Ewsd Training Module[1][1]

hello!! hello!! hello!!Sounds Familiar?

A to “X” of Telephone

“Mr. Watson… come here!”

1876. The first successful experiment

with the telephone. Alexander Graham Bell spoke

to his assistant – to his delight, he heard

and came and stood by him!

A cry of exhilaration 129 years ago…

It all started with ……….

That’s me.. Graham’s phone

• Since my discovery in 1876 my looks and properties have undergone significant

changes from time to time.

• At heart I still perform the basic task of transporting Voice from one point to the other.

My Network

• As a standalone unit I am dead.

• To make me live the basic requirements are:

– Connectivity to the Central Office / Exchange– Connectivity of the Central Office to other similar

Central Offices / exchanges across the national / International geography.

• Let me tell give you a top down view of the Telecom network as a Whole

Elements of Telecommunication

A telecommunication network can be broadly classified into 3 parts:

Telecommunications

Access part Central Office Backbone Part

The Access Part

The portion of the Telecom networks which delivers the voce / data to the end subscriber can be termed as the access network.

Access Part

Wire line Wireless

The Access Part- Wire line

In this case there is some physical medium of connecting the subscriber which could be

Wire line

Copper cableCo-axial cable

HF CableOptical Fiber

The Central Office It can be further be classified

Switching Systems

Manual Automatic

Electromechanical Electronic

Strowger(or step-by-step)

Crossbar Digital Analog

Circuit switch Packet switch

ATM Switch Soft Switch

CBNM CBM

The Backbone Part

It basically is the connectivity between two Central Offices.

Back Bone

Open Wire systems UHF /MW systems Cable basedSatellite based

Switch /

Exchange

Access networkAccess network

CuCu

Central OfficeCentral Office

Modern digital exchange

Modern digital exchange

Switch /

Exchange

Access networkAccess network

City BCity B

Central OfficeCentral Office

Switch /

Exchange

City ACity A

Access networkAccess network

Backbone networkBackbone network

Central OfficeCentral Office

Access network• Gradually with the increase in the number of telephone need was

felt to introduce flexibility in the copper network to accommodate uncertainties of the number of telephones required in a particular area.

• Here came the concept of network elements like Cabinets / Pillars / Sub – pillars and DP’s in the access network

• The Copper cable of multiple pairs (typically 2400 / 1600 /1200 /800 /400 /200 /100 /50 /20 /10 /5 pairs of copper) originates from the exchange (from Main Distribution Frame – or the MDF) and terminates on multiple Cabinets / pillars.

1200 pairs Cu cable

800

Pillar A 400 pairs

Pillar B 800 pairs

SP

Sub Pillar

SP

400400

200

Exchange

DP

DP

DP

5050

20

Area XArea Y

Area A

Main Distribution frame of an Exchange Main Distribution frame of an Exchange

Tag blocks and jumpersTag blocks and jumpers

Pillar closed and openPillar closed and open

Tag blocks

and jumper

s

Tag blocks

and jumper

s

Access Network• Copper - very costly element in the network, attempts

made to reduce the thickness of the copper pair to reduce the cost.

• Restricted the distance for voice transmission

• This required multiple exchanges ( central offices) to be installed to cover a large city.

• The connectivity between two central offices within the same city was called the Intra-city Backbone

• It is exactly similar to the Intercity backbone but is

within the same city

Switch /

Exchange

Central OfficeCentral Office

SP

DP

DP

DP

5050

20

100

Cu networkCu network

Intra city Backbone

Intra city Backbone

RSURSURSURSU

RSURSU

In very simple words, we can define Switching, as forwarding the User1 (Source) data/ speech, using different Network Elements (DCE/DTE, Modems, Mux’s, SN Matrices etc..), to the far end User2 (Destination), in a Reliable and Understandable fashion.

In this case the User can be single or can be a group of Users.

Some Basic Telecommunication TermsTelecommunication

• Any transmission, emission, or reception of signs, signals, writing, images and sounds or intelligence of any nature by wire, radio, optical or other electromagnetic systems.

Telecommunication service• Service offered by a network or service provider to its customers in order to

satisfy a specific telecommunication requirement. Telecommunication services are divided into two broad families: bearer services and teleservices.

