BA.65 v2.0

GSM Association Confidential - Full, Rapporteur, and Associate Members

Official Document BA.65 - LTE Roaming Implementation Handbook

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LTE Roaming Implementation Handbook

Version 2.0

23 April 2015

This is a Non-binding Permanent Reference Document of the GSMA

Security Classification: Confidential - Full, Rapporteur, and Associate Members

Access to and distribution of this document is restricted to the persons permitted by the security classification. This document is confidential to the

Association and is subject to copyright protection. This document is to be used only for the purposes for which it has been supplied and

information contained in it must not be disclosed or in any other way made available, in whole or in part, to persons other than those permitted

under the security classification without the prior written approval of the Association.

Copyright Notice

Copyright © 2015 GSM Association

Disclaimer

The GSM Association (“Association”) makes no representation, warranty or undertaking (express or implied) with respect to and does not accept

any responsibility for, and hereby disclaims liability for the accuracy or completeness or timeliness of the information contained in this document.

The information contained in this document may be subject to change without prior notice.

Antitrust Notice

The information contain herein is in full compliance with the GSM Association’s antitrust compliance policy.



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Table of Contents

1 Introduction 4

1.1 Overview 4

1.2 Scope 4

1.3 Abbreviations 4

1.4 References 6

2 Documentation Needed For LTE launch 7

2.1 IRA / IR Hubbing Agreement 7

2.2 AA.14 (RAEX IOT and RAEX OpData) 7

2.3 Launch Letter 7

3 Connectivity 8

3.1 Signalling Connectivity - Diameter 8

3.2 User Data Connectivity 9

3.3 IPX Service 11

4 Voice and SMS 12

4.1 Circuit Switched Fallback 13

4.2 SMS 13

4.3 VoLTE 13

4.4 Local Breakout 14

5 Testing 15

5.1 Purpose 15

5.2 Requisites 15

5.3 Roaming Hubbing Testing 17

6 SIM Cards - The Role of the UICC in LTE Roaming 17

6.1 UICC OTA Configuration 17

6.2 Network Selection Overview 17

6.3 UICC Portability and LTE Spectrum Fragmentation 17

6.4 VoLTE and IMS Network Access 17

6.5 LTE Steering Issues 18

7 LTE Devices 18

7.1 Spectrum 18

7.2 Device Planning 19

8 Billing and Reporting 19

8.1 Data on LTE 19

8.2 Voice and SMS over LTE in TAP 20

8.3 Identification of Data on LTE 20

8.4 Fields Changed from 3G 21

9 Fraud Considerations 21

9.1 LTE Data Roaming 21

9.2 VoLTE Roaming 21

9.3 Unique LTE Fraud Risks 21

Annex A Related PRDs Referenced 22

A.1 BA.27 Charging Principles 22



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A.2 BA.40 Roaming Guide 22

A.3 BA.42 GPRS Packet Switched Charging Handbook 22

A.4 BA.50 Technology Neutral Agreements Handbook 22

A.5 IR.21 GSM Association Roaming Database 22

A.6 IR.23 Organisation of GSM International Roaming Tests 22

A.7 IR.25 VoLTER testing 22

A.8 IR.34 Connectivity Requirements 22

A.9 IR.38 LTE and EPC Roaming Tests 22

A.10 IR.58 IMS Profile for Voice over HSPA 23

A.11 IR.65 IMS Roaming and Interworking Guidelines 23

A.12 IR.88 LTE and EPC Roaming Guidelines 23

A.13 IR.92 IMS Profile for Voice and SMS 23

A.14 IR.94 IMS Profile for Conversational Video Service 23

A.15 RCC.50 RCS-e Advanced Communications Services and Client

Specifications 23

A.16 TD.43 TAP Test Cases (TTC) for GSM Phase 1 Services 23

A.17 TD.47 TAP Test Cases (TTC) for GPRS Services 24

A.18 TD.50 VoLTE Testing 24

A.19 TD.51 TAP Test Cases (TTC) for LTE and EPC Roaming Testing 24

A.20 TD.58 TAP 3.12 Implementation Handbook 24

Annex B LTE Questionnaire 25

Annex C Document Management 26

C.1 Document History 27

Other Information 27



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1 Introduction

1.1 Overview

Long Term Evolution (LTE) is a new air interface for wireless access based on an all IP

network, where the technology provides a framework for increasing capacity, improving

spectrum efficiency, improving cell-edge performance, and reducing latency. LTE has been a

reality in a lot of countries for some time. The industry is also experiencing increasing activity

from IPX vendors and mobile operators indicating that they are ready for LTE data roaming.

LTE roaming would be imperative to extend the home LTE experience when a customer is

outside of the home network.

The purpose of this handbook is to explain the necessary conditions and requirements which

will need to be in place and as such, would enable mobile operators to more quickly launch

LTE roaming. This handbook is intended to be a point of reference for this new area in

roaming, assisting operators in implementing LTE Roaming for the first time. By providing an

overview of the unique issues related to launching LTE services in one document, it is

expected that this handbook will help mobile operators eliminate lengthy searches for

information. Operators can reference the document for education on LTE and then seek

further information in relevant GSMA PRDs.

1.2 Scope

The handbook covers seven main activities required to enable roaming, as follows;

1. Documentation needed for LTE launch - covers the contractual aspects from the

roaming agreement to the launch letter.

2. Connectivity – explains the connectivity aspects of LTE roaming.

3. Voice and SMS – describes how voice and SMS calls are handled in LTE roaming.

4. Testing – covers the various aspects of LTE roaming testing.

5. SIM Cards – gives an overview of the SIM cards required for LTE.

6. Billing & Reporting – explains how to identify LTE traffic and 3G billing fields.

7. Fraud – discusses fraud implications in LTE roaming.

The handbook concludes with an annex containing an LTE questionnaire, which can be

used as a base to be modified and exchanged with roaming partners to gather information

needed to launch LTE services.

This handbook is intended to be a quick reference guide to implementing LTE roaming and

is not intended to replace the in-depth standard PRDs. This PRD will continue to be updated

as the LTE architecture and standards evolve.

