Content for TS 22.173 Word version: 18.0.1
C IMS Multimedia Telephony supplementary services applicable to the fixed access
D IMS Multimedia Telephony supplementary services applicable to the mobile 3GPP access
Da Network determined user busy.
Db services classification applicable to Inter IMS Network-to-Network Interface (II-NNI).
Dc Enterprise IP-PBX Supplementary Services to support 3GPP Voice Interworking
C (Normative) IMS Multimedia Telephony supplementary services applicable to the fixed access |R8| p. 64
The following services have been split into 3 categories applicable to CEPT members:
- Mandatory services: selected services that must form the basis of any set of services considered applicable to IMS Multimedia Telephony service. These are considered to meet the requirements of regulation concerning the processing of personal data and the protection of privacy in the electronic communications sector.
- Recommended services: selected services that offer service providers with a transition from CS mobile and fixed services.to IMS Multimedia Telephony service.
- Optional services: other services.
Originating Identification Presentation (OIP)
Originating Identification Restriction (OIR)
Terminating Identification Presentation (TIP)
Terminating Identification Restriction (TIR)
Malicious Communication IDentification (MCID)
Anonymous Communication Rejection (ACR)
Recommended services
Communication DIVersion (CDIV)
Communication Waiting (CW)
Communication HOLD (HOLD)
Communication Barring (CB)
Completion of Communications to Busy Subscriber (CCBS)
Completion of Communications on No Reply (CCNR)
Message Waiting Indication (MWI)
Optional services
CONFerence (CONF)
Advice Of Charge (AOC)
Explicit Communication Transfer (ECT)
Reverse charging
Closed User Group (CUG)
Three-Party (3PTY)
Flexible Alerting (FA)
Customized Alerting Tone (CAT)
Customized Ringing Signal (CRS)
Completion of Communications on Not Logged in (CCNL)
D (Normative) IMS Multimedia Telephony supplementary services applicable to the mobile 3GPP access |R8| p. 66
Only these services apply to UEs using a mobile 3GPP access:
Originating Identification Presentation (OIP)
Originating Identification Restriction (OIR)
Terminating Identification Presentation (TIP)
Terminating Identification Restriction (TIR)
Communication Diversion (CDIV)
Communication Hold (HOLD)
Communication Barring (CB)
Message Waiting Indication (MWI)
Conference (CONF)
Explicit Communication Transfer (ECT)
Completion of Communications on Not Logged in (CCNL)
Communication Waiting (CW)
Completion of Communications to Busy Subscriber (CCBS)
Completion of Communications on No Reply (CCNR)
Personal Network Management (PNM)
Customized Alerting Tone (CAT)
Customized Ringing Signal (CRS)
Additionally, EN 301 082 (OCB-fixed) does not apply to 2G and 3G Mobile terminals, for which the functionality is specified by means of Operator Determined Barring [6] and not through supplementary services.
Da (Normative) Network determined user busy. |R8| p. 67
The capability of network determined user busy is a network option.
The network may determine busy conditions at the time an incoming IMS Multimedia Telephony session is about to be offered.
The conditions for network determined user busy are identified, on a per subscription basis, based on the availability of limited resources assigned to the terminating user, or due to other information such as presence.
The conditions for network determined "user busy" include:
- the maximum number of total communications permitted has been reached;
- the maximum number of simultaneous media streams supported at the given subscriber's interface(s) has been reached;
- the maximum bandwidth supported at the given subscriber's interface(s) has been reached.
- subscriber making himself "busy" in a subscriber profile, involved in the incoming multimedia telephony session.
- a pre-determined number, or less, of communications are available (i.e. the maximum number of communications minus the current number); or
- a pre-determined number, or less, of simultaneous media streams available (i.e. the maximum number of simultaneous media streams minus the current number); or
- a certain limit in the bandwidth used at the given subscriber's interface(s) has been reached.
Db services classification applicable to Inter IMS Network-to-Network Interface (II-NNI). |R10| p. 68
The goal of this informative annex is to improve the service interconnection at II-NNI. The classification of services may simplify the cooperation between interconnecting networks but remains optional.
