13 Interception of Proximity Services (ProSe)

33.1083G Security3GPPHandover interface for Lawful Interception (LI)Release 17TS

13.1 General

13.1.1 Identifiers

13.1.1.1 Overview

Specific identifiers are necessary to uniquely identify a target for interception, and to correlate between the data, which is conveyed over the handover interface (HI2). The identifiers are defined in the subsequent subclauses of 13.1.1.

13.1.1.2 Lawful interception identifier

For each target identity related to an interception warrant, the authorized CSP shall assign a Lawful Interception Identifier (LIID).

Using an indirect identification to point to a target identity makes it easier to keep the knowledge about a specific target limited within the authorized CSP and the LEA.

The LIID is a component of the IRI records. It shall be used within any information exchanged at the handover interfaces HI2 for identification and correlation purposes.

The LIID format shall consist of alphanumeric characters. It might for example, among other information, contain a lawful authorization reference number, and the date when the lawful authorization was issued.

The authorized CSP shall either enter a LIID for each target identity of the target or a single LIID for multiple target identities all pertaining to the same target.

If more than one LEA intercepts the same target identity, there shall be LIIDs assigned relating to each LEA.

13.1.1.3 Network identifier

The network identifier (NID) is a mandatory parameter; it should be internationally unique. It consists of the following two identifiers.

1) Operator- (NO/AN/SP) identifier (mandatory):
Unique identification of network operator, access network provider or service provider.

2) Network element identifier NEID (optional):
The purpose of the network element identifier is to uniquely identify the relevant network element carrying out the LI operations, such as LI activation, IRI record sending, etc.

A network element identifier may be an IP address or other identifier. National regulations may mandate the sending of the NEID.

13.1.2 Timing and quality

13.1.2.1 Timing

As a general principle, within a telecommunication system, IRI, if buffered, should be buffered for as short a time as possible.

NOTE: If the transmission of IRI fails, it may be buffered or lost.

Subject to national requirements, the following timing requirements shall be supported:

– Each IRI data record shall be sent by the delivery function to the LEMF over the HI2 within seconds of the detection of the triggering event by the IAP at least 95% of the time.

– Each IRI data record shall contain a time-stamp, based on the intercepting node’s clock that is generated following the detection of the IRI triggering event.

13.1.2.2 Quality

The QoS used from the CSP to the LEMF is determined by what operators (NO/AN/SP) and law enforcement agree upon.

13.1.3 Security aspects

Security is defined by national requirements.

13.1.4 Quantitative aspects

The number of target interceptions supported is a national requirement.

The area of Quantitative Aspects addresses the ability to perform multiple, simultaneous interceptions within a CSP’s network and at each of the relevant intercept access points within the network. Specifics related to this topic include:

– The ability to access and monitor all simultaneous communications originated, received, or redirected by the target;

– The ability for multiple LEAs (up to five) to monitor, simultaneously, the same target while maintaining unobtrusiveness, including between agencies;

– The ability of the network to simultaneously support a number of separate (i.e. multiple targets) legally authorized interceptions within its service area(s), including different levels of authorization for each interception, including between agencies (i.e. IRI only, or IRI and communication content).

13.2 ProSe Direct Discovery

13.2.1 General

For ProSe Direct Discovery, the LI solution in this subclause provides an IRI solution only as there is no CC.

The IRI will in principle be available in the following phases of ProSe Direct Discovery:

1. At Discovery Request;

2. At Match Report.

The IRI may be subdivided into the following categories:

1. Control information for HI2 (e.g. correlation information);

2. Prose Direct Discovery information.

The events defined in TS 33.107 [19] are used to generate records for the delivery via HI2.

There are multiple different event types received at DF2 level. According to each event, a Record is sent to the LEMF if this is required. The following table gives the mapping between event type received at DF2 level and record type sent to the LEMF.

Table 13.2.1-1: Mapping between Direct Discovery Events and HI2 records type

Event

IRI Record Type

ProSe Discovery Request

REPORT

ProSe Match Report

REPORT

A set of information is used to generate the records. The records are used to transmit the information from the mediation function to LEMF. This set of information can be extended in the ICE or DF2 MF, if this is necessary in a specific country. The following table gives the mapping between information received per event and information sent in records.

