro-mobility solution for SIP networks

SIP is evolving as the dominant protocol for multimedia call control in IP networks and is expected to be widely deployed in the near future. Using SIP for supporting mobility in SIP-based networks appears as a very attractive alternative to mobile IP, taking advantage of existing SIP infrastructure and signaling, while avoiding duplication of functionality. However, existing proposals for supporting mobility with SIP are not efficient in handling micro-mobility and do not cater for all types of traffic. In this paper, we introduce hierarchical mobile SIP (HMSIP), for efficient micro-mobility management in SIP environments. HMSIP is a SIP-based scheme that builds on existing IP mobility protocols, aiming at integrating their key concepts in the most beneficial way. Our proposed scheme minimizes the handoff latency and the backbone signaling overhead, while catering for all types of traffic. Moreover, HMSIP can be effectively combined with micro-mobility schemes for QoS flows, producing, thus, a complete micro-mobility solution for SIP flows with QoS guarantees.

A survey of internet QoS signaling

The need for real-time services support over the Internet drives research efforts toward the provisioning of quality of service (QoS) guarantees in IP networks. Among the various aspects of QoS provisioning, QoS state establishment and maintenance in intermediate routers is a major factor, responsible for dynamic resource allocation. The dynamic manipulation of QoS state is possible through the utilization of appropriate QoS signaling that triggers the respective resource allocation in QoS-capable network elements. At first, protocol design assumed a homogeneous underlying network and resulted in end-to-end QoS protocols that applied a specific QoS configuration in all routers along the path. However, the need for accommodating network heterogeneity and flexibility led to a two-tier resource management model that utilizes separate signaling for intra- and inter-domain reservations and requires different signaling processing in domain interior and border routers. This article gives an overview of the QoS signaling protocols designed for the Internet and describes their characteristics. Moreover, the identified protocols are classified depending on their applicability for intra- or inter-domain usage. A comparison of the various protocols based on some common signaling elements is also provided, and future trends in the Internet QoS signaling area are identified.

5G Radio Access Network Architecture: Design Guidelines and Key Considerations

While there is clarity on the wide range of applications that are to be supported by 5G cellular communications, and standardization of 5G has now started in 3GPP, there is no conclusion yet on the detailed design of the overall 5G RAN. This article provides a comprehensive overview of the 5G RAN design guidelines, key design considerations, and functional innovations as identified and developed by key players in the field.1 It depicts the air interface landscape that is envisioned for 5G, and elaborates on how this will likely be harmonized and integrated into an overall 5G RAN, in the form of concrete control and user plane design considerations and architectural enablers for network slicing, supporting independent business-driven logical networks on a common infrastructure. The article also explains key functional design considerations for the 5G RAN, highlighting the difference to legacy systems such as LTE-A and the implications of the overall RAN design.

Adaptive charging accounting and billing system for the support of advanced business models for VAS provision in 3G systems

In the framework of the design of a flexible service provision platform for 3G systems and beyond, an integrated system for enabling advanced Charging, accounting and billing has been introduced. The CAB system is adaptive to VAS charging requirements and network/business environment concepts. Part of the system has been developed in the frame of IST-MOBIVAS project.

Enabling technologies for the 'Always Best Connected' concept

‘Always Best Connected’ (ABC) is considered one of the main requirements for next generation networks. The ABC concept allows a person to have access to applications using the devices and network technologies that best suits his or her needs or profile at any time. Clearly, this requires the combination of a set of existing and new technologies, at all levels of the protocol stack, into one integrated system. In this paper, a considerable set of the technologies, that are expected to play a key role towards the ABC vision, are presented. Starting from a reference architecture, the paper describes the required enhancements at certain levels of a traditional protocol stack, as well as technologies for mobility and end-to-end Quality of Service (QoS) support. The paper concludes with a case study that reveals the advantages of the ABC concept. This article replaces a previously published version (Wireless Communications and Mobile Computing; 5(2): 175-191. [DOI: 10.1002/wcm.207]). Retraction notice DOI: 10.1002/wcm.426. Copyright

A flexible UMTS/WLAN architecture for improved network performance

Current trends in cellular telecommunications suggest the incorporation of Wireless Local Area Networks (WLANs) as supplementary access technologies into the existing cellular infrastructure. Overlay network architectures are expected to improve both service provision and resource utilization under the condition that sophisticated architectural options are followed. Many proposals suggest that all active connections be handled through the same access network technology. However, this is not believed to be efficient in a heterogeneous environment. Therefore, a mechanism that allows each connection of a terminal to be served by different radio access technology is introduced. Based on a tight coupling architecture for interworking between Universal Mobile Telecommunications System (UMTS) and WLANs, the proposed scheme combines a sophisticated decision mechanism with flexible connection management in a way that ensures seamless service continuity during handover. The performance of the system is evaluated using a detailed simulation model and compared against existing architectures. Simulation results indicate an improvement in parameters such as connection and handover blocking probabilities, which justifies the enhancement in the overall usage of network resources when connections are handled separately.