Bearer Service• The Bearer Service is a type of telecommunication service that provides the

capability for the transmission of signals between access points.

Teleservice• The type of telecommunication service that provides the complete

capability, including terminal equipment functions, for communication. Examples of a teleservice include speech, fax etc.

Charging : Chargeable Event• An activity utilizing telecommunications network infrastructure and related

services for user to user communication (e.g. a single call, a data communication session or a short message), or for user to network communication (e.g. service profile administration), or for inter-network communication (e.g. transferring calls, signalling, or short messages), or for mobility (e.g. roaming or inter-system handover), which the network operator wants to charge for. The cost of a chargeable event may cover the cost of sending, transporting, delivery and storage. The cost of call related signalling may also be included.

Tariff • The set of charges that apply depending to a specific call plan.

CDR - Call Detail Record• A database record unit used to create billing records. A CDR contains details such as

the called and calling parties, originating switch, terminating switch, call length, and time of day.

Traffic• The information moved over a communication channel.

Traffic capacity• The maximum traffic per unit of time that a given telecommunications

system, subsystem, or device can carry under specified conditions.

TCH - Traffic Channel• A logical channel used for the transport of user data.

Transmission• The propagation of a signal, message, or other form of information by any

means, such as telegraph, telephone, radio, television, or facsimile via any medium. These may include wire, coaxial cable, microwave, optical fibre, or radio frequency.

Transmission line• The material medium or structure that forms all or part of a path from one

place to another for directing the transmission of energy, such as electric currents, magnetic fields, acoustic waves, or electromagnetic waves. Transmission lines include wires, optical fibres, coaxial cable and waveguides.

E1• Wide area digital transmission scheme used predominantly in Europe that carries

data at a rate of 2.048Mbps. E1 lines can be leased for private use from common carriers. The E1 contains 32 timeslots at 64Kbps.

Trunk• A transmission channel between two points that are switching centres or nodes.

Trunks may be used to interconnect switches to form networks.

TS - Timeslot• In a TDMA (Time Division Multiple Access) system the carrier is split into multiple

timeslots, the duration being dependant on the technology. Each user is assigned one or more timeslots for communication purposes.

Routing• Routing is a Switching technique that determines the next network point to which

voice/fax/data call in the form of dialled digits should be routed towards its destination. The route is connected to at least two network elements (POIs).

ISDN - Integrated Service Digital Network• An ISDN is an end to end digital network capable of simultaneous transmission of a

range of services such as voice, data and video etc. The network is based upon 64Kbps circuits.

PRI - Primary Rate Interface• A Primary Rate Interface is a ISDN (Integrated Services Digital Network)

term describing either an E1 circuit in Europe or a T1 circuit in North America. These are comprised of 30 traffic channels and two signalling channels (E1, 30B+2D - 2.048Mbps) and 23 traffic channels and one signalling channels (T1, 23B+D - 1.544Mbps) respectively.

BRI - Basic Rate Interface• The Basic Rate Interface is an ISDN interface composed of two B channels

(at 64Kbps) and one d channel (at 16Kbps) for circuit switched communication of voice, video, and data.

DTMF - Dual Tone Multi-Frequency• System used by touch tone telephones where one high and one low

frequency, or tone, is assigned to each touch tone button on the phone.

PCM - Pulse Code Modulation• Pulse Code Modulation is a process in which an analogue signal is encoded into a

digital bit stream. The analogue is first sampled, then quantized and finally encoded into a bit stream. The most common version of PCM enables one voice circuit to be represented by a 64Kbps stream.

INTRODUCTION TO DIGITALELECTRONIC SWITCHING SYSTEM

EWSD

MODULAR DESIGN

EWSD APPLICATIONS

GENERAL INFORMATION

ARCHITECTUREMicroscopic view to the switching system

The Switching System architecture has 5 blocks-

– Switching Network (SN)

– Access– Signaling– Control &– Management

EWSD COMPONENTS

TASK DISTRIBUTION

INTERFACES

INTERFACES (EXT.)

INTERFACES (INT.)

