STF2000_Product_Description.pdf

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Speech Transcoding Frame-2000 (STF-2000)

ii Lucent Technologies – ProprietarySee Notice on first a e

Issue 5.0Date: Nov 2000

Copyright © 2000 by Lucent Technologies. All Rights Reserved .

This material is protected by the copyright and trade secret laws of the United States and other countries. It maynot be reproduced, distributed, or altered in any fashion by any entity (either internal or external to LucentTechnologies), except in accordance with applicable agreements, contracts or licensing, without the expresswritten consent of the Information Products Group organisation and the business management owner of thematerial.

Notice

Every effort was made to ensure that the information in this document was complete and accurate at the time of printing. Information, however, is subject to change.

Support Telephone Number

Lucent Technologies provides a telephone number for you to report errors or ask questions about the informationin this document. The support telephone/facsimile numbers are:

Telephone: +44 (0)1793 883333

Facsimile: +44 (0)1793 883232

Issue Date Reason for Change5.0 November 2000 Initial Issue

Issue History


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Lucent Technologies – ProprietarySee Notice on first page

iii

Contents

1 OVERVIEW 1-1Introduction 1-1

2 KEY BENEFITS 2-1

Introduction 2-1Transcoding 2-1High Capacity 2-1Cost Effective Scaling 2-1

3 PRODUCT FAMILY 3-1

Introduction 3-1Product Relationships 3-2Product Evolution 3-2

Increased Capacity 3-2Wider Codec Range 3-2Benefits of Transcoder Pooling 3-2

ARCHITECTURE OVERVIEW 4-1

Hardware 4-1DFU 4-1STU 4-1TCU 4-1

STF-2000 Buses 4-4Software 4-5

PRODUCT FUNCTIONALIT Y 5-1

Speech Transcoding 5-1Data Rate Adaptation 5-1Functionality 5-2

6 CAPACITY AND CONFIGURATION 6-1

RELIABILITY AND AVAILABILITY 7-1


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Contents Speech Transcoding Frame-2000 (STF-2000)

iv Lucent Technologies – ProprietarySee Notice on first page


8 ENVIRONMENTAL CHARACTERISTICS 8-1

Overview 8-1Physical Data 8-1Environmental Data 8-2Power Requirements 8-2

Service Voltage Ranges 8-2Safety Extra Low Voltage (SELV) 8-2Power Consumption 8-3

EMC 8-3

ACRONYMS 9-1


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1-1

1 Overview

Introduction

Global System for Mobile Communication (GSM) is the leading digital mobile telephone standard in the world.Lucent Technologies’ GSM 900, GSM 1800 and GSM 1900 cellular systems are the fundamental cornerstones ofthe company’s overall and wireless corporate strategies.

The Speech Transcoding Frame-2000 (STF-2000), illustrated in Figure 1, is a key component of these cellularsystems, providing highly reliable and cost effective speech transcoding, data rate adaptation and sub-multiplexingfunctions.

Figure 1. STF-2000


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Overview Speech Transcoding Frame-2000 (STF-2000)

1-2 Lucent Technologies – ProprietarySee Notice on first page


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2-1

2 Key Benefits

Introduction

The STF-2000 key benefits include:

• Transcoding function implemented according to the GSM Type 6 configuration

• High capacity

• Cost effective scaling

• Future proofing

• Independent Traffic Service Groups (TSGs)

• High reliability and low spares requirement

• A new connection panel

• STF Maintenance Application-2000 (SMA-2000)

• Fault recovery software

• Alarm reporting

• Compliance with recognised standards

Transcoding

Lucent’s Base Station Controller (BSC) implementation physically separates the STF-2000 transcoding functionfrom the BSC control and switching functions (GSM Type 6 configuration). This allows complete flexibility in

placement of equipment, combined with optimal use of transmission resources.

High Capacity

In a single, compact, ETSI-compliant frame the STF-2000 provides up to 1440 Traffic Channels (TCH) for full-rate, 720 TCH for dual-mode with STU/2.