1.3 Abbreviations

Term Description

AAA Authentication, Authorization and Accounting

APN Access Point Name

CAMEL Customized Application for Mobile network Enhanced Logic

CS Circuit Switch



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Term Description

CSFB Circuit Switch Fallback

DCH Data Clearing House

DEA Diameter Edge Agent

DNS Domain Name System

DRA Diameter Routing Agent

EPC Evolved Packet Core

E-UTRAN Evolved Universal Terrestrial Radio Access Network

FCA Financial Clearing Agent

HSS Home Subscriber Server

IMS IP Multimedia Subsystem

IPX IP eXchange

IRA International Roaming Agreement

IOT Inter-Operator Tariff

LTE

Long Term Evolution. LTE is a set of enhancements to the Universal Mobile

Telecommunications System (UMTS) which was introduced in 3rd Generation

Partnership Project (3GPP) Release 8

MAP Mobile Application Part (protocol)

MME Mobility Management Entity

MOC Mobile Originated Call

MTC Mobile Terminated Call

NAS Non-Access Stratum

NGMN Next Generation Mobile Networks

OCS Online Charging System

OEM Original Equipment Manufacturer

OpData Operational Data

P-GW Packet Data Network Gateway

PCC Primary Component Carrier

PCRF Policy and Charging Rules Function

PMN Public (Land) Mobile Network

PRD Permanent Reference Document

QoS Quality of Service

RAEX Roaming Agreement Exchange

RAU Routing Area Update

S-GW Serving Gateway

SCTP Stream Control Transmission Protocol

SGs interface between the Mobility Management Entity (MME) in the EPS and the Visitor

Location Register (VLR)

SGSN Serving GPRS Support Node

SKU Stock Keeping Unit



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Term Description

SMS Short Message Service

TAP Transferred Account Procedure

TCC TAP Completion Certificate

UICC Universal Integrated Circuit Card

ULI User Location Information

USIM Universal Subscriber Identity Module

VoLTE Voice over LTE

VPMN Visited Public (Land) Mobile Network

1.4 References

Ref Doc Number Title

[1] BA.27 BA.27 Charging Principles

[2] BA.40 BA.40 Roaming Guide

[3] BA.42 BA.42 GPRS Packet Switched Charging Handbook

[4] BA.50 BA.50 Technology Neutral Agreements Handbook

[5] IR.21 IR.21 GSM Association Roaming Database, Structure and Updating

Procedures

[6] IR.23 IR.23 Organisation of GSM International Roaming Tests

[7] IR.25 IR.25 VoLTE Roaming Testing

[8] IR.34 IR.34 Guidelines for IPX Provider networks

[9] IR.58 IR.58 IMS Profile for Voice over HSPA

[10] IR.65 IR.65 IMS Roaming and Interworking Guidelines

[11] IR.88 IR.88 LTE and EPC Roaming Guidelines

[12] IR.92 IR.92 IMS Profile for Voice and SMS

[13] IR.94 IR.94 IMS Profile for Conversational Video Service

[14] RCC.50 RCC.50 RCS-e - Advanced Communications Services and Client

Specification

[15] TD.43 TD.43 TAP Test Cases (TTC) for GSM Phase 1 Services

[16] TD.47 TD.47 TAP Test Cases (TTC) for GPRS Services

[17] TD.50 TD.50 TAP Test Cases (TTC) for VoLTE Roaming Testing

[18] TD.51 TD.51 TAP test Cases (TTC) for LTE and EPC Roaming Testing

[19] TD.57 TD.57 TAP3.12 Format Specification

[20] TD.58 TD.58 TAP3.12 Implementation Handbook

[21] AA.12 AA.12 International Roaming Agreement

[22] AA.13 AA.13 International Roaming Agreement - Common Annexes

[23] AA.73 AA.73 Roaming Hubbing Client to Provider Agreement

[24] AA.74 AA.74 Roaming Hub-to-Hub Agreement

[25] AA.80 AA.80 Agreement for IP Packet eXchange (IPX) Services

[26] AA.81 AA.81 PACKET VOICE INTERCONNECTION SERVICE SCHEDULE



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Ref Doc Number Title

to AA.80

[27] BA.12 BA.12 Transferred Account Procedure and Billing Information (TAP

3.12)

[28] BA.19 BA.19 RAEX Op Data Business Requirements

[29] BA.29 BA.29 RAEX IOT Business Requirements and IOT Rules and

Procedures

[30] TD.41 TD.41 Testing the Transferred Account Procedure (TAP)

[31] TD.60 TD.60 TAP 3.12 Scenarios

[32] TD.67 TD.67 RAEX IOT Format Specification

[33] TD.77 TD.77 RAEX Op Data Format Specification

[34] 3GPP TS 23.122 Non-Access-Stratum (NAS) functions related to Mobile Station (MS) in

idle mode

[35] 3GPP TS 31.101 UICC-terminal interface; Physical and logical characteristics

[36] 3GPP TS 31.103 Characteristics of the IP Multimedia Services Identity Module (ISIM)

application

[37] 3GPP TS 26.101 Mandatory speech codec speech processing functions; Adaptive Multi-

Rate (AMR) speech codec frame structure

2 Documentation Needed For LTE launch

2.1 IRA / IR Hubbing Agreement

Current Technology Neutral Roaming Agreement Templates AA.12 ‎[21] and AA.13 ‎[22], as

well as the Roaming Hubbing Agreements (AA.73 ‎[23] and AA.74 ‎[24]), are equipped to

support the implementation of this service between existing roaming partners.

No additional agreements need to be signed as these templates were future proofed for the

implementation of new mobile technologies and networks. Instead, LTE is launched as a

new service (see below).

2.2 AA.14 (RAEX IOT and RAEX OpData)

Operators need to complete the LTE related fields that have been included in RAEX IOT and

RAEX OpData formats, so that their roaming partners are aware that LTE service is

available. Please refer to BA.19 ‎[28], BA.29 ‎[29], TD.67 ‎[32] and TD.77 ‎[33] for more

information.

In the case where there is a differentiated rate to be applied between roaming partners for

LTE traffic, a separate section within the RAEX IOT would need to be populated with the

corresponding charging scheme. Also, if the PMN opts to assign specific personnel for LTE

roaming agreements or operational management, the RAEX OpData document would need

to be updated to include these new contacts.

2.3 Launch Letter

A new Launch Letter for LTE Roaming Service needs to be signed between roaming

partners, once the appropriate IREG testing has been completed and TAP Testing

Certificates are exchanged.



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This document needs to specify the reference to LTE Roaming Service launch and the

agreed date for commercial implementation between the parties. In BA.50 ‎[4] Annex 16 a

template for a Launch Letter for LTE Roaming Service can be found.

Within the Roaming Hubbing context, the launch procedure for LTE services would follow

existing hub established processes for the launch of new services.

3 Connectivity LTE entails a complete new roaming network architecture, principally as all LTE traffic (both

signalling and content) is provided over IP. This implies new infrastructure and protocols for

connectivity between roaming partners.

In the picture below, the basic differences between the 2G/3G roaming and LTE roaming

architectures are shown. For LTE, only the home-routed model is represented, which is

equal to how packet switched services are set up at present.

