Providing quality of service in always best connected networks

The next generation of mobile systems is expected to support multiple radio access technologies, as well as diverse types of terminals, including mobile phones, personal digital assistants, and laptops, as well as personal area, moving, and sensor networks. Thus, future wireless systems will not only continue to break technological barriers in terms of new air interface capabilities, higher bit rates, mobility, security, and QoS management, but will present new end-to-end scenarios in which applications access services over multiple L2 hops and multiple IP networks. The term always best connected refers to the concept of defining a set of access selection criteria and mechanisms that allow users to get connected to various services in a nearly optimal manner. Providing QoS in this type of heterogeneous multihop environment is a challenging task because applications may be completely unaware of them scenario and the underlying layer 2 technologies that can be quite different at different hops. For instance, some wireless links may have scarce resources and highly optimized QoS mechanisms; others may not support explicit QoS handling at all. In this article we consider the use of IP-level QoS signaling as a key component to support the end-to-end QoS for various applications. We propose a small set of application programmer- and wirelesslink-friendly IP QoS parameters (wireless hints) and illustrate the use of these in a specific WLAN-to-cellular handover situation. We conclude that the proposed model, signaling protocol, and wireless information elements can efficiently support QoS in heterogeneous mobile environments.     

A highly digitized multimode receiver architecture for 3G mobiles

A highly digitized multimode receiver architecture is described. It is configured primarily for the Universal Mobile Telecommunication System (UMTS) and Global System for Mobile Communications (GSM) modes, but has the potential to operate in other modes such as cdma2000 as well. The receiver uses a single down conversion to mix the RF signal to a zero intermediate frequency (IF) for UMTS mode and a low IF for GSM. It uses a reconfigurable analog-to-digital converter (ADC) to digitize the IF signals as early as possible and to transfer most of the channel filtering into the digital domain. Only a minimum of automatic gain control (AGC) is employed. The architecture aims to maximize reuse of common hardware and to make significant gains in terms of design costs, size, and adaptability. System simulations confirm the feasibility and performance of the new concept.     

A management and control architecture for providing IPdifferentiated services in MPLS-based networks

As the Internet evolves toward the global multiservice network of the future, a key consideration is support for services with guaranteed quality of service. The proposed differentiated services framework is seen as the key technology to achieve this. DiffServ currently concentrates on control/data plane mechanisms to support QoS, but also recognizes the need for management plane aspects through the bandwidth broker. In this article we propose a model and architectural framework for supporting DiffServ-based end-to-end QoS in the Internet, assuming underlying MPLS-based explicit routed paths. The proposed integrated management and control architecture will allow providers to offer both quantitative and qualitative services while optimizing the use of underlying network resources     

Reconfigurable multi-mode sigma-delta modulator for 4G mobile terminals

A reconfigurable sigma-delta modulator, which is able to support the predictable standards for the fourth generation (4G) of mobile communication systems, is presented in this paper. This modulator was designed to cope with six different communications standards relying on a flexible architecture. Furthermore, the proposed architecture introduces the ability to process concurrently two different signals. The major design issues are outlined and operation modes are detailed. The feasibility of the presented solution is demonstrated using high-level system-level simulations as well as device-level simulations of the modulator implemented with switched capacitor circuits.     

Service configuration and user profiling in 4G terminals

This paper presents a middleware platform for managing devices that operate in heterogeneous environments. The proposed management framework supports terminal-controlled, preference-based access network selection. Two separate problems are identified in this domain: one involving the computation of optimal allocations of services to access networks and quality levels (service configuration), and one concerning the dynamic inference of the user’s preferences, according to the usage context (user profiling). This paper includes an approach to the definition, mathematical formulation and solution of both these problems. Indicative results of the proposed solution methods are presented in the context of a real-life scenario simulating a day in the life of an ordinary user.     