Cost Effective Scaling

The STF-2000 modular structure provides cost-effective scalability to the optimum size for large and smallsystems. To accommodate traffic growth, capacity can be increased in small increments with additional circuit

packs that can be “hot inserted” and configured without service interruption.


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Key Benefits Speech Transcoding Frame-2000 (STF-2000)



Future-proofA unique, future-proof, pooling architecture allows cost-effective introduction of enhanced full-rate, or other futuretranscoding algorithm such as Adaptive Multi Rate (AMR) into systems with an embedded base of full-ratesubscribers. The architecture facilitates easy expansion, for example, supporting flexible introduction of highercapacity interface cards.

Independent TSGsThe STF-2000 comprises two or three fully independent TSGs. This provides system operators the flexibility toconfigure the TSGs for full-rate or dual-mode operation. The capability to configure individual TSGsindependently provides a high level of flexibility.

High ReliabilityThe STF-2000 utilises the minimum number of components, thereby improving reliability and decreasing spare

parts requirements.

New Connection Panel Pre-configured internal cabling and prefabricated common site material for external cabling can reduce installationtime by up to 50%, and the new connection panel provides simplified deployment.

SMA-2000Installation, configuration , testing and maintenance can be performed with the SMA-2000. This provides agraphical user interface and is implemented on Lucent’s Integrated Maintenance Workstation (IMW-2000) astandard Windows®-based notebook PC. The SMA-2000 supports download to the STF-2000 of default andcustomised configuration options and operating software. It also provides the capability to initiate loopback testsand monitors the health and status of the STF-2000. Each STF-2000 is pre-configured during manufacture to

support rapid deployment.

Fault Recovery SoftwareFault recovery software enables automatic recovery from internally and externally detected faults. Redundancy is

built into critical system components so that standby units can be readily switched into service if a fault occurs inan active unit.

Alarm ReportingThis provides specific equipment failure notification to the OMC-2000 to alert network operators, and speedrestoration procedures.

ComplianceThe STF-2000 complies with GSM technical specifications and meets European and US standards for safety andelectromagnetic compatibility (EMC). It has been awarded European Community (CE) markings, and meets EuropeanTelecommunication Standards Institute (ETSI) and Bell Communications Research (BELLCORE) specifications for

physical and environmental design.


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3-1

3 Product Family

Introduction

The STF-2000 is a key element of Lucent Technologies’ GSM Base Station Sub-System (BSS) product family. Itis a standards -based system, fully compatible with GSM recommendations that may be used in GSM 900,GSM 1800 and GSM 1900 applications.

As specified by GSM recommendations, the STF-2000 works in conjunction with the other elements of the BSSand the MSC, to provide the call processing path for the provision of wireless service. Specifically, the STF-2000interfaces and interworks with the other system elements, as illustrated in Figure 2.

Figure 2. BSS-2000 Example Configuration (three TSGs)

A

M

Base

TransceiverStation(BTS-2000)

Base Station

Controller Frame(BCF-2000)

Mobile Services

Switching Centre(MSC)

5ESS-2000(Switch)

Traffic ServiceGroup 2 (TSG 2)




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Product Family Speech Transcoding Frame-2000 (STF-2000)



Product Relationships

• The 5ESS-2000 Switch provides the cellular interface to the public switched telephone network(PSTN). The interface to the STF-2000, is via the GSM-defined A interface.

• The switching and control element of the Base Station Controller (BSC) is realised by the new Basestation Controller Frame (BCF-2000). The interface to the STF-2000 is via the Lucent-defined ”M”interface (described in the GSM recommendations as the ”A ter ” interface).

• The Base Transceiver Station products (BTS-2000 family and Compact BTS-2000) provide theradio link to the mobile subscribers.

Note: There is a close relationship between the BCF-2000 and the STF-2000. This provides the option of using acombined pool of shared cabinet spares.

Product Evolution

The planned evolution of the STF-2000 has three key goals, which will be introduced via a smooth migration path:

• Increased capacity

• Wider codec range

• Comprehensive transcoder pooling architecture

Increased Capacity

A new transcoder board will pave the way for an STF with higher capacity.

