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    2011年 第9卷 第1期    刊出日期:2011-03-25
    The whole issue of ZTE Communications March 2011, Vol. 9 No. 1
    2011, 9(1):  0. 
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    Chinese Tri-Network Convergence: Characteristics and Challenges
    Hequan Wu
    2011, 9(1):  1-2. 
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    In the 2010 Report on the Work of the Government, delivered by Wen Jiabao, tri-network convergence is interpreted as“the integration of telecommunications networks, cable television networks, and the Internet”[1]. Enabling these three networks to interconnect with each other and share resources will provide users with diverse voice, data, radio, and TV services. Pilot projects have already been launched in China with the aims of integrating radio, TV services, and telecommunication services; quickening overall planning and reconstruction of the networks, and reinforcing monitoring of information and cultural security. The ultimate goal is to promote the development of related sectors.

    Some developed countries have already achieved tri-network convergence, and others are promoting it. Tri-network convergence will bring about new management modes and new challenges, and China has its own characteristics in implementing it. First, only a small number of broadcast and TV networks are digital and connected to telecom networks. These are prerequisite for broadcast and TV networks to deliver telecom services. According to the State Administration of Radio, Film and TV, Next Generation Broadcasting (NGB) networks will be constructed to connect radio and TV networks. NGB networks adopt IP technologies to support telecom services. However, adopting packet technologies in broadcast video transmission is untried, and its cost-effectiveness is yet to be assessed.

    Second, the Chinese government pays special attention to security. Transforming a TV set into an Internet terminal opens the possibility that it may be attacked by hackers or viruses. Undesirable or even illegal content, which cannot be completely eliminated in the open Internet, may appear on the television screen at home. However, the existing security platform, technical infrastructure, and guaranteed mechanism of broadcast and TV networks are not capable of processing a sharp increase in video flow that would arise as a result of network convergence. The existing broadcasting control mechanism also needs to be improved to meet the demands of operating multiple services. In short, both information security and network security issues have to be addressed.

    Third, a new management mode is required for tri-network convergence. For content security, Chinese authorities have issued regulations stipulating that for a telecom operator to transmit broadcast and TV services, its video services must be managed by the integrated broadcasting control platform of the Broadcast and TV Authority. However, some issues are not clearly defined and need further clarification; for example, to what extent is content controlled and what interfaces and functions should the platform provide? The benefits of IPTV lie in the Internet-based value-added services that come with it. But these services may not be video services and need not be managed and operated by the platform. The problem arises of how to coordinate value-added services with IPTV. According to the requirements of the pilot projects, the integrated broadcasting control platform should manage not only content, but also users and billing. This means a user may be managed by both the telecom operator and the broadcast and TV operator when accessing a service. This is a great challenge to the network management system and client management mechanism. Therefore, it is necessary to coordinate management and services of the broadcast and TV operator with those of the telecom operator. In short, an integrated broadcasting control platform brings new challenges to the management mode. Meeting these challenges requires cooperation and innovation. It requires reform of management mechanisms of administrative bodies and reform of the technical and service modes of operators.

