How WARC '92 will affect mobile services

The US proposals to, and the decisions of, the 1992 World Administrative Radio Conference (WARC '92) that relate to mobile and mobile-satellite services are described. Mobile-satellite service (MSS) issues addressed at WARC '92 include new allocations for low Earth-orbit (LEO) satellite operations, new MSS spectrum allocations, and modifications to current allocations used to support mobile-satellite operations. Allocation issues on the agenda of WARC '92 that related to the terrestrial mobile services include allocations for mobile services between 1 and 3 GHz, allocations for aeronautical public correspondence, and designation of frequency bands for future public land mobile telecommunications services. A number of proposals which were put forward by the US to support MSS allocations and operations that did not explicitly require allocations to the MSS are discussed     

Improving mobile network performance with two queueing buffer allocations of priority-based queueing scheme

As current mobile core network systems are expected to evolve into all-IP networks, packet switching will be a prerequisite for all mobile applications. Next-generation mobile networks, as envisioned by ITU-T, are packet-based networks capable of providing consistent and ubiquitous service to end users, independent of the network, access technology, and device used. This study discusses the differentiated packet forwarding performance of four major types of mobile network traffic under the proposed mobile network priority-based queueing (MPQ) scheme with two queueing buffer allocations, namely dynamic queueing buffer (DQB) allocation and overflow queueing buffer (OQB) allocation. As different queueing buffer allocations are adopted to store arriving packets in DQB and OQB, the MPQ scheme shows different packet forwarding performance under these two methods. In this study, we use ns2 (Network Simulator version 2) as the simulation platform to simulate several scenarios. The simulation results show that the MPQ scheme is able to support differentiated packet forwarding behavior for mobile traffic with both DQB and OQB allocations in a mobile core network. Some issues were identified in the MPQ scheme with both DQB and OQB allocation, which will need to be addressed.     

New waves for new systems [radio frequency spectrum allocation]

Everywhere changes in telecommunications, from liberalization of regulations to progress in radio technology, have increased the use of radio services to unforeseen levels, bringing in their wake a pandora's box of problems. In response, the world community has altered time-hallowed methods of spectrum management, not least the organization of the International Telecommunication Union (ITU) and the way in which radio conferences are convened and scheduled. The 1995 World Radiocommunication Conference (WRC-95) to be held in Geneva will tackle the broad challenges of managing the frequency spectrum in a rapidly changing world. WRC-95 will consider allocations of the electromagnetic spectrum and their effects on systems vital to national economies, including mobile communication services. The thrust will be more sharply on simplification of agreements governing the spectrum's use, and on just when to make broader provision for new satellite systems for mobile communications     

Europe prepares for WRC-95: mobile satellite service issues

European preparations for World Radiocommunication Conferences are coordinated within the European regional posts and telecommunications organization known as the CEPT. The basic objective of the European proposals is to achieve an even playing field for the introduction of competitive mobile satellite services that can provide global services from the earliest feasible common date. Europe believes the additional allocations made at the 1992 conference are sufficient for the foreseeable future, especially now that there is an opportunity every two years to make additional allocations should the need be proven. What must be agreed upon, however, are the allocations for the feeder links to the mobile satellite service to complement the 1992 allocations for service links. Europe also need to consider the technical constraints that were placed on the use of these service links at the 1992 conference. Of particular concern to Europe, is the most unsatisfactory conclusion in 1992 on the date of availability of the 2 GHz mobile satellite service allocations. The article describes the European proposals on these mobile satellite issues     

The maritime radio spectrum future

Future satisfaction of the electromagnetic spectrum needs of the maritime mobile service is dependent on the translation of those needs to frequency allocations. In September 1979, over 100 countries will consider all of the spectrum, and make changes to meet perceived needs of radio services, including maritime needs up to the year 2000. This conference, the World Administrative Radio Conference 1979, will have a significant impact on future maritime radio operations. Issues, procedures, competing requirements, are explored to enable a better understanding of the regulatory process for frequency allocations.     

Spectrum sharing considerations for the proposed ESA ‘archimedes’ satellite DAB service

At the 1992 World Administrative Radio Conference (WARC), spectrum was allocated, on a primary basis, to the broadcast satellite service (sound). The allocations were not, however, uniform worldwide, nor will the BSS(S) have sole use of these allocations. In addition, many countries have reserved primary use of the spectrum for existing services until 2007, with the BSS(S) permitted only on a noninterference basis. This situation will impose serious constraints on the proposed ESA S-DAB service, to be radiated from the ‘Archimedes’ constellation of satellites. The launch date for this service may be before the end of the century, and sharing with other spectrum users will therefore be necessary. Such users include fixed telephony links, broadcast links and mobile aeronautical telemetry. This paper reviews current spectrum usage in Europe and elsewhere, and investigates the restrictions thus imposed on the ESA S-DAB service. Numerical examples based on real-world systems are given, and demonstrate the feasibility, in many cases, of spectrum sharing.     