Wider Codec Range

A new transcoder board development will successively replace its first generation equivalent. This will bedesigned to fully exploit the benefits of the dual codec STF-2000. In particular, it will provide enhanced codecapplication capacity (Enhanced Full Rate, Adaptive Multi Rate). Later developments will also provide redesignedinterface boards, which will produce savings in both resources and costs.

Benefits of Transcoder Pooling

Pooling transcoders saves customer resources and hence reduces costs. Even during busy hours, the entire linkcapacity is never actually used in full, nor are all calls (in dual codec networks) of one codec type. Poolingstrategies exploit these factors, rather than supplying simultaneous transcoder capacity for all codecs at thetheoretical maximum.

The STF-2000 offers operators the deployment of transcoding resources based on traffic models, statisticalestimations on the distribution of codec types and acceptable blocking rates.


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4-1

4 Architecture Overview

Hardware

The STF-2000 comprises two (Figure 3) or three (Figure 4) identical and interchangeable Traffic Service Group(TSG) modules.

Each TSG consists of either two or three equipment shelves, comprising three types of unit:

• Digital Facilities Unit (DFU)

• Speech Transcoding Unit (STU)

• TSG Control Units (TCU)

DFU

The DFU provides the physical terminations for both the M and A interfaces. Each DFU is capable of supportingtwo terminations (one M and one A, or two A). Separate DFU models are available to terminate 120-ohm twis ted-

pair cable via impedance converters or 100-ohm twisted-pair DSX-1 interfaces.

STU

The STU performs speech coding, data rate adaptation and subrate multiplexing on the M interface. Each STU cansupport up to 30 full-rate speech/data channels or eight enhanced full-rate (EFR) channels. STUs connect throughDFUs to the relevant M and A interface ports. STU/2 supports up to 32 enhanced full-rate (EFR) channels.

TCU

The TCUs control all functions in a TSG, including the supervision of the installed DFUs and STUs. TCUs operatein pairs to achieve redundancy, where one TCU is active and the other is in standby.


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Architecture Overview Speech Transcoding Frame-2000 (STF-2000)



Shelf 1

Shelf 2

Shelf 2

Shelf 1

Shelf 0

Shelf 0

M0 M1

M0 M1

TSG 0

TSG 1

even-numbered M-Group odd-numbered M-Group

TCU

DFU

DFU

DFU

DFU

DFU

STU

STU

STU

STU

STU

STU

STU

STU

Unu

sed

Unu

sed

A0 A2 A0

M0A1 A3 M1A2

A1 A3

SHELF 0

Transcoder STU Pool

Transcoder STU Pool

Transcoder STU Pool

Transcoder STU Pool

TCU

STU

STU

STU

SHELF 1/2

STU EFR Pool

STU

STU

STU

STU

STU

STU

STU

STU

STU

STU

STU

STU

Figure 3. STF Dual Mode Configuration (2TSG)


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Speech Transcoding Frame-2000 (STF-2000) Architecture Overview



4-3

Shelf 1

Shelf 0

Shelf 1

Shelf 0

Shelf 1

Shelf 0

M0 M1

M2 M3

M0 M1

M2 M3

M0 M1

M2 M3

TSG0

TSG2

even-numbered M-Group odd-numbered M-Group

TCU

DFU

DFU

DFU

DFU

DFU

STU

STU

STU

STU

STU

STU

STU

STU

Unu

sed

Unu

sed

A0 A2 A0

M0A1 A3 M1A2

A1 A3

SHELF

TSG1

Figure 4. STF Full Rate Configuration (3 TSG)

Note: To provide flexible handling of growth in Enhanced Full -Rate (EFR) subscriber numbers, a three TrafficService Group (TSG) configuration is available. This offers 50% more capacity at a lower EFR penetration rate.


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STF-2000 Buses

The STF-2000 circuit boards communicate with each other over two types of buses:

• Private -- The two TCUs within each TSG, are interconnected by a private bus that uses the high-

level data link control (HDLC) protocol. The private buses are embedded in shelves 0 and 1 foreach TSG, requiring the TCUs to be installed in shelves 0 and 1. The standby TCU uses the private

bus to monitor the status of the active TCU, so that it can take control of the TSG in the event ofmalfunction of the active TCU.