    Fourth, the pilot projects have clear requirements in terms of access rate: In 2012, the downlink and broadband access rates for broadcast and TV services will exceed 2 Gbit/s and 100 Mbit/s respectively; while the downlink and household access rates for telecom services will reach 1 Gbit/s and 100 Mbit/s respectively. As Chinese urban areas are densely populated, the costs of Fiber to the Building (FTTB) and Fiber to the Zone (FTTZ) will be much lower than those in developed countries. FTTB and FTTZ have become the main access methods in tri-network convergence programs in China. A telecom operator may adopt FTTB or FTTZ plus Digital Subscriber Line (DSL) or Local Area Network (LAN), while a broadcast and TV operator may use FTTB or FTTZ plus Ethernet over Coax (EoC). For FTTB/FTTZ, Ethernet Passive Optical Network (EPON) or Gigabit Passive Optical Network (GPON) or a combination of these is suitable for densely populated areas in China. Because tri-network convergence involves a huge number of users, developing low-cost access systems such as PON is key for success. The household access rate of 100 Mbit/s is not difficult to achieve in an optical access system, but it is a great challenge for core networks, especially Metropolitan Area Networks (MANs). The rate requirement of 100 Mbit/s is higher than that in some developed countries, and high bandwidth requires high value and high return on investment. Therefore, we should explore advanced technologies that are suitable for China’s situation and develop new broadband services and business models that bring value to users and provide sustainable return to operators. According to a statistics report of the China Internet Network Information Center (CNNIC), Chinese netizens spend around 4% of their disposable income on the Internet. If mobile communications are included, the ratio of communications expenses to income is higher than in some developed countries. Despite this, telecom operators are suffering from a lack of profit-making modes. Therefore, the development of new services and business models is key to the success of tri-network convergence.

    Fifth, the multicasting problem needs to be solved. Other countries also encounter this problem when deploying IPTV services. But because of the huge number of users in China, existing telecom networks have to be reconstructed as manageable IP networks that can support large-scale multicasting. The network layer multicasting solution based on routers is complicated to implement. And while application layer multicasting based on terminals is easy to deploy and does not involve changing infrastructure, it does not perform as well as network layer multicasting in terms of stability and efficiency. Multicasting suffers problems such as multicast video source fraud and registration packet fraud by illegal users. In sum, it is necessary to develop a large-capacity and manageable IPTV multicast solution.

    Sixth, Chinese telecom operators and broadcast and TV operators differ from their counterparts in other countries in monitoring mechanisms and scale. These differences impact network technologies, services and maintenance management mechanisms to be adopted.

    In China, tri-network convergence is regarded as an important program for deepening reform in the telecom industry, fostering the emergence of strategic industries, and bringing benefit to the public. It is expected to drive the development of the telecom industry, and broadcast and TV industry. Achieving tri-network convergence demands the efforts of all parties in the telecom, and broadcast and TV industries. Chinese tri-network convergence has a long way to go and 2011 will be a critical year.
    Guest Editorial: Mobile Cloud Computing and Applications
    Chengzhong Xu
    2011, 9(1):  3-3. 
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    In 2010, cloud computing gained momentum. Cloud computing is a model for real-time, on-demand, pay-for-use network access to a shared pool of configurable computing and storage resources. It has matured from a promising business concept to a working reality in both the private and public IT sectors. The U.S. government, for example, has requested all its agencies to evaluate cloud computing alternatives as part of their budget submissions for new IT investment.

    In recent years we have also witnessed the rapid growth of mobile applications due to the increasing popularity of smartphones and ubiquity of wireless access. Cloud computing fuels innovation in mobile computing and opens new pathways between mobile devices (where an application is launched) and the infrastructure (where data is stored and processed). Because mobile devices have intrinsic storage, processing, and battery power constraints, mobile applications often hit a performance wall. Unlimited computing and storage resources offered by cloud computing can help break through this wall and turn the problem into a vast opportunity for the growth of mobile computing. According to the latest study from Juniper Research, the market for cloud-based mobile applications is expected to grow 88% annually and reach $9.5 billion by 2014.

    To a typical mobile user, a mobile application driven by the cloud should look and feel just like any native mobile applications installed and run in their mobile device. There are already some well-known cloud-based mobile applications; for example, Google’s Gmail for iPhone and Cisco’s WebEx on iPad. These are largely run as Software-as-a-Service (SaaS), in which a cloud provider’s applications are deployed and run in the cloud and can be accessed by users. In general, cloud computing goes beyond the SaaS model by offering computing and storage Infrastructure as a Service (IaaS) or application development Platform as a Service (PaaS). Each cloud service model has proved efficacious in desktop computing. However, the benefits of IaaS and PaaS in mobile cloud computing have not been fully exploited.

