Radio transmission technologies for IMT-2000 are being studied and standardized all over the world. Several national/regional standardization bodies are developing proposals on radio transmission technologies to meet the cut off date of June 30, 1998 set by ITU. This paper shows necessity to develop and standardize IMT-2000 in Japan, principle attitude on IMT-2000 standardization, selection process of W-CDMA, and the current situation of study on IMT-2000 in ARIB (Association of Radio Industries and Businesses).

The Future Public Land Mobile Telecommunication Systems (FPLMTS) standards have made it quite clear that in the near future, the capability in doing wireless data transmission will become necessary in order to make the tether-free use of multimedia applications possible. CDMA is considered the most appropriate and probable radio access method of FPLMTS for its high capacity and flexibility in accommodation of multimedia and variable rate users. In order to further increase the capacity of CDMA system, several techniques have been studied and proposed such as an interference canceller and adaptive array antenna. We propose the novel multi-user detection type interference cancellation technique named SRIC (Symbol Ranking type IC) in this paper. SRIC is very feasible for its small amount of operation compared with other multi-user detection type ICs and can be added to a base station with slight alteration according to the requirement of higher capacity. The performance of SRIC depends on the method of calculating the likelihood. We studied three methods. In order to reduce the operations, we tried to propose two more methods. We confirmed that SRIC can make the system capacity about three times greater than that of a conventional RAKE receiver. We also confirmed that SRIC can be reduce its operations very much at some sacrifice of their performance. There are nine variants of SRIC, which have a trade off between performance and amount of operation. We can choose one of them which is most fit to our requirement. The first operation of SRIC is common with that of a conventional RAKE receiver. Therefore, SRIC can be introduced to conventional systems afterwards by inserting the interference canceller block which functions replica generation, removal, and ranking between output of a RAKE receiver and FEC decoder.

In this paper, we consider conventional signaling link fault tolerance and error correction mechanisms to provide reliable services of mobile multimedia telecommunication network based on ATM (Asynchronous Transfer Mode) technology. Also, we propose an efficient signaling protocol interworking architecture and a reliable distributed interworking network architecture between SS7 based FPLMTS and ATM networks. Besides, we evaluate the performance of proposed method through computer simulation. According to the results, proposed signaling architecture shows efficient and fast fault restoration characteristics than conventional MTP-3/3b based network. Functional signaling protocol stack and network architecture of proposed fast rerouting mechanism provide reliable and efficient restoration performance in view of interworking between SS7 based FPLMTS and ATM networks.

Research and standardization activities on FPLMTS are under way throughout the world. This paper shows recent study results on radio transmission technologies in ARIB (Association of Radio Industries and Businesses), which in the standardization organization in Japan. On-going study shows two TDMA based and four CDMA based radio transmission technologies under study. These technologies need to be further studied in detail. The proposal from ARIB is expected to be summarized around the end of the year 1996.

The advance of mobile network and radio techniques has been rapidly expanding the service area for mobile terminals. Thus, mobile communications have been devoted to the improvement of terminal mobility (TM). Recently, the personal mobility (PM) concept appeared which gives a freedom to use personal telecommunication numbers at any terminal. Therefore, mobile network must next enable a user to access telecommunication services with his/her personal telecommunication number from any terminal at any geographic location. In other words, the mobile network must implement universal mobility (UM) that integrates TM and PM. This paper first provides a definition of UM. Next, it describes the identity and number configurations for UM and then presents network techniques for UM, i.e., the network architecture and UM management procedures. It also presents the current status of standardization on UM in the Personal Digital Cellular system (PDC) and Future Public Land Mobile Telecommunication Systems (FPLMTS).