For Voice over LTE (VoLTE), it is assumed that operators will implement the local-breakout

architecture. In local-breakout architecture, PGW of the VPMN is used (also see chapter 4

on Voice and IR.88 ‎[11]).

Figure 1: Network Achitecture High Level: 2G/3G Comparison with LTE

3.1 Signalling Connectivity - Diameter

Legacy GSM/3G networks mainly use Signalling System nº7 (SS7) for authentication and

authorization of a customer´s registration at a visited network. The LTE network uses the

Diameter procedure which is transported on the Session Control Transmission Protocol

(SCTP) to provide the Authentication, Authorization and Accounting (AAA) framework, as

well as real-time policy management and resource control.

Diameter is implemented through the following elements:

VISITED NETWORK

IPX (recommended)

VISITED NETWORK

SS7 message = MSU

Diameter message = Commands

HOME NETWORK

LTE roaming architecture – Home Routing

Diameter (SIGNALLING)

GTP v2 (USER TRAFFIC)

HOME NETWORK

SS7 (SIGNALLING)

GTP v1 (USER TRAFFIC)

GRX

2G/3G roaming architecture

S6a interface

S8 interface Operator A

HSS

PDN GW

Operator B

MME

Serving GW

Operator A

HLR

GGSN

Operator B

VLR MSC

SGSN



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A Diameter Routing Agent (DRA) is rolled out between multiple key mobile core

network components (e.g. PCRF, OCS, MME, HSS) and routes, manages and

simplifies the operation of the network. If a DRA is not deployed, individual links

between each network element should be installed, which would be very inefficient.

Diameter Edge Router (DEA) is placed at the edge of the mobile network to secure a

network when interfacing with external networks. This can enable GSM/3G and LTE

roaming with third-party networks.

Taking into account the “always connected” state of smartphones and other devices, it is

important to guarantee that congestion in the “signalling channels” (due to the massive

numbers of Diameter messages needed to establish and maintain the service or real-time

policy management and charging) is avoided. To help manage this, some operators have

chosen to deploy load-balancers that can be coupled to network-critical components for

customer or billing management.

Operators have the option to outsource the handling of the (international) Diameter

procedure using DEA to their IPX provider.

Two important services impacted by the switch from SS7 signalling to Diameter are CAMEL

and network steering. The functions of CAMEL are replaced with other functions in the new

network architecture (see ‎3.2 User Data Connectivity). Steering will require upgrades or a

new system (6.5 LTE Steering Issues).

3.2 User Data Connectivity

The design of the LTE network architecture optimizes the connectivity of the user for

extended data volumes, reduced latency, complete guarantee of Quality of Service and, for

improved battery life of the device (due to better management of the idle mode).

The LTE access network consists of a range of base stations, E-UTRAN NodeB (eNB),

generating a flat architecture with the network intelligence distributed amongst them, instead

of centralizing this as in GSM/GPRS/3G. Due to this distribution, the connection set-up is

faster and the time required for a handover is reduced. To support this in signalling, a new

interface (X2) has been defined between eNodeB, working in an interlaced way. The main

purpose of this interface is to minimize packet loss when the terminal moves across the

access network, as now unsent or unacknowledged packets stored in the old eNodeB can

be forwarded or tunnelled to the new eNodeB.

A roamer is connected to the E-UTRAN, Mobility Management Entity (MME) and Serving

GateWay (S-GW) of the visited LTE network. However, depending on the scenario, in LTE

either the PDN-GateWay (P-GW) of the visited or of the home network is used. It is expected

that data-services that do not require a high Quality of Service and a low latency will

continue the current home-routed scenario, but that Voice over LTE (VoLTE) will be

implemented with local breakout. For the home-routed scenario, the home network's P-GW

is used. For the local breakout scenario, the VPMN´s P-GW gives the roamer access to the

requested service.



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Figure 2: Overview LTE Traffic Routing - Local Breakout and Home Routed

Figure 3: LTE Roaming Architecture (IR.88 [11])

The LTE Evolved Packet Core (EPC) includes a Policy and Charging Control (PCC)

architecture that provides support for dynamic control of QoS and charging requirements for

the services the customers require. It also provides improved support for roaming.

The PCRF (Policy & Charging Rules Function) is the essential network component for this,

being responsible for policy control decision-making, as well as for controlling the flow-based

charging functionalities. In the home-routed scenario, the PCRF of the HPMN is in charge of

Services

HSS

MME

PGW

hPCRF

S6a S8

VPMN

HPMN

E-UTRAN

User Plane

Control Plane

SGW

S9

PGW

(Visited)

vPCRF



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this. In the future local breakout scenario, a proxy-PCRF (V-PCRF), which is aligned with the

H-PCRF, may intervene.

Figure 4: OCS/PCRF Control Home Routed Scenario

In this new network-design, CAMEL is no longer supported, nor required, as it is possible to

include the Home Online Charging System (OCS) within the diameter flows and control the

customers´ usage through this.

In local breakout scenarios, though, the HPMN has less visibility of its customer’s data

usage, and, in order to capture real-time information, the diameter interface should be

established between the OCS and the P-GW/PCRF.

Figure 5: OCS P-GW/PCRF Control Local Breakout Scenario

3.3 IPX Service

The IP Packet Exchange (IPX) was developed to cope with the increasing all-over IP

infrastructure of mobile and fixed networks. An IPX service provider or carrier should support

end-to-end QoS and service-awareness, features not available with GRX.



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According to GSMA, the IPX supports three interconnect models, which service providers

are free to choose on a per service basis:

Bilateral Transport Only – the IPX provides transport at a guaranteed QoS. Each

service provider will pay their respective IPX provider costs for transport. The bilateral

agreement is between end service providers and any payment of termination charges

is a matter for the service providers.

Bilateral Service Transit – the IPX provides QoS based transport and cascading

interconnect payment facilities. This enables an originating service provider to make a

single payment to its IPX provider who passes a payment on to the next IPX provider

in the value chain who pays the final termination charge to the terminating service

provider.

Multilateral Hub Service – the IPX provides QoS transport and cascading

interconnect payments to a number of interconnect partners via a single agreement

between the service provider and IPX. This “one-to-many” mode is operationally

highly efficient for the service provider. Charging transparency is a requirement on

both IPXs and service providers in this model.

The IPX should be isolated from the public internet both for routing, DNS and peering. A

connection between a provider and the IPX should use a Border Gateway (BG) to protect

the mobile network from the IPX network. It is up to the operator and the IPX carrier to define

how the Diameter routing is arranged, as this role could be outsourced to the carrier.