• Time Division Multiplexed (TDM) -- Each TSG contains four TDM buses: TDM 0, TDM 1, TDM2, and TDM 3. These buses interconnect all the units within a TSG and provide the transfer pathsfor digital speech and user data.

The TCU communicates with the DFUs and STUs over TDM 0. As illustrated in Figure 5, theexternal 2 Mbit/s lines to the BCF-2000 ( M interface) and the MSC ( A interface) are connected tothe TDM buses through the DFUs. Links with the BCF-2000 are connected to TDM 0. Links to theMSC are connected to TDM 1, TDM 2, or TDM3.

The TDM buses are synchronised to one of the 2 Mbit/s lines on the A interface side through theinterconnecting DFU. The synchronisation line is selected using the SMA-2000 when the system iscommissioned. If the synchronisation line later becomes unusable, the active TCU switches toanother A interface with sufficient clock stability. The TCU generates two system clocks for theTDM buses: a 2048 kHz timeslot clock and an 8 kHz framing clock.

Figure 5. Simplified TSG Block Diagram (Full-rate)


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Speech Transcoding Frame-2000 (STF-2000) Architecture Overview



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Software

In the STF-2000, all software functions are accomplished by firmware modules in the TCU, DFU and STU.Firmware is stored in electrically erasable programmable read-only memory (EEPROM) in each of these modules.

The SMA-2000 application is run on the IMW-2000 notebook PC and is used to download system configurationsand operational software. These are initially stored in the TCU EEPROM and subsequently loaded into its activememory.

The operational software includes TCU application software, DFU software and STU software. During TSGinitialisation, the TCU broadcasts the DFU and STU software to the appropriate units in the STF-2000 frame.


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5-1

5 Product Functionality

The STF-2000 performs two principal functions:• Speech transcoding (speech transmissions)

• Data rate adaptation (user data transmissions)

Speech Transcoding

Standard digital speech is coded at 64 kbit/s. In GSM, speech must be coded at 13 kbit/s (full-rate) fortransmission over the air interface. The STF-2000 converts incoming speech from 64 kbit/s to 13 kbit/s andreverses the process for outgoing transmissions from the network. Control data is added to the converted speech,which results in an overall traffic channel rate of 16 kbit/s. The transcoder and radio terminal use in-band

signalling to communicate with each other.On the A interface between the STF-2000 and the MSC, each speech channel occupies 64 kbit/s. Aftertranscoding by the STF-2000, each speech channel occupies only 16 kbit/s (full-rate) on the M interface betweenthe STF-2000 and the BCF-2000. Four speech channels are carried on the 64 kbit/s timeslot occupied by astandard channel, enabling a 4-to-1 reduction in the landline capacity required between the STF-2000, the BCF-2000 and the BTS.

Data Rate Adaptation

For user data transmission, the STF-2000 provides data rate adaptation between the air interface to the mobilestation and the connection point to external networks, such as Integrated Services Digital Network (ISDN),

Circuit Switched Packet Data Network (CSPDN) and Public Switched Packet Data Network (PSPDN).Data rate adaptation is in accordance with the speed classes of the data services, whose bit rates range from 600

bit/s to 9.6 kbit/s.

The STF-2000 adapts the standard 64-kbit/s transmission rate of the A interface to the 12, 6, and 3.6 kbit/stransmission rate of the air interface.


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Product Functionality Speech Transcoding Frame-2000 (STF-2000)



Functionality

STF-2000 features provide the following functionality :

• 4: 1 Digital Speech Compression/Expansion. The source encoding process in the STF-2000

compresses each 64 kbit/s speech channel into a 13 kbit/s (full-rate) channel with minimum lossof fidelity. The addition of enhanced full-rate transcoding will provide standard landline tollquality speech at the 13 kbits/s bit rate of normal full-rate speech.