Regulatory Procedures and WARC-79

There are two major elements of a General World Administrative Radio Conference such as WARC-79. One is to review and revise allocations of radio frequencies to functional services such as fixed, mobile, satellite, and radionavigation. The other major element is the detailed radio regulations concerning use of these allocations by member Administrations. These regulations combine technical, economic, geopolitical, and other considerations into a framework which attempts to satisfy the perceived requirements of all Administrations. This aspect of WARC79 is the subject of this paper. As will be seen, some substantial changes in regulations were made at the Conference, especially those concerning HF assignments and use. Other changes are implicit in the Resolutions for future conferences which were adopted at WARC-79. The key to success in framing effective and acceptable allocations, and regulations, is cooperation. In this respect, WARC-79 was not much different from preceding conferences, despite contrary misgivings.     

Summary of conclusions of the 1992 World Administrative RadioConference

The major decisions made at the conference are briefly described. Additional frequency bands for shortwave (HF) radio broadcasting were agreed upon. Frequency allocations were made to support a number of US proposals, to provide advanced mobile radio services using low Earth orbit satellites. Allocations for land based mobile services adopted at WARC '92, in the range 1700 to 2600 MHz, are meant to foster improved mobile services that can be used worldwide. An allocation was also made to support commercial telephone service between passengers flying on aircraft and individuals on the ground. Allocations were made for sound broadcasting from satellites, as well as for providing a means to accommodate a complementary terrestrial-based digital audio broadcasting service. New frequency allocations to support space activities were agreed upon, and an allocation was made to the fixed satellite service in the band 13.75 to 14.0 GHz     

Spread spectrum for commercial communications

The authors describe how spread spectrum operates and explain why the FCC has allocated several spectral bands for spread spectrum. They examine what is wrong with the spectrum allocations the way they are now. They show who is using and will use spread spectrum and why. In particular, they discuss the use of spread spectrum for mobile cellular communications: the personal communications network; digital stereo; alarms; sports applications; communications in the stock exchange; police radars, radios, and covert communications, and amateur radio     

Space radio services and WARC-MOB-87

A recent conference of the ITU has agreed upon worldwide frequency allocations near 1600 MHz for communication by satellite with mobile stations on land, and has permitted the use of some aeronautical mobile-satellite frequency bands for passengers' in-flight telephone calls to the ground. Frequencies for systems for locating mobile stations by radio, using satellites, were allocated.     

A Noncooperative Game-Theoretic Framework for Radio Resource Management in 4G Heterogeneous Wireless Access Networks

Fourth generation (4G) wireless networks will provide high-bandwidth connectivity with quality-of-service (QoS) support to mobile users in a seamless manner. In such a scenario, a mobile user will be able to connect to different wireless access networks such as a wireless metropolitan area network (WMAN), a cellular network, and a wireless local area network (WLAN) simultaneously. We present a game-theoretic framework for radio resource management (that is, bandwidth allocation and admission control) in such a heterogeneous wireless access environment. First, a noncooperative game is used to obtain the bandwidth allocations to a service area from the different access networks available in that service area (on a long-term basis). The Nash equilibrium for this game gives the optimal allocation which maximizes the utilities of all the connections in the network (that is, in all of the service areas). Second, based on the obtained bandwidth allocation, to prioritize vertical and horizontal handoff connections over new connections, a bargaining game is formulated to obtain the capacity reservation thresholds so that the connection-level QoS requirements can be satisfied for the different types of connections (on a long-term basis). Third, we formulate a noncooperative game to obtain the amount of bandwidth allocated to an arriving connection (in a service area) by the different access networks (on a short-term basis). Based on the allocated bandwidth and the capacity reservation thresholds, an admission control is used to limit the number of ongoing connections so that the QoS performances are maintained at the target level for the different types of connections.     

A novel collaborative approach for location prediction in mobile networks

Human location prediction has been a matter of concern for several years due to its many applications. It has become more important nowadays because of prevalence of mobile devices which have adequate tools for inferring location. Different approaches for making this prediction could be divided into three categories, based on the movement history they use. These include history of mobile user himself, history of all mobile users in a place, and history of only related mobile users. Besides the problem of limiting shared data to only required data, preserving privacy is the matter of concern for persuading mobile users to share their data. In this paper we have proposed a new method in which the amount of the shared data is decreased to a minimum, and only the data which will improve the partner’s prediction will be shared. Our method preserves privacy by blurring the shared data up to different degrees. The experimental results show that regardless of amount of blurring, as long as the user movement is not lost because of blurring, the accuracy of prediction will be improved about 7 %.     

Provisions for High Frequency Future Use

An area of widespread interest at the 1979 World Administrative Radio Conference (WARC-79) was concerned with allocation proposals related to the modification of the high-frequency (HF) (4-27.5 MHz) portion of the spectrum. From a wide range of proposals, the Conference adopted allocation provisions that reduced the exclusive fixed-service bands by two-thirds, made significant allocations to the broadcasting and maritime-mobile services, and provided somewhat lesser spectrum provisions for the amateur service. Shared use of fixed bands by the mobile service was greatly increased. Few changes were made to aeronautical service allocations. Provisions were planned to remove an unused fixed-service assignment from the International Telecommunication Union (ITU) Master Frequency Register, and to provide special assistance to Less Developed Countries (LDC's) to enable them to better meet their fixed requirements. A conservative schedule of changes, through 1994, was adopted, including several specialized planning conferences to assist in optimizing the use of HF bands. With continued national needs and improved technology being developed and adopted by the ITU member countries, systems in all authorized HF services will be widely used to meet requirements of the world community for a long time to come.     