Table 13.2.1-2: Mapping between Events information and IRI information

parameter

Description

HI2 ASN.1 parameter

observed IMSI

Target Identifier with the IMSI of the target.

prosedirectdiscovery(targetimsi)

event type

Description which type of event is delivered ProSe direct discovery: Discovery Request, Match Report

prosedirectdiscovery(prosedirectdiscoveryevent)

event date

Date of the event generation in the ProSe Function.

Timestamp

event time

Time of the event generation in the ProSe Function.

Timestamp

Network Identifier

Operator ID plus unique identifier for the ProSe Function

network-identifier

lawful interception identifier

Unique number for each lawful authorization

lawfulInterceptionIdentifier

Role of target

Whether the target is an announcing or monitoring UE

prosedirectdiscovery(targetrole)

Discovery PLMN ID

PLMN where the discovery process takes place.

prosedirectdiscovery(discoveryPLMNID)

ProSe Application ID Name

Identity of a user within the context of a specific application

prosedirectdiscovery(proseappidname)

Metadata

Metadata relating to a ProSe Application Identity

prosedirectdiscovery(metadata)

Timer

The ‘Validity Timer’ or ‘Time to Live’ value assigned by the network to a specific ProSe Application Code or Discovery filter that controls how long the UE can announce/monitor for it

prosedirectdiscovery(timer)

Identity of the other UE

In Match reports, there is a second UE involved

prosedirectdiscovery(otherueimsi)

ProSe Application Code

Bitstring that is actually announced over the air, or included in a discovery filter applied by UE

prosedirectdiscovery(proseappcode)

Prose App Mask

Bitmask that allows the monitoring UE to perform full or partial matching. Multiple Masks may be included in a Discovery Filter. The length of the mask is the same as the length of ProSe Application Code

prosedirectdiscovery(proseappmask)

NOTE: LIID parameter needs to be present in each record sent to the LEMF.

13.2.2 Events and information

13.2.2.1 Overview

This clause describes the information sent from the Delivery Function (DF) to the Law Enforcement Monitoring Facility (LEMF) to support Lawful Interception (LI). The information is described as records and information carried by a record. This focus is on describing the information being transferred to the LEMF.

The IRI events and data are encoded into records as defined in the Table 13.2.1-1: Mapping between Direct Discovery Events and HI2 records type and Annex B.13 Intercept related information for ProSe. IRI is described in terms of a ‘causing event’ and information associated with that event. Within each IRI record there is a set of events and associated information elements to support the particular service.

The direct discovery events described in Table 13.2.1-1: Mapping between Direct Discovery Events and HI2 records type and Table 13.2.1-2: Mapping between Events information and IRI information convey the basic information for reporting direct discovery. This clause describes those events and supporting information.

Each record described in this clause consists of a set of parameters. Each parameter is either:

mandatory (M) – required for the record,

conditional (C) – required in situations where a condition is met (the condition is given in the Description), or

optional (O) – provided at the discretion of the implementation.

The information to be carried by each parameter is identified. Both optional and conditional parameters are considered to be OPTIONAL syntactically in ASN.1 Stage 3 descriptions. The Stage 2 inclusion takes precedence over Stage 3 syntax.

13.2.2.2 REPORT record information

The REPORT record is used to report non-communication related target actions (events).

The REPORT record shall be triggered when:

– The ProSe Function receives a Discovery Request from the UE. See Table 13.2.2.2-1.

– The ProSe Function receives a Match Report from the UE. See Table 13.2.2.2-2.

Table 13.2.2.2-1: ProSe Discovery Request REPORT Record

Parameter

MOC

Description/Conditions

Observed IMSI

M

Shall be provided.

Event Type

M

Provide ProSe Discovery Request event type

Event Time

M

Provide the time the event is detected.

Event Date

M

Provide the date the event is detected.

Lawful Interception Identifier

M

Shall be provided.

Role of target

M

Shall be provided.

Network Identifier

M

Shall be provided.

Discovery PLMN ID

M

Shall be provided. More than one may be reported if target has monitoring role.

ProSe Application ID Name

M

Shall be provided. More than one may be reported if target has monitoring role.

Timer

M

Shall be provided. More than one may be reported if target has monitoring role.

ProSe Application Code

M

Shall be provided. More than one may be reported if target has monitoring role.

ProSe App Mask

C

Provided if available and applicable (only applicable if target has monitoring role). More than one may be reported if target has monitoring role.

