Converting to MARTIN of computing and telecommunications as separate en- tities. Both are based on the same mi- croprocessor technology and both han- dle information. Information is input at one end and output at the other, with only the physical transportation mecha- " existing analog telecommunications network has been able to handle this type of traffic be- cause computer output is in digital for- mat. Relatively low-speed data commu- nications (at speeds from 1,200 bits per second to 9.6K bps and up to 19.6K bps) are easily possible via modems over the analog network. However, analog net- works are not able to offer the high- speed communication links necessary to support effective communications and video transmission. Design Changes The incorporation of digital switching and transmission technigues into tele- communications has begun to alter the foundation upon which networks are de- signed. Although voice communication is, and will continue to be, the primary means by which information is trans- mitted, the philosophy of network de- sign is changing. Voice is no longer the dominant feature around which net: works are designed; data communica- tions now plays the major role. This is not to say that voice communication is decreasing in importance; it is just that, in a digital network, voice or data no longer become issues. All communica- tions, including digitized voice, are con- sidered to be data. The key concept of a digital network is that it lays the foundation for creat- ing a ubiguitous, integrated network ca- pable of handling all our communica- tions reguirements—from a simple tele: phone call to the broadcasting of high- | definition television. Economic Factors The scale of the task involved in con- verting networks from analog to digital is guite daunting. The telephone net- work has evolved over the past 100 pam By the mid-1990s, the majority of be fully digital. This reguires the replacement of all switehing and transmission facili and the introduction of a wide rane ot d social well- the economic an ; He dig. bution to oble Wi a a Ma o ications veh EL 5 S non Š a om paterš to such an extent that be: ki mor tav NE o iti ould result in total avallability of more bandwidti. ča ing without them me a vibe zar nee itno UGO Bee podil continued expan: Cost mni s lepe jecommunicationns nee G ea roematičn is one of the una J k: s sata valuable traded commodities, an PTTs (state controlled Gu a ee tions facilities), common čreda s network operators of all types, eit H public or private, have long had prob- Jems associated with running and main- taining an analog network; some of the basic principles date back to the early part of this century. The cost of operat: The Move Towart Integtatlon Of CornmunicatloH S ing of information process! K vommunjcatjons le IT Mio effectiveness ani o nke Ml sectors of o e a! commerce. In order to ensur' m: 's investment in a digi z ee is compatible with another's, m ISBN lhtettace The Netwotk: The Hlifteretit types of nativotkš dre physically šeparata Digital. Central' H FI H Office | K H H A digital network las the foundation for creating an integrated network capable of - handling ali our communications reguirements. O a aa era ing and maintaining large analog net: works is becoming prohibitive. The older type of mechanical switehing systems have many moving parts, are unreljable and reguire a large number of trained engineers to maintain them. Modern dig- ital switching systems are inherently much more reliable as many of the old moving parts have been repldced with Microprocessor-controlled cireuitry, Expandable Infrastructures A major economic factor go the introduction of ISDN relates to in. k A communications net Work is like a central nervous system, It Js a vital organ making a unigue contri- | the application of common, internation- ally agreed-upon network standards is critical, The creation of and adherence to standards for digital networks by all countries is vital, Tariffs ; Because both voice and data will be transmitted over the same ISDN net: work, the network operator will have no means of distinguishing between the , two types of traffic. This raises a num- ber of potential problems that have not yet been resolved. One of the most, im- portant is the guestion of tarifis for ISDN. An ordinary circuitswitched | Yeice call is charged on the basis of con. i s Behin ect time and di š packetswitehct 1 e basis o 4 GA UKO of data trans oe pnbve - -] ost cases, it iS more €2 pupledai Ed data over a voice circuit i How ser- i estment in ISDN. ; a sei k anifed is crucial to the devel opment of ISDN. Transition to ISDN z i are A number of major o oditi unresolved—standards fo ffic that oper: ISDN, circuits for voice tra d peeds less than 64K bps, an ge at eni of international ISDN net: e oj js oe ito example. Many of an d sues will be clarified oloane Če operator experience, user experien m and additional standards KE ONAJI tions from CCITT, ka internationa! ds-making body. ji E rine the initial stages of ISDN im- plementation, access to various ISDN circuit. and packet-switched services will be via a single network interface. At this stage, individual traffic types will still be switched separately, as illus- trated. Progress toward the integration of both switching and transmission facil- ities is not generally expected until the mid-1990s with the integration of high- speed circuits and the completion of the transition to digital packet-switched networks. Throughout, the development of ISDN, the level of services, facilities and de- gree of network integration will depend upon the individual PTT or network op- erator. The speed at which each opera- tor develops his or her network will de- pend upon many factors, not the least of which will be financial/investment considerations, guality of an existing plant, as well as user demand and the willingness to pilot new services. Depending on the individual network operator, ISDN will develop at different speeds and provide different levels of sophistication. In North America, it is likely that operating companies will de- velop ISDN at different speeds and with different priorities. How and in what way this development takes place will be due in no small part to the pressure exerted on the local operator by the business £ommunity. It is the business £oramunity that potentially will benefit, ost during the early stages of ISDN; therefore, it is up to it to ensure that the network operator makes the right Planning and implementation decisions based on present and anticipated co; rate telecommunicatjons reguirements, Next week, we-will 100k at broadband ISDN channels that Operate on very high-capacity opticabfiber circuit, B The James Martin Productivity Seri an information service Update Gas, terly, 1s available through High Pro- ductivity Software Ine., of Marble- head, Mass. (€ 800) 2292-1240. For infor. mation on seminars, please contact (in the United States and Canada) Tech- nology Transfer Institute, 741 10th St., Santa. Monica, Calif. 90402 (213) 393. 8305. In Europe, contact Savant, 2 New St., Carnforth, Lanc: , LA5 9BX United Kingdom (0524) 734 505.