3 300~3 400 MHz频段无线电定位与LTE室内 覆盖系统同频共存分析

2015年世界无线电大会（WRC-15）的1.1议题（AI 1.1）正在开展关于新增频谱用于未来移动通信的相关研究。3 300~3 400 MHz频段具有较宽带宽,此频段适于移动宽带系统在密集城区提供高速数据传输业务,满足移动宽带系统对于频谱容量的需求。我国在这一频段目前主要存在无线电定位业务。本文分析了如果在3 300~3 400 MHz频段引入IMT室内系统,保护已有无线电定位业务所需的隔离要求。     

3G移动可视电话系统测试方案设计

本文主要设计了开发3G移动可视电话系统过程中,在VT系统设计完成后脱离其它软件模块进行有效测试的几套方案。首先介绍了具有独创性的针对CommDevice的Loopback方案的基本编程思路与部分程序代码,对COITI-H0耐ce以外的模块进行陕速检测;第二套利用简单便捷的VIVA手机＋MD8470A的Loopback方案对手机整体效果进行初步检测;第三套通过VIVA手机到DNA的测试方案复杂但精确性高。本文中设计的各套方案各有优劣,具有可调性高,测试效果好的特点,合理使用各种测试方案,对于提高可视电话开发速度和产品质量都有很大帮助。     

Propagation results at 11 GHz for microcellular radio

Given the limited spectrum allocated to cellular mobile radio, the authors consider the use of microwave frequency bands where larger bandwidth allocations may be feasible. A radio network of 'microcells' has been proposed for such bands. They have conducted a propagation experiment at 11 GHz to characterise such communication channels in various environments. Results are given for rural and semi-urban environments, where propagation is found to be dominated by interference between the direct ray and a roadway-reflected ray.<>     

On the diversity analysis of symbol remapping in cooperative BICM–OFDM scheme for frequency selective Rayleigh fading channels

In this paper, diversity analysis of a symbol remapping scheme in cooperative systems is considered. We employ Bit Interleaved Coded Modulation and Orthogonal Frequency Division Multiplexing, which are widely used at wireless networks. In this paper, at the cooperative scheme, relays operate in DF mode and the effect of their erroneous detection will be considered. We present a closed form of the asymptotic worst-case pairwise error probability at the destination for our proposed scheme. It will be shown that this scheme exploits full spatial and frequency diversities. After that, we work on designing a new precoder matrix. Moreover, we propose two new subcarrier allocations for the proposed scheme. All new methods have been suggested to achieve the available diversities with a better performance than current state of the art. Finally, the simulation results reveal the analytical derivations and confirm the obtained diversity gain of the proposed systems.     

行业竞合变革下移动通信市场格局趋势

2019年10月,伴随携号转网全面实施,工业和信息化部及国务院国有资产监督管理委员会加强行业竞争监管,开启三大电信运营商的竞合变革。利用马尔可夫链模型分析移动通信市场占有率的变化,创新性地通过对比研究通信行业竞争环境变化前后的状态转移概率矩阵,预测移动通信市场格局短期发展趋势。研究发现,行业竞合变革影响大于携号转网政策影响,移动电话用户留在本网的概率反而有所提升。根据行业竞合变革后的状态转移概率矩阵预测,未来中短期3家运营商的竞争格局呈现中国电信移动市场占有率提升,中国移动和中国联通移动市场占有率下降的趋势,但是中国移动的市场占有率仍居第一位。未来行业竞合还需进一步加强法律建设、政策监管、共建共享和运营管理,加快5G及高质量发展,开拓移动通信市场新格局。     

Managing SONET equipment

The initial deployment of SONET products in the network has raised the issue of how to manage bandwidth allocations and use network management features to support existing and future network services. The requirements for managing the new transport with the features available, using management systems in existence today, are addressed. It is concluded that SONET will require new solutions in managing tomorrow's, networks, and that operations systems must develop a graceful migration plan in managing the existing and new networks     

The Content Driven Mobile Internet

The development of future mobile networks will be driven, in large part, by content and web based services. In this paper, we examine several performance, scalability and architectural challenges faced by future mobile web applications and how advanced mobile content delivery techniques can address these challenges. We review existing content delivery using a taxonomy that consists of three categories: network scaling, end system acceleration, and content and protocol optimization. While wireline content delivery focuses on network and server scalability, mobile content delivery will likely benefit most from optimizing radio link usage. We also present our ongoing work in this area, which extends the functionality of edge caching to the terminal, uses user interest correlation information to maintain low terminal power consumption and adds a new dimension to radio resource management. This revised version was published online in August 2006 with corrections to the Cover Date.