Quality-of-service signaling for next-generation IP-based mobile networks

We present a novel end-to-end QoS architecture that enables seamless services over heterogeneous wireless access networks. We discuss the main architectural approaches and design issues of mobility-aware QoS signaling in IP networks. Then we introduce a QoS signaling architecture that integrates resource management with mobility management. It is based on a domain resource manager concept and nicely supports various handover types in an integrated approach. In particular, we support anticipated handover with pre-reservation of resources over the old network before the mobile node is attached to the new access point.     

Transparent IP radio access for next-generation mobile networks

Advances in network architecture, enhancements in signaling protocols, provisioning of end-to-end QoS, worldwide seamless mobility, and flexible service provision are among the major research challenges toward next-generation wireless networks. The integration and interoperability of all these technologies, along with new truly broadband wireless innovations and intelligent user-oriented services will lead toward the so-called 4G wireless networks. In this article we identify the key issues of an innovative transparent IP radio access system that targets 4G networks.     

Multiresolution data integration using mobile agents in distributedsensor networks

We describe the use of the mobile agent paradigm to design an improved infrastructure for data integration in a distributed sensor network (DSN). We use the acronym MADSN to denote the proposed mobile-agent-based DSN. Instead of moving data to processing elements for data integration, as is typical of a client/server paradigm, MADSN moves the processing code to the data locations. This saves network bandwidth and provides an effective means for overcoming network latency, since large data transfers are avoided. Our major contributions are the use of mobile agent in DSN for distributed data integration and the evaluation of performance between DSN and MADSN approaches. We develop an enhanced multiresolution integration (MRI) algorithm where multiresolution analysis is applied at a local node before accumulating the overlap function by mobile agent. Compared to the MRI implementation in DSN, the enhanced integration algorithm saves up to 90% of the data transfer time. We develop objective functions to evaluate the performance between DSN and MADSN approaches. For a given set of network parameters, we analyze the conditions under which MADSN performs better than DSN and determine the condition under which MADSN reaches its optimum performance level     

IPv6 integration and coexistence strategies for next-generation networks

IPv6 has been designed, among other things, to provide an expanded address space to satisfy the future networking requirements. In this article, we analyze and discuss important aspects of IPv6 deployment scenarios, and propose the system architecture coexisting and integrating with IPv4/MPLS networks. We investigate on various IPv6 deployment strategies along with network design examples, comparing these techniques. Then the IPv6 deployment in service provider environments is proposed.     

下一代光数据网络的新模型

过去的十年里,光网络技术的两项突破已经成为了满足业务提供商对容量的日益增长的需求的关键因素。第一项是DWDM,它可以将一根光纤分解为多个通道从而提高了现有光纤的可用带宽。第二项是通过使用像波长路由器和交叉连接系统这样的设备实现了带宽的智能化管理,这些设备能够支持具有智能配置和恢复功能的日益动态化的网络。那么下一步是什么呢？目前摆在人们面前的主要有两个挑战。其一是在需求以超乎想象的速度增长的情况下,对以数据为核心的网络不断地进行扩充,从用户接入点到城域网乃至整个长途核心网。另一个挑战是有效地创建并管…     

A distributed database architecture for global roaming in next-generation mobile networks

The next-generation mobile network will support terminal mobility, personal mobility, and service provider portability, making global roaming seamless. A location-independent personal telecommunication number (PTN) scheme is conducive to implementing such a global mobile system. However, the nongeographic PTNs coupled with the anticipated large number of mobile users in future mobile networks may introduce very large centralized databases. This necessitates research into the design and performance of high-throughput database technologies used in mobile systems to ensure that future systems will be able to carry efficiently the anticipated loads. This paper proposes a scalable, robust, efficient location database architecture based on the location-independent PTNs. The proposed multitree database architecture consists of a number of database subsystems, each of which is a three-level tree structure and is connected to the others only through its root. By exploiting the localized nature of calling and mobility patterns, the proposed architecture effectively reduces the database loads as well as the signaling traffic incurred by the location registration and call delivery procedures. In addition, two memory-resident database indices, memory-resident direct file and T-tree, are proposed for the location databases to further improve their throughput. Analysis model and numerical results are presented to evaluate the efficiency of the proposed database architecture. Results have revealed that the proposed database architecture for location management can effectively support the anticipated high user density in the future mobile networks.     

Heuristic data dissemination for mobile sink networks

Wireless Networks - Mobile sinks have advantages such as solving the hotspot problem which occurs because some sensor nodes deplete energy faster than others and enhancing energy balance among the...     