    This special issue of ZTE Communications discusses related issues in mobile cloud computing. The purpose is to provide an overview of this cutting edge field and to describe its development, trends, challenges, and current practices. Papers have been included that cover a broad spectrum of interesting topics, including mobile cloud computing architectures, mobile search and data management, energy management and sustainability, privacy and security, mobile social networks, and novel cloud-assisted smartphone applications.

    In the paper,“A Survey of Mobile Cloud Computing,”Fan et al. classify mobile cloud computing systems. Two representative systems, Hyrax and Cloudlet, are discussed in detail. In their paper“Mirroring Smartphones for Good: A Feasibility Study,”Zhao et al. propose a framework that keeps a mirror for each smartphone on a computing infrastructure in the telecom network. In this framework, some computational workload is offloaded from a smartphone to its mirror. They demonstrate the efficacy of the framework in data caching applications and antivirus scanning services.

    “A Cloud-Based Virtualized Execution Environment for Mobile Applications,”by Hung et al. presents a cloud-based virtualized execution environment framework for mobile applications, with a focus on schemes for migrating applications and synchronizing data between execution environments. Performance and power saving issues involved in application migration are also discussed. In“Building a Platform to Bridge Low End Mobile Phones and Cloud Computing Services,”Tso et al. propose a Thumb-in-Cloud platform to break the performance wall in low-end mobile phones. The platform consists of virtual machines that are deployed in low-end phones for execution of mobile applications. It also consists of Thumb gateways that tailor cloud services by reformatting and compressing the service content to fit into the phone’s profile.

    Zhang et al. in“WiFace: A Secure Geosocial Networking System Using Wi-Fi Based Multihop MANET,”present a geosocial networking system running on a Wi-Fi based multihop ad hoc network platform for personal mobile devices. The system allows users to access cloud services in environments with or without networking infrastructure or GPS modules. In“A Case for Cloud-Based Mobile Search,”Gao et al. design an Internet search case for cloud-based mobile applications. Searches launched in a mobile device invoke a cloud-based search engine to fulfill the tasks. Key enabling technologies are discussed.

    “An On-Demand Security Mechanism for Cloud-Based Telecommunications Services,”by Lin et al. investigates the security issues in cloud computing and a security model is proposed based on a security domain division concept. This helps provide dynamic, on-demand, and differentiated protection for services.

