In the past, the only function for telecommunication terminals was to provide the user with access to a telecommunications network. Later, many other functions were added to the terminals that were designed to simplify the use of the telecommunications equipment. In the case of the telephone, the old telephone terminals were only providing access to the public switched telephone network (PSTN) while today’s telephone terminals provide other services, such as personal directory and answering services. The old text-oriented data terminals that were used to enter the data are now mixed with word processors that were not originally designed for telecommunication applications. By equipping the word processor with a communications interface, however, the differences between telecommunications text terminals and communicating word processors disappear, and we obtain a multifunctional workstation. The old PSTN with analog circuit switches is now replaced by a more complex network using integrated services digital network (ISDN) and asynchronous transfer mode (ATM) switches, thus introducing new services and associated telecommunication terminals. Access to the old PSTN that was once only through copper wires is
J. Webster (ed.), Wiley Encyclopedia of Electrical and Electronics Engineering. Copyright # 1999 John Wiley & Sons, Inc.

data.310. . or operation. telephony. standards. This recommendation is only applicable to digital telephones using encoding conforming to Recommendations G. facsimile.310 provides audio performance requirements and associated testing for telephone band (300 Hz to 3400 Hz) digital telephones. opening a new horizon for introducing variety of new terminals.) by means of any electromagnetic system (electrical transmission by wire. harmonic distortion. visible or audible signals. and data. stability loss. Telecommunication terminals for different wired and wireless access technologies are considered based on their applications in voice. it also investigates different wireless terminals. It defines the meaning of the telecommunication terminal and categorizes them. The terminal is a point at which information can enter or leave a communication network. electrical. telex. conditions. system. The telephone handset has gone through major changes to provide better quality of service (QoS) for users. Traditional Telecommunication Terminals There are three fully standardized ITU-T services: telegraphy. sensitivity frequency response. There are four other ITU-T services under the name telematic in the process of standardization: teletex. etc. including levels. Although there is no widely accepted and quoted definition of the term standard. or measurement of quantity and quality in describing materials.). etc. and protocols for wired terminals. In the rest of this section we provide a short description of telephony. ITU-T Recommendation P. The connection method at the demarcation point shall enable easy detachment of the facilities. or practices (2). noise. frequency response.TELECOMMUNICATION TERMINALS 433 now complemented with variety of wireless services. Requirements and test methods are specified for the major audio transmission parameters affecting wideband audio. guaranteed end-to-end compatibility and ITU-T standardized terminals. The waveform encoding for telephone terminals is specified by Recommendations G. teletex. videotex. services. classification of components. and videotex terminals and their relation to other services. and procedural characteristics of communication equipment. such as telegraph and facsimile. ITU-T Recommendation P. out-of-band signals. services. and message handling service. This article provides an overview of a large class of telecommunication terminals. the article discusses different telecommunication terminals. PCM) and G.711 (64 kbit/s. fixed or moving pictures. The transmission structure of the telephone network assisted some other services. and multimedia. ADPCM). A telecommunication terminal is a device that can provide telecommunication services used by end users. Table 1.711 for the Pulse Code Modulation (PCM) at both 64 kbit/s and 56 kbit/s and G. performance. and delay. Table 1 shows some examples of telecommunications terminals that are used domestically or internationally. The electrical interface specifications are referred to in Recommendation P. public facsimile. The goal with all of these services is to ensure highquality international telecommunications for the end user re- gardless of the make of the terminal equipment and the type of network to support the service. It gives recommended values or masks for the following parameters: loudness ratings. it is accepted in the telecommunication industry that standards are required to determine the physical.342 provides audio performance requirements for telephony terminals in the telephone band (300 Hz to 3400 Hz). and P. or any device capable of sending and/or receiving information over a communication channel. Telecommunication Terminals Examples Packet switching terminals Circuit switching terminals Telex terminals Facsimile communications user terminals Facsimile communication center terminals Videotex communications user terminals Videotex communications center terminals Video conference terminals Gathering telephone terminals Four-wire telephone circuit terminals Nonringing circuit terminals Signal supervision communications service terminals Airport radio phone terminals Convenience radio phone terminals Teleterminal communications terminals Maritime mobile telephone terminals Satellite mobile telephone terminals Airplane telephone terminals Marine telephone terminals Leased circuit terminals Frame relaying terminals Cell relaying terminals Acoustic couplers Integrated digital telecommunications terminals WHAT IS A TELECOMMUNICATION TERMINAL? Telecommunication is any process that permits the passage from a sender to one or more receivers of information of any nature delivered in any usable form (printed copy. The term service has a very specific meaning in International Telecommunication Union-Telecommunication (ITU-T) standards that is mainly characterized by complete. delineation of procedures. guided waves. optical transmission.726 for adaptive differential pulse code modulation (ADPCM) 32 kbit/s.726 (32 kbit/s. product. The following definition from the 1979 National Policy on Standards for the United States was offered (1): a prescribed set of rules. specification of materials. and a large part of the world can be reached without operator intervention. Based on the terminal definition as an endpoint to offer telecommunication services to end users with wired or wireless interfaces. Telephone service is now almost completely automated.311 provides preliminary audio performance requirements for wideband audio (7 kHz) handset telephones (3). terminal coupling loss. The invention of the electromagnetic selector in 1896 made telephone service automation possible. ITU-T Recommendation P. data. Terminal equipment connected by a user shall have a demarcation point between the terminal equipment and the telecommunication facilities used for telecommunications business. Telephone Terminals.35 standardizes handset telephones. The data services that were using the PSTN through modems are not complemented by long-haul and local packet switched data networks demanding for new terminals to connect to these networks. radio. or requirements concerning definition of terms.