Metadata

C

Provided if available and applicable (only applicable if target has announcing role)

Table 13.2.2.2-2: ProSe Match Report REPORT Record

Parameter

MOC

Description/Conditions

Observed IMSI

M

Shall be provided.

Event Type

M

Provide ProSe Match Report event type.

Event Time

M

Provide the time the event is detected.

Event Date

M

Provide the date the event is detected.

Lawful Interception Identifier

M

Shall be provided

Role of target

M

Shall be provided.

Network Identifier

M

Shall be provided.

Discovery PLMN ID

M

Shall be provided.

ProSe Application ID Name

M

Shall be provided.

Timer

M

Shall be provided.

ProSe Application Code

M

Shall be provided.

Metadata

C

Provided if available.

Identity of other UE

C

Provided if available.

13.3 ProSe Remote UE communications

13.3.1 General

The provisions in this clause specify the LI handover interface to report IRIs in case a ProSe Remote UE communicates through a ProSe UE-to-NW Relay.

TS 33.107 [19] specifies, see clause 17.3.3, in case the ProSe UE-to-NW Relay is a target, the conditions under which CC is required to be intercepted.

CC interception, when required, shall be reported according to annex B.10.

The IRIs will in principle be available in the following phases of ProSe Remote UE communications:

1. When a target ProSe Remote UE connects to or disconnects from a ProSe UE-to-NW Relay;

2. When a ProSe Remote UE connects to or disconnects from a target ProSe UE-to-NW Relay;

3. When a target ProSe Remote UE starts communication by using a ProSe UE-to-NW Relay;

4. When a target ProSe Remote UE ends communication by using a ProSe UE-to-NW Relay;

5. When interception is started for a target ProSe Remote UE with ongoing communication;

6. When interception is started for a Prose UE-to-NW Relay with connected ProSe Remote UE(s).

In addition, requirements specified in clause 10 are also applicable:

1. When a Tracking Area/EPS Location Update occurs for a target ProSe UE-to-NW Relay;

2. When a target ProSe UE-to-NW Relay uses one or more PDN connections for any activity/communication which is not related to relaying;

3. To IRI and CC interception related to a target ProSe UE-to-NW Relay, when national regulations require to intercept all the CC handled by a target ProSe UE-to-NW Relay.

The IRI may be subdivided into the following categories:

1. Control information for HI2 (e.g. correlation information);

2. Prose Remote UE communications information.

The events defined in TS 33.107 [19] are used to generate records for the delivery via HI2.

There are multiple different event types received at DF2 level. According to each event, a Record is sent to the LEMF if this is required. The following table gives the mapping between event type received at DF2 level and record type sent to the LEMF.

Table 13.3.1-1: Mapping between ProSe Remote UE communications Events and HI2 records type

Event

IRI Record Type

ProSe Remote UE Report

REPORT

ProSe Remote UE Start of Communication

BEGIN

ProSe Remote UE End of Communication

END

Start of interception with ProSe Remote UE ongoing communication

BEGIN or CONTINUE

Start of interception for ProSe UE-to-NW Relay

REPORT

A set of information is used to generate the records. The records are used to transmit the information from the mediation function to LEMF. This set of information can be extended in the ICE or DF2 MF, if this is necessary in a specific country. The following table gives the mapping between information received per event and information sent in records.

The ASN.1 specified in Annex B.9 shall be used to provide HI2 to LEMF.

Table 13.3.1-2: Mapping between Events information and IRI information

parameter

Description

HI2 ASN.1 parameter

Observed IMSI

Target Identifier with the IMSI of the target.

partyInformation (party-identity)

Observed MSISDN

Target Identifier with the MSISDN of the target.

partyInformation (party-identity)

Observed IMEI

Target Identifier with the IMEI of the target.

partyInformation (party-identity)

Event type

Description which type of event is delivered: ProSe Remote UE Report, ProSe Remote UE start of communication, ProSe Remote UE end of communication, Start of interception with ProSe Remote UE ongoing communication, Start of interception for ProSe UE-to-NW Relay.

ePSevent

Event date

Date of the event generation in the ProSe Function.

timestamp

Event time

Time of the event generation in the ProSe Function.

timestamp

Network Identifier

Lawful interception identifier

Unique number for each lawful authorization. It shall be present in each record sent to the LEMF.

