JRC REVIEW No.57 Technical Reports

- Special Issues 1 : Mobile WiMAX System -

This paper provides an overview of the mobile WiMAX system developed by JRC. Mobile WiMAX has received a great deal of attention in recent years as a promising next-generation mobile broadband technology. JRC has developed a total system solution for communications operators by developing mobile WiMAX base station, server software for base station management and subscriber management systems, and outdoor terminals.

The first half of this paper provides an overview of the mobile WiMAX system, and the second half provides an overview of JRC WiMAX devices and software.

Ikuya Hirano
Takeshi Koarai
Tamotsu Kobayashi

- Special Issues 1 : Mobile WiMAX System -

The Ministry of Internal Affairs and Communications assigned the 2.5 GHz frequency band for WiMAX in December 2007. JRC has developed all-in-one type and outdoor installable base station for the regional mobile WiMAX system, which has high installability and maintainability.

The base station has MIMO Matrix A and Matrix B functions for the multi-antennas technology. By switching between them according to channel condition, it provides the system that can adaptively choose effectiveness of communication quality or throughput performance. In addition, by supporting both Profile B and C ASN configurations, the base station enables operators to deploy scalable ASN system.

Akira Tago
Kiyohito kobayashi
Katsuhiko Sato

- Special Issues 1 : Mobile WiMAX System -

Along with the development of the mobile WiMAX base station, we also developed an Element Management System (EMS) for management of base station installation, operation, and maintenance. The EMS has many features that make mobile WiMAX system management easier, such as pop-up GUI windows for the setup and testing of base stations, overall management of complex and advanced base station configuration parameters, display of topology of active mobile stations with their wireless conditions and mobility status by handovers, and scheduling function of firmware and software update for widely deployed multiple base stations. This paper introduces the EMS features and the GUI.

Katsuhiko Sato
Yusuke Dohi

- Special Issues 1 : Mobile WiMAX System -

JRC has developed a subscriber management system (CSN Lite) that integrates the DHCP, AAA, and PF server functions that are necessary for the connectivity service network (CSN) of mobile WiMAX system. CSN Lite can be installed in a single hardware platform and provides all the necessary basic CSN functionalities. Also, this system enables the efficient setup and operation of CSN by offering integrated GUIs for each server's configuration and monitoring. This paper explains the system's functions and software architecture.

Katsuhiko Sato
Koichi Yagishita

- Special Issues 1 : Mobile WiMAX System -

Various companies are currently offering WiMAX terminals, such as USB dongles for PCs and WiMAX-WiFi CPE (Customer Premises Equipment) , but almost all of these devices are designed for indoor use. When devices are used indoors, buildings and other obstructions can cause problems, such as signal attenuation, that reduce the service area and make communications less reliable. Similar problems also arise in devices that have separate antennas because of signal loss in antenna cables. Because of these problems, the demand for terminals that can be used outside is strong. This report describes the outdoor terminal that JRC has developed.

Shinsuke Miyazaki
Akira Hasegawa

- Special Issues 1 : Mobile WiMAX System -

This wireless module conforms to the IEEE802.16e-2005 mobile WiMAX standard. WiMAX has national and local frequency bands. This module supports both. The interface section has been designed to be easy to attach to embedded devices, and it uses the common PCI Express Mini Card 2.0 connector. Also, the module is compact, with external dimensions of 30 ?? 27 mm, thanks to its simple circuit design, which consists of a BB SoC, an RF module, a power management IC, ROM, and RAM. The module makes high-speed data transmission possible. The theoretical data throughput is 16Mbps (SISO Down Link) . The actual measured data throughput achieved by the module is approximately 15 Mbps.

Kazutaka Endo
Masahito Kamimura
Masamitsu Ogasawara
Hiromitsu Sugiyama
Kazunori Nakada
Yugo Sugizaki

- Special Issues 2 :Communication Module -

Of the wireless LAN frequency bands that are available for use in Japan, the 4.9 GHz band is particularly promising as a reliable means of high-speed data transmission because interference and conflict are expected to be low - the expectations are that the 4.9 GHz band will not be shared with other systems and that it will require registration and so have a limited number of users. JRC has developed a module for use with 4.9 GHz wireless LAN devices. This module uses a lowdistortion power amp and a specialized band filter to effectively reduce unnecessary radiation such as spurious radiation and out-of-band radiation. This has enabled the use of a high-gain antenna for long-distance transmissions. Additionally, the module's small size and low power consumption have been achived.

Akira Yoshimoto
Katsumi Shimoda
Michiya Toyota

- Special Issues 2 :Communication Module -

This compact wireless module supports UHF audio and data transmission. It contains an interface which has an application in which serial communications with an external device allows command control and analog I/O so that MSK modulation can be directly controlled. In another application, the module can be used as a standalone device through the customization of the internal control software.

Also, this module has been designed for use as an embedded device. Unnecessary circuitry and components that were used in earlier mobile wireless devices have been removed. This module, with external dimensions of 97×55×26mm, now has approximately 40% less volume than the previous JHM-428 series of wireless devices for automobiles.

Yasuaki Kushida
Hideaki Kanaya
Katsuhiro Yahata

- Special Issues 2 :Communication Module -

Public safety portable radio vary greatly depending on the modulation methods and frequency bands that they handle, but their fundamental circuitry and programs can be integrated into a multi-use platform, which should have advantages such as increased quality and development speed. To create hardware for such a platform, JRC developed a multi-use circuitry with baseband signal platform SOC and radio frequency signal platform LSI combined at its core. JRC has also developed softwares that make the development of multi-use applications easier.

Gen Suganuma
Tetsuya Nakagomi
Hiroshi Daimon

- Special Issues 2 :Communication Module -

Recently, more and more wireless RF components have been incorporated into IC. However, it is difficult to integrate SAW devices into IC. This is why JRC has been working to integrate the SAW filter peripheral devices into a compact module. In response to the demand for modularized GPS receiver front-end, JRC has developed a front-end module that integrates components such as a SAW filter and LNA. The module mounting area is 50% smaller than previous models. Also, in response to the demand for a compact, adjustment-free One Segment TV notch filter mobile phone internal component, JRC has developed a compact notch filter with an inductor built into the package board. JRC has developed a notch filter that is compact, has no outside parts, and does not need adjustment, but also boasts a wide pass-band and a steep damping characteristic.

Makoto Nara
Sakae Kamiseki
Masaki Yamazaki
Kazuya Ohta
Akihiro Tokunoh

- Technical Papers -

In October 2008, we developed the waterproof PHS cellular phone "WX330J" for Willcom, Inc. This is the first Willcom waterproof PHS cellular phone. Its waterproof performance complies with IPX5/IPX7 standards.

Cellular phones have come to be used everywhere where people carry out their daily lives. However, a cellular phone is a precision instrument and so is vulnerable to moisture. Thus, the demand for cellular phones that are waterproof has grown recently. To meet this market need, we have developed the above waterproof PHS cellular phone, which we introduce here below.

Masatoshi Ikeda
Takeshi Kaneko
Jun Mikami
Naoki Shimizu