DIGITAL LINE UNIT

DLU FUNCTIONS

SYSTEM STRUCTURE

SLMA (SUBSCRIBER LINE MODULE, ANALOG)

SLMD (SUBSCRIBER LINE MODULE, DIGITAL)

(DLU) DIGITAL INTERFACE UNIT FUNCTIONs

DLUC (DIGITAL LINE UNIT CONTROL)

LINE TRUNK GROUP (LTG)

• FUNCTIONS:

LINE TRUNK GROUP STRUCTURE (LTGS)

SWITCHING NETWORK (SN)

The actual switching process establishing a call connection between two subscribers takes place in the hardware subsystem called Switching Network (SN).

SN OVERVIEW

SN FUNCTIONAL INTERFACES

SN: LTG EXPANSION

SWITCHING

SN VER 15

SN VER63

SN VER126

COORDINATION UNIT

• The EWSD system incorporates largely independent subsystems with separate microprocessor controls.

• The coordination processor handles the coordination of these microprocessor controls and the data transfer between them.

COORDINATION TASK

MESSAGE BUFFER

MESSAGE BUFFER (USAGE)

• The following types of information are sent through the MB:

__ Messages

__ Reports

__ Orders

__ Commands

The transmission channel between

the LTGs and the MB is called the

Message Channel. The Switching

Network (SN) provides a semi- permanent path for this channel.

MB CONNECTION TO SN AND LTGs

The Message Buffer

Units are connected to the

Line/Trunk Groups and SN

in the following manner:

The MB 0 accesses only the

SN 0, and the MB 1 accesses

only the SN 1

The CP receives and transmits

to the MB 0 and the MB 1.

A MBG can serve 2x63 LTGs.

The SN, including the SGC, can

serves those units in the SN that

are required to support up to

2x63 LTGs.

CENTRAL CLOCK GENERATOR

CLOCK DISTRIBUTION HIERARCHY

CLOCK DISTRIBUTION HIERARCHY AMONG

EXCHANGES

SYSTEM PANEL (SYP)

SYP DISPLAY UNITS

SYSTEM PANEL ALARMS

COORDINATION PROCESSOR

Individual units of the EWSD

system are provided with separate

controls.

Due to this load sharing capacity,

the EWSD is a flexible and powerful system.

Coordination Processor controls all common

system procedures and coordinates the

operating, safeguarding, and switching process.

COORDINATION PROCESSOR TASK

COORDINATION PROCESSOR UNITS

BUS SYSTEM (B:CMY)

The bus system (B:CMY) allows the processors to:

- access the Common Memory (CMY)

- and communicate directly with other.

Both bus systems transfer the same information simultaneously to both memory banks.

COMMON MEMORY

In addition to the (CMY) which

is accessed by all processors,

each processor has its own

local memory.

CP UNITS AND TASKS

INPUT/OUTPUT CONTROL PROCESSOR

INPUT/OUTPUT PROCESSOR USAGE

TASKS OF BAPs

COMMON CHANNEL SIGNALING NETWORK

CCNC STRUCTURE

FUNCTIONAL UNITS OF CCNC

CONNECTION TO LTG

MAIN FUNCTIONS OF SILTGs

The EWSD switching system is suitable for a wide range of applications with respect to :

-- Exchange size.-- Range of features.-- Range of services.-- Network environment.-- Equipment Stability.

CALL SETUP

CALL SETUP BETWEEN A-SUBSCRIBER AND A-LTG

CALL SETUP BETWEEN A-SUBSCRIBER AND A-LTG

EVALUATION BY THE CP

Network Management System(NMS)

TRAFFIC & CCR MANAGEMENT

TRAFFIC

• The unit of traffic is Erlang.• Erlang is a measure of the time for which a

particular circuit is busy continuously.• For the duration of 1 hour, if the circuit is busy

for complete one hour we call it 1 Erlang.• If there are N circuits, then the maximum traffic

will be N erlang, which means all circuits busy for the complete duration of the observation period.

Aims of Traffic Measurement

Analysis of Traffic Measurement helps in :

Network planning and Traffic forecast Planning new networks & expansion of existing networks Reveals extreme load situations Optimum ratio of “Investment to Yield”

Network Traffic Management Detect overload situations Helps in defining overflow on alternate routes Detects faults in the network

TRAFFIC MONITORING

Networks are subject to considerable traffic fluctuations. Traffic monitoring helps in detecting traffic bottlenecks

and overload situations.