the government subsided videotex by automating telephone books using videotex. Class II. videotex systems have been started as national systems. One of the differences in functionality is that telex transfers the message content without placing any format on the text. Data Terminals. Teletex uses communication protocols that conforms to the international organization for standardization (ISO) model. Several standards for the facsimile terminals have been defined by CCITT. CCITT has also specified a store-and-forward facsimile switching service called comfax. the Group 3 and Group 4 terminals are being used on a very large scale worldwide.9). display terminals and personal computers are usually connected to X. echo path. The Group 3 protocol specifies CCITT T. In a number of countries teletex is being promoted as the successor to telex. X. With a suitable screen. Transmitting diagrams with teletex is possible. data link layer. In X. The access speeds and the throughputs may go up to 2 Mbit/s. The optical scanner generally does not offer the same quality of resolution as stand-alone scanners. Teletex and Telex. The number of available letters. and packet layer. This class can support documents with text and diagrams or mixed mode documents. reproduction can be in color.25 protocols.25 describes the interface and access protocols for data terminal equipment (DTE) operating in packet mode connected by a data circuit terminating equipment (DCE) to a public data network (PDN). via a telecommunication network. The mixed mode terminals that support both text and diagrams have been specified by the CCITT. The procedure to build up a connection or virtual call begins from the terminal (DTE) by transmitting a call request packet. while telex does not support diagrams. Wideband audio represents a considerable departure from traditional telephony. in which the higher-protocol layers are independent of the lower-protocol layers. Teletex terminals use the teletex code (CCITT Recommendation T.434 TELECOMMUNICATION TERMINALS distortion. The Group 3 facsimile terminals operate over the PSTN. offering significantly improved quality.25 defines three layers: physical layer. and symbols in teletex is also much larger than in telex. with international compatibility.301 describes a high-speed terminal access to videotex services for use on the PSTN. while teletex does impose certain constraints on the format.48 specifies the procedures for a DTE operating in accordance with Recommendation X.7). These terminals operate at 2400 bit/s (5). Class I terminals can send/receive facsimile encoded documents. More description of the visual telephone systems described by the H.322 standard is provided later in the section on multimedia terminals. a printer for printing incoming facsimile messages. in addition to Class I. ITU-T Recommendation X.4 data compression and a maximum transmission rate of 9600 Bd. both text and diagrams from the database can be reproduced on a screen. which means they require a special kind of paper. The Group 4 terminals have been designed for use on data networks or ISDN. The service offered is compliant with the OSI network service and permits the transmission of data without loss and duplication. while more modern facsimile machines use standard papers.25 it is possible to define a maximum of 4000 virtual circuits on one physical layer. Currently. and the called terminal answers with a call accepted packet. Group 4 terminals operates on 64 kbit/s channels. spurious signals. The overriding goal of this Recommendation is to make no changes to the DTE that wishes to participate in this service (4).61). Some printers on facsimile machines are thermal. The latter is also referred to unofficially by the name American standard code for information interchange (ASCII). In reference to the Open system interconnection (OSI) model. In this group three classes of terminals have been defined.301 provides not only for faster throughput but also access to new capabilities that are not feasible at lower speeds. There are two levels of resolution for Group 3 facsimile terminals: 203 by 98 and 203 by 196. This service is intended to provide interoperability between different types of facsimile terminals. Comfax also accepts the input from text terminals and converts the text to facsimile form for delivery to facsimile terminals (6. to the memory of the receiving terminal. Teletex is an international service that enables subscribers to exchange correspondence between two teletex terminals. In spite of the efforts of CCITT. In France. sidetone. Telecommunication Terminal Classification In terms of the services. and delay. Class III is a superset terminal that can transmit teletex documents besides the Class II terminal services.25 interface is mainly used by computer systems. ITU-T Recommendation F. Although the X. A permanent virtual circuit does not require any call buildup. they are not interoperable and a converter is required. Consultative committee on international telephone and telegraphy (CCITT) Recommendation X. which is similar to the CCITT IA5 8-bit code.25 indirectly by a packet assembly/disassembly (PAD) facility which translates the simple terminal protocol to the more complicated X. telecommunication terminals can be categorized as Voice terminal equipment Data terminal equipment Visual terminal equipment Multimedia terminal equipment The telecommunication terminal equipment can be further categorized in terms of the access interface by which they access the telecommunication network: Wired terminal equipment Wireless terminal equipment . and terminals were supplied free to subscribers (8. A facsimile terminal consists of an optical scanner for digitizing images on paper. The majority of videotex terminals are connected via PSTN with a special videotex modem made for sending at 75 bit/s and receiving at 1200 bit/s.6. While the functionality of the two devices are similar. These terminals operate on the basis of the transfer of data from the memory of the transmitting terminal. ITU-T Recommendation F. and a telephone for making the connection. The videotex service is an interactive service that allows users of videotex terminals to communicate with databases servers via telecommunications network. digits.25 also supports a flow control mechanism. services can also receive teletex encoded documents. Videotex. and packets specific to the virtual call are not used by the DTE.25 to participate in a multicast data transmission service described in Recommendation X. X. Facsimile.

the CPE is communicating directly with the exchange. Some ISDN exchange manufacturers further break down the functions of the LE into two subgroups called local termination (LT) and exchange termination (ET). It is not uncommon for a business location to have many individual lines connecting it to the CO for such services as telephony. timing. 1. physical S ISDN terminal equipment (TE1) Customer premises switching equipment (NT2) T Local loop terminator (NT1) U ISDN local exchange (LE) R Non-ISDN terminal equipment (TE2) S Treminal adapter (TA) Figure 1. The ISDN and ATM are networks capable of providing a variety of services to telecommunication terminals. represents the termination of the physical connection between the customer site and the LE. for example. there are several device-to-device interfaces. while multiple trunk circuits can provide multiple lines between a customer’s private branch exchange (PBX) and the CO. a single connection to the local central office (CO). while the ET handles switching functions. Each of these functional device interfaces is called a reference point. SERVICES. and provision of requested user services. As far as the customer is concerned. ISDN uses a standard phone line (a copper wire pair) in a home or office and converts it from a single analog circuit into multiple high-speed digital circuits capable of transmitting audio. Multimedia for LANs and POTS are application-related topics. STANDARDS. and remote security. Other LE responsibilities include maintenance. Several different devices may be present in the connection between consumer premises equipment (CPE) and the network to which the CPE is attached. still images. and text data simultaneously. the standards call them functional devices. the junction box is transparent. or local loop terminator equipment. one for user-network signals and one for user data (voice and tones). the requirement for the number of physical resources to handle those users also increases. . motion video. WIRED TELECOMMUNICATION TERMINALS. for example. a pointof-sale terminal. have a single-line telephone and. As the number of simultaneous users increases at a customer location. The ISDN standards define several different types of devices. can provide a second telephone line. Since the ISDN recommendations describe several functional device types. ISDN protocols are implemented in the LE. A second local loop. ISDN functional devices and interface access. Access to other networks and/or network services (such as a packet or telex network) can be provided by bringing additional lines to the customer’s premises. Each device type has certain functions and responsibilities but may not represent an actual physical piece of equipment. In the sections related to ATM and ISDN. At first we introduce terminals for the ISDN and ATM services and then we introduce multimedia terminals for the local area networks (LAN) and plain old telephone system (POTS). The NT1’s responsibilities include line performance monitoring. ISDN Functional Devices. accordingly. timing. which is also the network side of the ISDN local loop. ISDN Terminals and Functional Devices ISDN is a fully digital communications technology implemented throughout the infrastructure of the existing world- wide telephone network. the local loop provides the physical connection between the junction box and the local exchange (LE). Material presented in these sections describes the ITU-T standards for multimedia terminals that are connected to LANs and POTS. fax. The LT handles those functions associated with the termination of the local loop. Consider the relatively simple example of a customer’s connection to the telephone network. which are shown in Fig. AND PROTOCOLS In this section terminals using wired networks are presented. an overview of these networks and a description of the services available to the terminals are presented.TELECOMMUNICATION TERMINALS 435 An access interface is the physical connection between the user and the telecommunication network that allows the user to request and obtain services. The network device that provides ISDN services is the LE. physical interface operation. All of the subscriber’s telephones are connected with inside wiring to a junction box in the customer’s building. Network termination type 1 (NT1). For that reason. Most residences. The following paragraphs describe the different functional devices and reference points. This single local loop can comprise two logical channels. each requiring a communications protocol.

