1、TIA/EIA TELECOMMUNICATIONS SYSTEMS BULLETIN C ellular Sub scr ib er Unit Inter face for TDD TSB121 June 2001 TELECOMMUNICATIONS INDUSTRY ASSOCIATION The Telecoininiiiiicatioiis Industry Associatioii represents the communications sector of Elscttonis Indushies Alliance Copyright Telecommunications In
2、dustry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NOTICE TIMEIA Engineering Standards and Publications are designed to serve the public interest through eliminating misunderstandings between manufacturers and p
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6、Bulletin. Technical Bulletins are distinguished from TIMEIA Standards or Interim Standards, in that they contain a compilation of engineering data or information useful to the technical community, and represent approaches to good engineering practices that are suggested by the formulating committee.
7、 This Bulletin is not intended to preclude or discourage other approaches that similarly represent good engineering practice, or that may be acceptable to, or have been accepted by, appropriate bodies. Parties who wish to bring other approaches to the attention of the formulating committee to be con
8、sidered for inclusion in future revisions of this Bulletin are encouraged to do so. It is the intention of the formulating committee to revise and update this Bulletin from time to time as may be occasioned by changes in technology, industry practice, or government regulations, or for other appropri
9、ate reasons. (From Project No. 4558, formulated under the cognizance of the TIA TR-45.1 Subcommittee on Analog Technology. ) Published by TELECOMMUNICATIONS INDUSTRY ASSOCIATION 200 1 Standards and Technology Department 2500 Wilson Boulevard Arlington, VA 22201 PRICE: Please refer to the current Cat
10、alog of ELECTRONIC INDUSTRIES ALLIANCE STANDARDS and ENGINEERING PUBLICATIONS or call Global Engineering Documents, USA and Canada (1-800-854-7179) International (303-397-7956) All rights reserved Printed in U. S.A. Copyright Telecommunications Industry Association Provided by IHS under license with
11、 EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Copyright Telecommunications Industry Asso
12、ciation Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TINEIMSB 12 1 1 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 1. INTRODUCTION This Telecommunications Systems Bulletin (TSB) describes a p
13、ossible implementation of the interface between a mobile station and a TTY. Recognizing that: FCC Rule and Order CC Docket No. 94-102 “E9-1-1/TTY Compatibility“ requires wireless service providers to support TTY compatibility for contacting assistance in an emergency. The CTIAIPCIA TTY Forum request
14、ed that TIA TR-45 specify a 2.5mm connection with appropriate electrical parameters which would allow reliable audio interconnection between TTYs and mobile wireless handsets. The majority of legacy TTY terminals only support audio connection to the telephone network via: (See Section 6.: Interconne
15、ct Options) - Acoustic coupling utilizing the wire-line handset placed into flexible cups designed for Type G or Type K handsets. . - FCC Type RJ-11 modular connection. Due to the wide variety of shapes and sizes of modern wireless handsets, neither of these modes of connection are applicable to mob
16、ile wireless handsets. TIA/EIA/IS-789-A describes electrical specifications to adapt wireless This TSB specifies an interface that will support direct audio connections between TTYs and mobile wireless handsets based upon TIA/ EIA/ IS-789-A. handsets to a vehicular environment. 2. REFERENCES The fol
17、lowing standards pertaining to mobile stations may be useful in implementing this TSB. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this TSB are encouraged to investigate the possibility of applying the most
18、recent editions of the standards indicated below:. 2.1. TIA/EIA/IS-789-A: Electrical Specification for the Portable Phone to 2.2.TIA/EIA-690: Reamunended Minhum standarid jr BOO IMHz Celallar Vehicle Interface Subscriberunits Duaz-M typical level from Optimal Level : TTY G I I Signal TX Signal I = -
19、12 to -25dBm = -10dBm I typical (max.) I I I 6 Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TI A/E IA/TS B 1 2 1 7 Copyright Telecommunications Industry Association Provided
20、by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Copyright Telecom
21、munications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Copyright Telecommunications Industry Association Provided by IHS under license with EIANot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