For LTE data transport over S8 interface (GTP tunnel between S-GW and P-GW), it is a

best-effort transport, which follows the same principle as GRX. However, on the Diameter

interfaces (e.g. S6a interface), QoS must be implemented to ensure the delivery of the

Diameter messages. See IR.34 ‎[8] for more details.

For other services, work is ongoing within GSMA to standardize the requirements for IPX

peering: the definition of IPX transport and to what point this should be included in the

service level agreements is not yet finalized. Also, work continues on the charging principles

between the carriers as it is not clear that all parameters are in place to apply the “sending

party pays” principle. Other charging principles could be based on the Class of Service

(Conversational, Streaming, Interactive, Background) applicable to each type of service the

customer is using. Furthermore, QoS parameters such as service availability, jitter, delay

and packet loss should be defined in the service level agreement.

For technical details of the IPX backbone, see IR.34 ‎[8]. For the commercial and agreement

requirements, see AA.80 ‎[25] & AA.81 ‎[26].

4 Voice and SMS The handling of voice calls on LTE handsets is evolving as the mobile industry infrastructure

evolves towards higher LTE availability.

In the first phase, currently under way, all voice traffic is handled by legacy circuit switched

2G and 3G networks, while with data, LTE packet switched networks handle traffic, where

available.



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In the second phase of LTE voice evolution, Voice over LTE (VoLTE) along with enhanced

IP multimedia services such as video telephony, HD Voice and Rich Communication Suite

(RCS) are expected to become the standard format for voice calls. Even as VoLTE is initially

launched, VoLTE handsets will continue to require circuit switched fallback for roaming.

4.1 Circuit Switched Fallback

The VoLTE (Voice over LTE) standards and network definitions for interconnection and

roaming are still being worked on. In the first phase of LTE roaming deployment, the voice

service will therefore be delivered through the circuit switched fallback feature.

Voice is delivered over 2G/3G networks only through circuit switched services. Where the

legacy 2G/3G network and the LTE network co-exist the fallback mechanisms need both

VPMN and HPMN to support this model.

Mobile devices with CS fallback function will be needed by the subscriber. The mobile device

needs to be attached to both 2G/3G and on LTE via LTE access via SGs interface. The SGs

is a new interface between the MME and the MSC. When the device starts to receive a call,

it must be able to automatically switch to 2G/3G with no impact on roaming interfaces in

2G/3G or LTE interfaces (SS7, Diameter and IPX carrier).

In IR.88 ‎[11] the technical details of this scenario can be found.

4.2 SMS

When circuit switched fallback has been deployed, SMS messages are delivered via SMS

over SGs. The SMS is transferred via SGs to the MME and then sent via NAS signalling to

the LTE device. Without SGs support, a device connected to an LTE network cannot even

perform fall back to 2G/3G to send or receive an SMS message and voice calls. When SMS

over SGs is used, no changes to existing billing and charging mechanisms should be

required.

Once VoLTE is deployed, a combined attach to the circuit switched network may no longer

be required. SMS messages can be sent and received via IMS. The new Messaging Event

record type supported in TAP 3.12 will be used for charging of SMS over IMS records.

4.3 VoLTE

VoLTE (Voice over LTE) provides to the network operator the ability of its subscribers to

make and receive calls over an LTE network. VoLTE standards and definitions were defined

by GSMA in 2010 with the first version of IR.92 ‎[12] IMS Profile for Voice and SMS. Both

home and visited networks need to support IMS and VoLTE for the service to work. Local

breakout for VoLTE is the standard. Further information can be found in IR.92 ‎[12] and IR.88

‎[11].

VoLTE calls involve 3 types of “chargeable units”:

1. Underlying signalling for call setup and control should always be IMS anchored to the

HPMN: Signalling should be zero rated in roaming scenarios

8. Bearer traffic associated with the VoLTE call. VoLTE bearer traffic utilizes the “well

known” IMS APN, which is broken out locally by the VPMN. Bearer traffic for VoLTE

calls should be zero-rated in TAP or not present, depending on the VPMN’s ability to



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identify and filter. If additional IMS services such as Rich Communications Services

(RCS) have also been deployed on the IMS APN, the VPMN must implement flow

based charging mechanisms to identify the non-chargeable VoLTE bearer traffic from

billable data traffic generated by other IMS based services.

9. Minutes of usage = duration as currently for CS voice call: charged as per IOT

VoLTE “calls” are represented in a single Mobile Session TAP CDR in the same manner like

the case with voice over circuit switched. As such, VoLTE calls cannot be partially presented

on TAP and are not allowed to be included in CS MOC and CS MTC Events on TAP.

The Radio Access Technology GPRS/UMTS/LTE can’t be used as a price differentiator for

services on top of the bearer. Voice and SMS services over CS or LTE are subject to a

single IOT independent of the underlying bearer.

The VPMN should not charge for the underlying packet switched bearer usage where it

decides to charge for the service invocation itself. This is actually the recommended

charging principle, i.e. to charge for the service independently of the technology used and to

charge for the voice call and not for the data used in a VoLTE call.

From a commercial perspective a double charging regime is highly undesirable and even

may not be sustainable in some instances (for example in case regulation is applicable).

Roaming and Interconnect (and in particular the combination of the two) have proved difficult

to complete. Examples of the difficulties encountered include:

1. Technically optimal approaches do not take into account the need to interwork or fall

back to existing circuit switched techniques.

10. Commercial requirements further restrict the technical solution.

11. Work in 3GPP completed to address the requirements

VoLTE and SMS over LTE are currently set up to rely on local breakout in the VPMN. These

services are not yet completely defined at the interconnection level.

4.4 Local Breakout

Local breakout is where an operator chooses to allow its customers to use the services of

the visited operator (VPMN) to optimise the customer experience and offer local services.

Local breakout for data is a known concept in GPRS and 3G standards that no operator has

truly adopted. The real issue has been the lack of demand from operators that have

preferred a roaming situation with an ‘always home’ orientation where home policies can be

enforced.

The business case for local breakout for data in roaming is still evolving. It is unclear

whether local breakout for any data services other than IMS will be required. Both HPMN

and VPMN will be required to have policy control functions fully implemented and

synchronised. Local breakout is a requirement for the “well known” IMS APN used for VoLTE

roaming. Local breakout could be deployed by APN with some services requiring local

breakout while others continue to be home routed.



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Local Break Out drivers:

Lower latency for conversational communication within VPMN country

Access to local services

IR.92 ‎[12] requirement for VoLTE roaming (Capacity savings and no call tromboning)

But many issues and challenges:

No Service Aware Charging (retail and wholesale) without OCS

Strong impact on prepaid roaming

Both HPMN and VPMN need to be capable and agree to offer the service.