ISDN workstation. the TA manufacturer will determine and specify how the TE2 and TA communicate with each other. The three layers of the PCI’s user plane protocols are represented in three parts. Network termination type 2 (NT2) equipment includes those devices providing customer site switching. and parameters used to access the ISDN services. such as an analog or digital telephone terminals. V. it is responsible for writing the I-series recommendations defining ISDN and specifying appropriate services and protocols. X. This recommendation covers the routing plan for interconnection between public land mobile network (PLMN) and PSTN/ISDN and between PLMN and PDN. This Recommendation defines services available and signaling procedures operated at the S/T reference point of an ISDN for subscribing packet mode terminal equipment and terminal adapter functionality to support existing X. and other CPE for voice and data switching. is described in Recommendations I. PCs.200 is the introduction to the multipart specification that defines a standard programming communication interface (PCI) allowing applications to access and manage the services provided by an ISDN. several Iseries recommendations are also assigned Q. The TA will allow the TE2 to appear to the network as an ISDN device. ISDN signaling procedures on the D channel are listed as both Recommendations I. Supporting other non-ISDN terminals is also considered in ISDN recommendations such as X. such as the analog telephones in use on today’s telephone network. the NT2 might perform some protocol conversion functions as well as distribution functions. and power transfer. and/or concentration. including ISDN. As an example. The S reference point is between ISDN user equipment (i.462 and X. The NT2 is responsible for all signaling to the network. or other series’ recommendation numbers. each cable connected to the controller. Some IVDTs are PBX-proprietary devices.e. systems consisting of a cluster controller and multiple handset/screen keyboard stations. the primary international standards body for ISDN. while other are independent stand-alone devices.25 data terminal equipment. or integrated voice/data terminal (IVDT). multiplexing. and. Support of X. Terminal equipment type 1 (TE1) includes those devices that utilize the ISDN protocols and support ISDN services. Four protocol reference points are commonly defined for ISDN. for example. a keyboard.544 Mbit/s for a connection to other subscribers. There are no specific standards for the R reference point. the user-network interface is usually called the S/T reference point. Among other things. The R reference point is between non-ISDN terminal equipment (TE2) and a TA. and it indicates some basic rules . specifically address protocols for the S and T reference points.25 terminals on an ISDN. and a powerful microprocessor. nearly every device in use in today’s data and telecommunications environment is TE2. and U. IVDT configurations include computer terminals with telephones. therefore. A terminal adapter (TA) allows a non-ISDN device (TE2) to communicate with the network. One of the primary distribution functions is network signaling on behalf of the attached terminals.25 DTEs. Similarly. IVDTs generally consist of a dual tone multifrequency (DTMF) telephone handset or speakerphone. ISDN Reference Points. TE1 or TA) and network termination equipment (NT2 or NT1). multiplexers. such as an ISDN telephone or workstation. and the industry standard architecture (ISA) bus. in some instances. a PBX might terminate an analog telephone and allow access to an ISDN primary rate interface (PRI) with 1. The ISDN reference points define the communication protocols between the different ISDN functional devices. ISDN recommendations from the ITU-T. see Refs. Other SGs participate in the ISDN standards process by virtue of the recommendations that they prepare. with detailed procedures. which often overlap. X. for example. the ITUT views the S or T reference points as the user-network boundary and does not address U reference point (for more information. Examples of TA-to-TE2 communication include EIA 232-E. It provides mechanisms to support most protocols used for communication between ISDN applications. In this role. ITU-T Recommendation T.451 and Q.931.436 TELECOMMUNICATION TERMINALS signaling protocol conversion. The T reference point is between customer site switching equipment (NT2) and the local loop termination (NT1).31. In the absence of the NT2. can all pertain to ISDN.35. messages. TAs have particular importance in today’s ISDN marketplace. the general aspects for the management of and access to the user plane protocol supported by the PCI are explained. X. For this reason. An important aspect for the success of ISDN will be the availability of user applications (in particular. TAs allow analog telephones. Recommendations for public data networks (X series). In the user plane protocols management architecture part.173.25 terminals at the R reference point of the ISDN. applications based on personal computers) making use of ISDN. Since the ITU-T considers the physical NT1 device to be owned by the network administration. This includes PBXs. such as Windows and Unix. The basic services part provides a technical overview and defines the basic functions supported by the ISDN-PCI. these two standards are identical. The importance of the different reference points is that different protocols may be used at each reference point.31. ISDN and telephone network switching and signaling (Q series). S.. Terminal equipment type 2 (TE2) includes non-ISDN-compatible devices. It defines the PCI architecture and includes a detailed definition of the PCI messages and parameters used for administration and connection control. 10 and 11). The other useful standard that is applicable for interoperability between ISDN and wireless networks is ITU-T Recommendation E. host computers. and other nonISDN devices to use the network by providing any necessary protocol conversion. electrical conversion. terminal controllers. an integral or a detachable CRT. telephones with built-in display screens and the ability to interface with computers. Terminal equipment (TE) refers to end-user devices. and addressing and numbering plans (E series). T. ITU-T Study Group 11 (SG11) has responsibility for digital networks. called R. just like a modem allows a terminal or PC to communicate over today’s telephone network. In this case the PBX is providing protocol conversion from the analog voice to the ISDN digital voice and is collecting the dialed digits from the telephone and creating a signaling message for the LE. One of the important features of this recommendation is providing information for binding PCI to different operating systems. NT2s distribute ISDN services to other devices that are attached to them. It provides guidelines for routing when interconnecting PLMN and fixed terminal networks.

call control arrangements. Typical services provided by ATM terminals are as follows: Constant Bit Rate (CBR). connection-oriented switching technology that is designed to support a wide variety of services. SVCs establish short-term connections that require call setup and teardown. ITU-T Recommendation H. distribution. G. H. retrieval and remote terminal (telecommuting). Variable Bit Rate (VBR). such as G. This is suitable for any application for which the end system can benefit from statisti- cal multiplexing and can tolerate or recover from a potentially small random loss ratio.310.261 on video coding. and process monitoring. typically for videoconferencing and videophone services. but also in the ATM-based B-ISDN. ATM transmits all information using small (53 byte) fixed-length cells over broadband or narrowband transmission facilities. Unspecified Bit Rate (UBR). Examples are videoconferencing. terminal aspects. Multiplex the cells from various sources together onto the outgoing transmission link. SMDS. This interface. while PVCs are similar to dedicated private lines because the connection is set up on a permanent basis. critical data transfer (defense information. ATM was designed to provide large amounts of bandwidth economically and on demand.324. interactive audio (e. Recommendation E. videoconferencing. An optimal exploitation framework for the ATM service categories will be achieved with the development of new ATM-aware applications that access the network through an ATM application programming interface (API). audio/video retrieval (e.323. The following steps summarize the basic functions of an ATM interface: Packetize or segment the incoming data into fixed-length cells with a header and a payload field. frame relay. audio library). the bandwidth is available for use by another connection that does need it. and H. and frame relay interworking Available Bit Rate (ABR). This category provides economical support to those applications that show vague requirements for throughput and delay and require low cell loss ratio. distance learning.g.320 terminal is a visual phone terminal over ISDN which has been standardized by ITU-T. H.320 Terminal.322.173 covers terrestrial-based PLMNs. depending on the type of data. ATM provides two virtual circuit communications services: switched virtual circuits (SVC) and permanent virtual circuits (PVC). This can provide a suitable solution for less demanding applications. This is handled by the destination ATM switch. Address the cell by prefixing it with a logical destination virtual path (VP) address. It describes a generic system configuration consisting of a number of elements that are specified by respective ITU-T recommendations. and AVMMs not only in narrowband ISDN (N-ISDN) (e. are very tolerant to delay and cell loss. and general switched telephone network (GSTN) environments. ITU-T provides the Joint Coordination Group (JCG) on Audio-Visual Multimedia Services (AVMMS). translating them back into their native format. and data communications like remote procedure call. in which study groups of ITU-T are working together on AVMMS. Routing between networks must adhere to regulatory conditions that exist within a given country or administration. banking transactions. will bypass the bottleneck legacy protocol stacks to provide the application with direct visibility and control of the ATM network resources.g. Demultiplex or ‘‘unpack’’ the cells from various sources. SG15 leads the JCG and has issued many recommendations for videotelephony. The asynchronous and multimedia characteristics of ATM are what make it possible for ATM networks to carry both circuit and packet types of traffic simultaneously. Most data applications.. Non-real-time VBR can be used for data transfer. H.TELECOMMUNICATION TERMINALS 437 for routing of calls between the networks. When a user does not need access to a network connection. video and audio coding methods. Assign different virtual channels (VC) within the virtual path. banking services). definition of communication modes and terminal types. such as response-time-critical transaction processing applications like airline reservations.263. such as sig- . Flexibility of the ATM network allows variety of services to the user.g. H.723. This series of recommendations is composed of multimedia multiplexing. including ATM. Desktop-to-desktop ATM applications will benefit from an ATM API and from other developments. LAN emulation. This is any transfer application that contains smooth traffic or for which the end system’s response time requirements justify occupying a fully reserved CBR channel. ATM Terminals and Services ATM is a cell-based. mapping the incoming VPI/ VCI to the associated outgoing VPI/VCI address. and circuit emulation. It is asynchronous because the cells carrying user data are not required to be periodic. distributed file services. and computer process swapping/paging. audio/video distribution (such as television. with complete transparency to the applications. supercomputer applications.320 on audiovisual terminal and system). Examples may include text/data/image transfer. Examples include LAN interconnection/internetworking services. The H. H. H. and audiovisual terminals and systems (12). Any non-time-critical application running over an end system capable of varying its emission rate can exploit ABR service. when available on widespread computing platforms. These services can take advantage of any spare bandwidth (10). communication procedure and protocol.262. Real-time VBR can be used by native ATM voice with bandwidth compression and silence suppression.320 specifies technical requirements for narrowband visual telephone systems and terminal equipment. LAN. such as background file transfers with minimal service requirements.1. and delivering them to the appropriate device or port. Recommendation H.. payper-view). video-on-demand. This Recommendation represents the relationship with other relevant H-series recommendations. messaging..729. It may also be appropriate for multimedia communications. Recommendation H. telephony). and interworking requirements.

