For Information
May 9, 1996

NTT Announces Details of Calling Line Identification Presentation and Call Return Trial Services

Nippon Telegraph and Telephone Corporation (NTT) has been making preparations for trials of Calling Line Identification Presentation service (CLIP) and Call Return service, and has now determined the specific details involved. This report outlines the contents of said trials.

As the "Telephone Service Contract" will be changed prior to the start of the trial service, NTT submitted an application for approval to the Minister of Posts and Telecommunications.

I. Outline of Trial Service

(1) Purpose of service offering

In anticipation of the coming multimedia age, NTT has been making preparations for CLIP service and Call Return service to provide more convenient and reliable service to customers through the network linking more than 60 million telephones.

These services are expected to solve one particular problem arising in current telephone service, the invasion of the called party's privacy, mainly nuisance calls. At the same time, NTT also hopes to explore the potential of new telephone communications, realize a more comfortable life, and vitalize industrial activities through these services.

(2) Purpose of trial service

The trial service is designed to survey customer opinions regarding changes in basic telephone usage practices as well as customer requests for new services. Various evaluations, including social impact derived from these surveys, will be reflected in the actual service.

(3) Trial period

About six months starting around December 1996.

(4) Trial areas

* Yokohama (subscribers served by area code 045)
* Nagoya (subscribers served by area code 052)
* Fukuoka (subscribers served by area code 092)

(5) Target customers

[Calling party's side]

Customers in the trial areas (Yokohama, Nagoya, and Fukuoka) are subject to trial service and their telephone numbers are presented when making calls. However, calls from customers served by some types of switches are not included.

[Called party's side (trial service contract)]

Users of CLIP service and Call Return service are selected from among those who made applications for such services.

(6) Target calls

Calls subject to the trial are those within or between the trial areas. Interconnection calls between the trial areas that involve other long-distance carriers (DDI Corp., Japan Telecom Co., Ltd., and Teleway Japan Corp.) are also included.

II. Notification of Blocking Procedures

During the trial, the basic telephone usage practices will be changed to one in which the telephone number of the calling party is presented to the called party by ordinary dialing procedures in the trial areas. All customers in the trial areas will be notified of this and individually asked about the selection of blocking procedures.

(1) Blocking procedures available for customer selection
* Per-call blocking:If "184" is dialed prior to the called telephone number, this will block the presentation of the callingtelephone number; whereas, if a call is made by ordinary dialing operation, the calling telephone number is presented. As this blocking function is provided as part of the basic telephone functions, individual applications are not required.
* Per-line blocking:If this blocking method is selected, the calling telephone number is not presented for all calls from the line designated by the customer even by ordinary dialing operation. As this blocking method is considered as a supplementary function, individual applications are required in advance. Installation and supplementary function usage fees are not charged.

(2) Method to confirm customer selection

  1. A notice will be enclosed with three successive telephone billing statements. As well, application form for "per-line blocking" will be included twice.

    *A customer who selects per-line blocking is requested to complete the form and submit it by mail or by fax. Upon receipt of applications, NTT will carry out per-line blocking work.

    *"Per-call blocking" will apply for customers who do not make applications.

  2. Before the start of the trial, a notice to confirm if per-line blocking is selected will be mailed to all customers in the trial areas.

III. Confirmation of Telephone Number to be Presented for Customers Using Pilot Number Service and Direct Inward Dialing Service

At the time of confirming customer selection concerning the blocking method, NTT will also confirm the telephone number to be presented for customers using pilot number service and direct inward dialing service.

IV. Inviting Participation of Trial Users of CLIP Service and Call Return Service

NTT solicits the participation of customers who want to use CLIP service and Call Return service. For CLIP service, general customers who use the service via a single line using an individual-line telephone set, etc., are invited.

# The solicitation for system-use customers for CLIP service was ended in September 1995.

(1) Invitation contents

A Clip Service B Call Return Service

(Additional CPE not necessary)

(All subscriber telephones)

A-1 No-cost lease of CPE to customers (all subscriber telephones) A-2 CPE is provided by customers (INS-Net)
Number of lines used for trial
3,680 lines

Telephone sets (7 types) 1,750
Display units (8 types) 1,900
Slot-in PC card with telephone function (1 type) 30

(Application accepted for each CPE unit)

500 lines 9,000 lines

# The number of lines previously indicated is the total involved, and the invitation is made for an equal distribution of lines among trial areas.

(2) Invitation conditions

* Customers who select "per-line blocking" as the blocking procedure at the calling side are not permitted to make applications for service usage.

* Participating customers are requested to cooperate in completing the questionnaire for service evaluation.

(3) Trial participation expenses

* An installation fee of 2,000 yen is required at the start of the service. Monthly supplementary function usage fees are not charged.

* If the "Anonymous Call Rejection Service," which is an optional function of CLIP service, is used, then an additional 1,000 yen is required.

(4) Application method

Application instructions will be mailed to all customers in the trial areas in the telephone charge billing statement. To apply, please complete the necessary items on the return card and mail or fax it to NTT. (You may also use a postcard to apply.)

Should more than the required number of users apply, participants will be selected through a draw.

V. As NTT has established a "Calling Line Identification Presentation Service Customer Center" to answer inquiries and offer consultation concerning the service and trials, please contact NTT should you have any questions.