lawfulInterceptionIdentifier

Target type

Indicates whether the target is a ProSe Remote UE or a ProSe UE-to-NW Relay

proSeTargetType

ProSe Remote UE IDs

The identities of the connected or disconnected ProSe remote UEs.

proSeRemoteUeContextConnected,

proSeRemoteUeContextDisconnected

ProSe Remote UE IP info

The IP address(es) of the connected to the ProSe Remote UE(s) provided by the ProSe UE-to-NW Relay.

proSeRemoteUeContextConnected

APN

The Access Point Name used by the ProSe UE-to-NW Relay for the connection

aPN

MSISDN of the Prose UE-to-NW Relay

MSISDN of the Prose UE-to-NW Relay (only applicable when the ProSe Remote UE is the target)

proSeRelayMSISDN

IMSI of the Prose UE-to-NW Relay

IMSI of the Prose UE-to-NW Relay (only applicable when the ProSe Remote UE is the target)

proSeRelayIMSI

IMEI of the Prose UE-to-NW Relay

IMEI of the Prose UE-to-NW Relay (only applicable when the ProSe Remote UE is the target)

proSeRelayIMEI

PDN address(es)

The ProSe UE-to-NW Relay IP address(es) for the PDN connection

pDNType, pDNAddressAllocation

Correlation number

The correlation number is used to correlate CC and IRI (in case the target is a ProSe remote UE)..

ePSCorrelationNumber

Location information

When authorized, this field provides the location of the ProSe UE-to-NW Relay.

National regulations may require to provide the E-CGI of the ProSe UE-to-NW Relay when the target is the ProSe Remote UE

ePSlocationOfTheTarget

Additional Cell IDs

The Secondary Cell (PSCell) groups of the target, if available

additionalCellIDs

Note: The Additional Cell IDs parameter is used to report a primary cell of a secondary cell group. The Location Information parameter is used to report the primary cell of a primary cell group. Within the event message tables in this clause, for short hand, the Location Information parameter indicates that the primary cell id of the primary cell group and if available the primary cell id of the secondary cell group is reported meaning that both of the aforementioned parameters are reported assuming the conditions for including them have been met.

13.3.2 Events and information

13.3.2.1 Overview

This clause specifies the information sent from the Delivery Function (DF) to the Law Enforcement Monitoring Facility (LEMF) to support Lawful Interception (LI). The information is described as records and parameters carried by a record. The focus is on describing the information being transferred to the LEMF.

The IRI events and data are encoded into records as specified in the Table 13.3.1-1: Mapping between ProSe Remote UE communication Events and HI2 records type and Annex B.9 Intercept related information (HI2 SAE/EPS and IMS). IRI is specified in terms of a ‘causing event’ and parameters associated with that event. Within each IRI record there is a set of events and associated information elements to support the particular service.

The ProSe Remote UE communication events specified in Table 13.3.1-1: Mapping between Direct Discovery Events and HI2 records type and Table 13.3.1-2: Mapping between Events information and IRI information convey the basic information for reporting the ProSe Remote UE communication. This clause describes those events and supporting information.

Each record described in this clause consists of a set of parameters. Each parameter is either:

mandatory (M) – required for the record,

conditional (C) – required in situations where a condition is met (the condition is given in the Description), or

optional (O) – provided at the discretion of the implementation.

The information to be carried by each parameter is identified. Both optional and conditional parameters are considered to be OPTIONAL syntactically in ASN.1 Stage 3 descriptions. The Stage 2 inclusion takes precedence over Stage 3 syntax.

13.3.2.2 REPORT record information

The REPORT record is used to report non-communication related target actions (events).

The REPORT record shall be triggered when:

– The target ProSe Remote UE connects to or disconnects from a ProSe UE-to-NW Relay. See Table 13.3.2.2-1.

– One or several UEs connect to or disconnect from a target ProSe UE-to-NW Relay. See Table 13.3.2.2-1.

– LI is activated on a target ProSe UE-to-NW Relay with already connected ProSe Remote UEs. See Table 13.3.2.2-2.

– A failure occurs when the target ProSe Remote UE attempts to start communication by connecting to a ProSe UE-to-NW Relay. See Table 13.3.2.2-3.