At this time no operators have come forward to offer a local breakout service for LTE and

there is a question whether local breakout will be adopted before VoLTE roaming is ready for

market.

5 Testing

5.1 Purpose

This section does not intend to go into detail on the definition or explanation of the testing

scenarios, as there is an existing list of PRDs (IR.24, IR.35 and others) currently providing

the relevant level of detail, scope and purpose for each testing, with the appropriate depth

when it comes to LTE.

The goal though is to give a general overview of the functional capabilities necessary to

make the most of the testing process for LTE, as well as the main aspects to consider in the

testing phase, in opposition to those applicable for 2G and 3G. Besides that, related topics

like SIMs, devices, cost, etc…will be covered with different level of detail depending on the

impact in the testing process.

It is advised to look at IR.38, which covers LTE data services, CS Fallback and SMS over

SGs, and TD.43 [15] for CS Fallback for more indepth information about the testing process.

NG has also defined IR.38 LTE and EPC Roaming Tests and IR.25 [7] VoLTER Testing.

5.2 Requisites

Operators starting a testing process to open a roaming LTE relationship are advised to

check the proper functioning of user and any network features required by both the HPMN

and VPMN separately. The scope also includes the confirmation of acceptable quality of

transmission, absence of echo and call set-up delay as basic principles.

The overall objective of the tests is to confirm that the functions and features, which are

already known to operate correctly within each separate PMN, will also operate correctly for

Inter-PLMN roaming.

In addition to the regular objectives (voice calls, SMS, supplementary services,), the specific

objectives for LTE testing are to make sure:



V2.0 Page 16 of 28

The test cases are repeated for each manufacturer, in case either the HPMN or

VPMN contain IP Multimedia Subsystem/ Evolved Packet System (IMS/EPS)

Network Entities which are supplied by more than one manufacturer.

And, therefore, If the HPMN contains Home Subscriber Server (HSS) and Serving –

Call Session Control Function (S-CSCF) from M suppliers and the VPMN contains

Proxy – Call Session Control Function (P-CSCF) from N suppliers, and all the

different nodes can be used in a roaming scenario, then potentially the tests should

be performed (M x N) times. The actual number of repeats of the test cases is for

bilateral agreement between the HPMN and VPMN.

However, if agreement is not straightforward, it is up to the HPMN to decide the

scope of the repetition of test cases, because it is ultimately responsible towards

its customers for the services supported when roaming.

With regards to the testing itself, three new test cases have been added to IR.38 and TD.47

‎[16] in order to cover data over LTE. For VoLTE testing, NG has defined IR.25 ‎[7] and IDS

will create a TD.50.

Some basic user equipment requirement, necessary for undertaking the test cases

described in the relevant PRDs (note only a one way testing is considered here, but the

same should be replicated on the other edge to make the bilateral testing):

Two Mobile devices supplied by VPMN (b) supporting LTE.

Two PSTN telephones in PSTN (b).

Two USIMs supplied by HPMN (a), (in opposition to regular SIM cards which might

be already at VPMN side from previous testing processes).

Two USIMs supplied by VPLMN (b).

The tests are to cover the following domains involved in roaming:

Diameter interconnection testing

Packet switched services

Circuit switched fallback

Non regression testing of roaming services

Wholesale and retail roaming billing

End to end QOS measures

Some additional considerations:

LTE testing will have to cover a set of different frequencies to support worldwide

roaming;

Diameter replaces MAP and a new interface S6a between MME and HSS need to be

implemented.

New types of DNS resource records have to be supported and implemented in

authoritative DNS

SGSN will have to be upgraded to support enhanced gateway selection

Circuit switched fallback is the intermediate solution adopted by both NGMN and

GSMA waiting for Voice over LTE

TAP version 3.12 is advised for LTE traffic (required for VoLTE).



V2.0 Page 17 of 28

This means the elements in the testing (USIM vs. regular SIM) plus the additional testing

compared to well-known 2G-3G testing may result in an increased cost for the overall testing

process in LTE, but no more specific figures are available to illustrate the difference between

the costs of both(absolute figures nor percentage wise).

5.3 Roaming Hubbing Testing

For an LTE opening through a Roaming Hub, the operator will have to perform the same IR

document tests as for the bilateral LTE opening, before sharing such documents with the

Roaming Hub.

6 SIM Cards - The Role of the UICC in LTE Roaming The LTE flat and open architecture brings high-security risks that must be mitigated by

deploying highly secure and tamper proof devices. The security is provided by the use of

UICCs (Universal Integrated Circuit Cards) more commonly known as the SIM (Subscriber

Identity Module). Just as in 2G/3G networks, the UICC authenticates the subscriber to the

network while ensuring the integrity and security of personal data. The UICC provides a

higher level of security allowing carriers to cope with the security threats present in all digital

networks. To access LTE, a USIM is required.

6.1 UICC OTA Configuration

With LTE technology and the introduction of the all IP environment, current OTA (Over The

Air) exchanges for administration between the UICC and servers will be done through HTTP.

Each card acts as an HTTP client and the OTA platform as an HTTP server. OTA success

rate and efficiency of massive updates is maximized by combining TCP/IP reliability with pull

mode from the UICC.

6.2 Network Selection Overview

The UICC card contains different PLMN (Public Land Mobile Network) lists. Each PLMN

identifies a specific network from a country. As per 3GPP TS 23.122 ‎[34], the device shall

check the content of the right PLMN to attach to the network. “PLMN Lists with Access

Technology” files contain radio access technologies, i.e. the way the device shall connect

(GSM, UTRAN, etc.) to the MNO network. LTE (also called E-UTRAN) has been added to

the list of reachable radio technologies in those files.

6.3 UICC Portability and LTE Spectrum Fragmentation

One of the most problematic issues facing LTE roaming today is spectrum fragmentation.

Different countries are using different LTE bands and since devices today do not support all

bands, this prevents subscribers from enjoying LTE mobile broadband service continuity

when traveling. The removable UICC cards grants subscribers the possibility to use a local

device (with the right LTE frequency bands) while keeping their operator subscription (phone

number), tariffs and services.

6.4 VoLTE and IMS Network Access

In the LTE network, new services move to IP (Internet protocol) and are operated through

the IP Multimedia Subsystem (IMS) network. Co-existing on the same UICC platform with

the USIM application is the ISIM - IP Multimedia Services Identity Module – defined in the

3GPP TS 31.103 ‎[36] & 3GPP TS 31.101 ‎[35] and that provides access to the IMS via any



V2.0 Page 18 of 28

IP access network. The ISIM enables each subscription to have multiple public identities. It

enhances interoperability by reducing the options for implementation as there is no need to

accommodate legacy USIM or CSIM (CDMA Subscriber Identity Module) applications. In

addition, the ISIM facilitates the provisioning of important parameters across all mobile

terminals. However, the use of ISIM is not mandatory. See IR.92 ‎[12] for more details.

