5G meets satellite: Non-terrestrial network architecture and 3GPP

With 3GPP Release-17, global 5G standards now support non-terrestrial mobile networks comprising radio access network, terminals, and core network. This enables multi-vendor interoperability as well as interoperability with 3GPP-compliant 5G systems. This paper describes the key features enabling the NG-RAN architecture defined for 5G to support non-terrestrial networks. Starting from a general overview of NG-RAN and of the new paradigms of NTN, we introduce the NTN functionality in NG-RAN specifications with respect to feeder link switchover, cell handling, terminal registration, and OAM aspects. We also discuss different scenarios combining satellite access with 3GPP-defined core networks. We also describe some further enhancements expected to be seen in the next 3GPP release (Rel-18). We believe current and upcoming 3GPP work for NTN represents a solid basis on which 5G satellite networks can be built in the upcoming future.     

Key concepts for evolution toward beyond 3G networks

Now, when the first commercial 3G services based on Third Generation Partnership Project (3GPP) specifications have been launched around the world, is the right time to start considering the evolution potential of 3G systems. It is assumed that the majority of the traffic in future mobile networks will be generated by content consumption related services, which are realized with IP technologies. Thus, it is necessary to optimize the cellular networks for carrying IP traffic as efficiently as possible. We describe an evolution scenario for the 3G network architecture specified by 3GPP. The IP delivery part of the network architecture is first optimized within each subsystem, while maintaining interoperability with the legacy network. Later, the network is streamlined as a whole to provide the most efficient solution. We show how graceful evolution of the 3GPP system can benefit from possibilities of the new technologies, especially IP-based transport, while maintaining compatibility with existing user equipment and capitalizing on existing infrastructure investments.     

Evolution of CAMEL Service Platform beyond 3G networks

At present time it is broadly recognized the existence of three generations of mobile telephone systems. In this work it is analysed the evolution of the three generations systems in terms of the services provided in each generation, focusing in the entity known as CAMEL (Customized Applications for Mobile Networks Enhanced Logics), which is an important platform influencing the evolution of 2G and 3G and beyond mobile telephony systems. This work starts with a general overview of mobile telephone systems, their architectures and services platforms, going further into the evolution of CAMEL that occurs together with the evolution of third generation system UMTS (Universal Mobile Telecommunications System) and would play an important role when the “all-IP” network and multimedia applications become part of everyday use by million of subscribers part of the mass market. CAMEL evolution is important as it is the evolution of 3G into 4G networks such as Ambient Networks, where CAMEL will be a fundamental element in order to make it easy the creation, control, and establishment of advanced and personalized services to subscribers, wherever they would be, and whenever they require the services, with full mobility and service portability, independently of the radio-access technology, the networks and the operators.     

A tutorial on multiple access technologies for beyond 3G mobile networks

In this article, some fundamental technical concepts of the main multiple access schemes for wireless mobile systems are reviewed, and a path for the development of appropriate multiple access technologies for next-generation mobile networks, or so-called beyond 3G (B3G), is established. We first review the multiple access technologies in second- and third-generation wireless cellular systems from historical and technical points of view. This review is followed by a novel formulization of the multiple access schemes through mathematical expressions that could simplify the process of development of new multiple access schemes for B3G wireless cellular systems. We then list the most important features of multiple access schemes in 3G mobile systems. Finally, we conclude the article by reviewing the most promising multiple access technologies for B3G mobile cellular systems     

Cross-layer design for resource allocation in 3G wireless networks and beyond

Cross-layer design approaches are critical for efficient utilization of the scarce radio resources with QoS provisioning in the third-generation wireless networks and beyond. Better system performance can be obtained from information exchanges across protocol layers, which may not be available in the traditional layering architecture. This article provides an overview of cross-layer design approaches for resource allocation in 3G CDMA networks, summarizes state-of-the-art research results, and suggests further research issues. In addition, a cross-layer design approach for real-time video over time-varying CDMA channels is proposed, where link layer resource allocation benefits from information in both the application and physical layers. Simulations results are given to demonstrate the effectiveness of the proposed approach.     