Table 13.3.2.2-1: ProSe Remote UE Report REPORT Record

Parameter

MOC

Description/Conditions

Observed IMSI

C

Provide at least one and others when available

Observed MSISDN

Observed IMEI

Event Type

M

Provide ProSe Remote UE Report event type

Event Time

M

Provide the time the event is detected

Event Date

M

Provide the date the event is detected

Lawful Interception Identifier

M

Shall be provided

Target type

M

Shall be provided

Network Identifier

M

Shall be provided

ProSe Remote UE(s) connected IDs

C

Provided if the ProSe UE-to-NW Relay is the target

ProSe Remote UE(s) connected IP info

C

Provided the ProSe UE-to-NW Relay is the target

ProSe Remote UE(s) disconnected IDs

C

Provided if the ProSe UE-to-NW Relay is the target

MSISDN of the ProSe UE-to-NW Relay

C

Provided if available and if the ProSe Remote UE is the target

IMSI of the ProSe UE-to-NW Relay

C

Provided if available and if the ProSe Remote UE is the target

IMEI of the ProSe UE-to-NW Relay

C

Provided if available and if the ProSe Remote UE is the target

APN

C

Provided if available

PDN Address(es)

C

Provided if available

Location information

C

Provide, when authorized, to identify location information for the target UE, including the primary cell ID from each of the Master Cell (PCell) and Secondary Cell (PSCell) groups of the target, if available

Table 13.3.2.2-2: Start of interception for ProSe UE-to-NW Relay

Parameter

MOC

Description/Conditions

Observed IMSI

C

Provide at least one and others when available

Observed MSISDN

Observed IMEI

Event Type

M

Provide Start of interception for ProSe UE-to-NW Relay event type

Event Time

M

Provide the time the event is detected

Event Date

M

Provide the date the event is detected

Lawful Interception Identifier

M

Shall be provided

Target type

M

Shall be provided

Network Identifier

M

Shall be provided

ProSe Remote UE(s) connected IDs

C

Provided if available

ProSe Remote UE(s) connected IP info

C

Provided if available

APN

C

Provided if available

PDN Address(es)

C

Provided if available

Location information

C

Provide, when authorized, to identify location information for the target UE

When the ICE (i.e. S-GW, PDN-GW) is not aware of the activation of multiple lawfully authorized intercepts on a ProSe UE-to-NW Relay with already attached ProSE Remote UE, the MF/DF shall generate the Start of Intercept ProSe UE-to-NW Relay REPORT record on its own using information that it has retained.

The DF2 shall not send the Start of Interception for ProSe UE to NW Relay REPORT record to the LEMFs that were already intercepting the ProSe UE to NW Relay (i.e. target) due previous LI activation on the same ProSe UE to NW Relay (i.e. target).

Table 13.3.2.2-3: ProSe Remote UE Start of Communication REPORT Record

Parameter

MOC

Description/Conditions

Observed IMSI

C

Provide at least one and others when available

Observed MSISDN

Observed IMEI

Event Type

M

Provide ProSe Remote UE Start of Communication event type

Event Time

M

Provide the time the event is detected

Event Date

M

Provide the date the event is detected

Lawful Interception Identifier

M

Shall be provided

Target type

M

Shall be provided

Network Identifier

M

Shall be provided

MSISDN of the ProSe UE-to-NW Relay

C

Provide at least one and others when available

IMSI of the ProSe UE-to-NW Relay

C

IMEI of the ProSe UE-to-NW Relay

C

APN

C

Provided if available

PDN Address(es)

C

Provided if available

ProSe Cause

C

Provided if available

Location information

C

Provide, when authorized, to identify location information for the target UE

13.3.2.3 BEGIN record information

The BEGIN record is used to report the first event of a ProSe UE-to-NW Relay communication.

The BEGIN record shall be triggered when:

– The target ProSe Remote UE starts communication by connecting to a ProSe UE-to-NW Relay. See Table 13.3.2.3-1.

– Interception is started on a target Remote UE which has an already established communication being connected to a ProSe UE-to-NW Relay. This includes also the case where the ProSe UE-to-NW Relays undergoes a S-GW relocation with an already connected target ProSe Remote UE, if there is a change in the PLMN or when the information about the change in the PLMN is not available at the DF/MF. See Table 13.3.2.3-2.