Following objects can be put under monitoring:-

Trunk Groups (TGRP)Traffic loadPeriod during which all trunks in a group were busy (ATBT)

Coordination Processor (CP) DLU / LTG

NETWORK MANAGEMENT Traffic measurement helps in network management. It aims at -

Ensuring optimum usage of network resources even during periods of high load.

Also aims at providing the subscribers with the highest possible level of connection quality.

It involves – Reducing volume of traffic to a destination Route the traffic to alternate paths during congestion Block the traffic

It results in – Protection of the network against unsuccessful traffic and thus

saves Revenue.

TRAFFIC REDUCTION & CONGESTION CONTROL

Call Blocking Points (CBPT) Code Blocking

Blocking specifiable % of all seizures for all specific digit combinations.

Call GappingBlocking the seizures for specifiable time interval for specific digit combination.

Leaky BucketDynamic reduction of seizure attempts.

Crank Back

A max. of 10,000 code block points can be created.Rejected call attempts can be successfully diverted to appropriate incepts (announcements).

ENHANCING NETWORK CAPACITY

There are some features which can enhance the network capacity :

ODR (Optimized Dynamic Routing)

HTRC (Hard To Reach Control)

MCC (Mass Call Control)

CCR

• CCR – Call Completion Rate

• Ratio of number of successful calls to number of call attempts.

• Measure of network stability and more importantly “Revenue generation”

• Call failure-– Network reasons– Subscriber reasons

CCR A city is divided in to number of smaller regions.

Periodic record of CCR is maintained for each region.

A series of graphs shows the increase or decrease in the CCR of different areas.

If a dip is observed in any of the graphs of a particular region, ICTST is used to monitor the incoming or outgoing calls to/from a particular region.

This helps in detecting the reason for the failure of the unsuccessful calls.

Let’s have a look on some of the reports

Call Waiting (CW)

Description:The Call Waiting (CW) feature indicates to a subscriber involved in a call that another call is waiting. A subscriber option allows the waiting party to be informed of the call wait-ing status by means of a message or recorded Announcement. The called subscriber can either accept, reject or ignoring call.

Operator benefits– fewer busy situations

– more successful traffic

– higher level of acceptance among end customers

Subscriber benefits– greater availability

– the waiting subscriber is informed of the activated feature

Selective call Waiting

Description:

With the Selective Call Waiting (SCW) feature, waiting call requests from defined directory numbers (DN) are indicated to the called subscriber.The defined numbers are contained in a subscriber-specific screening list.

Operator benefits– improved service

Subscriber benefits– Call Waiting allowed only for selected directory numbers

Call Forwarding Description:

• With the feature Call Forwarding , the subscriber can automatically forward incoming calls to a different directory number which he/she has determined in advance.

• Types of call Forwarding:

1. Call forwarding Immediate.2. Call forwarding no reply.3. Call forwarding on busy.4. Call forwarding do not ans.5. Call forwarding to fixed announcement. Operator benefits• increase in the volume of successful traffic, resulting in higher call-charge

revenues• improved service Subscriber benefits• more user-friendly• improved accessibility• Call Forwarding Controlled by subscriber

-

6.Call forwarding to VMS

Operator benefits• voice mail service made simpler and therefore more attractive, resulting in increased revenue

Subscriber benefits• messages can be left for the forwarding subscriber at any time of the day if

he or she is unavailable• feature is easy to use

7.Call forwarding selective

Operator benefits•enhancement of the call forwarding feature, providing added marketing opportunities

Subscriber benefits•selection of calling subscribers whose calls are to be forwarded

Rejection of Forwarded Calls

Description:

The feature Rejection of Forwarded Calls (RFC) allows a subscriber to automatically reject calls that have been forwarded to him or her.

Operator benefits•improved service

Subscriber benefits•no forwarded calls

Selective Call Origination

Description:

With the feature Selective Call Originating (SCO), calls to defined directory numbers can be specifically prevented or permitted. The subscriber can define up to 50 directory numbers. It is also possible to specify partial directory numbers. The relevant directory numbers are stored in subscriber-specific screening lists:

Two types of lists can be defined for a subscriber a “black list” (for calls that are permitted) or a “White list” (for calls that are not permitted.).