6.5 LTE Steering Issues

Most existing steering solutions rely on SS7 node based redirections. The LTE architecture

does not use SS7 signalling so operators will need to evaluate LTE steering solutions. When

evaluating solutions, operators should consider both LTE steering and solutions that can

address circuit switched fallback scenarios.

Whilst an HPMN and a VPMN may have an established UMTS/GSM roaming agreement,

LTE roaming may not yet be available. Without LTE roaming enabled between the HPMN

and VPMN, UMTS/GSM inbound roamers with LTE-capable UMTS/GSM handsets may be

restricted from roaming on to the UMTS/GSM network unless and until manual re-selection

of the UMTS/GSM network is made.

Without LTE roaming being enabled the access control in the VPMN rejects the LTE Attach

request with an applicable cause code to allow the device to select another radio access

technology for the same PMN (e.g. UMTS/GSM). The issue specified above is caused by a

non-recommended LTE attach reject cause code being returned by some LTE networks, to

roaming subscribers. The result is that handsets will not attempt to roam onto the

UMTS/GSM network and therefore access is restricted to the roaming subscriber, even

though an existing roaming relationship for UMTS/GSM exists.

GSMA IR.88 ‎[11] (LTE Roaming Guidelines) recommends LTE networks should return #15

(no suitable cells in tracking area), however a number of LTE networks are returning #11

(PLMN not allowed) or #14 (EPS services not allowed in this PMN).

The impact on the VPMN when returning a wrong reject cause would be the loss of inbound

roaming traffic.

7 LTE Devices

7.1 Spectrum

LTE spectrum fragmentation mentioned in Section 6.3 presents challenges when designing

LTE devices to work both in a home and roaming environment. As of September 2013, LTE

has been deployed in 26 different bands. It is important to understand the difference

between frequency and bands. The frequency (referred in MHz and allocated as FDD or

TDD) is the spectrum licensed to each operator. Spectrum can be assigned to multiple

device bands; and multiple licenses may be assigned to a single band. As an example, there

are at least ten spectrum licenses and seven bands within 700MHz frequency range. 3GPP

TS 26.101 ‎[37] version 12.0.0, Table 5.5-1 E-UTRA Operating Bands contains the list of

available LTE bands.



V2.0 Page 19 of 28

7.2 Device Planning

Operators should review the LTE bands supported by devices to understand what LTE

networks devices can utilize when away from home. Device OEMs have released several

SKUs of the same device model in order to support specific network and regional LTE band

requirements. Operators desiring to roam in a band not used in the home network may need

to work with their device planning group to identify strategic roaming bands. A device needs

to include the band of the serving network in order to attach to and facilitate LTE roaming

with a roaming partner. As an example, an operator who has deployed LTE in 800MHz

(band 20) will not be able to roam on an 800MHz network (band 18) unless the device

supports both bands.

8 Billing and Reporting

8.1 Data on LTE

Apart from the new air interface, E-UTRAN, the main architectural change at the core

network level is a logical split of the GGSN into two separate Gateway nodes, the Serving

Gateway (S-GW) and the Packet Data Network Gateway (P-GW). In the case of roaming, an

S-GW of the VPMN is employed. The charging scenario varies depending on the choice of

P-GW:

Home Routing: S-GW in VPMN, P-GW in HPMN

Local Breakout: S-GW in VPMN, P-GW in VPMN

All existing GPRS and 3G PS charging mechanisms are also supported in LTE/EPC. The S-

GW and the P-GW create charging information similar a GGSN in 2G/3G. Enhanced

charging mechanisms (Flow Based Charging) is only supported at the P-GW. The VPMN

can use the call records from SGSN and SGW for home-routed access and additionally from

PGW for local-breakout, like today for GPRS/3GPS.

In addition, LTE/EPC provides the necessary infrastructure so that a VPMN could employ

Flow Based Charging in case of local breakout in order to charge more in line with the

service invocation of the customer rather than for mere bearer usage.

For inter operator charging this means that the existing accounting mechanisms will also

work for LTE/EPC based roaming subject to an enhanced identification of the packet

switched charging scenario which needs to take into account the location of the P-GW

(alternatively, to the location of the GGSN in 2G/3G).

The implementation of a Service Based Accounting regime which takes advantage of Flow

Based Charging will require a switch from home routing to local breakout and is still for

further study at this stage.

Below is a brief list of changes made in TAP to support LTE/EPC

Added two new Recording Entity Type values to define the S-GW and P-GW in TAP.

Editorial change to CallTypeLevel1 to reflect HP-GW, VP-GW & Other P-GW.

Updated the Duplicate Check for GPRS to include P-GW.



V2.0 Page 20 of 28

8.2 Voice and SMS over LTE in TAP

The following section provides a brief overview of voice and SMS over LTE in TAP. This

summary was taken directly from BA.27 ‎[1], which covers the topic in greater depth and

should be referred to for the most up to date information.

Packet switched bearer services are not invoked as services in their own right but typically

form the basis for services such as browsing, email, person-to-person communication

services such as voice or messaging.

Due to the original bit pipe architecture of 3GSM packet switched services, service

invocation on top of a packet switched bearer service was, in almost all instances, not visible

to the VPMN and therefore the VPMN could only charge a packet switched ‘bit pipe’ tariff to

the HPMN.

In general, it is an objective for VPMNs to become service aware in order to provide adaptive

bearer capabilities to the roaming customer (typically optimised quality of service) and to

charge accordingly, that is, according to the service invocation in line with service specific

charging principles stated in other sections of this document.

Service awareness in the VPMN will typically rely on local breakout and the possibility to

apply Flow Based Bearer Charging mechanisms.

If a VPMN is able to recognize the service invoked on top of the bearer and decides to

charge for the service invocation itself, the VPMN should not additionally charge for the

underlying packet switched bearer usage.

The first category of services for which this will be applicable is VoLTE (Voice over LTE)

which is the GSMA endorsed variant of voice and SMS implementation over LTE, as VoLTE

is designed to support service awareness in the VPMN.

It is recognised that operators may, in some instances, have a requirement to charge for the

underlying bearer usage even if they charge for the service invocation itself (for example in

order to prevent misuse/fraud). From a commercial perspective a double charging regime is

highly undesirable and may not be sustainable in some instances (for example in case

regulation is applicable) [End BA.27 ‎[1] information].

