Abstracts of Magazine FUJITSU 2000-1 (VOL.51, NO.1)

Special Issue : IMT-2000

• IMT-2000 Network

The mobile phone services and data communication services currently provided around the world are based on second-generation mobile networks such as PDC (Personal Digital Cellular), cdmaOne, and GSM (Global Systems for Mobile communications). To prepare for future growth in mobile traffic capacity and the sophistication of services, the international standardization organization is studying the specification of a third-generation mobile system called IMT-2000. This paper outlines the services recommended in IMT-2000 and introduces the configuration of an ITM-2000 network composed of base station systems, switching systems, and various servers. It also introduces the packet processing mechanism and the techniques for building an IMT-2000 network. Lastly, this paper describes the intelligent network-related technologies installed for providing advanced added services.

• Specifications of Radio Transmission Technologies for W-CDMA System

W-CDMA is a radio interface of the IMT-2000 third-generation mobile communication system. IMT-2000 is currently undergoing global standardization and is expected to provide the infrastructure for mobile multimedia communications. In Japan, W-CDMA system and its equipment have been developed with the aim of launching its commercial service in 2001. There will be a greater demand for services and contents that take advantage of the features in IMT-2000, such as higher data rate transmission. This paper outlines the layer-1 specifications that describe physical channel structure, channel coding, spreading, modulation, synchronization, handover procedure, and transmitting power control method of the radio interface of W-CDMA system.

• Radio Interface Specifications for W-CDMA System

W-CDMA is a radio interface for International Mobile Telecommunications-2000 (IMT-2000), which is currently undergoing global standardization for use as the next-generation wireless mobile telephone system. W-CDMA provides voice services whose voice quality is as high as that of a fixed network. Also, it provides multimedia mobile communication services and global roaming services that enable common worldwide use of mobile terminals (wireless mobile telephones) as well as the conventional voice-call services. The standardization organizations in Japan, Europe, USA, and other countries have jointly organized a framework called the 3rd Generation Partnership Project (3GPP) to examine the radio interface specifications for W-CDMA.
This paper describes the functions provided by layers 1, 2, and 3 of the radio interface protocol of W-CDMA and describes the channels defined in each layer.

• W-CDMA Field Trials

The W-CDMA system, which is the radio access method of the IMT-2000 third-generation mobile communication system, supports real mobile multimedia communication.
Fujitsu has conducted field trials of the W-CDMA system in cooperation with Orange, an operator in England. The system was run in a trial area using Orange's office, antenna tower, and antennas and Fujitsu's experimental W-CDMA equipment, including a base transceiver station, network simulator, and mobile station equipment.
During the trial Fujitsu did basic transmission characteristics tests such as propagation measurements and checking of the antenna diversity effect. Fujitsu also did transmitting power control and soft hand-off access tests and video data transmission and packet transmission application tests. These tests have provided us with valuable field trial data and expertise that is useful in W-CDMA system-specific cell design and control.
This paper outlines these field trials.

• Experimental System for cdma2000 Wireless Mobile Telephone

The cdma2000 (IS-2000) system is the radio interface specification for the IMT-2000 third-generation mobile communication system that the Telecommunication Industry Association (TIA) has proposed to the International Telecommunication Union (ITU).
Fujitsu, Oki, and Matsushita have jointly developed an experimental system that conforms to the cdma2000 system and delivered it to DDI and IDO.
The experimental system was developed to verify the indoor and outdoor system performance of the high-speed communication service function of IMT-2000, evaluate the radio transmission characteristics, and apply the results to the development of a commercial system.
This paper outlines the cdma2000 experimental system and describes its major specifications and features.

• Network Node for IMT-2000

The IMT-2000 Core Network of NTT DoCoMo is a combined circuit switching/packet switching network that uses ATM technology. Fujitsu is developing the switching node (MMS) based on the FETEX-150 E-Cube ATM system.
The radio access high layer control features of the IMT-2000 switching node, for example, the call control and mobility management protocol, conform to the extended system of GSM/GPRS as a basic policy. An ATM ALL type2 system was also applied to the transmission system between RNC and MMS and in the core network. The hardware and software platforms in the MMS system configuration are specific to the vendors. The devices specific to the IMT-2000 system are equipped as peripheral devices for ATM-SW, and the software has an interface for common vendor-independent applications.

• Base Transceiver Station for W-CDMA

Fujitsu has already developed an experimental W-CDMA BTS for NTT DoCoMo and is ready to commercialize it. An experimental BTS is also currently being used for joint field trials with Orange of the UK.
Currently, Fujitsu is concentrating on developing radio techniques, network technologies, and device technologies based on the standardization specification forwarded in the 3rd Generation Partnership Project (3GPP) to develop a commercial BTS.
This paper outlines the experimental BTS and the commercial prototype BTS being developed and introduces their features.

• Equipment for Radio Network System

To manage not only voice-call services but also high bit rate data transmission and video communication, the W-CDMA system is required to accommodate multimedia communication services.
To meet these requirements, the equipment for the Radio Network System (RNS) adopts technologies such as asynchronous transfer mode (ATM) for handling various services and diversity handover for high-quality communication.
This paper outlines the functions of this equipment and describes the features of its hardware and software technologies.