面向5G业务的乡镇SPN规划及组网架构

切片分组网凭借其技术优势已成为5G业务主流传送承载网的技术之一。伴随乡镇、农村5G业务高速发展及各类5G垂直行业对5G业务的更高更广需求,前期在市区县城区域部署的SPN已无法完全满足业务需求。为满足乡镇、农村的5G业务发展需求,需考虑将SPN下沉至乡镇层级。基于乡镇5G业务发展趋势,综合考虑乡镇SPN建设条件,结合SPN架构、组网拓扑等条件,搭建乡镇SPN架构模型并深入分析获得某地市实际应用场景建设方案,为后期乡镇SPN建设提供参考和思路。     

A multilayer differentiated protection services architecture

Metropolitan area and long-haul networks are migrating toward the deployment of optical mesh technologies. This requires, among other things, a new generation of highly intelligent protection and restoration mechanisms to perform functions of protection and bandwidth management. We introduce an architecture that provides differentiated protection services across multiple layers of network hierarchy. A connection at any client layer can request a protection against resource failures at any lower layer. A key aspect of the architecture is the hierarchical tree organization of shared risk link group (SRLG) resources. They represent routing-related failures across all layers of protocol stack. The architecture is very scalable in terms of communicating link-state and bandwidth information between adjacent layers. SRLG trees are used to aggregate this information and provide a summary to the client layer. We discuss the requirements and challenges for routing and signaling mechanisms in order to support the proposed architecture. The complexity of this architecture is evaluated and compared with the complexity of a nonhierarchical alternative.     

5G和4G融合网络部署架构研究

本文根据3GPP讨论的十种5G和4G融合组网架构,研究了5G网络独立部署和非独立部署方式,分析了各组网架构的优势和劣势,对各种5G部署方式的性价比进行了对比分析,分析了5G网络部署的近期、中期、远期部署方案,提出了循序渐进的5G网络建设过渡方案。     

在以太网中提供电路仿真业务的方法

文章介绍了以太网中提供电路仿真业务的应用参考模型,接着阐述了该业务的主要技术要求,最后提出了几种典型的电路仿真业务在以太网中的实现方案。     

IPTV QoS adaptation for multi-homed mobile terminals in a new IMS based architecture

With the emergence of multimedia applications that have real constraints, ensuring a satisfying quality of service to mobile users presents a big challenge in heterogeneous wireless networks. In such environment, the asymmetry of the available resources as well as user’s mobility can cause offered QoS degradation. In this paper, we propose the use of the Stream Control Transmission Protocol (SCTP) within a QoS adaptive IPTV services in a novel IMS architecture. The multi-homing feature and the partial reliability extension allow improving the network performance and increasing the user satisfaction. In addition, we have proposed an mSCTP based mobility scheme to guarantee service continuity during handover to IPTV users over IMS. The handover decision includes Perceived QoS (PQoS) measurement reflecting the user satisfaction and Media Independent Handover (MIH) information. An analytical study of the time required to perform IPTV adaptation, show that our approach improves the performance by minimizing the delay and maximizing the user satisfaction.     

A scale database architecture for network services

A radical technology for databases, called the Datacycle architecture, which implements a relational model for network services and scales to support throughput of thousands of transactions per second is proposed. A set of data manipulation primitives useful in describing the logic network services is described. The use of the relational model together with an extended structured-query-language-like query language to describe 800 service, network automatic call distribution, and directory-assisted call completion services, is examined. The architectural constraints on the scalability of traditional database systems is reviewed, and an alternative, the Datacycle architecture is presented. The Datacycle approach exploits the bandwidth of fiber optics to circulate database contents among processing nodes (e.g. switching offices or other network elements) in a network, providing highly flexible access to data and controlling the administrative and processing overhead of coordinating changes to database contents. A prototype system operating in the laboratory is described. The feasibility of the Datacycle approach for both existing and future applications is considered     

Toward a generic "always best connected" capability in integrated WLAN/UMTS cellular mobile networks (and beyond)

The next generation of mobile communications, broadly referred to as 4G, is based on a heterogeneous infrastructure comprising different wireless (and wired) access systems in a complementary manner. 4G mobile users enjoys seamless mobility and ubiquitous access to applications in an always best connected (ABC) mode that employs the most efficient combination of available access systems. The ongoing commercialization of 3G cellular mobile networks and their upcoming enhancement with WLAN radio access provides a wireless platform suitable for the introduction of "ABC" capabilities. We analyze the implications of the "ABC" vision in a UMTS/WLAN network context, and reveal important issues that arise. Further on, we identify major requirements, point out the limitations of current UTMS/WLAN standards from an ABC viewpoint, and discuss key enabling technologies and research efforts. We formulate a generic application model for an ABC capability in the interworked UMTS/WLAN architecture and analyze its complexity proving that, in principle, being always best connected translates to a family of NP-hard problems. To complement our analysis, we present an object-oriented design of a real-time UML model for an ABC mobile system. Finally, we summarize the advantages of our ABC model and provide directions for future work.     