VoLTE roaming will offer the option to use local breakout (LBO). After the originating call is

routed to the HPMN to execute originating services the HPMN can decide on a per VPMN

and on a per call basis whether the VPMN can do the onward routing directly instead of

doing the onward routing from the HPMN. The reason is that a direct routing of the call from

the VPMN will reduce latency for voice calls.

Rates for SMS and voice will, for the moment, continue to be independent of the enabling

technology. For example, the same SMS rate will be used for SMS over packet switched and

SMS over signalling.

8.3 Identification of Data on LTE

Data traffic carried on LTE can be identified by the Recording Entity Type. A new value of “8”

was added to indicate an S-GW (Serving Gateway) which is used in LTE.



V2.0 Page 21 of 28

8.4 Fields Changed from 3G

The table below identifies some new fields that apply to LTE

Item CS LTE

User Identities IMSI / MSISDN IMSI complimentary with Private User ID

Public User ID

Originaition / Destination

E.164 Number E.164 Number , SIP URI, Tel URI

CDR Source MSC SGSN , S-GW , P-GW , P-CSCF

CDR Correlation Not Required Required by using the Charging ID present in the EPC & IMS Domain

CDR Unique Identifier Call Reference & SMS Reference

IMS Charging Identifier

Location Information LAC / Cell ID ULI – User Location Information

9 Fraud Considerations

9.1 LTE Data Roaming

The transmission of NRTRDE records for data continues to remain optional for LTE data

roaming. Assuming that local breakout has not been implemented, the home network should

consider utilizing records from the home P-GW to monitor roaming data consumption.

Records from the P-GW contain similar detail to those created by a GGSN.

Assuming local breakout is deployed at the visited network, alternative methods for

monitoring data roaming will be required as the home P-GW will not have visibility of this

traffic. There are multiple locations within the HPMN’s core network that can provide visibility

of bearer traffic volumes once IMS roaming has been implemented.

9.2 VoLTE Roaming

Since the HPMN has real-time visibility of VoLTE calls made on the VPMN network,

NRTRDE voice records are no longer needed for fraud monitoring purposes. It is suggested

that the HPMN utilize a source on its IMS network (such as the Telephony Application

Server) to monitor for fraudulent calls that originate on a VoLTE roaming network.

9.3 Unique LTE Fraud Risks

The Security Group reviewed LTE and identified physical security of eNode Bs and cabling

as a new threat for LTE fraud. If fraudsters are able to access the eNode Bs or cabling, they

can “clip in” to the system and inject their own traffic which the operator will end up paying

for. Additionally, the Security Group is maintaining an LTE Risk Register identifying risks

unique to LTE systems. This register can be obtained on request to [email protected]

and operators are encouraged to report LTE security incidents to that email address to

ensure they are added to the register.

mailto:[email protected]



V2.0 Page 22 of 28

Annex A Related PRDs Referenced

A.1 BA.27 Charging Principles

This document sets out the charging and accounting principles/framework to be used

between operators for roaming.

A.2 BA.40 Roaming Guide

This manual is mainly intended for new operators who are implementing roaming for the first

time. It is also intended for existing operators as an aid to train new personnel in the roaming

function. This is a package of information to get started fast, minimizing the background

research needed to get started. The information is gathered from people who have years of

experience in the roaming business. In addition to the formal process documentation, some

real life experiences and tips on how to get started are included.

A.3 BA.42 GPRS Packet Switched Charging Handbook

The content of this document is for information only and is to provide additional explanations

for the understanding of the rules in BA.27 ‎[1] and BA.12 ‎[27], which remain the only PRDs

where the rules are contained.

A.4 BA.50 Technology Neutral Agreements Handbook

This document contains guidelines for the usage of the Technology Neutral Roaming

Agreement and templates for launch letters of roaming services and enablers.

A.5 IR.21 GSM Association Roaming Database

The IR.21 Database has been created for operators to provide their technical network

information which is required by roaming partners in order to support roaming. The IR.21

document describes the structure of the database, the type of reports, the procedures for

updating it and the update schedule. The IR.21 Database is updated when a PLMN updates

its network information or when a new PLMN is introduced. The database has been

designed to update all PLMNs automatically when a change is made to the database. IR.21

Annex A provides the template for PLMNs to fill in their technical network information.

A.6 IR.23 Organisation of GSM International Roaming Tests

The scope of this document is to define a methodology for testing, and maintaining in the

presence of faults, the inter-PLMN international roaming facility.

A.7 IR.25 VoLTER testing

This document provides IREG test cases that are required to be performed before starting

VoLTE roaming.

A.8 IR.34 Connectivity Requirements

The document provides a brief introduction to the requirement for IP interworking and the

IPX. It covers the background to the forerunner of the IPX, the GRX.

A.9 IR.38 LTE and EPC Roaming Tests

This document provides IREG test cases that are required to be performed before starting

LTE data roaming, 2G/3G data roaming via EPC, CS fallback roaming and SMS over SGs

roaming.



V2.0 Page 23 of 28

A.10 IR.58 IMS Profile for Voice over HSPA

The IP Multimedia Subsystem (IMS) Profile for voice over High Speed Packet Access

(HSPA), documented in this Permanent Reference Document (PRD), defines a profile that

identifies a minimum mandatory set of features which are defined in 3GPP specifications

that a wireless device (the User Equipment (UE)) and network are required to implement in

order to guarantee an interoperable, high quality IMS-based telephony service over HSPA

radio access.

A.11 IR.65 IMS Roaming and Interworking Guidelines

IR.65 gives common guidelines for IMS (IP Multimedia Subsystem as specified by 3GPP)

inter-operator connections in order to prevent non-interoperable and/or inefficient IMS

services and networks. Areas covered in the document are IMS specific issues in roaming

and interworking, addressing of users and network elements, routing of traffic, inter-operator

related security issues, IP version usage and requirements for inter-PLMN backbone caused

by IMS. The document concentrates on network level issues.

A.12 IR.88 LTE and EPC Roaming Guidelines

This PRD presents material about LTE roaming, 2G/3G data roaming via EPC, CS fallback

and SMS over SGs. The document addresses aspects which are new and incremental to

LTE: It recognises that much of the data roaming infrastructure is reused from GPRS and

High-Speed Packet Access (HSPA) roaming, and for which information and specification is

found in other PRDs.

A.13 IR.92 IMS Profile for Voice and SMS

This document defines a minimum set of features that UE and networks must support for

IMS voice and SMS in EUTRAN. The PRD lists a number of Evolved Universal Terrestrial

Radio Access Network, evolved packet core, IMS core, and UE features, which are

considered essential to launch interoperable IMS based voice. The Annex A also describes

features to complement IMS with CS.