• W-CDMA Mobile Terminal

This paper introduces our experimental W-CDMA mobile terminal. The W-CDMA system can provide a high-speed radio transmission path that is 10 to 100 times faster than the conventional second-generation cellular phone systems (PDC, GSM, and D-AMPS). The key to the widespread use of the third-generation mobile communication system is how to provide these high-speed services (high-resolution still images, video, and other data files) without degrading talk time, standby time, size, weight, and cost as compared with the second-generation systems. In addition to low-power consumption technologies and digital signal processing technologies obtained through PDC, Fujitsu has developed several key components (power HBT amplifiers, SAW devices, and system LSI chips) for mobile equipment. Optimum implementation of these key components for W-CDMA mobile terminals is important item. This paper describes the current development status and the technologies necessary for achieving the new transmission method standardized by 3GPP, which is the global standardization organization of the third-generation mobile communication systems.

• Audio/visual Signal Processing Technologies for Mobile Services

One of the problems to achieve multimedia services using high-speed mobile digital communications provided by IMT-2000 is how to realize sufficient robustness in audiovisual signal transmission against channel errors. The retransmission method can solve this problem for media such as text and still pictures, but it is generally difficult to apply this method to media such as video and audio. It is also difficult to apply the retransmission method for conversational services in terms of the delay time. However, because audiovisual signals can be understood despite the presence of certain levels of errors, the transmission of audiovisual data with zero bit errors is not mandatory.
This paper describes overview and transmission error tolerances of two technologies: the GSM-AMR speech codec which is likely to be applied to IMT-2000, and a reduced-resolution method developed by Fujitsu for video which has been adopted to the ITU-T H.263 Ver.2 and will also be included in the ISO MPEG-4 Ver.2.

• Interference Canceler for W-CDMA System

Organizations around the world have been jointly developing a next-generation mobile communication system to meet the demand for multimedia mobile communications. Japan and Europe have proposed the Wideband Code Division Multiple Access (W-CDMA) system, which has a large system capacity and ensures efficient communications at low to high transmission rates. The subscriber capacity of this W-CDMA system is deteriorated by interference caused by cross-correlation among the spreading codes assigned to users. In response to this problem, the authors of this paper have proposed a partial interference canceler that significantly reduces the number of mounted canceler units and greatly improves performance by selectively canceling interference from high bit rate users. This paper describes the impact of interference signals on the W-CDMA system's channel capacity and explains the configuration and features of the proposed interference canceler. It then introduces the prototype interference canceler and describes the results of experiments done to evaluate its characteristics.

• Adaptive Antenna Array for IMT-2000

The adaptive antenna array is one of the advanced techniques which could be implemented in the IMT-2000 mobile telecommunications systems to achieve high system capacity. In this paper, an integrated adaptive antenna array system for W-CDMA, which consists of both the uplink and the downlink beam-formers in the baseband, is described. The uplink beam-former is based on the concept of "finger beam-former" in which each dominant component of the multi-path signal is allocated to a dedicated beam, and the normalised least mean square algorithm (NLMS) is used as the beam-forming algorithm. In the meanwhile, a low complexity but high performance algorithm known as the iterative beam steering (IBS) is applied to the uplink signal to form a steering beam for the downlink. Simulation results show that, compared with using the conventional sectorial antenna, about four times as much system capacity can be achieved by employing a four-element adaptive antenna array. In addition, the effectiveness of the antenna array is demonstrated by experimental results.

• Mobile Multimedia Service in IMT-2000

IMT-2000 will enable cellular phones to be used as a major tool for mobile multimedia communications. It features high speed, high quality, and a global roaming service.
In the future, these features will be used to provide mobile multimedia services that will include not only multimedia communication between individuals but also extensive distribution of contents such as music and video from businesses to individuals. The services for businesses might also be used for fixed-installation communication in SOHOs (small office home office) as well as for mobile communication. By using these services on the terminal integrated with PC or car navigation system, or on a large liquid crystal display terminal, users will be able to enjoy rich multimedia contents in a mobile environment. This paper introduces these services in IMT-2000 and discusses the role of IMT-2000 in services that provide integrated information.

• High-performance Data Mining System

Extensive R & D into data mining systems, which locate useful information in data, has been done to enable businesses to extract valuable information from large amounts of data and then use that information to develop business strategies. A data mining system should include multiple analysis technologies (mining engines) so that the user can select a technique that suits the type of data to be analyzed and the type of information to be extracted.
Also, it must have a configuration that is flexible enough for use with a general-purpose system and must be able to be customized for its specific business purpose.
This paper describes the overall configuration and the mining engines of a data mining system that was developed at Fujitsu Laboratories and installed in a Fujitsu product called "SymfoWARE Mining Server." It then describes the advantages of Memory Based Reasoning (MBR), which is one of the system's mining engines, some enhancements made for application to real business problems, and an example application which shows the system's effectiveness. Finally, this paper looks at the features of an advanced data mining system.