Two Trends of NGN: Network Convergence and M2M Application

The standardization and R&D of Next Generation Network (NGN) have made outstanding progress. With regard to the development of NGN in future, network convergence and Machine-to-Machine (M2M) application should be paid attention.

1 Network Convergence
Network convergence has become the theme of the global telecom industry. Technologies, networks, and services are all going to converge. The convergence of the fixed and mobile networks has been emphasized since 2004. With convergence, network resources may be fully used, reducing operation costs and improving network competence. Moreover, with convergence, diversified services and one-stop services will be available to subscribers, which help them enjoy the services with the same quality no matter when they are in a fixed environment or in a mobile one. Network convergence also brings opportunities to the operators to increase their income with lower risk at introducing new services. It gets particularly fit for full-service operation. American telecom giant AT&T broke up into one long-distance telephone company and seven Regional Bell Operating Companies in 1984. However, it is back with the wave of convergence after it was bought by SBC for US$16 billion. It becomes again a full-service telecom giant with long-distance, local and mobile services.

    In fact, the idea of network convergence emerged in the middle and late 1990´s.

    Three-network convergence was first proposed, followed by Fixed-Mobile Convergence (FMC). The author of this article wrote in one of his articles published in 2000:  "In order to realize real personal communication, and to let users get the same applications and enjoy the same services no matter when they are in a fixed environment or in a mobile one, the fixed and mobile communication networks will go to convergence. This convergence should start at the convergence of the core networks, and gradually extend to the network edges. Data streams with different rates would be offered to users via access nodes. Moreover, IP, as an adhesive, integrates the functionalities of the fixed and mobile networks."

    FMC became an important subject of the study of NGN in 2004, and the NGN architecture based on IP Multimedia Subsystem (IMS) was then proposed to implement FMC. At the same time, such organizations as ITU-T and ETSI also put FMC on the core position of NGN standardization. In the following several months, the study of IMS made great progress, the standardization work was pushed ahead, and numbers of equipment vendors and operators announced their IMS strategies one after another. In 2004, several operators including NTT, British Telecom, Korea Telecom and Brazil Telecom co-founded the Fixed-Mobile Convergence Alliance, aiming at promoting the joint operation of fixed telephony and mobile communication. IMS was also the hottest topic at 3GSM World Congress 2005 in Cannon.

    The so-called IMS-based NGN architecture is an integrated platform based on Session Initiation Protocol (SIP). It would simultaneously support multiple fixed-mobile access models (such as WiMAX, WiFi, 3G and FTTx), implementing the convergence of the fixed and mobile networks. As shown in Figure 1, IMS defines three layers. Based on SIP, the control layer has open interfaces to both the lower transmission layer and the upper service layer. In addition, it allows the operator to adopt a single core network to offer SIP-based services such as VoIP and multimedia messages simultaneously to the subscribers of the fixed and mobile networks. IMS meets the requirement of NGN to separate call control and transmission. It is an extension of Softswitch. It makes further separation of the control function based on the Softswitch. It aims at forming a communication platform with high flexibility to implement multimedia communication from the person to the content (customer host/server), as well as person-to-person (end-to-end) IP multimedia communication, as shown in Figure 2. FMC, as shown in Figure 3, integrates both the wired and the wireless technologies and services to form a single network infrastructure, which help operators make use of all kinds of services to attract potential customers. With the implementation of FMC, the fixed-network operator won´t be limited to the terrestrial fixed network any more, while the mobile operator is able to meet the growing demands of mobile subscribers by using the most reliable network resources.

    IMS-based FMC was doubted, but it is getting more and more recognition, especially from fixed-network operators. The popular acceptance of the layered network and ITU´s acceptance of the IMS were the cornerstone. Presently in the industry, IMS is generally thought as the development trend of the core network in future. In a survey made by a foreign company, 60.6% of those surveyed said the main scene would be FMC in 5 years. They also said that most users would own a multi-mode phone to call through the most appropriate network (which might be the fixed network or the wireless network).  25.7% of those surveyed thought mobile replacement would be a trend, and most calls would be initiated by mobile phones or similar terminals via the mobile network, while the fixed network would mainly offer broadband, entertainment and data services. The last 13.7% insisted that no changes would happen, that was to say, the fixed phones keep using the fixed network while the mobile terminals still use the mobile network. Therefore, it could be concluded that IMS-based FMC has the most recognition.

    The author thinks the main reason is the IMS simultaneously owns two convergence points: the point of technology convergence — IP and the point of service convergence — Multimedia.