Interference coordination and cancellation for 4G networks - [LTE part II: 3GPP release 8]

This article provides an overview of contemporary and forward looking inter-cell interference coordination techniques for 4G OFDM systems with a specific emphasis on implementations for LTE. Viable approaches include the use of power control, opportunistic spectrum access, intra and inter-base station interference cancellation, adaptive fractional frequency reuse, spatial antenna techniques such as MIMO and SDMA, and adaptive beamforming, as well as recent innovations in decoding algorithms. The applicability, complexity, and performance gains possible with each of these techniques based on simulations and empirical measurements will be highlighted for specific cellular topologies relevant to LTE macro, pico, and femto deployments for both standalone and overlay networks.     

3GPP 3G家庭基站标准化进展

文章介绍了3GPP在3G家庭基站的业务需求、网络架构、无线射频、管理维护(OAM)和安全等方面的标准化进展,并指出了当前研究的一些主要技术方向.     

The role of high altitude platforms in beyond 3G networks

High altitude platforms represent a new alternative to terrestrial and satellite communications systems, and have gained considerable interest in the past few years due to some of their outstanding features. Of the multitude of services HAPs can provide, in this article we, focus on the potential role of HAPs in beyond 3G networks. First, a short introduction to HAPs is made. Then we discuss different hybrid system architectures with emphasis on the merits of HAPs and provide a potential mapping of services to the components of a terrestrial-HAP-satellite integrated system. We also examine critical issues that stem from the use of HAPs. Finally, the maximum uplink capacity is evaluated for a multiservice W-CDMA HAP network.     

Research on the access network and MAC technique for beyond 3G systems

Based on the requirements of beyond 3G mobile communication systems, the access network architecture and media access control technique for B3G systems are studied. The proposed novel access network architecture, which can reduce network complexity and improve system performance, is introduced. Centralized mini-slot packet reservation multiple access (CMPRMA), based on OFDMA, is proposed, which not only can inherit the advantages of MPRMA and support real-time traffic well, but can also supply the resource reservation scheme for data traffic and support transmission for data traffic efficiently     

E3G技术--3GPP LTE和3GPP2 AIE的核心技术与标准化进展

演进型3G（E3G）技术是3GPPLTE（长期演进）和3GPP2 AIE（空中接口演进）项目的统称.这项技术名为“演进”,实则是一场技术“革命”.对两种演进型3G技术--3GPP LTE和3GPP2 AIE的标准化进程、需求指标和核心技术作了简略的介绍.     

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.     

Adaptive call admission control in 3GPP LTE networks

In this article, we propose new methods to reduce the handoff blocking probability in the 3rd Generation Partnership Project Long Term Evolution wireless networks. This reduction is based on an adaptive call admission control scheme that provides QoS guarantees and gives the priority of handoff call over new call in admission. The performance results of the proposed schemes are compared with other competing methods using simulation analysis. Simulation results show the major impact on the performance of the 3rd Generation Partnership Project Long Term Evolution network, which is reflected in increased resource utilization ratio to (99%) and in the ability in satisfying the requirements of QoS in terms of call blocking probability (less than 0.0628 for Voice over IP service) and dropping probability rate (less than 0.0558).Copyright © 2012 John Wiley & Sons, Ltd.     

Coherent passive optical network for 5G and beyond transport

Building low-latency and high-capacity optical networks is vital for new high-speed cellular technologies. Coherent wavelength division multiplexing passive optical networks (WDM-PONs) are expected to play a key role in these applications. In this article, an overview of PON technologies for the 5th generation (5G) transport systems has been given. Moreover, a modified scheme based on coherent WDM-PON has been investigated using a dual polarization quadrature phase shift keying (DP-QPSK) transceiver. The aim of the scheme is to build a 1 600 Gbit/s network that will be used in the construction of the transport architecture of 5G and beyond cellular networks either in mobile front haul (MFH) or mobile back haul (MBH). The results indicate that the proposed scheme offers a promising solution for future 5G transport systems.     