# Calling Line Identification Presentation Service/Customer Center

TEL: 0120-848521 (toll-free, available only in Japan)
Time: 9:00 a.m.- 5:00 p.m. (except Saturdays, Sundays and holidays)

A detailed schedule for the "confirmation of customer selection concerning blocking procedure" and "solicitation of service users" will be provided in another report.

(Reference 1)

Service Outline

I. Calling Line Identification Presentation Service

This is a service in which the telephone number for the telephone from which a call is made is presented to the telephone at which the call is transmitted. CPEs, such as telephone sets, that satisfy technical conditions for the display and display units are required to display the calling telephone number.

(1) Service functions

[Calling party's side]

When calls are made by ordinary dialing operations, the telephone number of the calling line is displayed on the receiving terminal. In case callers do not want their telephone numbers to be presented, dialing 184 prior to dialing the called party's telephone number will prevent the caller's telephone number from being displayed (per-call blocking). With advance registration, it is also possible to prevent number display for all telephone calls made by ordinary dialing operations from designated lines (per-line blocking).

[Called party's side]

Information, such as the telephone number, etc., of a calling line is displayed on the called party's CPE before the telephone is answered. Depending on whether the caller has selected telephone number presentation, messages are displayed on the receiver's CPE.

Type of call Information transmitted from network Examples of CPE display
(Recommended by the Communications Industry Association of Japan)
Number presentation call (Calling from subscriber telephone) Calling telephone number, including area code OOO-OOO-OOOO
(Calling from public telephone)"C"Public telephone
Anonymous call (from both subscriber and public telephones)"P"Anonymous (Call incoming)
Call for which number presentation is not available"O"
Out of area

An "Anonymous Call Rejection Service" is also available on request. This optional function uses network guidance to ask callers making anonymous calls to "call again with telephone number presentation," without connection to receiver's CPE.

(2) Switching conditions

Both the calling and called CPEs must be those of subscribers served by digital switching systems or INS Net subscribers.

II. Call Return Service

This is one of the services that utilizes calling telephone number information to enable the called party to be notified of the caller's telephone number by voice. The service also makes it possible to return calls by additional dialing operations. It is not necessary to replace the existing CPE.

(1) Service function

[Calling party's side]

Same as "Calling line identification presentation service"

[Called party's side]

By dialing "136" on the receiver CPE, the called party is notified by voice of the telephone number of the last call received, including calls that the receiver did not answer. (This is available only for "number presentation" calls.)

Dialing "3" will automatically initiate a return call to the last telephone number received.

(2) Switching conditions

Same as those for "calling line identification presentation service" with respect to the calling side.

For the called party's side, the service is offered only to telephone subscribers who are served by digital switching systems.

(Reference 2)

List of CPEs Provided to General Customers under No-Cost Leases for Calling Line Identification Presentation Service

TypeName of providing
Name of CPEFeaturesUnits
Telephone set type (1) SANYO Electric
Cordless automatic answering telephone
* Answers with user's original message for specified callers when automatic answering is set
* Call-rejection function
(2) SHARP CORPORATIONCordless automatic answering telephone
(CJ-G8EX) for CLIP
* One-touch call return from received call number
* Memory for 30 incoming call numbers and time received
(3) TAKACOM CORPORATIONAutomatic answering telephone with calling number display
* Registration of three telephone numbers for nuisance calls
* Memory for 30 incoming call numbers during absence, etc.
FP100 Telephone Terminal Unit-C* Registration for 100 telephone numbers (available for registration of three types of ringing tones)
* Memory for 10 incoming call numbers and time received
NS-CID Telephone* Setting of three ringing tones
* Memory for 10 incoming call numbers during absence, etc.
(6) Meisei Electric
EMP-55 Telephone* Display of registered caller names (50 entries)
* Memory for 20 incoming call numbers and time received
Display unit type(7) NTT Automatic answering telephone with calling number display* Setting of three ringing tones
* Memory for 30 incoming call numbers and time received
(8) ANRITSU CORPORATIONFT-900* Telephone directory management system with attached software for connection to PC's
* Memory for 50 incoming call numbers and time received
Display unit for individual-line telephone set with calling number display function* Notification of called parties names via synthesized voice ("Father", etc.)
* Memory for 50 incoming call numbers and time received
(10) KAZTECH Corp.Call screener
* Color distinction display for acceptable or rejected calls
* Memory for 60 incoming call numbers and time received
Call line number display unit (NAMBAN-TORAI) * Calling line number memory-clearance function
* Memory for 30 incoming call numbers and time received
(12) MOUBIC,INC.CLIP display unit MC121P* Automatic calling to pager during absence; transfer of calling line number* Memory for 121 incoming call numbers and time received50
(13) RIKEI CORPORATIONCall line number display unit* Memory for 30 incoming call numbers and time received100
(14) NTTCall line number display unit A* Memory for 30 incoming call numbers and time received750
(15) NTTCall line number display unit B* Memory for 30 incoming call numbers and time received750
PCMC IA card
(16) OKI Electric
Industry Co.,Ltd.
PC-TEL Card C* Display of calling number on PC screen upon receipt of call
* Distinctive ringing tone and setting of answering message
(*Note) Slot-in PC card that provides telephone functions via PC