Db.1 High Priority Category p. 68
List of services with high priority to be supported at II-NNI (it is recommended to be able to deliver these services at II-NNI). These services have technical impact the II-NNI:
- Basic Voice,
- Originating Identification Presentation (OIP),
- Originating Identification Restriction (OIR),
- Incoming Communication Barring (ICB) – including Anonymous Communication Rejection (ACR),
- Advice Of Charge (AOC),
- Communication DIVersion (CDIV) – Call DIV signaling information saying that this call has been already diverted.
- Malicious Communication Identification (MCID),
- Communication HOLD (HOLD),
- Communication Waiting (CW).
Db.2 Medium Priority Category p. 68
List of services with medium priority to be supported at II-NNI (it is recommended that interconnecting parties agree on using these services before planning to open them at II-NNI). These services have technical impact the II-NNI:
- Terminating Identification Presentation (TIP),
- Terminating Identification Restriction (TIR),
- Message Waiting Indication (MWI),
- Completion of Communications to Busy Subscriber (CCBS),
- Completion of Communications on Non Reply (CCNR),
- Explicit Communication Transfer (ECT),
- Closed User Group (CUG),
- Personal Network Management (PNM),
- Three-ParTY (3PTY),
- CONFerence (CONF),
- User to User service.
Db.3 Low Priority Category p. 69
List of services with low priority that have no identified impact on II-NNI (the delivery of these services is inside of originating network):
- Flexible Alerting (FA),
- Outgoing Communication Barring (OCB),
- Customized Alerting Tone (CAT),
- Customized Ringing Signal (CRS)
- Call Completion Not Logged In (CCNL).
Dc (Normative) Enterprise IP-PBX Supplementary Services to support 3GPP Voice Interworking |R11| p. 70
Dc.1 General p. 70
The services in this annex are the services that could be supported in an enterprise IP-PBX environment. These are provided in order to support implementation of interworking between an Enterprise IP-PBX and IMS. 3GPP UEs that are designed to work in an Enterprise environment could support these types of supplementary services.
Dc.2 Individual Line Services p. 70
Dc.2.1 Introduction p. 70
IP-PBX features are generally classified as either Individual Line or Group Line Services. Individual Line services are applicable to individual Enterprise users (aka "lines" or "extensions"). Group Services, in contrast, are applicable to groups of users.
Dc.2.2 Call Transfer (Unattended, Attended & Early Attended) p. 70
This is based on Explicit Communications Transfer (ECT) as described in Clause 8.2.15.
In a Unattended Call Transfer, an ongoing call is transferred to a 3rd party by one of the parties (called the transferring party) without checking the status of the 3rd party. This is supported as a service provider option of ECT in Clause 8.2.15.
In an attended call transfer (sometimes called Supervised Call Transfer) the ongoing call is placed on hold by the transferring party, another call is established between the transferring party and the party to whom the call is proposed to be transferred, and then the call is (or may be, depending on the result of that discussion) transferred to that party. This is effectively a combination of the Communication HOLD service defined in Clause 8.2.9 and ECT defined in Clause 8.2.15.
In an Early Attended Call Transfer the ongoing call is placed on hold and the transferring party waits to hear the 3rd party's phone ring. Once the transferring party hears ring tone, he transfers the call. This is supported as a service provider option of ECT in Clause 8.2.15.
Dc.2.3 Multi-party Ad-hoc Conference with Rosters p. 70
Multi-party and Conference Calls provide communications between multiple users. Such calls may or may not be arranged in advance. Multi-party calls not arranged in advance are termed "ad hoc".
Conference calls generally involve multiple parties, so the terms multi-party call and conference call are in some senses synonymous. Conventionally, the term conference call refers to a call that is arranged in advance by a moderator or host who has special privileges (e.g., can mute and un-mute other participants), with logistics communicated e.g., through email or a calendar system. To participate in a conference call one typically calls a number associated with a conferencing server.
An Ad Hoc Multi-party call is usually not pre-arranged and participants are generally all "equal" (they can mute and un-mute themselves). There may or may not be a conferencing server involved.
The list of participants in a multi-party / conference call is known as the roster. The IP-PBX may have the ability to supply the roster to the device of any participant.