the subworking group Voice and Telephony over ATM (VTOA) has started a draft implementation agreement for VTOA at the desktop that can trigger some other activities.245 are also used by Recommendation H.245.438 TELECOMMUNICATION TERMINALS naling capabilities. including videotelephony.323 terminals communicate may be a single segment or ring. H. Recommendation H.732.723. data.324 capability can be used in different videophones.245 control. H.324 is a new standard adopted by ITU that provides a foundation for interoperability and high-quality video.320 systems.723 audio codecs. Since the procedures of H. the ability to use a specified common mode of operation is required. contrary to H. including videotelephony. Other recommendations in the H.223 multiplex.324 is interoperable with other terminals.320 terminals on N-ISDN. G. This Recommendation also defines the criteria for classification of the ATM equipment types (13). It transcodes the H. data.323 terminals may be integrated into personal computers or implemented in stand-alone devices such as videotelephones. G. service providers.728.722. Multimedia Terminals over POTS H. The H. or any combination. Today’s membership comprises network equipment providers.242 to H.323 Terminal.1 audio codec.261 and H. H. Support for voice is mandatory. The Forum is not a standards body. so transmissions are limited to what receivers can decode. and data to be shared simultaneously over high-speed modem connections utilizing V. or TV-based video phone.320 terminal is by using an interworking adapter that is located at the interface between ISDN and GSTN signals. and a liquid crystal display (LCD).321. and V. Multimedia Terminals over LANs H.263 video codecs. The ITU-T standard body fully recognizes the ATM Forum as a credible working group. Recommendation H. most recently.0 packet and synchronization. and data-based phone calls. interworking with these systems should not require H.263 video codec. and plane management functions. H. One way to achieve interoperability with an ISDN H.323 terminals over multiple LAN segments (including the Internet) may result in variable performance. equipment. in which the content of each logical channel is described when the channel is opened. G.200/AV. and the T. H. while data and video are optional.731 Recommendation provides an overview description of the ATM NE functional blocks in terms of the user plane.324 for GSTN.223 and H. The I.310 terminals on B-ISDN.324 terminals may carry real-time voice.221 multi- . and video.711. Supporting an ATM application programming interface in Winsocket 2 is an important issue that facilitates the use of nonexpensive personal computers as ATM terminals.323 terminals and equipment may carry real-time voice. such as a standalone video phone. This terminal. H. The LAN over which H.731.322 Terminal. each of which is configured and managed to provide a guaranteed (QoS) equivalent to that of N-ISDN such that no additional protection or recovery mechanisms beyond those mandated by Recommendation H.321 terminals on B-ISDN. in those situations where the transmission path includes one or more LAN. such as explicit call transfer service within the ATM Forum.323.324 standard to use videophone by installing compression/decompression software or using some hardware with digital signal processing capability to compress/ decompress audio and video signals. or it may be multiple segments with complex topologies. voice.15). ITU-T Recommendation H.324 is the first standard to specify interoperability over a single analog line.323 terminals may be used in multipoint configurations and may interwork with H.120 series of multimedia communications protocols.320 need be provided in the terminals (16). and services for multimedia communication over LANs that do not provide a guaranteed quality of service. H.323 makes use of the logical channel signaling procedures of Recommendation H.323 describes terminals. H.324 terminals on GSTN and wireless networks.70. and so that receivers may request a particular desired mode from transmitters. G. carriers and. Since voice communication is very important in ATM and B-ISDN environments. H. or any combination. H.324 standard specifies a common method for video.225. PC-based video phones can also use the H.320 multimedia telephone terminals over the ISDN. H. which describes the general functional architecture and characteristics of ATM network elements (NE) in terms of specific functional blocks derived from the B-ISDN protocol reference model (PRM) described in Recommendation I.34 operating over GSTN. in which the TV will be used for displaying a videophone image.322 covers the technical requirements for narrowband visual telephone services defined in H. and G. These specifications are then passed up to ITU-T (formerly the CCITT) for approval. so that all terminals supporting that media type can interwork.120-series recommendations. H. H. Other recommendations in the H. including speech-only terminals and H. which has a telephone. guarantees quality of service over LANs. H. The major activity for formal ATM standardization is done by ITU-T by investigating proposals from other organizations such as ATM Forum. semiconductor manufacturers. Procedures are provided for expression of receiver and transmitter capabilities. a camera mounted on top. The ATM Forum was started in October of 1991 by a consortium of four computer and telecommunication vendors.310 for ATM networks. and G.323 allows more than one channel of each type to be in use.70 terminals on GSTN (14. H. and V. A more detailed description of the individual functional elements is given in the companion Recommendation I. voice.245 translation as would be the case for H. with references to the appropriate recommendations that describe these interfaces in detail. The ATM Forum is a consortium of companies that writes specifications to accelerate the definition of ATM technology.324 series include the H. end users.245 control. The main ITU-T recommendation for ATM is Recommendation I.322 terminals on guaranteed quality of service LANs. It should be noted that operation of H. H. The physical interfaces required for interoperability between the ATM NEs are defined.729.324 Terminal. but if supported. and video. H. H. layer management. The intent of this Recommendation is to enable interoperability between ATM equipment based on the specific requirements described for the functional blocks. H.323 series include H.

