|December 9, 1999|
Trial Implementation of ADSL Internet Access Service
NTT East and NTT West are planning to initiate a flat-rate ADSL (asymmetric digital subscriber line) Internet access service on a trial basis beginning late this month.
1. ADSL Access Service Overview
(1) Service outline
The service will provide Internet access over digital lines with asymmetric upstream and downstream transmission speeds. Key features are outlined below.
First, various technical challenges are involved, including potential interference with our ISDN services. Accordingly, the ADSL service initially will be provided in limited areas and for a limited time chiefly to test the technology, ensure sound operation, and gauge trends in demand.
The trial program will comprise two types of ADSL service. Under the Type 1 service arrangement, ADSL modems for use by participating subscribers will be installed by NTT. Under the Type 2 service, however, the ADSL modems will be installed by Internet service providers (ISPs), and the connection to each subscriber line will be made through main distribution frames (MDFs) at the corresponding central office.
The Type 1 and Type 2 services will both have two subtypes. The first subtype will be shared with regular subscriber phone sets and phone lines, and the second subtype will be exclusively for ADSL connections alone. In particular, the Type 2, subtype 1 (i.e., Type 2-1) variant of the service will be the world's first test of a line-sharing configuration.
< Illustration >
＜ Diagram of ADSL Network Installation ＞
1. ADSL modems (and ADSL transceiver units at the central office end) are devices that utilize ADSL technology for communications purposes.
2. Splitters are devices used to superimposing or split phone (low-frequency) and data (high-frequency) transmissions sharing the same line.
(2) Terms and conditions for service
ADSL Access Service
| Type 1 service (ADSL modem installed in subscriber's home by NTT)|
|Type 1-1 (shared with subscriber's regular phone line)|
Type 1-2 (not shared with subscriber's regular phone line)
Type 2 service (ADSL modem installed by subscriber's ISP; connection into central office MDF)
|Type 2-1 (shared with subscriber's regular phone line)|
|Type 2-1-1 (splitter installed by NTT)|
Type 2-1-2 (splitter installed by ISP)
|Type 2-2 (not shared with subscriber's regular phone line)|
For Type 1 services
Downstream (from NTT central office to subscriber's home): 512 kbits/sec (max)
Upstream (from subscriber's home to NTT central office): 224 kbits/sec (max)
For Type 2 services
Dependent on terms of subscriber contract with ISP.
<3>Under certain circumstances, interference from other communications lines may result in poor ADSL throughput speeds or prevent ADSL connections entirely. For this reason, the trial service will be provided without any guarantee of connection quality.
<4>Line-sharing with ISDN service is not feasible.
(3) Trial service areas
Service will be offered in the areas managed by the following central offices. Please see Supplement 1 for a full listing of all area codes to be covered.
Central offices in Tokyo
Kayaba-kabuto, Aoyama, Mita, Yotsuya, Yodobashi, and Ikebukuro (Chuo, Minato, Shinjuku, Shibuya, and Toshima Wards of Tokyo)
Central offices in Osaka
Osaka-chuo, Higashi, Osaka-kita, Kita, and Osaka-yodogawa (Chuo, Kita, and Yodogawa Wards of Osaka)
Central offices in Oita Pref.
Oita-funai (in City of Oita)
(4) Trial service period
About one year, effective from late December 1999
(5) Fees during trial service period
The tables below list the fees applicable to the provision of this trial service. Participating subscribers will also be responsible for any fees separately assessed by their ISPs.
<1>Monthly service fees
|Type of service
||Line usage fee
||Line-terminating equipment usage fee (Note 1)
|Type 1 service
|Type 1-1 (Note 2)
(shared with subscriber's regular phone line)
|Type 1-2 (Note 3)
(not shared with subscriber's regular phone line)
|Type 2 service
central office MDF)
|Type 2-1 (Note 2)
(splitter installed by NTT)
|Type 2-1-2(splitter installed by ISP)
|Type 2-2(Note 3)
(not shared with subscriber's regular phone line)
1. For ADSL modems and splitters.
2. Does not include metallic line depreciation or maintenance costs. Fees reflect additional costs anticipated with the provision of ADSL service.
3. No equipment-related fees required.
||For Type 1 services
|For Type 2 services
||2,800 yen (Note 3)
||2,000 yen (Note 3)
|For line conditioning (Note 2)
||Base conditioning fee
(for tests of transmission speed, quality, etc.)
|Bridge tap removal
1. The above fees are for standard installations, only. In practice, customers will be billed for the installation work actually required.
2. In principle, conditioning will be made on request: for example, in the event a subscriber experiences poor ADSL transmission speeds.
3. For installation-related work at the central office end.
<3>Contract fee: \800
2. Service-related Queries
We will begin accepting service-related queries from December 10. For query-related contact points and other information, please see Supplement 2.