Context-aware cooperative testbed for energy analysis in beyond 4G networks

The complexity of heterogeneous wireless networks in synergy with battery powered mobile devices is driving new stringent requirements in terms of power efficiency to ensure that battery life, environmental and thermal criteria can be met. Modern mobile devices are equipped with multiple interfaces, which allow them to exploit the benefits offered by heterogeneous networking environments, but on the other hand, drain battery swiftly. In this paper, architecture for a context-based node and a testbed platform for the analysis of energy consumption of heterogeneous cooperative communications are presented. The demonstrative testbed comprises a WiFi Access Point, which provides WiFi coverage in the infrastructure mode, as well as nodes capable of communicating through short-range ultra-wideband WiMedia. The testbed includes a context aware module that provides and stores information related to different nodes in the system. The paper shows how context information can be used to save the energy of mobile devices and extend their battery lifetime using short-range communications. The testbed is used as a proof-of-concept for the practical implementation of the cooperative communications concept. The obtained results show that significant amount of energy can be saved using context information along cooperation among multiple interfaces, in comparison to direct communications.     

WCDMA and WLAN for 3G and beyond

The WCDMA air interface was initially designed to support a wide variety of services with different QoS requirements having a maximum bit rate of 2 Mb/s. In order to satisfy the future service and application needs several technical enhancements are being studied and standardized for WCDMA in 3GPP. Even with evolved WCDMA, there is a need for another public wireless access solution to cover the demand for data-intensive applications and enable smooth online access to corporate data services in hot spots. This need could be fulfilled by WLAN together with a high-data-rate cellular WCDMA system. WLAN offers an interesting possibility for cellular operators to offer additional capacity and higher bandwidths for end users without sacrificing the capacity of cellular users. The evolved WCDMA air interface will provide better performance and higher bit rates than basic WCDMA, based on first releases of the specifications. Eventually, evolution may not be the answer to all the needs, and come revolutionary concepts need to be considered. However, before some future wireless system can be regarded as belonging to 4G it must possess capabilities that by far exceed those of 3G systems like WCDMA. Judging from an application and services point of view, one distinguishing factor between 3G and 4G will still be the data rate. We could define that 4G should support at least 100 Mb/s peak data rates in full-mobility wide area coverage and 1 Gb/s in low-mobility local area coverage. Other possible characteristics of 4G need to be further studied.     

3GPP R165G核心网络技术研究

5G通信技术开启了一个新的通信时代.5G核心网作为5G网络架构中重要的组成部分,具有重要的研究意义.对此,从3GPP 5G标准化演进情况、5G核心网网络架构和R165G标准中新增核心网关键技术等几个部分对5G核心网络技术进行介绍.     

Hotspot wireless LANs to enhance the performance of 3G and beyond cellular networks

At present, WLANs supporting broadband multimedia communications are being developed and deployed around the world. Standards include HIPERLAN/2 defined by ETSI BRAN and the 802.11 family defined by the IEEE. These systems provide channel adaptive data rates up to 54 Mb/s (in a 20 MHz channel spacing) over short ranges up to 200 m. The HIPERLAN/2 standard also specifies a flexible radio access network that can be used with a variety of core networks, including UMTS. It is likely that WLANs will become an important complementary technology to 3G cellular systems and will typically be used to provide hotspot coverage. In this article the complementary use of WLANs in conjunction with UMTS is presented. In order to quantify the capacity enhancement and benefits of cellular/hotspot interworking we have combined novel ray tracing, software-simulated physical layer performance results, and optimal base station deployment analysis. The study focuses on an example deployment using key lamppost mounted WLAN access points to increase the performance (in terms of capacity) of a cellular network.     

Network-based mobility management in the evolved 3GPP core network

A key aspect of the 3GPP system architecture evolution is the specification of an evolved packet core that supports multiple access networks. The EPC enables operators to deploy and operate one common packet core network for 3GPP radio accesses (E-UTRAN, UTRAN, and GERAN), as well as other wireless and wireline access networks (e.g., eHRPD, WLAN, WIMAX, and DSL/Cable), providing the operator with a common set of services and capabilities across the networks. A key requirement of the EPC is to provide seamless mobility at the IP layer as the user moves within and between accesses. This article provides an overview of the EPC specifications that use a network-based mobility mechanism based on Proxy Mobile IPv6 to enable mobility between access networks. An important facet of providing seamless mobility for a user?s sessions across technologies is to ensure that quality of service is maintained as the user moves between accesses. An overview of the ?off-path? QoS model to supplement PMIPv6 is also provided.