An Entire View on Research Trends in the Technology Evolution of Mobile Telecommunications

＂Without an appropriate research setting, a study cannot be qualified as a reasonable piece＂, this notion is manifested in the methodological polices. In this research, we attempt to examine previous studies within the scope of technology evolution and market perception in telecommunication industry through extracting research structures, methodologies, corresponding variables, and processing methods. A general process of social scientific research is adopted to analyze eighty-four selected papers; and simultaneously, the framework for doing this analysis is established, as well. In this manner, we inspect the subjects and the issues in these papers according to product types, academic domains, and divisions of technological evolution （from 1G to 4G）. Then, their research designs are anatomized into the key dimensions of general research conventions. This research eventually provides an entire picture of a research scenario for mobile telecommunication industry; and apparently, this framewbrk can help scholars to establish specific tendencies for academic scenarios in future research plans. Also, we propose the main streams and emerging issues can be expected to engage in the future within both theacademic and the operational fields.

Estimating network effects in China’s mobile telecommunications

A model is proposed along with empirical investigation to prove the existence of network effects in China’s mobile telecommunications market. Futhernore, network effects on China’s mobile telecommunications are estimated with a dynamic model. The structural parameters are identified from regression coefficients and the results are analyzed and compared with another literature. Data and estimation issues are also discussed. Conclusions are drawn that network effects are significant in China’s mobile telecommunications market, and that ignoring network effects leads to bad policy making.

Application of CVAM-based management accounting in mobile telecommunication enterprises

CVAM-based management accounting emphasizes that enterprises should make efforts not only to provide goods or service to customers but also to create value for customers. In practice, customer value should be measured reasonably first. Then according to its condition, enterprise can apply the CVAM-based management accounting method by improving management quality, perfecting costing planning, brand operation and business innovation to create value for customers thus achieving increase of corporate value as well as social value.

Exploring the Relationship between Corporate Social Responsibility, Employee Engagement, and Organizational Performance: The Case of Jordanian Mobile Telecommunication Companies

The aim of this research is to explore the relationship between corporate social responsibility, employee engagement, and organizational performance in Jordanian mobile telecommunication companies. A total of 350 questionnaires containing 37 items were used to collect information from the respondents. Multiple and simple regression analyses were conducted to test the research hypotheses. Results of the current study revealed that corporate social responsibility (both internal and external) and employee engagement (vigor, absorption, and dedication) have a significant positive relationship with organizational performance. Also, the results revealed that there is a significant positive relationship between corporate social responsibility (internal CSR and external CSR) and employee engagement. The Baron and Kenny mediation model and Sobel test were used to test whether employee engagement mediated the relationship between corporate social responsibility and organizational performance. The results showed that employee engagement fully mediated the relationship in a significant way. The results of the current study have many managerial implications for mobile telecommunication companies. In order to enhance organizational performance, decision makers must work on creating and maintaining an efficient corporate social responsibility agenda, which would increase employees’ engagement in their work which will lead to improved performance outcomes.

Shanghai Siemens Mobile Telecommunications Co. Ltd.

In February 1993, a contract was signed for the establishment of the joint venture Shanghai Siemens Mobile Telecommunications Co. Ltd. in Pudong’s Jinqiao export processing area. The signatories were the Shanghai Changjiang Telecommunications Equipment (Group) Corporation and the Shanghai Posts and Telecommunications Administration Bureau, the First Institute of the Ministry of Posts and Telecommunications,

Doppler shift estimation methods in mobile communication systems

Several Doppler shift estimators, including mean logarithm envelope difference (MLED) method, auto-correlation function (ACF) method, zero crossing rate (ZCR) method and mean square phase difference (MSPD) method were discussed and compared. The estimation principle and theoretical estimation bias of these estimators under Rayleigh fading channels were analyzed; furthermore, the Cramer Rao bound (CRB) of Doppler shift estimation was deduced, and a novel modification method based on two-dimensional polynomial fitting was proposed to reduce the Doppler shift estimation bias. We verified our algorithms with the Monte Carlo computer simulation; simulation results showed better variance performance of modified methods than those of the original methods. In addition, the applicable situations of these estimators were discussed.

