Tektronix LTE Solutions

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Testing Next Generation Networks 3G to 4G The
Core Infrastructure Revolution and the impact on
IMS
Broadband Communication Technology May 2008
Bernd Wessling, Application Engineer, Tektronix
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Testing Next Generation Networks From IMS to LTE

• Testing 4G Networks
• Testing of IMS Server Systems
• Testing LTE Core Networks (SAE)
• 4G Network Test Strategy The Big Picture

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Testing 4G Networks General Guidelines

• 4G technologies (WiMAX, LTE) are still rapidly
  changing
• Staying close to industry forums and
  standardization bodies remains key
• TTCN-3 support of 3GPP, WiMAX Forum
• Industry led test initiatives attempt to
  accelerate 4G technologies
• LTE Field Trial Initiative
• NGMN
• IMS Forum
• Multi-Service-Forum (MSF)
• WiMAX Forum

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Testing 4G Networks4G Core Networks

• 4G Core Networks need to evolve with the
  deployment of 4G Access Technologies (LTE, WiMAX)
  
• LTE transmits 100MBit/s per cell one single
  six-cell eNodeB can transmit up to 600MBit/s into
  the core network!
• WiMAX transmits 40MBit/s per cell one single
  six cell WiMAX Base Station can transmit up to
  240MBit/s into the core network!
• Circuit Switched connections do not exist anymore
  all transport is IP based XoIP!
• QoS mechanisms need to function well otherwise
  real time critical services (voice, video) will
  have problems
• Core network will go All-IP Carrier-grade,
  five-9 reliable IP network needs to be deployed
• IP based End-to-End Security Mechanisms will be
  introduced (IP-Sec)

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Testing 4G Networks4G Core Networks

• Testing 4G Core Networks
• Extreme load levels require next generation probe
  systems and new data reduction algorithms (real
  time data mining)
• Due to the different, sophisticated services with
  varying transport requirements (real time
  criticality) user plane testing is taken to the
  next level
• In-band QoS mechansims
• Application based switching /routing
• Service specific KPIs, etc.
• XoIP networks have very different operating
  characteristics. New sets of KPIs, which
  correlate with actual operational state of the
  network need to be defined, tested and
  implemented
• New end-to-end security methods (IPSec based
  authentication and ciphering) complicate
  management, analysis and troubleshooting
• IMS based services will replace proprietary
  service delivery platform

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Testing 4G Networks4G Core Networks

• IMS Network Properties Relevant for Testing
• IMS Architecture introduces standardized
  interfaces for the 4G core network interfaces
  UNI, NNI and Application Server Interface
• Introduction of advanced security, billing and
  registration mechanisms
• Support for complex integrated services
• Testing IMS Networks
• Comprehensive interoperability testing at P-, I-,
  and S-CSCF interface
• Backwards interoperability with Early-IMS, SIP,
  Proprietary Core
• Comprehensive security, billing and registration
  testing
• Functional Load testing for new services POC,
  Location, Presence

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Testing Next Generation Networks From IMS to LTE

• Testing 4G Networks
• VI Testing of IMS Server Systems
• Testing LTE Core Networks (SAE)
• 4G Network Test Strategy The Big Picture

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VI Testing of IMS Server Systems

• Key for success in IMS is
• Conformance to IMS transport, security, AAA and
  service protocols
• Proven interoperability with existing IMS
  implementations
• Proven interoperability with IMS service
  applications
• Proven interoperability with IMS terminals
• Performance of IMS implementations
• Required Test Scenarios are comprehensive and
  complex
• Authentication
• Registration
• Call/Session Setup
• Call/Floor Control
• Media Authorization
• Media Transport
• PDP Context Management
• Configuration/GM

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IMS Standardization 5 Segments with different
interest areas and focus
VI Testing of IMS Server Systems
Which Standard?
1
OMA
GSMA
3GPP
IETF
ITU SG9 (IPCableCom)
DSLWiFI
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2
Corba
CMTS (WiMAX)
OSA
ITU SG11NGN
CableLabs (Private company industry
consortiumbut own standards)
TISPAN
Parlay
Jain
Public Internet (Meshed Networks/ Client Centric
Approach)
ECMA (ETSI)Next Generation Corporate Networks
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5
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VI Testing of IMS Server Systems

• Use Case 1 Pure IMS test
• Tester focused on the IMS domain
• Enables functional and load testing of IMS
  network elements and subsystems
• Use Case 2 End-to-end test
• Covers complete mobile network
• Includes UE, mobile access network (e.g. UTRAN)
  and CS/PS core network
• Impact of access network parameters on IMS
  services can be tested
• Enables end-to-end QoS testing

Option 2
Option 1
IMS Enabling Services
IMS Core Functions
CS/PS Core Network
Access Network
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VI Testing of IMS Server SystemsIMS Test Suite
NNI Test Cases
UNI Test Cases
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Testing Next Generation Networks From IMS to LTE

• Testing 4G Networks
• VI Testing of IMS Server Systems
• Testing LTE Core Networks (SAE)
• 4G Network Test Strategy The Big Picture

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LTE/SAE System Test Architecture
(1) Interface based on GTP
Gb
Iu
(1)
S3
S4
Rx
(1)
S6a
S7
PDN SAEGateway
HPLMN
S11
VPLMN
S1_MME
Serving SAEGateway Local non 3GPPAnchor
SGi
S8b
S1_U
S2b
Evolved Packet Core
S2a
WLAN AccessNetwork
WLAN 3GPP IP Access
Source 3GPP TR 23.882 v1.6.1
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LTE SAE Test Challenges

• General Test Requirements
• 2.5G/3G Interworking regarding MM Scenarios such
  as Multi-RAT HO, Cell Selection/Re-Selection
• Interworking with Non 3GPP IP Access (e.g. WiMAX)
  and WLAN 3GPP IP Access
• IP-Service Domain Interworking (e.g. IMS)
• QoS Handling/Management
• Protocol Monitoring correlating multiple
  interfaces (S1, X2, S3, Iu, Gb,)
• Interoperability Testing
• Multi-Technology (LTE ltgt GSM, GPRS, UMTS, WiMAX)
• Multi-Vendor
• System Integration
• Performance Verification and Test
• High performance tests for network nodes, such
  e-NodeB and MME/UPE
• Multi-Technology
• Multi-Vendor

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Testing Next Generation NetworksFrom IMS to LTE

• Testing 4G Networks
• VI Testing of IMS Server Systems
• Testing LTE Core Networks (SAE)
• 4G Core Network Test Strategy The Big Picture

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4G Network Test StrategyThe Big Picture

• Stay close to test initiatives, plug-fests, field
  trial initiatives and standardization bodies
• Build IP Test Expertise to achieve Five9 IP
  reliability
• Develop XoIP test concepts
• Create and implement a 4G Core Network Test
  Strategy
• Prepare for 10x load levels
• Implement working load balancing / QoS
  mechanisms
• Develop relevant KPIs reporting actual
  network/service performance
• Prepare for managing in secure, Ipsec protected
  environment
• Prepare migration to standardized IMS based
  service deployment infrastructure

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Unmatched Expertise, Unparalleled Portfolio
Thank You

• Test Solutions from Tektronix