Operator benefits• feature with additional marketing possibilities

Subscriber benefits• blocking of specific directory numbers

Selective Call Termination

Description: With the feature Selective Call Termination (SCT), call requests from certain

defined directory numbers are accepted for termination. The subscriber can define up to 50 directory numbers. It is also possible to specify partial directory numbers. The numbers in question are contained in subscriber-defined screening.

Two types of lists can be defined for a subscriber a “black list”(calls from the nos. in the list are rejected) or a “White list”(calls from the nos. in the list are accepted).

Operator benefits• improved service

Subscriber benefits• distinguish between important and non-important incoming calls• barring of unwanted directory numbers

Kickout

Description: The Kickout feature enables the subscriber to enter the directory

numbers of undesirable callers into a screening list. Call requests from subscribers whose directory numbers are in the screening list are rejected. All other calls are switched through.

The directory numbers can be placed in the screening list by means of a subscriber procedure performed either during or shortly after an undesirable call.

Operator benefits• An attractive feature to differentiate from the competition

Subscriber benefits• This feature prevents calls from undesirable subscribers

Multiple Simultaneous Call Forwarding

Description The feature Multiple Simultaneous Call Forwarding (MSCF) makes it

possible to forward a number of incoming call requests simultaneously to a defined destination (e.g. a voice mailbox). This feature supplements the call forwarding feature (CF). It is of relevance for the following types of call forwarding:

• Call Forwarding Unconditional (CFU)

• Call Forwarding on Busy (CFB)

• Call Forwarding on No Reply (CFNR)

Operator benefits• higher call completion rate, resulting in higher revenues from call

charges

Subscriber benefits• greater availability

Parallel Ringing Definition

Description: The Parallel Ringing feature simultaneously signals calls to two

separate lines belonging to the same subscriber, e.g. a fixed line in the PSTN and a mobile number. The subscriber can accept the call on either of the two lines.

Operator benefits• increased call charge revenue through additional call setups (called

subscriber 1-• called subscriber 2 subscriber)• enhanced service offered to subscribers: greater accessibility

Subscriber benefits• for mobile phone users, e.g. greater accessibility• call diversion need not be activated explicitly• it is not necessary to publicize the directory number of the second line

Do Not Disturb (DND) Description

The feature Do Not Disturb (DND) allows a subscriber who does not wish to be disturbed to have incoming calls forwarded immediately to a recorded announcement. The announcement informs the calling subscriber, for example, of the reason why he or she cannot reach the called party at the moment.

Operator benefits• higher call completion rate and therefore increased

revenue

Subscriber benefits• no disturbance by calls• calling subscriber hears a recorded announcement

Distinctive Ringing (DR)

Description

The Distinctive Ringing (DR) feature is used to assign a subscriber line up to four different ringing tones for incoming calls. For example, the following call types can be differentiated

• normal call• forwarded call (CFU)• call completion to busy subscriber (CCBS)• operator call

Operator benefits• improved service

Subscriber benefits• greater transparency for incoming calls

Selective Ringing

Description: With the feature Selective Ringing (SR), call requests from certain

defined directory numbers (DN) are signaled to the subscriber by means of different ringing sequences. The subscriber can define up to 50 directory numbers.

It is also possible to specify partial directory numbers. The numbers in question are contained in subscriber-specific screening lists, i.e. in a “white list” or a “black list”.

Operator benefits• improved service

Subscriber benefits• distinguish between important and non-important calls

Automatic Recall (AR) Definition• The Automatic Recall (AR) feature allows an called subscriber to

automatically initiate a call that could not be set up by a calling subscriber. The recall number is stored in the system. The called subscriber can initiate a recall with the aid of the recall number (without the subscriber having to know it) by entering an appropriate feature code.

Operator benefits• This feature establishes calls that might not otherwise take place

• Higher charges rate by more successful connections

Subscriber benefits• This feature enables called subscribers to automatically set up calls that

were not

• originally established by the caller (because the called party is delayed in reaching

• the telephone or cannot accept the call at the time).