Design of an Interconnection Architecture and Sizing of Two (2) EPC Core Networks: The Case of Orange-Guinea

With the arrival of the 4G and 5G,the telecommunications networks have experienced a large expansion of these networks.That enabled the integration of many services and adequate flow,thus enabling the operators to respond to the growing demand of users.This rapid evolution has given the operators to adapt,their methods to the new technologies that increase.This complexity becomes more important,when these networks include several technologies to access different from the heterogeneous network like in the 4G network.The dimensional new challenges tell the application and the considerable increase in demand for services and the compatibility with existing networks,the management of mobility intercellular of users and it offers a better quality of services.Thus,the proposed solution to meet these new requirements is the sizing of the EPC(Evolved Packet Core)core network to support the 5G access network.For the case of Orange Guinea,this involves setting up an architecture for interconnecting the core networks of Sonfonia and Camayenne.The objectives of our work are of two orders:(1)to propose these solutions and recommendations for the heart network EPC sizing and the deployment to be adopted;(2)supply and architectural interconnection in the heart network EPC and an existing heart network.In our work,the model of traffic in communication that we use to calculate the traffic generated with each technology has link in the network of the heart.

Mobile telecommunication companies’investment and pricing strategies for content service

Several mobile telecommunication companies(MTCs),such as AT&T,Verizon,and China Mobile,are investing in content services to drive continued growth as the telecom industry has become saturated.In this study,we investigate the competition between two MTCs,one of which(MTC 1)provides both data and content services,while the other(MTC 2)provides only data services.We propose a two-stage game-theoretic model to analyze the two MTCs'optimal pricing strategies for data service and content service as well as the investment strategy for the content service.Our analysis reveals that a higher value of value-added service offered by MTC 1 will incentivize it to raise its subscription fee for the content service and induce both MTCs to reduce the prices of their data services,which results in an increased demand for the content service and a decreased demand for MTC 2's data service.As MTC 1 invests further in the quality of the content service,it would benefit from increasing the subscription fee for the content service,and the two MTCs should increase the subscription fee for the data service.However,compared to the decisions in the scenario where MTC 1 does not provide content service,the provision of this service by MTC 1 leads to a lower subscription fee for the two MTCs'data services,an increase in the demand for MTC 1's data service,and a decrease in the demand for MTC 2's data service.These findings reveal that regularly monitoring market competition,as well as adjusting pricing strategies based on market scenarios and the value of services,can enhance competitiveness and long-term profitability for MTCs.

Primary Analysis of Development Approach to Chinese Satellite Mobile Communication

The paper describes the development of mobile communication first and then points out that it is necessary for China to develop satellite mobile communication after comparing the cellular mobile communication with the satellite mobile communication. After comparing the geostationary satellite system with the low earth orbit satellite mobile communication system, as well as the single-beam system with the multibeams system, both used in satellite mobile communication, we suggest that China, according to its economic status and level of satellite technology, should develop a geostationary multibeam satellite for its domestic mobile communication.

Customer Retention: Behaviour Perspective Model of Ghanaian Telecommunication Industry Using Multinomial Regression Analysis

To stay competitive, the mobile telecommunication companies spend millions of Ghana cedi each year on building long-term relationships with their customers. Marketing managers are constantly challenged with the problem of where to channel the limited resources in order to retain existing customers. This study approaches the customer retention problem in the mobile phone sector from a behavioural perspective, applying the Behavioural Perspective Model as the main analytical framework and further exploits some other factors that influence customer retention. The model includes a set of pre-behaviour and post-behaviour factors to study consumer choice, and explains its relevant drivers in a viable and comprehensive way, grounded in radical behaviourism. Data for the analysis were collected from tertiary students from Accra and Takoradi. Data collected were analysed using the multinomial regression technique. Analysis of the data revealed that the Behaviour setting factor is the only significant element in Behaviour Perspective Model. Further exploitation of behaviour situation revealed that the number of networks a customer uses, previous experience of a customer and customer’s intention are significant factors in determining customer retention in Ghana’s mobile telecommunication industry.