Dc.2.4 Call Forwarding p. 71
Call Forwarding, or Communications Diversion (CDIV), is defined in Clause 8.2.7. Call Forwarding Activation is an action on the part of the user to change the call forwarding behaviour of his device; e.g., by activating or deactivating forwarding to a pre-designated number, or changing the forwarded to number.
Call forwarding (aka Communications Diversion or CDIV) is provided to incoming calls based on the called party's status and service configuration. It may be invoked for the reasons summarized below. Call forwarding for other reasons is not precluded, as a network option.
- Call Forward on Busy - Call Forwarding is invoked because the called party's line is not able to accept the incoming call (e.g., it is in use, or off hook). This is known as Communication Forwarding Busy (CFB) in Clause 8.2.7.1.
- Call Forward on No Answer - Call Forwarding is invoked after the called party is alerted a configured number of times without response. This is known as Communication Forward on No Reply (CFNR) in Clause 8.2.7.1.
- Call Forward Unconditional - Call Forwarding is enabled by the user (e.g., prior to leaving the office) so that all subsequent calls will be immediately forwarded to the specified destination. This configuration typically remains in effect until manually cancelled. The forwarded line may indicate that it is in this state by issuing a special dial tone (e.g., "stutter dial tone") when the receiver is taken off hook. Call Forward Unconditional may be invoked using special key sequences (Vertical Service Codes), e.g., *72 in North America or *21* in Europe, followed by the forward-to number; or via a special button or soft key on the device. This is known as Communication Forwarding Unconditional (CFU) in Clause 8.2.7.1.
- Call Forward on Do Not Disturb - similar to call forward unconditional, but invoked by pressing the Do Not Disturb button or soft key. Most devices will visually display that they are in the Do Not Disturb state. Pressing the Do Not Disturb button or soft key while in the Do Not Disturb state, causes the line to exit this state. This is known as Communication Deflection (CD) in Clause 8.2.7.1.
Dc.2.5 Single Number Reach (SNR) p. 71
The Single Number Reach (SNR) capability allows calls to a IP-PBX extension to be picked up on or transferred to, alternate devices such as a home phone or mobile phone.
In the case of a call incoming to the number associated with the IP-PBX extension, the IP-PBX will normally ring that line first. If it is unanswered, the IP-PBX will ring one or more alternate numbers.
An in-progress call may be "pushed to" a pre-configured alternate device by pressing a special button or key sequence on the device with which the IP-PBX extension number is associated. Similarly it can be "pulled back" to that device.
Dc.2.6 Do Not Disturb (DND) p. 71
The Do Not Disturb (DND) function prevents calls from being terminated to an extension for which DND is activated.
Calls to an extension for which DND is activated may be directed to a pre-assigned extension (e.g., a secretary), receive a busy signal, or receive an indication that the called party is busy. In some IP-PBXs the call may be allowed through to the extension but displayed differently (e.g., with a visual indication, but without ringing). It may be possible to circumvent the called party's DND status by policy (e.g., the called party's boss can "get through") or by entering a circumvention code.
Dc.2.7 Immediate Divert (to messaging system) p. 72
The Immediate Divert function allows a call to be connected to a messaging system (typically a voice mail system). The call may be active, on hold or in the process of being established. The messaging system may be associated with the party invoking the Immediate Divert function or (if they differ) with the original called party. When the call is in the process of being established this is known as Communication Diversion (CDIV) as defined in Clause 8.2.7. When the call is active or on hold, this is known as Explicit Communication Transfer (ECT) as defined in Clause 8.2.15.
Immediate Divert is invoked by a special key, softkey or key sequence depending on the capability of the device. The IP-PBX typically informs the diverted party that the call has been diverted, and to whose messaging system the diverted party is now speaking.
Dc.2.8 Shared-line Features (remote-in-use, call-Barge) p. 72
A shared line is a telephone number associated with multiple devices at the same time. A set of devices sharing the same number is called a Shared Line Group. This is a variant of the Closed User Group defined in Clause 8.2.17. The Call Barge function allows a user to join an in-progress call in which it and one of the currently participating devices are members of the same Shared Line Group.
Call Barge is only possible from device 'A' if at least one device in the same Shared Line Group as 'A' has a call in progress. This status may be indicated to the user of device 'A' by the IP-PBX.