and the content of control.8 kbps and is modulated using Gaussian minimum shift keying (GMSK) onto the 200 kHz carrier frequency. in terms of bandwidth and cost. and personal digital assistants (PDA) now provide pocketsized computing. and data logical channels between the H. which includes adaptation to varying quality of service.18). radio transmission limitations. and . do not allow the standard ISDN B-channel bit rate of 64 kbps to be practically achieved. movement between different geographical locations. Speech in a GSM terminal is digitally coded at a rate of 13 kbps. which attempts to minimize the radio transmission power of the terminals and thus minimize the amount of co-channel interference generated.577 ms for a total bit rate of 270.25 bits and contains two 57bit blocks and a 26-bit training sequence used for equalization.324) terminals on the ISDN. Using the ITU-T definitions. These 456 bits are divided into eight 57-bit blocks. These include discontinuous transmission.221 multiplex. current wide area wireless networks cannot deliver the bandwidth necessary to adequately support full multimedia applications. Data-oriented networks often use a variety of random access methods. data.320 terminals via interworking adapters. The gross bit rate after channel coding is 22. The second way to provide interoperability between H. One of the most important Phase 2 additions will be the introduction of a half-rate speech codec operating at around 7 kbps. The traditional analog cellular systems. This is quite efficient compared with the standard ISDN rate of 64 kbps.324 GSTN signals by the use of a ‘‘virtual modem. A common multiple access method employed in digital cellular systems is the time division multiple access (TDMA). Voice-Oriented Terminals GSM Terminals. The IS-95 is the North American standard for the CDMA technology.TELECOMMUNICATION TERMINALS 439 plexes. teleservices. Mobile terminals have varying capabilities. increase the mobile’s battery life. and discontinuous reception when monitoring the paging channel. at rates up to 9600 bps. in which channels are identified by specific codes. Forward error control and equalization contribute to the robustness of GSM radio signals against interference and multipath fading. Another feature used by GSM is power control. However. When this mode is in use. so-called full-rate speech coding. Much of this information makes use of video and audio in addition to text and graphics. In the rest of this section we first describe terminals connected to the voice-oriented digital cellular and PCS services and then we go over the terminals connected to data-oriented wireless networks.263 BCH error correction and error correction framing as appropriate for each terminal type. This terminal sends H. H.320 video bit rate in use by the H. packet switched public data networks (PSPDN). out of the radio spectrum. and supplementary services. WIRELESS AND MOBILE TERMINALS.324 and H. interworking adapters shall insert and remove H. A burst is transmitted in 0. GSM users can send and receive data.711 audio bitstream over the ISDN (17.261 and H.324 is by using dual-mode (H. usually expressed in a number of kilohertz (kHz).320 protocols. The growth in mobile communications and portable computing enables multimedia information services on mobile networks.324 and H. Each time slot burst is 156. audio.34 analog signal encoded as a G. ISDN compatibility was one of the goals in designing GSM in terms of the services offered and the control signaling used. and improve spectrum efficiency. The latest technology for the voice-oriented networks is the code division multiple access (CDMA). A variety of data services is offered. and multimedia communications and then we cover evolving broadband wireless terminals. reconfigurable real-time multiparty connections. GSM. such as dynamic slotted-ALOHA and digital sense multiple access (DSMA).324 video streams can be matched to the H. frequency hopping. AND STANDARDS On fixed networks the widespread use and popularity of the World Wide Web (WWW) has dramatically increased the volume. As with all other communications.320 and H. SERVICES.261 video codec in the quarter common intermediate format (QCIF) picture format so that the additional delay of video transcoding can be avoided. roaming between different operators and network types. where the nearest emergency-service provider is notified by dialing three digits (similar to 911). and the result is interleaved among eight successive time slot bursts for protection against bursty transmission errors. ISDN.’’ which generates and receives a V.324 terminals that support video shall support the H. effectively doubling the capacity of a network. Portable computers are becoming powerful.324 terminals shall respond to the H. To ease communication between H. use frequency division multiple access (FDMA). FDMA channels are defined by a range of radio frequencies. H. The mobile environment imposes a number of challenges that impair the robustness of client/server operation. and personal digital cellular (PDC). In this section we first introduce the traditional wireless terminals used for voice.245 flow control command. However. to users on POTS. The most basic teleservice supported by a GSM terminal is telephony. The digital TDMA nature of the signal allows several processes intended to improve transmission quality. and personalized information filtering. telecommunication services can be divided into bearer services. Traditional Wireless Terminals Different types of cellular systems employ a variety of multiple access methods.320 and H. speech is digitally encoded and transmitted by the GSM terminal as a digital stream. There is also an emergency service.8 kbps (or 456 bits every 20 ms). ranging from a global system for mobile communications (GSM) phone or personal communicator to PDAs with small screens to fully multimedia capable laptops. richness. such as those based on the advanced mobile phone service (AMPS) and total access communications system (TACS) standards. TDMA digital standards include North American Digital Cel- lular (known by its standard number IS-54). The 26bit training sequence is of a known pattern that is compared with the received pattern in the hope of being able to reconstruct the rest of the original signal. so that transmitted H. and availability of information. We complete this section by addressing multimedia wireless terminals. This 13 kbps digital stream (260 bits every 20 ms) has forward error correction added by a convolutional encoder. robustness in the face of disconnected links.

although an audio modem is required inside the GSM network to interwork with POTS. A unique feature of GSM terminal. which allows 32K data transmission and which means that the PHS terminal could be used like a modem. batteries should last longer than the equivalent GSM version of the terminal. not found in older analog systems. PHS (personal handyphone system) was developed in Japan in mid-1995. Logging onto a base station is the terminal responsibility for receiving the call. each terminal is assigned a pseudonoise (PN) code to modulate transmitted data. and some will display the message ‘‘STOLEN HANDSET. and call barring of outgoing or incoming calls (for example. a message can be sent to another subscriber to the service. It also has a better multimedia performance since 32 kbit/s bearers can be concatenated. If a terminal is stolen. It is also used internally within the networks for transfer of call logging information from the switches to the billing centers. The PN code is a long sequence of ones and zeros similar to the output of a random number generator of a computer. In CDMA. In the current (Phase 1) specifications. This terminal is similar to GSM terminal with similar services. there are 224 user data bits per 20 m frame. such as X. if users go overseas. Messages are transported in a store-and-forward fashion. DECT uses TDD to support a two-way conversation on the same carrier. CT2 Terminal. they include several forms of call forward (such as call forwarding when the mobile terminal is unreachable by the network). The DCS1900 terminal is one of the many standards proposed for digital mobile phones in the United States. The Japanese Digital Cellular (JDC) terminal uses a digital protocol unique to Japan that operates in two different frequency bands. CT2 has the ability to hand over to adjacent base stations. some terminals will then continue to broadcast their location. The 900 MHz GSM band and the 1800 MHz DCS1800 band are not available in the United States. The subscriber information. By inserting the SIM card in any GSM mobile equipment. personal mobility is provided to GSM users. The channel bit rate is 42 kbit/s. DECT (Digital European Cordless Telecommunications) is a standard for cordless phones. CT2 is the first standard for digital cordless phones. For point-to-point SMS. implemented as a smart card. The channel bit rate is 72 kbit/s. Theoretically. DCS1900 Terminal. such as caller identification. In the DECT terminal there are more radio frequency (RF) channels (10 RF carriers ϫ 12 duplex bearers per carrier ϭ 120 duplex voice channels). the PHS terminal now supports a protocol called PHS internet access forum standard (PIAFS). the user is able to make and receive calls at that terminal and receive other subscribed services. like a text message pager. The protocol is the same as DCS1800. and multiparty conversations. Also due to the reduced power levels. and an acknowledgment of receipt is provided to the sender.25 or X.’’ which cannot be removed without the operator unblocking the terminal. and a calling directory. The PHS terminal offers similar service to CT2. when roaming in another country). the provider can block the terminal and the SIM card.32. In the full rate system. such as activating a phone for the first time. Changing to an- other base station requires re-registration. which is anonymous. There is no hand-over between base stations. but delivery is guaranteed (when the phone is unavailable due to being out of service area. which is supported by use of an appropriate fax adapter. SMS is a bidirectional service for short alphanumeric (up to 160 bytes) messages. However. in an office situation. By decoupling subscriber information from a specific terminal. Other data services include Group 3 facsimile. SMS is also used for ‘‘internal’’ messages. unless the base stations themselves cooperates. the network will hold the message and deliver it shortly after the phone comes back into range). (1800 MHz). SIM roaming is possible. as described in ITU-T Recommendation T. is the support for short message service (SMS). a modem is not required between the GSM terminal and GSM network. PHS Terminal. 