    I am grateful to the authors who submitted for this special issue and to the reviewers who spent their valuable time to provide constructive feedback. I hope that you find this special issue interesting and useful.
    A Survey of Mobile Cloud Computing
    Xiaopeng Fan, Jiannong Cao, and Haixia Mao
    2011, 9(1):  4-8. 
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    Mobile Cloud Computing (MCC) is emerging as one of the most important branches of cloud computing. In this paper, MCC is defined as cloud computing extended by mobility, and a new ad-hoc infrastructure based on mobile devices. It provides mobile users with data storage and processing services on a cloud computing platform. Because mobile cloud computing is still in its infancy, we aim to clarify confusion that has arisen from different views. Existing works are reviewed, and an overview of recent advances in mobile cloud computing is provided. We investigate representative infrastructures of mobile cloud computing and analyze key components. Moreover, emerging MCC models and services are discussed, and challenging issues are identified that will need to be addressed in future work.
    Mirroring Smartphones for Good: A Feasibility Study
    Bo Zhao, Zhi Xu, Caixia Chi, Sencun Zhu, and Guohong Cao
    2011, 9(1):  9-14. 
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    An increasing number of applications and functions are being introduced into smartphones, but smartphones have limited computation ability and battery resources. To enhance smartphone capacity, cloud computing and virtualization techniques can be used to shift the workload from smartphone to computational infrastructure. In this paper, we propose a new framework in which a mirror is kept for each smartphone on a computing infrastructure in the telecom network. With mirrors, the workload can be greatly reduced, and smartphone resources can be virtually expanded. The feasibility of deploying this framework in telecom networks is demonstrated in the protocol design, a synchronization study, and a scalability test. Two applications are introduced to show how computational workload on the smartphone and traffic in the telecom network are significantly reduced using our techniques.
    A Cloud-Based Virtualized Execution Environment for Mobile Applications
    Shih-Hao Hung, Tei-Wei Kuo, Chi-Sheng Shih, Jeng-Peng Shieh, Chen-Pang Lee, Che-Wei Chang, and Jie-Wen Wei
    2011, 9(1):  15-21. 
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    Smartphones and cloud computing technologies have enabled the development of sophisticated mobile applications. Still, many of these applications do not perform well due to limited computation, data storage, network bandwidth, and battery capacity in a mobile phone. While applications can be redesigned with client-server models to benefit from cloud services, users are no longer in full control of the application. This is also a serious concern. We propose an innovative framework for executing mobile applications in a virtualized cloud environment. With encryption and isolation, this environment is controlled by the user and protected against eavesdropping from cloud providers. We have developed efficient schemes for migrating applications and synchronizing data between execution environments. Performance and power issues within a virtualized execution environment are also addressed using power saving and scheduling techniques that enable automatic, seamless application migration.
    Building a Platform to Bridge Low End Mobile Phones and Cloud Computing Services
    Fung Po Tso, Lin Cui, Lizhuo Zhang, and Weijia Jia
    2011, 9(1):  22-26. 
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    Two waves of technology are dramatically changing daily life: cloud computing and mobile phones. New cloud computing services such as webmail and content rich data search have emerged. However, in order to use these services, a mobile phone must be able to run new applications and handle high network bandwidth. Worldwide, about 3.45 billion mobile phones are low end phones; they have low bandwidth and cannot run new applications. Because of this technology gap, most mobile users are unable to experience cloud computing services with their thumbs. In this paper, a novel platform, Thumb-in-Cloud, is proposed to bridge this gap. Thumb-in-Cloud consists of two subsystems: Thumb-Machine and Thumb-Gateways. Thumb-Machine is a virtual machine built into a low end phone to enable it to run new applications. Thumb-Gateways can tailor cloud computing services by reformatting and compressing the service to fit the phone’s profile.
    WiFace: A Secure GeoSocial Networking System Using Wi-Fi Based Multihop MANET
    Lan Zhang, Xuan Ding, Zhiguo Wan, Ming Gu, and Xiangyang Li
    2011, 9(1):  27-32. 
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    A number of mobile Online Social Networking (OSN) services have appeared in the market in recent times. While most mobile systems benefit greatly from cloud services, centralized servers and communications infrastructure is not always available. Nor are location-based services offered to mobile devices without GPS. To take advantage of cloud and to address these problems, a Wi-Fi based multihop networking system called MoNet is proposed. On top of MoNET we propose a privacy-aware geosocial networking service called WiFace. Where there is no infrastructure, a distributed content sharing protocol significantly shortens the relay path, reduces conflicts, and improves data availability. Furthermore, a security mechanism is developed to protect privacy. Comprehensive experiments performed on MoNet show that the system is more than sufficient to support social networking and even audio and video applications.