Dc.2.9 Callback p. 72
The Callback function notifies a user when the party to whom a call was previously attempted, becomes available. It is effectively the combination of Communication Completion on Busy (CCBS) and Communication Completion on No Reply (CCNR) defined in Clause 8.2.11 and Clause 8.2.23.
If IP-PBX user 'A' attempts to call IP-PBX user 'B' but the call fails, e.g., because user B's line was busy or the call was unanswered, user 'A' may invoke the Callback function. Doing so causes the IP-PBX to monitor B's status, and notify user A when user B becomes available. For example if B's line was previously off hook, he will be deemed available when he next goes on hook.
Dc.2.10 Connected Name and Number Display p. 72
This feature allows the device to display the name and/or telephone number of both current parties on a 2-party call.
This feature uses the Connected Line ID Presentation (COLP/COLR) and Connected Name Presentation (CONP/CONR) services to allow or restrict presentation of this information on a call by call basis.
This feature requires that the IMS or the IP-PBX maintains the name associated with Enterprise specific identities (short numbers).
Dc.2.11 Call Whisper p. 72
Call Whisper identifies to the called party, information about the caller (e.g., the caller ID, and the telephone number the caller dialled) while the caller continues to hear ringing. This information allows the called party to know how to greet the caller, and/or whether to accept the call. This is an optional service described in Clause 7.5.1 of TS 22.228.
This capability is often used when multiple non-geographic numbers (e.g., toll free numbers) are used to route calls to the same directory number. For example a call center may take calls for many companies, and the receptionists need to greet the caller differently based on the company to which the call is related. It can also be used in a FMC scenario where e.g., a call to either the fixed or the mobile device will cause both to ring. The implementation will typically translate the called number into a pre-defined phrase (e.g., "this call is for Acme Rockets" or "this call is for your mobile"). The format of the "whisper" may vary (e.g., audio vs. visual presentation) depending on the capabilities of the device.
Dc.3 Group Line Services p. 73
Dc.3.1 Introduction p. 73
A IP-PBX often provides a set of advanced services to groups of users within the Enterprise. The groups generally correspond to job functions (e.g., help desk attendants) or organizations (e.g., marketing, sales). Group Services may for example allow enhanced collaboration among group members, or allow the distribution of work across them.
Dc.3.2 Enterprise Music On Hold p. 73
Music on Hold (MOH) is played to the party whose line has been placed on hold.
The Music on Hold (MOH) feature allows users to place on-net and off-net users on hold with music that is streamed from a streaming source. In an Enterprise MOH is often used to provide information rather than music. The caller may interact with the MOH capability using simple key sequences, e.g., "enter *0 to hear about our sales, or *1 to disable this announcement". The announcement may be customized based e.g., on the number dialled. The media is typically streamed from a Music on Hold Server, which may or may not be considered part of the IP-PBX.
This is an add-on to the Communication HOLD service defined in Clause 8.2.9. The network should be capable of suppressing MOH when the held party is part of a multi-party call.
Dc.3.3 Call Park p. 73
The Call Park feature allows a party involved in a call to place that call on hold on one device and resume it from another.
Traditionally Call Park has been activated using a special button (the "call park" button) or key sequence. The call is at that point transferred to an idle extension, and is said to be "parked on" that extension. The IP-PBX may provide some means of "paging" the desired party, e.g., through a public address system or via some form of messaging. The call can be resumed from any IP-PBX line, by providing the extension number on which it is "parked".
This is a variation of the Communication HOLD service defined in Clause 8.2.9, where the call can be picked up from a different terminal than placed on hold.
Dc.3.4 Call Pickup/Group Pickup p. 73
Call Pickup allows a user to answer on one line or device, an incoming call directed to another line or device. Lines or devices may be assigned to groups, in which case call pickup is restricted to lines or devices in the same group. That is known as Group Pickup.
Imagine a large room with many phones and few people. One of the phones, on the far side of the room, starts to ring. Rather than walking across the room, a user can press a special button or key sequence on his own phone to transfer that call to his phone. That is Call Pickup.
In a distributed environment it may not be possible for the user to hear the other phone ringing, so an alternative alerting mechanism may be used. For example a text message could alert a user on his mobile that his office or home phone was ringing.