Enabling multimedia applications in 2.5G and 3G wireless terminals through a combined RISC/DSP architecture: OMAP

This paper describes how multimedia applications will be enabled in 2.5 and 3G wireless terminals thanks to the efficiency of the DSP core embedded in the TI OMAP platform. OMAP H/W architecture will be described with an emphasis on how multimedia applications (video, audio, speech) will benefit from this advanced architecture. The advantages provided by a combined RISC/DSP architecture, compared to a single RISC architecture, for multimedia mobile applications will be depicted.     

A new architecture for 3G and WLAN integration and inter-system handover management

WLAN has strong potential to provide a perfect broadband complement to the 3G wireless systems. This has raised much interest in their integration. In this paper, a novel architecture using the Network Inter-operating Agent (NIA), and Integration Gateway (IG) is proposed to integrate the 3G systems and WLANs of various providers that may not necessarily have direct service level agreement (SLA) among them. The proposed architecture is scalable as it eliminates the need for the creation of bilateral SLA among the 3G and WLAN operators. In addition, inter-system handover (ISHO) protocols using the concept of the dynamic boundary area is proposed to support seamless roaming between 3G and WLAN. The dynamic boundary area is determined based on the speed of the user and WLAN cell size. The ISHO procedures are initiated when a mobile user enters the boundary area of the WLAN and are completed before the user leaves the coverage area of the serving WLAN. This ensures that the roaming from WLAN to 3G is transparent to the applications. The performance evaluation shows that the proposed boundary area based ISHO algorithm outperforms the existing 3G/WLAN ISHO algorithms. Shantidev Mohanty (SM’04) received his B. Tech. (Hons.) degree from the Indian Institute of Technology, Kharagpur, India and the M.S. degree from the Georgia Institute of Technology, Atlanta, Georgia, in 2000 and 2003, respectively, both in electrical engineering. He is currently a graduate research assistant with the Broadband and Wireless Networking Laboratory and a Ph.D. candidate at the School of Electrical and Computer Engineering, Georgia Institute of Technology. His current research interests include wireless networks, mobile communications, mobility management, ad-hoc and sensor networks, and cross-layer protocol design. From 2000 to 2001 he worked as a mixed signal design engineer for Texas Instruments, Bangalore, India. He worked as a summer intern for Bell Labs, Lucent Technologies, Holmdel, New Jersey, during the summers of 2002 and 2003 and for Applied Research, Telcordia Technologies, Piscataway, New Jersey, uring the summer of 2004.     

Controlled use of excess backbone bandwidth for providing new services in IP-over-WDM networks

We study an approach to quality-of-service (QoS) that offers end-users the choice between two service classes defined according to their level of transmission protection. The fully protected (FP) class offers end-users a guarantee of survivability in the case of a single-link failure; all FP traffic is protected using a 1:1 protection scheme at the wavelength-division multiplexing (WDM) layer. The best effort protected (BEP) class is not protected; instead restoration at the IP layer is provided. The FP service class mimics what Internet users receive today. The BEP traffic is designed to run over the large amounts of unused bandwidth that exist in today's Internet. The goal is to increase the load carried on backbone networks without reducing the QoS received by existing customers. To support two such services, we have to solve two problems: the off-line problem of mapping logical links to pairs of disjoint fiber paths, and an on-line scheduling problem for differentiating packets from two classes at the IP layer. We provide an algorithm based on a Tabu Search meta-heuristic to solve the mapping problem, and a simple but efficient scheduler based on weighted fair queueing for service differentiation at the IP layer. We consider numerous requirements that carriers face and illustrate the tradeoffs they induce. We demonstrate that we can successfully increase the total network load by a factor between three and ten and still meet all the carrier requirements.     

An IP-based QoS architecture for 4G operator scenarios

This article describes a global QoS architecture for multimedia traffic in mobile heterogeneous environments. This architecture supports both multiple access networks and multiple service provider scenarios. The architecture is able to provide QoS per user and per service, implementing the notion of a user profile associated network management in the case of heterogeneous and mobile network access is presented based on cooperative association between QoS brokers and authentication, authorization, accounting, and charging systems. The overall exchange of messages is exemplified for the case of a field test with specific optimizations for voice traffic.