800/900 MHz and 1. PCN uses SIM cards to identify the customer. The CT2 terminal uses the 864 MHz to 869 MHz band and provides 40 channels that are 100 kHz apart. PCN and GSM both have the ability in their protocols for customers to receive text messages. PCN is also known as DCS1800. for sending messages such as traffic updates or news updates. These are smart cards that hold the user’s phone number. there is a larger frequency range to work with and lower power. and alerting the user of voicemail. or GSM. CDMA Terminals. Since GSM is a digital network. subscription details. The access method is FDMA. Many additional supplementary services will be provided in the Phase 2 specifications. In the first phase of JDC implementation there are three TDMA user channels per frame.2 kbit/s comprising coded voice bits and error-protection coding. for a transmitted bit rate of 11. Similar to GSM. call waiting. they could insert their SIM card and take their phone number with them. DECT Terminal. by using a specific algorithm . therefore.5 GHz. JDC Terminal.30. Supplementary services are provided on top of teleservices or bearer services. In Japan. a CT2 PBX can be used to support many CT2 phones. ETSI undertook the task of developing standards for CT2. is stored in the subscriber identity module (SIM). The European Telecommunications Standards Institute (ETSI) is the organization responsible for the GSM standards (19). and in future implementations there will be six per frame. The message can be sent by a central paging service. and each carrier supports one cell with time division duplex (TDD) for two-way conversation. If the call is unsuccessful. The DECT terminal is intended to be a far more flexible than the CT2 terminal. Although the numbers are not really random. CDMA is a spread spectrum technique for multiple access. Messages can also be stored in the SIM card for later retrieval. remote programming of numbers into the directory on the SIM card. The PCN terminal uses the GSM protocols in higher frequencies. The mobile terminal in GSM is really two distinct entities. the call is routed onto voicemail. The actual hardware is the mobile equipment. SMS can also be used in a cell-broadcast mode. ETSI is the organization responsible for the GSM standards.440 TELECOMMUNICATION TERMINALS circuit switched public data networks (CSPDN) using a variety of access methods and protocols. which includes a unique identifier called the international mobile subscriber identity (IMSI). and the range of terminal is very limited. PCN/DCS1800 Terminal. In SIM roaming. even though GSM and PCN phones have different technologies.

the actual data rate is approximately 9. a ‘‘collision’’ occurs and all users involved try to transmit again a short time later. or ‘‘hops’’ to another available channel and continues its sessions. The laptop portable terminals access the network using data sense multiple access (DSMA). control of mobile terminal power is a critical element of the system design (19). (Because of overhead. data. Forward-error correction as well as retransmission are used to ensure the bit-error-rate quality of delivered data packets. with 1 to 3 seconds delay. which provides roaming for the mobile terminal. Convenient. and imagery traffic in telecommunication networks. However highly portable terminals provide low-quality displays since they have limited space. In addition. with the capabilities of a multimedia terminal. the U. The ARDIS terminal is a laptop radio terminal that uses the 800 MHz band with separate transmit and receive frequencies. The CDPD terminal consists of a personal communications device. Rather.5 kHz channels. Data-Oriented Terminals ARDIS Terminal. Each channel on a CDPD network can be accessed by up to 30 CDPD terminals at a time. CDMA appears increasingly attractive as the wireless access method of choice. which consists of a laptop computer with a cellular modem transmitting data over the existing cellular telephone network.TELECOMMUNICATION TERMINALS 441 they appear to be random. In March 1992. while providing color video and audio output and pen and microphone inputs (20). it automatically reregisters with new base station and the terminal’s location information is relayed to a higher level. certain channels are set aside solely for use by the CDPD network. used for downloading files or checking e-mail. When the terminal enters an adjacent service area. number of sectors in each base station antenna. this is not a fixed number. The terminals take turns transmitting on the channel stream. which usually require a backlight to give sufficient contrast (this light dominates the power consumption of most portable terminals). and Canadian networks are used to provide data service only. The Advanced Radio Data Information Service is a two-way radio service that was first implemented by IBM and Motorola. Because the codes are nearly random. there is very little correlation between a specific code and any time shift of that same code. with the charter of developing a spread spectrum digital cellular standard.2 kbps.S. For cellular telephony. they are dropped. CDPD Terminal. The CDPD terminal then moves. In July of 1993. The packet size is 512 bytes. The access method is dynamic slotted-ALOHA. Thus the electronic viewing device should have the convenience of paper.6 kbps. CDPD uses the same transmission channels as the cellular telephone network for short transmissions of small data packets. When the busy-bit is off. the capacity of the system will be dependent on a number of different factors. The CDPD terminal vacates the channel within 40 ms of detecting voice activity to transfer the channel to the cellular voice user. If there is no channel available to the CDPD terminals. The transmission rate is 8000 bit/s half duplex in 12.25 MHz) wide. IS-95 systems divide the radio spectrum into carriers that are 1250 kHz (1. A cellular phone call has preemptive priority over any CDPD call. the TIA established the TR-45. the CDPD terminal packetizes the data and also encrypts them for security (19). such as credit card verification. In a dedicated channel network. the Mobitex terminal finds the base station with the strongest signal and registers with the base station. Since . The radiated power from terminal is 4 W.) Before transmitting the data. there is very little correlation between the different codes. or it may serve a specialized purpose. including bandwidth efficiency. the voice activity factor that determines what percentage of time voice is active. The terminal uses dynamic power setting in the range of 100 mW to 10 W for mobile terminals and 100 mW to 4 W for portable terminals. or a point-of-sale terminal. The user data rate is 8000 bit/s. This implies that the portable device should weigh less than a pound and a form factor that allows convenient observation (such as a full size 8 ϫ 11 inch notepad) with a long battery life. Thus. all the channels are shared by CDPD and the cellular telephone network. CDMA is a digital multiple access technique specified by the Telecommunications Industry Association (TIA) as IS-95. Multimedia Terminals Portable Wireless Multimedia Terminal. In a channel hopping network. chances are two or more terminals transmit simultaneously. The CDPD terminal both sends data to the network and receives data from the network at a rate of 19. which is suitable for file transfer up to 20 kbytes. The Mobitex system is a nationwide. If more than one terminal tries to send data at the same time. Because in a CDMA system every terminal is a source of interference to every other CDMA terminal. There continues to be rapid progress in the area of LCD displays. When the busy-bit is off. and the interference increase factor (19). the TIA gave its approval of the CDMA IS-95 standard. which results in collision and retransmission is required. The service is suitable for two-way data transfer of size less than 10 kbytes. interconnected trunked radio network developed by Ericsson and Swedish Telecom. is inconvenient because of the usual fixed desktop placement of the screen. the distinct codes can be transmitted over the same time and the same frequencies and the signals can be decoded at the receiver terminal by correlating the received signal (which is the sum of all transmitted signals) with each PN code. One of the unique aspects of CDMA is that while there are certainly limits to the number of phone calls that can be handled by a carrier. the terminal can transmit.5 subcommittee. in which a remote terminal listens to the base station transmitter to determine if a busybit is on or off. ubiquitous access to the network requires a portable input/output (I/O) device. resolution. The Mobitex terminal transmits at 896 MHz to 901 MHz and receives at 935 MHz to 940 MHz. commonly referred to as AMPS (advanced mobile phone system). and power available for display. With growing interest in the integration of voice. CDPD stands for cellular digital packet data. There are two types of CDPD networks: dedicated channel and channel hopping. such as a laptop computer connected to a cellular data modem. The CDPD terminal may operate as a normal computer. To access the network. Mobitex Terminal. Reading large amounts of text on a computer screen. instead of paper. While the Mobitex system was designed to carry both voice and data service. For these reasons the user interface of a portable terminal needs to be designed for monochrome presentations in a very small screen area.