    A Case for Cloud-Based Mobile Search
    Yan Gao, Li Fu, Zhenwei Zhang, Shengmei Luo, and Ping Lu
    2011, 9(1):  33-36. 
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    Mobile search is beset with problems because of mobile terminal constraints and also because its characteristics are different from the traditional Internet search model. This paper analyzes cloud computing technologies—especially mass data storage, parallel computing, and virtualization—in an attempt to solve technical problems in mobile search. The broad prospects of cloud computing are also discussed.
    An On-Demand Security Mechanism for Cloud-Based Telecommunications Services
    Zhaoji Lin, Ping Lu, Shengmei Luo, Feng Gao, and Jianyong Chen
    2011, 9(1):  37-40. 
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    As cloud computing gains in popularity, data migrated off premises is exposed to more threats than ever before. This is because data is out of control of the owner while floating in the cloud. Traditional device-centric security systems are not efficient enough and need to be evolved to data-centric protection systems. Cloud telecommunications services require security measures in three domains: data storage, processing, and transmission. Data stored in the cloud requires a mechanism to protect it; data in transit needs to be protected either at the service or transmission level; and data being processed needs to be protected during the processing stage. In this paper, we propose a security model based on a new method of security domain division to provide on-demand, dynamic, and differentiated protection for cloud-based telecommunications services.
    Multifrequency Networking Solution for TD-SCDMA
    Min Jin, Wenbo Wang, and Mugen Peng
    2011, 9(1):  41-44. 
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    This paper introduces the characteristics of TD-SCDMA, and analyzes some networking schemes and methods of multifrequency. For the 5 MHz frequency bandwidth, a frequency planning scheme containing three frequencies is examined, and a simulation model is built to validate the performance of this scheme. Finally, this paper analyzes the advantages and disadvantages of the scheme, and proposes some directions for the future study of networking planning.
    ZP-CI/OFDM: A Power Efficient Wireless Transmission Technology
    Pei Gao, Xiaohu Chen, and Jun Wang
    2011, 9(1):  45-48. 
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    Low power efficiency is a deficiency in traditional Orthogonal Frequency Division Multiplexing (OFDM) systems. To counter this problem, a new wireless transmission technology based on Zero-Padding Carrier Interferometry OFDM (ZP-CI/OFDM) is proposed. In a ZP-CI/OFDM system, transmission symbols are spread to all OFDM subcarriers via carrier interferometry codes. This reduces the Peak-to-Average Power Ratio (PAPR) that traditional OFDM suffers and also exploits frequency diversity gain. By zero-padding at the transmitter, advanced receiver technologies can be adopted for ZP-CI/OFDM so that frequency diversity gain can be further utilized and the power efficiency of the system is improved.
    Research on the Next Generation Naming System
    Fuhong Lin and Changjia Chen
    2011, 9(1):  49-53. 
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    Academia has recently proposed new naming systems based on flat Distributed Hash Table (DHT). These naming systems are designed to overcome defects—such as lack of support for data migration and replication—in the Domain Name System (DNS). DHT naming systems have long resolution delay and are not suitable for practical application. This paper introduces two new naming systems that have the advantages of both DNS and DHT systems. The first is a three-layer system based on one-hop DHT and is suitable for small-scale application. The second adopts a hybrid DHT structure, can be implemented in different domains, and can be applied globally. Theoretical analyses demonstrate that these two systems are feasible for practical use.
    Adaptive Multiantenna Technology
    Huahua Xiao, Dengkui Zhu, and Liujun Hu
    2011, 9(1):  54-57. 
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    Multiantenna technology can be implemented in several modes. These modes have varying characteristics and are used in different scenarios. This paper introduces Beamforming (BF), Cyclic Delay Diversity (CDD), Spatial Diversity (SD), Spatial Multiplexing (SM), and other multiantenna technologies. It also analyzes various technical features and their application scenarios. An adaptive multiantenna switching algorithm is proposed that chooses a suitable mode for sending data according to the scenario or wireless channel conditions. This switching algorithm improves multiantenna technology and enhances the quality of wireless network communications.
    Green Base Station Solutions and Technology
    Zhiping Chen and Licun Wang
    2011, 9(1):  58-61. 
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    Base station power consumption is the biggest power issue concerning wireless networks. Saving power in base stations is therefore the primary focus in green wireless network development. This paper discusses green base stations in terms of system architecture, base station form, power saving technologies, and green technology applications. It explores effective ways of reducing power consumption in base stations.
    The Internet of Things and Ubiquitous Intelligence (1)
    Dongliang Xie and Yu Wang
    2011, 9(1):  62-64. 
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