Interworking techniques and architectures for WLAN/3G integration toward 4G mobile data networks

The intense wireless LAN standardization and R&D activities worldwide, combines with the recent successful deployment of WLANs, provide prime evidence that WLAN technology will play a key role in the fourth generation of mobile data networks. In this context, there is a strong need to integrate WLANs with 3G mobile data networks and develop hybrid mobile data networks capable of ubiquitous data services and very high data rates in strategic locations. This article addresses this need by proposing and discussing some novel architectures able to provide internetworking between WLAN and 3G networks, and meet the requirements of the most common internetworking scenarios. These architectures can enable 3G subscribers to benefit from high-throughput IP connectivity in hotspots and also to attain service roaming across several radio access technologies, such as IEEE 802.11, HiperLan/2, ULTRAN, and GERAN.     

An in-band power-saving protocol for mobile data networks

A new alternative is proposed for reducing the power consumption of the portable (battery-powered) units operating in a mobile packet-data network. First, a review of the current power-saving protocols is given. It is shown that the most common means for conserving power is the intermittent operation of the receivers (at the portable units) and a central administration authority that synchronizes the receivers. Some drawbacks of the synchronous operation lead us to the introduction of an asynchronous power-saving protocol, where no central synchronization is necessary and where each terminal may control its power consumption relative to its current needs. According to the proposed power-saving page-and-answer protocol, an acknowledgment paging procedure is preceding every packet transmission in order to alert mobile terminals with pending traffic. Steady-state performance is evaluated with the aid of simulation. The relationship between the achieved power-saving and the mean packet delay degradation is presented. Finally, we express some notable implementation issues and some considerations regarding the employment of this protocol as a supplementary power-saving service in microcellular mobile data networks and wireless local area networks     

Managing IP traffic in radio access networks of next-generation mobile systems

The strong research, standardization, and development activity currently focusing on the enabling technologies for the transition to a new generation of mobile networks represent a great opportunity to accomplish the goal of IP multimedia service provisioning to mobile users. This will contribute to the migration toward an all-IP platform with guaranteed end-to-end QoS provisioning, and will definitively fuel the deployment of new multimedia mobile applications and the further development of multimedia ubiquitous communications. This objective is not easily achievable, mainly due to the difficulties in handling IP multimedia applications in a mobile environment with a guaranteed QoS level. To contribute to this issue, in this article we discuss an evolutionary scenario from the current UMTS system to a next-generation QoS-aware mobile platform based on IP as the transport solution in the radio access network, UTRAN. Furthermore, we propose to fit the IntServ-over-DiffServ approach, in order to best manage the QoS level inside the UTRAN.     

A quadtree-based hierarchical data dissemination for mobile sensor networks

The envisioned sensor network architecture where some of the nodes may be mobile poses several new challenges to this special type of ad hoc wireless network. Recently, researchers have proposed several data dissemination protocols based on either some hierarchical structure mainly constructed by a source node or source/sink oriented dissemination tree to support mobile sinks. However, such a source-initiated hierarchical structure results in significant resource consumption as the number of source-sink pairs are increased. Additionally, stimulus mobility aggravates the situation, where several sources may build a separate data forwarding hierarchy along the stimulus moving path. In this paper, we propose a new data dissemination protocol that exploits “Quadtree-based network space partitioning” to provide more efficient routing among multiple mobile stimuli and sink nodes. A common hierarchy of cluster-head nodes is constructed where the data delivery to mobile sinks is independent of the current position of mobile stimuli. Therefore, the overhead needed for hierarchy (route) maintenance is lower. Simulation results show that our work significantly reduces average energy consumption while maintaining comparably higher data delivery ratio.     

Wideband DS-CDMA for next-generation mobile communications systems

Wideband wireless access based on direct sequence code division multiple access aimed at third-generation mobile communications systems is reviewed. W-CDMA is designed to flexibly offer wideband services which cannot be provided by present cellular systems, with various data rates as high as 2 Mb/s. The important concept of W-CDMA is the introduction of intercell asynchronous operation and the pilot channel associated with individual data channels. Intercell asynchronous operation facilitates continuous system deployment from outdoors to indoors. Other technical features of W-CDMA include fast cell search under intercell asynchronous operation, fast transmit power control, coherent spreading code tracking, a coherent RAKE receiver, orthogonal multispreading factor forward link, and variable-rate transmission with blind rate detection. The introduction of the data-channel-associated pilot channel allows W-CDMA to support interference cancellation and adaptive antenna array techniques that can significantly increase the link capacity and coverage. This article presents the radio link performance evaluated by computer simulation. Field experiment radio link performance results are also presented     