which makes portable terminals heavier and slower. which will have a number of programmable AAL interfaces capable of supporting ATM applications over different wireless and wireline physical layers and allow universal roaming. implicitly. and. and filters. Filters provide user-level access to the raw network at the device driver level. and specify and implement medium access. The computation re- maining in the mobile terminal is implemented with the lowest possible power consumption by design of a custom chip set (for more information see Refs. The most demanding function is the decompression and associated frame buffering of the video data. Another challenge in designing wireless multimedia terminals is decreasing the delay time for accessing information on the network. They tend to be fast and can be based on a model other than the stack. Usually several PIM application icons reside within the display. The primary challenge of reducing the weight of the terminal is the power consumption of the circuitry to convert the data from the downlink data stream to the form required by the video and graphics displays and audio output. Also. a stylus. Broadband Wireless Terminals Wireless ATM. and several combining techniques from the reception of multiple antenna systems (23). capable of coping with the increased latency and poor reliability of wireless links. Terminal mobility is supported using both wireless terminal features and B-ISDN signaling for end-to-end connections between a mobile and a fixed ATM terminal (24. system for advanced mobile broadband applications (SAMBA). A PDA is a terminal that consists of a backlit LCD. The PDA usually is used by field engineers to access information remotely. The project will support limited. and wireless ATM network demonstrator (WAND) are important. This results in a design in which there is no user-accessible computation in the portable terminal. In the long term. and network contention.442 TELECOMMUNICATION TERMINALS portable terminals lack the space for keyboards. and radio resource management for a cellular system. among which are Advanced Communications Technologies and Services’ (ACTS) ATM wireless access communication system (AWACS).245 flow control command. If the delay between two consecutive displays on the monitor is performed in under 30 ms. The portable wireless multimedia terminals require high performance at low energy. Thus a latency specification of less than 30 ms appears to be adequate and should be considered as a design parameter. Standard PIM applications are an expense tracker and an e-mail application. experience with echoes in long-distance phone connections shows that delays under 30 ms are also not objectionable to the user. therefore. Thus the lightweight protocols and specialized filters can be useful in designing portable terminals to lower the weight and to increase speed. They attempt to minimize processing. they require high processing power. design and realize transparent ATM connections via radio transmission for mobile applications. 21 and 22). and gateway. PDA.25). To enter data. it will not be detected by the human eye since this is the update rate of the display. Wireless operation is for further study. base station. such as Xerox remote procedure call (RPC). there is no need to send error-free computer data over the wireless link. and flow control overhead. on the other hand. Filters are not strictly protocol implementations. Heavyweight protocols make guarantees such as in-order delivery and reliability and provide multiplexing/demultiplexing as a standard feature. Latency control is the most important factor in those applications in which there is a tight interactive loop between the user input and the display output. by not incorporating user-accessible generalpurpose processing in the portable unit. icon-based interfaces and pen-based input have been considered as an alternative. There are some activities in the European Community (EC) for implementing and demonstrating wireless ATM. Similarly. requiring some form of error correction capability in the wireless protocols. and its subsequent conversion to analog signals to drive the display. Multimedia Telephone Terminals over Mobile Radio. It is expected that multimedia telephone terminals will also be used on mobile radio networks. This includes all the processing and delays in the portable unit. handover. the network protocols can be divided into three classes: heavyweight. a high-speed general-purpose processor subsystem. which not only relieves the portable unit of the requirement to support a general-purpose operating systems such as Windows NT or Unix. diversity at the receiver and transmitter. connection. Another factor in wireless portable multimedia terminal is the antenna system for transmission of information at increasingly higher bit rates per hertz. Transferring data through a serial connection from the PDA is also possible. but with improved portability. AWACS will operate in the 19 GHz band with user bit rates up to 34 Mbit/s and radio transmission ranges between 50 m and 100 m. slow-speed mobility in line with expected use of high data services. Lightweight protocols. The key objectives for SAMBA are to demonstrate mobile applications of bit rates up to 34 Mbit/ s. which requires practical methods like adaptive equalization. costly memory. Thus the focus will be on highly integrated complementary metal on semiconductor (CMOS) implementations that have the lowest possible energy consumption while using advanced communication algorithms. and a wireless connectivity device. and the delays in the Internet. The key element in the wireless ATM terminal is represented by a wireless ATM adaptation layer (AAL). a few navigational keys. One solution for this problem is to move as much of the processing as possible out of the portable unit into servers on the network. The ATM Forum Wireless ATM Working Group is standardizing mobility support within an ATM network and a radio access layer for ATM-based wireless access. From the networking point of view. lightweight. The Magic WAND project covers the whole range of functionality from basic (wireless) data . often do not provide strong guarantees and can be specialized. this results in very inefficient transfer when the error rates are 10Ϫ3 or higher. As mentioned. either the on-screen keyboard or the on-screen graphics-based writing pad can be used. they are mechanisms for extracting data from a network. this development will offer the technological base for a seamless multimedia multimode personal communication system. the latter responds to a form of shorthand and comes with a stick-on guide for easy reference. Rate matching between wireless terminals and GSTN terminals can be achieved by the use of the H. which must be performed in real time. but also eliminates the need for expensive and power-hungry mass storage devices.