A.14 IR.94 IMS Profile for Conversational Video Service

This document provides a definition of an IMS profile by listing a number of Evolved

Universal Terrestrial Radio Access Network (E-UTRAN), Evolved Packet Core, IMS core,

and UE features which are considered essential to launch interoperable IMS based

conversational video service.

A.15 RCC.50 RCS-e Advanced Communications Services and Client Specifications

The purpose of this document is to provide detailed specifications that are based on the

current RCS Release 2 specification in order to set the initial reference implementation of the

RCS-e services that are planned to be implemented by a number of operators throughout

the world.

A.16 TD.43 TAP Test Cases (TTC) for GSM Phase 1 Services

This document includes the TADIG test cases for CS fallback.



V2.0 Page 24 of 28

A.17 TD.47 TAP Test Cases (TTC) for GPRS Services

This document specifies the TAP Test Cases (TTC) for GPRS services that have to be

executed by the roaming partner in its quality testing as a visited network, as applicable and

in accordance with the TAP Testing Procedures as defined in PRD TD.41 ‎[30] "Testing the

Transferred Accounts Procedure (TAP)".

A.18 TD.50 VoLTE Testing

This document includes the TADIG test cases for VoLTE roaming and is related to IR.25.

A.19 TD.51 TAP Test Cases (TTC) for LTE and EPC Roaming Testing

This document includes the TADIG test cases for LTE and EPC roaming and is related to

IR.38.

A.20 TD.58 TAP 3.12 Implementation Handbook

The document is intended to supplement the TAP specification as detailed in PRD TD.57

and the scenarios detailed within PRD TD.60 ‎[31]. There will be no detailed examples in this

document. For detailed examples see related TD.60 ‎[31] document.



V2.0 Page 25 of 28

Annex B LTE Questionnaire Answers to the following questions should provide some basic guidance regarding timing

and the features supported by your future LTE and VoLTE roaming partners.

HPMN asking VPMN - Support of Inbound LTE Roaming

What frequencies are being used to deploy your LTE network? (Specify 3GPP bands)

What duplex scheme is being deployed (TDD or FDD)?

Please provide details on your LTE coverage. (e.g. city, suburban, rural, hot-spot/small cells)

When will your network be able to support inbound LTE data roaming?

Does your network support circuit switch fall back (CSFB)?

Do you plan to implement an IMS core for your network? (If so, for what services?)

Will your network support local breakout of the "well known" IMS APN? Other APNs? How many APNs will you require to be supported?

Do you support IPv6 and/or dual stack IPv4/v6 on your PDN GW and IMS core?

Will your network provide RAU and ULI information?

Does your network plan to support VoLTE for inbound roamers? If so, approximately when?

What methods of SMS delivery will be supported for inbound roamers?

Do you plan to implement differentiated IOTs for LTE data, SMSoLTE or VoLTE?

What version of TAP will you send your roaming partner for LTE data roaming, for VoLTE and for SMSoLTE?

Will you comply with the TAP standard for VoLTE and SMSoLTE and supply your roaming

partner with the new TAP records?

If not, how will you supply VoLTE and SMSoLTE usage information in TAP?

Will you provide S-GW Recording Entity Type in TAP sent to your roaming partner for all LTE generated data?

Will you utilize your existing TADIG code for LTE or use a new one?

VPMN asking HPMN - Support Outbound LTE Roaming

When will your network be able to support outbound LTE roaming?

What type and how many LTE devices have you deployed?

What LTE bands do your devices support?

What SMS delivery methods do your devices support?

Will you support VoLTE when capable devices roam?

Do you require circuit switch fallback (CSCB)?

Have you selected an IPX provider(s)? If so, who has your company selected?

Do you require local breakout of the IMS APN? Other APNs?

For VoLTE and/or SMSoLTE do you require the new TAP 3.12 records?

Do you require TAP to differentiate LTE data usage from other data usage?



V2.0 Page 26 of 28

Annex C LTE Roaming Partner Implementation Checklist

# Item Completed

1 Verify frequency compatibility □

2 Ensure you have a signed Technology Neutral roaming agreement □

3 Negotiate IOT (Optional) □

4 Exchange RAEX IR.21 □

5 Exchange RAEX OP Data □

6 Update your network with IR.21 received from your partner □

7 Exchange LTE provisioned SIM card(s) □

8 Exchange LTE devices for testing (To ensure frequency compatibility

for CSFB behaviour) □

9 Open diameter exchange (screening) with your partner □ 10 Validate Roaming partner supports CSFB and SMS over SGs

11 Support QoS requirements from your roaming partner □

12 Make sure your IPX provider is peering with your partners IPX

provider (If they are not the same IPX provider) □

13 Exchange operator specifics test scenarios ( example: IR.24, IR.25 &

IR.35) □

14 Setup billing system for your partner □

15 Schedule testing □

16 Test IR.24 for CSFB and SMS over SG, and also IR.25 for VoLTE □

17 Test IR.35 for LTE data □



V2.0 Page 27 of 28

18 Generate TAP TD files □

19 Complete TADIG test TD 47 for IR 35 and TD 43 for IR 24 □

20 Exchange TCC for LTE □

21 Sign launch letter (Template found in BA.50 annex 16) □

22 Advise your DCH of new launch (Or a new relationship in case this is

the first launch for this roaming partner) □

23 Advise FCA of new relationship □

Annex D Document Management

D.1 Document History

Version Date Brief Description of Change Approval

Authority

Editor /

Company

1.0 9 April

2014

LTE Roaming Implementation

Handbook

BARG #83 &

PSMC

Ryan Weikert -

Verizon

Wireless

1.1 23 October

2014

Provided correct references to

TADIG testing documentation for

LTE roaming.

BARG #84 Ryan Weikert -

Verizon

Wireless

1.2 15 Dec

2014

Transferred PRD from BARG to

WAS as BA.65 v1.2

WAS David Chong.

GSMA

N/A 7 Jan 2015 Editorial Update to change

reference to IREG to NG

N/A Ryan Weikert -

Verizon

Wireless

1.3 20 Mar

2015

Added checklist Annex C - Tasks

required to launch LTE with a

roaming partner.

WAS Ryan Weikert -

Verizon

Wireless

Other Information

Type Description

Document Owner WAS

Editor / Company Ryan Weikert - Verizon Wireless



V2.0 Page 28 of 28

It is our intention to provide a quality product for your use. If you find any errors or omissions,

please contact us with your comments. You may notify us at [email protected]

Your comments or suggestions & questions are always welcome.

mailto:[email protected]

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