Analysis of Global System for Mobile Communication (GSM) Subscription Fraud Detection System

This work is concerned with GSM subscription fraud detection system using some network techniques. Fraud is a hitch around the globe with huge loss of income. Fraud has an effect on the credibility and performance of telecommunication companies. The most difficult problem that faces the industry is the fact that fraud is dynamic, which means that whenever fraudsters feel that they will be detected, they devise other ways to circumvent security measures. In such cases, the perpetrators’ intention is to completely avoid or at least reduce the charges for using the services. Subscription fraud is one of the major types of telecommunication fraud in which a customer obtains an account without intention to pay the bill. Thus at the level of a phone number, all transactions from the number will be fraudulent. In such cases abnormal usage occurs throughout the active period of the account;which is usually used for call selling or intensive self usage. This provides a means for illegal high profit business for fraudsters requiring minimal investment and relatively low risk of getting caught. A system to prevent subscription fraud in GSM telecommunications with high impact on long distance carriers is proposed to detect fraud. The system employs adaptive flexible techniques using advanced data analysis like Artificial Neural Networks (ANN). This study aims at developing a fraud detection model occurrence in GSM Network. The paper also gives analysis of the fraud detection Systems, fraud detection and prevention, fraud prevention methods etc. Fraud affects us all and is of particular concern to those who manage large government and business organisations where the potential losses are greatest. The operation of a mobile network is complex, and fraudsters invest a lot of energy to find and exploit every weakness of the system. A typical example would be subscription fraud, where a fraudster acquires a subscription to the mobile network under a false identity;and start reselling the use of his phone to unscrupulous customers (typically for international calls to distant foreign countries) at rate less than the regular tariff.

Performance analysis of coded OFDM systems using a novel class of LDPC codes

A new method of constructing regular low-density parity-check (LDPC) codes was proposed. And the novel class of LDPC codes was applied in a coded orthogonal frequency division multiplexing (OFDM) system. This method extended the class of LDPC codes which could be constructed from shifted identity matrices. The method could avoid short cycles in Tanner graphs with simple inequation in the construction of shifting identity matrices, which made the girth of Tanner graphs 8. Because of the quasicyclic structure and the inherent block configuration of parity-check matrices, the encoders and the decoders were practically feasible. They were linear-time encodable and decodable. The LDPC codes proposed had various code rates, ranging from low to high. They performed excellently with iterative decoding and demonstrate better performance than other regular LDPC codes in OFDM systems.

Cooperative Communication with Asymmetric Channel State Information: A Contract Theoretic Modeling Approach

In relay-assisted cooperative communication,relay nodes help forwarding the information of a source node in case of link failure between the source and a destination.Although user cooperation improves the overall efficiency of the network,it requires incentive to stimulate potential relay nodes to assist the source by forwarding its data to the destination.Moreover,the potential relays are better informed than the source about their channel conditions to destination,which results in asymmetric information between the source and the relays.In this paper,we study the problem of lack of forwarding incentive in cooperative communication when channel state information of relays is private information and not known by the source.To tackle this problem,we apply the principle of contract theory to a cooperative wireless system.Source first designs incentive compatible and individually rational contract,consisting of a set of power-credit pairs.Then it broadcasts contract items to nearby nodes.Once the source node receives reply messages from the volunteer relays,it chooses one or more relays based on its requirements and communication starts.Simulation results show how credit assignment works in order to stimulate relays to cooperate and prevents relays from cheating behavior.

STUDY ON GIS BASED PREDICTION SYSTEM FOR RADIO WAVE PROPAGATION IN URBAN REGION

In this letter, an integrated application of the prediction for radio wave propagation with the Geographic Information System (GIS) is presented and a real prediction system based on GIS is implemented.

Optimum Transmitter Power Control in WCDMA Cellular Systems

Power control is an important technique in WCDMA mobile systems for both increasing system capacity and guaranteeing the required QoS (time delay and wireless link transmission quality) of multimedia services. The optimum power control for narrow band CDMA cellular systems is a problem of single threshold optimization. Because these systems have only one type of traffic and have the same QoS requirement. However, WCDMA mobile system should provide multimedia services and different types of traffic have different QoS requirements. Thus, the power control in WCDMA mobile systems isn't a problem of single threshold optimizing, but turns into the optimizing problem of multi-threshold. We analyze the power control problem in WCDMA cellular mobile systems and propose the optimum transmitter power control algorithm. Three criteria to optimize transmitter power levels of multi-thresholds based on grading the priority orders of multimedia services are proposed. Simulation results show that the proposed algorithms are more effective than conventional algorithms and can provide better performance for WCDMA cellular mobile systems.