• More user-friendly for the subscriber

Selective Call Originating

Description• With the feature Selective Call Originating (SCO), calls to defined

directory numbers can be specifically prevented or permitted. The subscriber can define up to 50 directory numbers. It is also possible to specify partial directory numbers. The relevant directory numbers are stored in subscriber-specific screening lists: in a “white list” for calls that are permitted, and in a “black list” for calls that are not permitted. A subscriber can have both screening lists, but only one can be active at any one time.

Operator benefits

• feature with additional marketing possibilities

Subscriber benefits

• blocking of specific directory numbers

Abbreviated Dialing (ABBD)

Description The Abbreviated Dialing (ABBD) feature enables a subscriber to

create an individual abbreviated dialing list and store this list in the network node. Each directory number in the list is assigned an abbreviated directory number. The abbreviated dialing list can contain internal, national and international directory numbers. The network node automatically converts this to the full directory number when establishing the connection.

Operator benefits

• feature with additional marketing opportunities

Subscriber benefits• more user-friendly

• shorter dial procedure

Call Completion to Busy Subscriber

Description• The Call Completion to Busy Subscriber (CCBS) feature enables

a subscriber to have the network node redial a subscriber who was busy when originally called. Once the busy subscriber becomes free again, the network node calls back the subscriber who activated the feature. If the subscriber accepts the call from the network node, a connection is automatically set up to the subscriber who was previously busy without the caller having to redial the number.

Operator benefits

• improved service• higher revenues generated due to increased acceptance

of the featureSubscriber benefits

• no need to redial a busy subscriber directory number• greater ease of use thanks to simplified feature control

Call Completion on No Reply

Description• The Call Completion on No Reply (CCNR) feature enables a

subscriber to have a call attempt repeated automatically by the network node if the called subscriber does not re-ply. When the called subscriber has become active again the network node starts a re-call to the subscriber who activated the feature. If the subscriber accepts the call from the network node, a connection is automatically set up to the subscriber without the call-er having to redial the number.

Operator benefits

• improved extent of utilization of node resources• improved service

Subscriber benefits

• time-saving• greater ease of use thanks to simplified feature control

Fixed Destination CallDescription

• With the feature Fixed Destination Call (Hotline) the subscriber can set up a call to a pre-defined destination by lifting the handset, without dialing any directory number. The subscriber can choose between two feature variants

• Type of Hotline1. Fixed Destination Call, immediate2. Fixed Destination Call, delayed

Operator benefits• improved service

Subscriber benefits• improved service• more security

Anonymous Call Rejection Description

• The feature Anonymous Call Rejection (ACR) allows a subscriber to automatically re-ject calls for which the calling subscriber suppresses the presentation of his or her call data (Calling Line Identification Restriction, CLIR). A call from an operator, who normally has the CLIR feature activated, is not rejected by the feature.

Operator benefits• Better chances of marketing the display features (e.g. CLIP) and

therefore higher• revenue

Subscriber benefits• Calls from subscribers who want to remain anonymous are

automatically rejected

Calling Line Identification Presentation on Call Waiting

Description• The Calling Line Identification Presentation on Call Waiting (CLIPCW)

feature expands the possibilities of the Call Waiting (CW) feature. The subscriber for whom a call is waiting receives a display of the call data of the waiting subscriber as additional information. requirements for the CLIPCW feature are the Calling Line Identification Presentation (CLIP) feature as well as the activated Call Waiting (CW) feature and authorization for FSK transmission.

Operator benefits

• enhanced acceptance for the Call Waiting (CW) feature

• more successful calls and therefore higher total charges

Subscriber benefits• enhanced protection against undesired calls by improved calling

subscriber identification• improved service

Connected Line Identification Restriction

Description

The Connected Line Identification Restriction (COLR) feature allows the called sub-scriber to prevent his or her call data being displayed to a calling party.

Operator benefits

• improved service

Subscriber benefits

• no presentation of the call data to the calling subscriber

Calling Line Identification Presentation

Description

The Calling Line Identification Presentation (CLIP) feature provides the called sub-scriber with information on the party attempting to set up the connection to him or her before accepting the call. This is done by displaying the directory number of the calling subscriber to the called subscriber.