capable of providing real multimedia services to mobile users. National Telecommunications and Information Administration. 2. such as navigation. mobile data. the office. 1979. and in the public environment. At present it is considered that Recommendation E. vehicle location. multiple users can simultaneously communicate using their ID numbers at FPLMTS mobile terminals. Report 84-170. Thus. in the home. ‘‘Identification Plan for Land Mobile Stations. UMTS related activities are lead by research conducted within the UMTS Forum program and standardization activities within the ETSI. The FPLMTS/IMT2000 terminals have high transmission speeds (below 2 Mbps and capable of transmitting simple moving pictures). December 1984. enabling standard terminal equipment to be connected to FPLMTS mobile terminals (19. In FPMTLS multiple calls can be connected at the terminal. is technically feasible. The project partners have chosen to use the 5 GHz frequency band for the demonstrator and perform studies on higher bit rate operation (Ͼ50 Mb/s) in the 17 GHz frequency band. National Policy on Standards for the United States. and to audio and visual communications. National Standards Policy Advisory Committee. They are considered by ITU-T and will follow their second-generation counterparts such as digital cellular phones. a wireless telecommunication system used in Japan Research into Advanced Communication in Europe Specific General Packet Radio Service Node Total Access Communication System Time Division Multiple Access UMTS Mobility Server Universal Mobile Telecommunications System World Administrative Radio Conference Wideband Code Division Multiple Access BIBLIOGRAPHY 1. which will become increasingly important in a pan-European market. For terminal mobility and FPLMTS user mobility. while the UPT can be enjoyed across several telecommunication platforms. UMTS is a third-generation mobile communication system currently being developed in Europe. to voice telephony (probably the prime requirement of the personal terminal). In addition.TELECOMMUNICATION TERMINALS 443 transmission to shared multimedia applications. FPLMTS mobility is available only within FPLMTS. telepoint. . and paging.28). Cerni.26). to digital data services.’’ can be applied to IUMI. but it is too early to say whether this goal will eventually be achieved (27. UPT is a telecommunication service that enables users to access various services through personal mobility on any fixed or mobile terminal. UMTS Terminal. FPLMTS/IMT2000 are thirdgeneration mobile communications systems. FPLMTS provides user identity module (UIM) portability. a selection of data services. The user of the personal terminal will be able to take it anywhere world wide and have access to at least a minimum set of services comprising voice telephony. which enables an FPLMTS user identity to be physically separate from the FPLMTS terminal. both in rural areas and city centers. These terminals are available in different sizes. FPLMTS cover the application areas presently provided by separate systems such as cellular. D. a standardized international mobile user identity (IMUI) is required. cordless. The primary goal of the project is to demonstrate that wireless access to ATM. The actual services obtained by a user depend on the user’s terminal capabilities and subscribed set of services and the service set provided by the relevant network operator. ABBREVIATIONS ACTS AMPS ATM B-ISDN CDMA DAMPS DCS-1800 DECT EC ETSI EU FPLMTS GSM IMT2000 IN IP IS-95 ISDN ITU JDC LAN MAC NMT PACS PCS-1900 PDC PDN PHS RACE SGSN TACS TDMA UMS UMTS WARC W-CDMA Advanced Communications Technologies and Services Advanced Mobile Phone System Asynchronous Transfer Mode Broadband Integrated Services Digital Network Code Division Multiple Access Digital Advanced Mobile Phone System Digital Cellular System 1800 Digital European Cordless Telephone European Community European Telecommunications Standards Institute European Union Future Public Land Mobile Telecommunication System Global System for Mobile Communications International Mobile Telecommunications 2000 Intelligent Network Internet Protocol Interim Standard-95 Integrated Services Digital Network International Telecommunication Union Japanese Digital Cellular Standard Local Area Network Medium Access Control Nordic Mobile Telephone Personal Analog Cellular System Personal Cellular System Personal Digital Cellular Packet Data Network Personal Handy Phone System. access to universal personal telecommunications (UPT). UMTS terminals also can be used anywhere. In FPLMTS an identical procedure between mobile terminals and networks is applied to both UPT and FPLMTS mobility. and an indication of other services available. from mobile terminals such as a low-cost pocket telephone (to be used by almost anyone anywhere) to sophisticated terminals that provide advanced video and data services. and road traffic information services. FPLMTS/IMT2000 terminals provide services ranging from basic wide area paging. FPLMTS provide standard terminal portability. FPLMTS/IMT2000 Terminals.212. In this project mobile terminals based on the portable computers in combination with wireless access points (AP) will be used. and high quality in the mixed networks. Standards in Process: Foundations and Profiles of ISDN and OSI Studies. UMTS terminals should support existing mobile services and fixed telecommunications services up to 2 Mbit/s and unique mobile services. It is expected that UMTS and IMT-2000 will be compatible so as to provide global roaming. service accessibility from anywhere in the world.

Recommendation ITU-R M. Pahlavan and A. October 1996.25: Interface between Data Terminal Equipment (DTE) and Data Circuit-terminating Equipment (DCE) for Terminals Operating in the Packet Mode and Connected to Public Data Networks by Dedicated Circuits. IEEE Commun. W. 1996. Prentice Hall. Mag. 1996. 8. 7. Pedram. 25. Correia and R.819-2: International Mobile Telecommunications (IMT-2000). ALI ZAHEDI KAVEH PAHLAVAN Worcester Polytechnic Institute . Stanford. 1995.. and P. 9. T. G.. 1995.35: Handset Telephones. June 1996. 26.4: Standardization of Group 3 Facsimile Terminals.731: Types and General Characteristics of ATM Equipment.). Dasilva et al. Wireless Information Networks. July 1996. 461–470. ITU-T Recommendation F.323: Visual Telephone Systems and Equipment for Local Area Networks Which Provide a Non-Guaranteed Quality of Service. Stallings.322: Visual Telephone Systems and Terminal Equipment for Local Area Networks Which Provide a Guaranteed Quality of Service. L. 10. Broadband wireless access. D. Low Power Design Methodologies.323: The multimedia communications standard for local area networks.100: International Information Exchange for Interactive Videotex.324: Terminal for Low Bit Rate Multimedia Communication. European third-generation mobile systems. S. 13. M. 28. Mag. IEEE Commun. IEEE Commun. Proceedings of the IEEE VLSI Signal Processing Workshop. Recommendation ITU-T H. 16. Landman. 14. 18. Recommendation ITU-T I. December 1996. Low power design methodologies—Introduction. 3rd ed. Narayanaswamy et al.. Magedanz. Lendberg. Rabaey. A. J. Recommendation ITU-T H. 11. 15. Recommendation ITU-T T. K. IEEE Commun. ISDN and Broadband ISDN with Frame Relay and ATM.. 4. Recommendation ITU-T T. 24. Recommendation ITU-T H. pp. 12. December 1996. The H. Rabaey and M. A. Mag. September 1996.60: Terminal Equipment for Use in the Teletex Service. W. 27. An overview of wireless broadband communications. Mag. Levesque. Mag. in J. Ulra-low-power domain-specific multimedia processors.320: Narrow-Band Visual Telephone Systems and Terminal Equipment. Thom. Mag. Honcharenko et al. Stanford University. lightweight unit to provide ubiquitous information access application and network support for InfoPad. Narrowband ISDN and broadband ISDN service and network interworking.444 TELECOMMUNICATION TRAFFIC 3. H. A.563: Terminal Characteristics for Group 4 Facsimile Apparatus. Recommendation ITU-T T. Recommendation ITU-T X.. J. IEEE Commun. A low-power. 17. January 1997. Boston: Kluwer Academic. Prasad.324 multimedia communication standard.. April 1996. H. New York: Wiley. 22.. Third Workshop on Smart Antennas in Wireless Mobile Communications. Paulraj. 6. Recommendation ITU-T P. Schwetje. B. IEEE Pers. CA.. Abnous and J. S. San Francisco. 23... IEEE Commun. IEEE Commun.. Pedram (eds. 20. 19. Center for Telecommunication and Information Systems Laboratory. Rabaey.301: Fast Speed PSTN Videotex. Mag. January 1997. Integration and evolution of existing mobile telecommunications systems toward UMTS.. Commun. Recommendation ITU-T H. 21. M. Petri and D. Mag. 5. Recommendation ITU-T T.

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