Large-Scale Traffic Characterization of Chinese Multimedia Messaging Service Using Hadoop

Recently, there have been many mo- bile value-added services in the Chinese mo- bile telecommunication market nowadays. Am- ong them, the characteristics of Multimedia Mes- saging Service （MMS） have not yet been fully understood. In this paper, with the help of a cloud computing platform, we investigated the flow-level charactefistcs of Chinese MMS. All of the experimental data were collected by the TMS equipment deployed in a major node in Sou- them China. The collection time spanned six mo- nths. We performed high-level analysis to show the basic distributions of MMS characteristics. Then, by analysing the detailed MMS features, we determined the distribution of personal MMS, and made a comprehensive comparison between 2G and 3G MMS. Finally, we tried to build a model on the personal MMS inter-arrival time, and we found that the Weibull distribution was optimum.

AN EFFICIENT APPROACH FOR DVB-H HANDOVER IN DVB-H/UMTS HYBRID NETWORKS

Handover in Digital Video Broadcasting for Handhelds(DVB-H) aims to provide continuous mobile broadcasting services when a user is traveling through cell boundaries.A good handover control can improve the power efficiency and gain much better reception quality.This letter provides a novel approach for DVB-H handover based on DVB-H/Universal Mobile Telecommunications System(UMTS) hybrid network,which moves the main handover function from the terminals to the networks,so that it reduces the operation complexity of the terminals and increases the power saving.When the terminal can not receive the DVB-H signal in the transmission shadow areas or because of some other reasons,the UMTS networks may offer the same service to users to make the service continuous.As the UMTS networks have the topology of the DVB-H networks,by communicating with the terminals,the UMTS networks can help the terminals to predict the handover,and avoid unnecessary handover.

Blind frequency offset estimation based on cyclic prefix and virtual subcarriers in CO-OFDM system

A new blind frequency offset estimation method based on cyclic prefix and virtual subcarriers in coherent optical orthogonal frequency division multiplexing （CO-OFDM） system is presented. It is able to estimate the fractional part and integral part of frequency offset at the same time. Its estimation range is about [-3.5 GHz, 3.5 GHz]. The influence of the integral frequency offset is comprehensively analyzed in COOFDM system. Its performances in the additive white Gaussian noise （AWGN） channel and the dispersive channel are investigated, respectively. Simulation results indicate that even in the dispersive channel, when the optical signal-to-noise ratio （OSNR） is low, it can still work very well.

On the stability of multicast flow aggregation in IP over optical network for IPTV delivery

The stable multicast flow aggregation （MFA） problem in internet protocol （IP） over optical network under the dynamical scenario is studied. Given an optical network topology, there is a set of head ends and access touters attached to the optical network, in which each head end can provide a set of programs （IP multicasting flows） and each access router requests a set of programs, we find a set of stable light-trees to accommodate the optimally aggregated multicast IP flows if the requests of access touters changed dynamically. We introduce a program correlation matrix to describe the preference of end users＇ requests. As the original MFA problem is NP-complete, a heuristic approach, named most correlated program first （MCPF）, is presented and compared with the extended least tree first （ELTF） algorithm which is topology- aware. Simulation results show that MCPF can achieve better performance than ELTF in terms of stability with negligible increment of network resource usage.

Overview of development and regulatory aspects of high altitude platform system

High Altitude Platform(HAP)systems comprise airborne base stations deployed above 20 km and below 50 km to provide wireless access to devices in large areas.In this paper,two types of applications using HAP systems:one with HAP Station(HAPS)and the other with HAPS as International Mobile Telecommunication(IMT)Base Station(HIBS)are introduced.The HAP system with HAPS has already received wide recognition from the academia and the industry and is considered as an effective solution to provide internet access between fixed points in suburban and rural areas as well as emergencies.HAP systems with HIBS to serve IMT user terminal have just started to draw attention from researchers.The HIBS application is expected to be an anticipate mobile service application complementing the IMT requirement for cell phone or other mobile user terminals in which the service field of HAPS application cannot reach.After describing and characterizing the two types of systems,coexistence studies and simulation results using both the Power Fluxed Density(PFD)mask and separation distance based methods are presented in this paper.This paper also predicts future trends of the evolution paths for the HAP systems along with challenges and possible solutions from the standpoint of system architectures and spectrum regulation.