    The 21st century is an era dominated by information, when the IP-based information network is the trend. Above 90% of the servers and databases in the world are connected to the Local Area Networks (LANs) and campus networks that are based on Ethernet and TCP/IP. Every new LAN is also based on a kind of Ethernet and TCP/IP. Both the real world and the development trend tell us that IP-based data services would not only surpass the voice services, but also keep growing with a high speed in the coming days. Therefore, the IP technology will still be most suitable for the network environment in the foreseeable future, although it is not the ideal technology. The technology convergence point must be IP.

    Multimedia is one of the main features of next generation services. Synchronously integrating voice, image, picture and text, it is the best form to present information in the 21st century, as well as an information form people like most. Multimedia communication has become an important part of information infrastructure in different countries. Therefore, the service convergence point must be multimedia, which would be applied more and more in diversified areas such as production, management, education, science research, healthcare and entertainment, and become an economic growth point with sustainable development capability.

    The horn of network convergence has been blown again in 2005. Several famous equipment vendors including Alcatel, Ericssion, Lucent and Siemens are positively pushing the network convergence technologies forward. Moreover, some operators such as British Telecom, France Telecom, NTT and Sprint have shown their great enthusiasm and are preparing for the convergence. However, according to the current situation, 2006-2007 rather than 2005 will be the key development period for the FMC technologies and services. The whole period for FMC going from the theory to the practice may last more than ten years. With regard to the core network, it is estimated that the convergence of the fixed and mobile technologies, presented as the evolution to all-IP network, would be implemented in 2010-2012. In the all-IP network, the core subsystems respectively at the edges of the fixed and mobile networks are same, while the access networks still allow the coexistence of multiple technologies after the FMC of the core networks. Although the access network is a field full of changeable technologies, the competition between equipment vendors, together with that between old and new service providers, will push FMC of the access network ahead.

    At present, both the equipment vendors and telecom operators are greatly interested in IMS. The implementation of IMS, on one hand, is the operators´ infrastructure strategy for the offering of next generation services, and on the other hand, it brings new income potentials. About 25 operators are using the IMS technology developed by Ericsson AB, a Finnish vendor, to do trials. Nokia is cooperating with TeliaSonera AB to develop IMS-based services and network solutions. France Telecom is using the IMS system of Siemens to do the trial on the network of Orange, its English subsidiary. Lucent is cooperating with eAccess, a Japanese Internet Service Provider (ISP), to develop IMS-based services. Nortel has teamed up with Motorola and IBM to offer a full set of IMS hardware and software products. Alcatel is going to provide its IMS equipment to T-Mobile of US.

    Almost all the leading operators in the world regard the IMS as important equipment for generating and controlling high-value real-time IP applications (such as videoconference, multimedia messages, multi-player games and VoIP). Some foreign operators have launched primary convergence services. For example, British Telecom is to kick off a convergence service called Bluephone this year. With it, special bluetooth/cellular fusion phones are able to communicate via the network of British Telecom indoors while via the network of Vodafone outdoors. Indoor and outdoor calls implement seamless handover. The bluetooth has a communication scope of 25 m and rate of 700 kb/s. British Telecom plans to use the WiFi technology to replace the bluetooth at the end of 2005 or the beginning of 2006. Business Everywhere, a service offered by France Telecom, provides the subscribers with a software interface.  With it, they could access the Virtual Private Networks (VPNs) of their companies via General Packet Radio Service (GPRS), Wireless Fidelity (Wi-Fi), Digital Subscriber Line (DSL), circuit switching line, or the future Universal Mobile Telecommunications System (UMTS). Verizon of US has launched the Verizon One/Verizon lobi service. That enables the unified messaging and call management among the fixed network, mobile phone and PC, and is able to directly send any E-mails, voice mails and Short Message Service (SMS) to the devices users would like to use.

    However, there are still several uncertain factors in the implementation of IMS, although it is now appears as a potential technology. The implementation of IMS-based FMC is more than technology, and is influenced by the network convergence, service convergence, management convergence, operation convergence and regulation convergence. It is difficult to predict the detail process of FMC because it is facing a series of challenges. It is definitely a long-term process to implement the FMC, therefore, equipment vendors and services providers should first focus on some specific convergence requirements on certain specific markets. They may tactically use those technologies that could meet the requirements, and strategically build an integrated platform
with high flexibility to meet diversified
emerging demands.