• Multiplexing/Demultiplexing . The compressed channels derived from four standard CEPTdigital speech channels are multiplexed and transmitted in the same 64 kbit/s bandwidth as asingle uncompressed channel.

• Data Rate Adaptation . The STF-2000 performs data rate adaptation between the air interfacewith the mobile station and the connection point to external networks such as ISDN, CSPDN andPSPDN.

• Through-Connection of CCS7 Signaling Channels. The STF-2000 transparently routes CCS7signaling messages between the MSC and BSC components, without performing any processing

on these signals.• Internal Diagnostics and Alarm Reporting . The STF-2000 reports alarms through the TCU to

the BTS-2000 to indicate failure of a hardware component or communication line. Alarmmessages are re layed to the OMC-2000 to alert network operators and are also forwarded to theSMA-2000, if connected.

• Automatic Redundant Switchover and Fault Recovery . The STF-2000 has fault -recoverysoftware that allows it to recover automatically from internally and externally detected faults. Nosingle failure of any active device causes the complete loss of frame functionality. This has beenachieved, in part, by building redundancy into the system for critical system components.

• Support for the SMA -2000. The SMA-2000 is run on the IMW-2000 notebook PC, which usesthe TCP/IP protocol to communicate with the STF-2000. The SMA-2000 is supplied with theSTF-2000, its purpose being to set and download configuration options, download operatingsoftware, initiate loopback tests and monitor the STF-2000 health and status. The STF -2000frame and all circuit boards can be tested using the SMA-2000 to perform resident diagnostics.The SMA-2000 connects to the STF-2000 through the TCU circuit board.

• Discontinuous Transmission . The STF-2000 implements the GSM Discontinuous Transmission(DTX) feature with Comfort Noise Insertion, in order to reduce radio interference levels andconserve mobile station battery power.


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6-1

6 Capacity and Configuration

The STF-2000 is currently configured to support standard full-rate speech transcoding and enhanced full -ratetranscoding (for improved speech quality). Each TSG may be configured to support standard full-rate channelsonly or dual-mode operation (full-rate and enhanced full-rate channels).

A full-rate TSG (Table 1) contains two TCUs, up to 15 DFUs and up to 24 STUs. A dual-mode TSG (Table 2)will contain two TCUs, up to 5 DFUs, and up to 38 STUs. The channel capacities of these TSG configurationsare described in the following text.

Due to the 1.5 Mbit transmission network in the USA (which uses the T1 protocol instead of E1) GSM 1900 hasthree-quarters of the channel capacity of GSM 900/1800 in each mode (full-rate or enhanced full-rate).

Full-rate (2 TSGs)

GSM 900/1800 GSM 1900

per cabinet per TSG per cabinet per TSG

No. of TCH 1440 720 1080 540

No. of A links 48 24 48 24

No. of Mlinks

12 6 12 6

No. of TCU 4 2 4 2

No. of DFU up to 30 up to 15 up to 30 up to 15

No. of STU up to 48 up to 24 up to 48 up to 24

Table 1 Full-rate Configuration Example (two TSGs)


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Capacity and Configuration Speech Transcoding Frame-2000 (STF-2000)



Dual-mode (3 TSGs)

900/1800 1900

per cabinet per TS G per cabinet per TSG

No. of TCH 720 240 540 180

No. of A links 24 8 24 8

No. of M links 6 2 6 2

No. of TCU 6 2 6 2

No. of DFU 15 5 15 5

No. of STU 69 23 69 23

No. of STU mailto: /1for Rel9.1 24 8 18 6

No. of STU/2 for mailto: Rel9.1 24 8 18 6

No. of STU mailto: /2, Rel10.x 30 10 24 8

No. of STU/2 to double TCHin one STF, Rel.11.x mailto:

60 20 48 16

Table 2. Dual -mode Configuration Example (three TSGs)


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7 Reliability and Availability

The availability of telecommunications equipment is dependent on both planned and unplanned outages. Factorsaffecting availability include:

• Service intervals and impact of system upgrades (planned outages).

• Frequency and severity of fault situations (unplanned outages).