Mobility management protocols for next-generation all-IP satellite networks [architectures and protocols for mobility management in all-IP mobile networks]

To provide ubiquitous terrestrial Internet coverage mobility and Internet-based access to data generated by satellites, there is a strong desire to integrate the terrestrial Internet and satellite networks. This requires satellites that are based on IP for communications. Rotation of low Earth orbit satellites around the Earth results in communicating with different ground stations over time, and requires mobility management protocols for seamless communication between the Internet and satellite networks. In this article we provide a comprehensive summary and comparison of state-of-the-art research on mobility management schemes for satellite networks. The schemes are based on network and transport layers for managing host and network mobility. This article clearly indicates the aspects that need further research and which mobility management schemes are the best candidates for satellite networks.     

Mobile next-generation networks

Mobile next-generation networks (NGNs) are a necessary element in reaching the goal of truly ubiquitous computing. The Universal Mobile Telecommunication System, the third-generation mobile service concept, is a technology step to mobile NGNs. We can view NGNs as a merger of the Internet and intranets with mobile networks and with media and broadcast technologies. The Universal Mobile Telecommunication System (UMTS) is-from a radio perspective-a third-generation cellular technology, which is defined by the International Telecommunication Union (ITU) in its IMT-2000 framework (2001). From a conceptual point of view, it represents a technology step to mobile NGNs' facilitating ubiquitous computing. Researchers conceived UMTS to combine Internet protocol (IP) and mobile technologies to offer personal communication and personalized content everywhere. Its goal is to apply Internet protocols for mobile services control and end-to-end applications. By analyzing the trends of key technologies, we can see how they drive the evolution of the Internet and mobile communications toward mobile NGNs. In this article, I describe the IP-based approach of UMTS for the provision of mobile multimedia services. The integration of WLAN into the UMTS architecture could indicate that the field is moving toward separating mobile and fixed Internet.     

Streaming processors for next-generation mobile imaging applications

Next-generation mobile devices will continue to demand high processing power for imaging applications. The expected performance is in the class of supercomputers, but delivered with limited energy and memory bandwidth for embedded systems. This article advocates a streaming computation model that leverages the deterministic access patterns in imaging applications to deliver the necessary processing throughput. A reconfigurable datapath connects a set of functional units, forming a computation pipeline to offer energy efficiency. The architecture and implementation of a stream processor are presented along with the memory subsystem to support stream data transfers. The results show speedup ranging from a factor of 2 to 28 for imaging applications, offering favorable comparison against scalar processors.     

Seamless integration of mobile WiMAX in 3GPP networks

As the wireless industry makes its way to the next generation of mobile systems, it is important to engineer solutions that enable seamless integration of emerging 4G access technologies within the currently deployed and/or evolved 2G/3G infrastructures. In this article we address a specific case of such a seamless integration, that of mobile WiMAX in evolved 3GPP networks. In this context we investigate the architecture and the key procedures that enable this integration, and we also introduce a novel handover mechanism that enables seamless mobility between mobile WiMAX and legacy 3GPP access, such as UTRAN or GERAN. The core characteristic of this novel handover mechanism is that mobile terminals do not need to support simultaneous transmission on both WiMAX and 3GPP accesses; therefore, it mitigates the RF coexistence issues that exist otherwise and improves handover performance. In addition, we provide a brief overview of mobile WiMAX and the evolved 3GPP network technologies, and we set the appropriate background material before presenting our proposed handover mechanism. Our main conclusion is that integrating mobile WiMAX in evolved 3GPP networks is a compelling approach for providing wireless broadband services, and mobility across WiMAX and 3GPP access can become seamless and efficient with no need for mobile terminals to support simultaneous transmission on both types of access.     

移动数据网络的越区切换

蜂窝网络的电波覆盖是通过各个小区所设的基站完成的,在每个小区之内,都需要保证信号的有效场强。当移动台处于移动状态或者距离原有基站过远时,移动终端的接收信号质量就会下降。此时如果移动台接收到来自其它基站的更强信号,移动台就会放弃原有的信号,开始接收来自新基站的信号。这一过程就称为越区切换。 话音和数据网络的业务要求是不相同的,因此越区切换的算法明显不同。语音业务允许有一定的误码率,但它的实时性要求非常强,如果时延超出了一定时间,信息对于用户来说,不仅没有实际意义,而且会造成对有效信息的干扰。数据…