2 M2M Application
Another characteristic of next generation services is ubiquitousness. Ubiquitous service means the object of communication service would be extended from human being to anything. In the future, network technologies will be ubiquitous, and computers and communication devices be found everywhere. Even when you take a walk, there will be a Body Area Network (BAN) on you. Besides communication between persons and that between the human and machine, communication between machines will come true.  The devices and appliances that could access the network will be ubiquitous, from TV to the MP3 player, from electronic newspaper to magazines, and even including accessory-like wearable application equipment. They work just like those computers online. That is M2M communication.

    The meaning of ubiquitousness is far more than the users´ access to the network at any time and any places. In fact, it means the users may feel the existence of the network and enjoy convenience brought by the network anytime and anywhere. For example, when you turn your TV on, the light would automatically become weaker; when the telephone is ringing or you are calling, your TV would go mute; when you approach the elevator, it will automatically work for you. A distributed temperature sensor network is able to control a heating system to save the cost; a transportation management system may dynamically adjust the traffic lights at different streets according to the real traffic flow. The examples are too numerous to be listed. In another words, the implementation of ubiquitous service depends on numbers of M2M applications. Therefore, the M2M application should get attention during the development of NGN. When describing services in the future, ITU thinks NGN should be a telecom-class and business-class full-service network that is able to meet new communication demands. The services supported include telephone and other legacy services, high-speed Internet access and its applications, video (such as VoD and stream media), and multimedia and digital TV broadcast. It is capable of interworking with legacy services, and has mobility and roaming capability. Moreover, it should offer services to human, as well as to machines. Service for a large number of machines is first emphasized by the ITU.

    M2M communication is usable in various fields. These include biological information transfer, remote backup, Web buffer, multicast feed, news feed, information batch processing, database synchronization, grid computing, multimedia email boxes, ground-air database mapping, database digging and large amounts of monitoring and controlling. In the future, various M2M applications will make the earth wear a "communication shell". It is responsible for monitoring and controlling of cities, highways and environments, and always sends the measuring data to the network to do data processing. It will protect the earth, just like the skin of the earth.

    In order to push the development of M2M applications, it is necessary to make all the mobile things have the capability of wireless communication, and to make all the places where fixed lines are difficult to set able to use wireless communication. In addition, it is necessary to add the wireless communication to all the appliances, including users´ wearable accessories that will execute orders, authentication and control. There are multiple wireless communication technologies that support M2M applications, and IEEE 802.15.4 (also called ZigBee) and Radio Frequency Identification (RFID) are given special introduction here.

    The network based on IEEE 802.15.4 belongs to the low-rate and short-distance wireless personal area network. It features low rate, low power consumption, low cost, self-configuration and flexible topology. Its rate can be lowered to 9.6 kb/s.  It mainly supports the simple devices that consume the least power and generally work in a personal space (with the diameter of 10 m or less). Therefore, as a global standard, IEEE 802.15.4 not only opens the door of abundant new applications, but also add value to numerous existing applications, creating good conditions for implementing the ubiquitous network. We can find, in the real world, low-rate applications are usually closer to our daily life than high-rate ones. Therefore, it is unnecessary to purely pursuit a high rate, but the low-rate applications should gain attention.

    RFID is a term used for any device that can be sensed at a distance by radio frequency. It usually refers to the use of radio frequency to read the information on a small device known as a tag. The RFID tag allows using radio waves to make batch reading and remote reading, which has attracted much attention for the past few years. What RFID brings is far more than the replacement of the bar code. A RFID tag not only has theft-proofing functionality, but also can be used to prove the ownership of goods, provide hidden authentication, speed shopping, save cabinets and floor space, and reduce the time needed for the whole supply chain.  RFID has widely applied in goods distribution management. With the birth of thin, small and low-cost RFID, the RFID tag will be embedded in almost all goods to replace the bar code. Besides, it will be more and more integrated into networks to be used for sales, information distribution, transportation, food, finance, healthcare and medicine, environment protection, the elderly and handicapped protection, fire and disaster prevention, education and culture, entertainment and life. It will become a basic tool in the ubiquitous network society, make all the people (including children, adults, the elderly and the handicapped) actively participate in the social life via the network, contributing to the building of harmonious society.
With the massive application of RFID and sensors and the popularization of such advanced applications as grid computing, the primary M2M application is growing more mature. If the dream of The Internet of Things (also called product Internet or T2T), launched by EPC Global, will come true, thousand billions of things online will communicate with each other. Therefore, thousand billions of tags (each tag has a unique electronic identification number) will be needed a year in the future. Some day, the M2M traffic will exceed both the P2M and P2P traffic, and even dominate the entire network traffic. The M2M application, no doubt, should be paid special attention during the course of NGN development.

Manuscript received: 2005-03-22