The STF-2000 is robust and fault -tolerant and a number of architectural features have been incorporated toachieve this:

• No Regular Service Intervals. The STF-2000 is designed to be completely free of regularservice actions. The only exception is that if an optional dust filter is used, it should be replacedevery two years.

• Background Service Actions. Local maintenance can be performed with minimal operatinginterference. Software updates and parameter changes can be performed in the background. Newimages or configuration data are activated after a single system reboot.

• Plug and Play. “Hot insertion” of system components allows a given STF-2000 configuration to be upgraded without affecting current service. This feature is particularly valuable if a defectivecomponent has to be replaced.

• High MTBF of Circuit Boards. Each individual replaceable unit of the STF-2000 has a veryhigh reliability factor. The printed circuit boards are designed to have a theoretical Mean TimeBetween Failure (MTBF ) of almost 100 years. The next generation of boards will provide a full100 years MTBF.

• Redundancy of Central Equipment. No single failure of any active device causes a completeloss of frame functionality. This is achieved by building redundancy into critical components,such as the Traffic Control Unit (TCU). If a fault occurs in an active component, the appropriatestandby controller is switched into service instead. A TCU that has been switched out of service,can be removed from the frame, repaired and placed back into service.

• N+1 Redundancy of Fan Unit. The fan unit is sufficiently dimensioned to ensure that if one fanfails, it does not reduce the overall performance of the unit. Fan failures are reported to theOperations and Maintenance Centre (OMC) and the defective unit can be replaced without

affecting operation.


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Reliability and Availability Speech Transcoding Frame-2000 (STF-2000)



• Graceful Degradation by Decentralisation. Each circuit pack is equipped with its own powerconverter to prevent complete frame failure in the event of power supply problems. If any powerconverter fails, only the capacity associated with its host circuit pack is affected. For example, theloss of one DFU results in the loss of the associated interface capacity; the loss of one full-rateSTU results in the loss of one A -link (30 calls).

• Robustness in Transcoder Pooling. The consequences of losing a pool transcoder can bealleviated by building redundancy into the pool capacity. Additionally, as a fallback solution,enhanced full-rate calls that cannot be served are automatically processed in full-rate coding.

• Independence of Traffic Service Groups. A single STF-2000 frame houses two or three TrafficService Groups (TSGs). However, as the TSGs operate completely independently there is no

possibility of mutual interference or fault propagation between them. TSGs reside in a separatesub -rack with their own mechanical housing (except the 2-TSG configuration), power line,grounding and so on. A pair of redundant TCUs controls each TSG.

• Fault Tolerant Software. Fault recovery software provides automatic recovery from bothinternally and externally detected faults. A heartbeat mechanism between each TCU pair checksfor the presence and status of the peer TCU. Periodic sanity checks are performed as backgroundtasks between the active TCU and the transcoder’s respective interface cards. Each board's

microcontroller periodically checks its co-located memory and digital signal processors.


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8-1

8 Environmental Characteristics

Overview

The STF-2000 is convenient and easy to install. All components and wiring may be accessed through the front ofthe cabinet; which allows cabinets to be installed side-by-side and with their rear against the wall.

The equipment is shipped with all circuit packs preinstalled. With the new connection panel, it is possible to use pre-configured internal cabling and prefabricated common site material for the external cabling. This solutioncan reduce on-site installation time by up to 50%.

Physical Data

The STF-2000 is housed in a front-access equipment cabinet – the physical data of which is detailed in Table 3.

Width 600mm (23.6 in)

Depth 600mm (23.6 in)

Height 2200mm* (86.6 in)

Weight

(fully equipped)

270kg (605 lb)

* Optional height: 2000 mm (79 in)

Table 3. STF-2000 Cabinet Dimensions

The top cover of the cabinet can be optionally omitted, as it is only necessary for the ETSI height specificationand has no functional role.


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Environmental Characteristics Speech Transcoding Frame-2000 (STF-2000)



Environmental Data

Table 4 details the environmental data.

