Private PHS Digital Cordless Phone Systems Adopted at Yebisu Garden Place


1. Yebisu Garden Place

Yebisu Garden Place, located in downtown Tokyo, has welcomed 16 million visitors in a year since it's opening in October 1994. Covering an area of about 800,000 square meters, it includes a department store and a hotel, as well as offices and apartment complexes. Yebisu Garden Place comprises a huge business, cultural and residential area, much like a self-contained city. Yebisu Garden Place Co., Ltd. is responsible for overall administration and operation of the facilities, including management of the greenery on the expansive grounds, cleaning operations and events held on the premises. It operates and maintains the electrical equipment, air-conditioning systems, and water, sewage and other sanitation facilities, in addition to providing for security services, all on a 24-hour basis.

2. Adoption

Yebisu Garden Place Co., Ltd. decided to adopt PHS digital cordless private phone systems at Yebisu Garden Place for the following reasons.

(1) The systems support two-way communications.

(2) The cost of installing the systems would not differ significantly from paging systems. Moreover, the systems would allow the use of nearly all advanced features of a digital PBX, including the provision of better speech quality and protection of privacy compared with analog business cordless phone systems, while also supporting data transmission and paging.

3. Outline of the Systems

As shown in the Fig. 3, two systems have been installed at Yebisu Garden Place, each of which operates independently. One system covers the business, commercial and cultural facilities, including the rental offices and various management centers, and is controlled by a PBX unit installed in the Yebisu Garden Place Tower. The other system is used within the Westin Hotel.

(1) The system installed in the Tower provides service in all outdoor areas of the premises and in 10 of the 13 wings, excluding the residential complexes. It supports the operation of 280 cell stations and 30 digital cordless phones on the premises.
The digital cordless phones are allocated to the facilities management group, security group, cleaning group, parking lot management group and the administration group. These phones are always carried by personnel when patrolling the grounds or making inspections in order to facilitate communications during regular routine work and in emergencies. Thirty of these digital cordless phones provides sufficient coverage when personnel make the rounds or work somewhere on the premises.
The PBX lines installed in the Tower are limited to extension telephone use for management of the premises facilities. Although the digital cordless phones have a function for making central office line calls, they are used only for the specific purpose of calling other extension lines on the premises.

(2) The digital cordless phones of the system installed in the Westin Hotel are carried by bellhops, housekeepers, room service personnel and the various managers in charge. This system has 100 digital cordless phones and 100 cell stations located throughout the hotel. It was installed to improve the information service provided to customers. Because the staff constantly carry a digital cordless phone with them, they can be deployed more efficiently, making it possible to give customers higher quality service.

4. Features and Consideration

The PHS digital cordless phone systems have been in operation since Yebisu Garden Place opened. The following describes some of the system features and considerations made regarding equipment installation.

a. Cell stations

  • (1) They are installed in the ceiling of hallways on the ordinary floors of the Garden Place Tower.
  • (2) In areas having a metal panel ceiling, such as the Tower lobby, only the antenna is exposed, while the main unit is mounted in the ceiling out of sight.
  • (3) In outdoor areas, some stations are installed on outer walls and others on independent outdoor lighting facilities.
  • (4) They are mounted directly to concrete walls that provide a common base in the case of exposed concrete surfaces.

    These installation methods make the cell stations relatively inconspicuous to the visitors of Yebisu Garden Place. They offer the advantages of maintaining the overall aesthetic beauty and avoiding potential danger due to breakage. On the negative side, however, it is more difficult to find the base stations when maintenance work is done.
b. The running cost is low, amounting to around 2.4 million yen annually.
c. Speech quality is exceptionally good.
d. In addition to voice communications, other ways of using the systems that take advantage of the digital lines will also be considered in the future.