Table 13.3.2.3-1: ProSe Remote UE Start of Communication BEGIN Record

Parameter

MOC

Description/Conditions

Observed IMSI

C

Provide at least one and others when available

Observed MSISDN

Observed IMEI

Event Type

M

Provide ProSe Remote UE Start of Communication event type

Event Time

M

Provide the time the event is detected

Event Date

M

Provide the date the event is detected

Lawful Interception Identifier

M

Shall be provided

Target type

M

Shall be provided

Network Identifier

M

Shall be provided

Correlation number

M

Shall be provided

MSISDN of the ProSe UE-to-NW Relay

C

Provide at least one and others when available

IMSI of the ProSe UE-to-NW Relay

C

IMEI of the ProSe UE-to-NW Relay

C

APN

C

Provided if available

PDN Address(es)

C

Provided if available

Location information

C

Provide, when authorized, to identify location information for the target UE

Table 13.3.2.3-2: Start of interception with ProSe Remote UE ongoing communication BEGIN Record

Parameter

MOC

Description/Conditions

Observed IMSI

C

Provide at least one and others when available

Observed MSISDN

Observed IMEI

Event Type

M

Provide ProSe Remote UE Start of Communication event type

Event Time

M

Provide the time the event is detected

Event Date

M

Provide the date the event is detected

Lawful Interception Identifier

M

Shall be provided

Target type

M

Shall be provided

Network Identifier

M

Shall be provided

Correlation number

M

Shall be provided

MSISDN of the ProSe UE-to-NW Relay

C

Provide at least one and others when available

IMSI of the ProSe UE-to-NW Relay

C

IMEI of the ProSe UE-to-NW Relay

C

APN

C

Provided if available

PDN Address(es)

C

Provided if available

Location information

C

Provide, when authorized, to identify location information for the target UE

When the ICE (i.e. S-GW, PDN-GW) is not aware of the activation of multiple lawfully authorized intercepts on a ProSe Remote UE that has an already established communication being connected to a ProSe UE-to-NW Relay, the MF/DF shall generate the Start of Interception with ProSe Remote UE ongoing communication BEGIN record on its own using information that it has retained.

The DF2 shall not send the Start of Interception with ProSe Remote UE ongoing communication BEGIN record to the LEMFs that were already intercepting the ProSe Remote UE (i.e. target) due previous LI activation on the same ProSe Remote UE (i.e. target).

13.3.2.4 CONTINUE record information

The CONTINUE record is used to report events during an ongoing ProSe UE-to-NW Relay communication.

The CONTINUE record shall be triggered when:

– Interception is started on a target Remote UE which has an already established communication being connected to a ProSe UE-to-NW Relay UE and the DF/MF is aware that there has been no change in the PLMN. See Table 13.3.2.3-3.

Table 13.3.2.4-1: ProSe Remote UE Start of Communication CONTINUE Record

Parameter

MOC

Description/Conditions

Observed IMSI

C

Provide at least one and others when available

Observed MSISDN

Observed IMEI

Event Type

M

Provide ProSe Remote UE Start of Communication event type

Event Time

M

Provide the time the event is detected

Event Date

M

Provide the date the event is detected

Lawful Interception Identifier

M

Shall be provided

Target type

M

Shall be provided

Network Identifier

M

Shall be provided

Correlation number

M

Shall be provided

MSISDN of the ProSe UE-to-NW Relay

C

Provide at least one and others when available

IMSI of the ProSe UE-to-NW Relay

C

IMEI of the ProSe UE-to-NW Relay

C

Location information

C

Provide, when authorized, to identify location information for the target UE

13.3.2.5 END record information

The END record is used to report the last event of a ProSe UE-to-NW Relay communication.

The END record shall be triggered when:

– The target ProSe Remote UE ends communication by disconnecting from a ProSe UE-to-NW Relay. See Table 13.3.2.5-1.

Table 13.3.2.5-1: ProSe Remote UE End of Communication END Record

Parameter

MOC

Description/Conditions

Observed IMSI

C

Provide at least one and others when available

Observed MSISDN

Observed IMEI

Event Type

M

Provide ProSe Remote UE End of Communication event type

Event Time

M

Provide the time the event is detected

Event Date

M

Provide the date the event is detected

Lawful Interception Identifier

M

Shall be provided

Target type

M

Shall be provided

Network Identifier

M

Shall be provided

Correlation number

M

Shall be provided

MSISDN of the ProSe UE-to-NW Relay

C

Provide at least one and others when available

IMSI of the ProSe UE-to-NW Relay

C

IMEI of the ProSe UE-to-NW Relay

C

Location information

C

Provide, when authorized, to identify location information for the target UE