SpecificationDescription GSM 900/1800 GSM 1900

Storage conditions ETS 300 019-1-1 Class 1-2 BELLCORE GR-63_CORE

Transport conditions ETS 300 019-1-2 Class 2-2 BELLCORE GR-63_CORE

Operating Conditions ETS 300 019-1-3 Class 3.1 BELLCORE GR-63_CORE

Operating Temperature Range +5 oC to +40 o C(+41 o F to +104 oF)

+5 to +40 oC(+41 o F to +104 oF)

Operating Humidity Range 5 to 85% noncondensing 5 to 85% noncondensing

Table 4. Environmental Data

Power Requirements

The STF-2000 operates from a -48 or -60 Vdc supply with battery backup. Power requirements for the STF-2000include a battery plant with a protected AC power source and external ringing. The battery plant can be anyelectronic switching system plant that provides -48 or -60 Vdc at the required current level, such as the LucentTechnologies Lineage 2000 ECS battery plant.

Service Voltage Ranges

The STF-2000 hardware platform has the following power requirements under normal service conditions (whichmeans voltages at which the STF-2000 will operate within its specifications):

• A required secondary s upply voltage range of -37.0 Vdc to -73.0 Vdc.

• A voltage range at Output of Intra-frame Protection and Distribution Equipment of -36.0 Vdc to -72.0 Vdc.

Safety Extra Low Voltage (SELV)

The output of a STF-2000 power converter is extra low voltage (ELV) when the input is ELV. For a converteroutput to be SELV (safety extra low voltage), one of the following conditions must be true of the power plant -48 or -60 Vdc input:

• The -48 or -60 Vdc input is SELV and floating with the converter output also floating, or

• The -48 or -60 Vdc input is SELV and grounded with the converter output also grounded.

To qualify as SELV, the primary power plant equipment must comply with the requirements stated in EN 60950, Safety Information Technology Equipment Including Electrical Business Equipment, or, in the US, thecorresponding UL 1950.


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Speech Transcoding Frame-2000 (STF-2000) Environmental Characteristics



8-3

Power Consumption

The frame-level power consumption of the STF-2000 is detailed in Table 5.

TSG type Power Consumption

Full -rate Max: 1500 Watts

Typical: 1100 Watts

Dual-mode Max: 2000 Watts

Typical: 1200 Watts

Table 5. Power Consumptions

EMC

The STF-2000 complies with EMC requirements according to EN55022 and ETS 30342 (Europe) and FCC 15Class B, BELLCORE GR-1089-CORE (US).


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Environmental Characteristics Speech Transcoding Frame-2000 (STF-2000)



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9-1

9 Acronyms

The following acronyms are used in this document:

AMR Adaptive Multi Rate

BCF Base-station Controller Frame

BSC Base Station Controller

BSS Base Station System

BTS Base Transceiver Station

CEPT Conference of European Postal and Telecommunications Administrations

CSPDN Circuit Switched Packet Data Network

DFU Digital Facilities Unit

DSX-1 Digital Cross Connect for Digital Signal Level 1

E1 CEPT/ETSI standard 2048 Kbit/s digital transmission system

EFR Enhanced Full Rate

ELV Extra Low Voltage

EMC Electromagnetic Compatibility

ETSI European Telecommunication Standards Institute

FR Full Rate


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Acronyms Speech Transcoding Frame-2000 (STF-2000)

GSM Global System for Mobile Communication

IMW-2000 Integrated Maintenance Workstation

ISDN Integrated Services Digital Network

MSC Mobile-Services Switching Centre

MTBF Mean Time Between Failure

OMC Operations and Maintenance Centre

PC Personal Computer

PCM Pulse Code Modulation

PSPDN Public Switched Packet Data Network

PSTN Public Switched Telephone Network

RFI Radio Frequency Interference

SELV Safety Extra Low Voltage

SMA-2000 STF Maintenance Application

STF-2000 Speech Transcoding Frame

T1 Terrestrial data channel handling 1.5 Mbits per second

STU Speech Transcoding Unit

TCE Transcoding Equipment

TCU TSG Control Unit

TDM Time Division Multip lex

TSG Traffic Service Group

UL Underwriter Laboratories

Documents

STF2000_Product_Description.pdf