Operator benefits

• improved serviceSubscriber benefits

• calling subscriber identification before accepting the call

• enhanced protection against undesired calls

Calling Line Identification Restriction

Description Using the feature Calling Line Identification Restriction (CLIR),

calling subscribers can prevent their call data from being displayed to the called subscriber. Certain subscriber groups (e.g. police) can be given special authorization allowing them to ignore this restriction. Anonymous

Operator benefits

• complementary function to the feature

• Calling Line Identification Presentation• (CLIP) with additional marketing Subscriber benefits

Subscriber benefits• the calling subscriber remains anonymous

Three-Party Conference (TPC)

Description

The Three-Party Conference (TPC) feature adds another subscriber to an existing connection. This additional connection can be

integrated as a three-party call or a three-party conference.

Operator benefits• improved service

Subscriber benefits• three subscribers able to talk to each other

Multiple Subscriber Number (MSN) with Different Ringing

Description The Multiple Subscriber Number (MSN) with Different Ringing

feature provides the possibility of assigning up to 4 directory numbers to an access. The network node han-dles each MSN as an independent subscriber number, each of which may have its own features. Incoming calls to each number can be signaled with different ringing sequences, so that the number dialed can be immediately recognized acoustically (e.g. office or private).

Operator benefits• improved service

Subscriber benefits• greater availability

Large Conference (LC)

Description

The Large Conference (LC) feature enables a subscriber acting as the conference initiator to interconnect other subscribers in a conference group. All subscribers participating in a large conference can speak to each other at the same time. A large conference may comprise up to 32 subscribers.

Operator benefits

• attractive feature generating additional traffic and therefore greater revenue from call

• chargesSubscriber benefits

• the conference initiator can connect the conference participators as required

• all exchanges of information and ideas are experienced directly by the individual

• conference parties• savings in time and money, e.g. by not having to travel to business

meetings

Subscriber Barge-in (SBI)

Description The Subscriber Barge-in (SBI) feature allows a GeoCENTREX subscriber to

break into an ongoing call with another GeoCENTREX subscriber in the same GeoCENTREX group without interrupting the call. To do this, the GeoCENTREX subscriber dials an access code, followed by the internal directory number of the subscriber he wishes to con-tact. A break-in tone (two warning tones at 425 Hz) is applied to the subscriber he wishes to connect before the three-way call is set up. To prevent break-in (listening in) by other subscribers, the ’Subscriber Barge-in Rejection’ (SBIR) feature can be assigned to the GeoCENTREX subscriber.

Operator benefits• increased billing revenue due to the higher number of successful

calls

Subscriber benefits• the user is able to break into calls to other terminals or he can

accept these calls• the user is able to contact a subscriber who is already busy with a

call• important calls are not lost

Malicious Call Recording (MCR)

Description

• The Malicious Call Recording (MCR) feature can be used to determine malicious callers and record the corresponding call. Subscribers can activate the feature during an ongoing call or within a limited period af-ter the end of a call.

Operator benefits• Fast identification of malicious callers

Subscriber benefits• Better protection against malicious callers• Calls can be saved as evidence

Remote Subscriber Controlled Input

(RSCI) Description• The feature Remote Subscriber Controlled Input (RSCI) enables a

subscriber to administrate the features of his or her home telephone line from any telephone line in the network. Using any telephone capable of MFC, the subscriber can activate, deactivate, program or request the status of his or her features.

Operator benefits

• improved control of subscriber features

Subscriber benefits

• greater user-friendliness in operation of subscriber features

• more flexibility

Call Hold (CH)Definition• The feature Call Hold (CH) allows a served subscriber to interrupt an

active call and to establish another call. The feature Call Hold (CH) can be used by the calling or called subscriber. It is available for all services and terminals using B-channels. The user can also subsequently re-establish the communication with the held call.

Operator benefits

• additional traffic

Subscriber benefits• toggling between calls• more availability• more flexibility

Call Pick Up (CPU)

Definition• The feature Call Pick Up (CPU) allows a GeoCENTREX subscriber to

answer calls that are intended for other lines in the local GeoCENTREX group but cannot be answered there (e.g. because the called party is absent).

Operator benefits• higher call completion rate and therefore increased

revenue from call charges

Subscriber benefits• pickup of specific calls intended for other subscribers• calls can easily be answered from a different telephone,

e.g. if the called subscriber• happens to be absent

Wasn’t it!!!

Questions ??