Presentation on theme: "TTCN-3 Based Automation Framework for LTE UE Protocol Stack Testing"— Presentation transcript:
1TTCN-3 Based Automation Framework for LTE UE Protocol Stack Testing Theofanis Vassiliou-GiolesTesting TechnologiesRanganath MahapatraLarsen & Toubro Infotech
2LTE Network Architecture GERANSGSNHSSOperator IP ServicesUTRANPCRFS3S6aMMES7S4LTE-UuS10S11InterneteNBServing GWPDN GWUELTE-UuS1uS5SGiS2aX2S2bS2cePDGTrusted non 3GPP IP AccessTrusted/Untrusted non-3GPP/3GPP IP AccessWn*Untrustednon 3GPP IP AccessUE
3Network Simulator Need for Simulated Environment Before porting a UE protocol stack to a Modem, a simulated environment is required for test and verificationNetwork simulator is implemented on a host environment consisting of an automation framework, test scripts and the UE side interface.Need for Simulated EnvironmentTest environment emulates the functionality of the network elements.It interacts with the UE protocol stack through a common interface in a pre-determined manner as per the test cases.Emulating Network Element FunctionalityThe frame work consists of a test manager, mechanism to capture logs, data analysis and debugging capability in text and graphical mode.It provides scope for integration of external codec and plug ins.Manager, Logger, Debugger
4Protocol Stack Functionality RRCS1-APPDCPSCTPRLCIPMACL2L1NASRRCPDCPRLCMACL1NASS1-APSCTPIPMACL1RelayUELTE-UueNobeBS1-MMEMMEUE protocol stack communicates with multiple elements in the network side though eNodeB.UE control plane protocol layers are mapped to eNodeB and MME.Except for the NAS layer messages, the other layers of UE interact directly with eNodeB protocol stack.
5ETSI Test Scripts in TTCN-3 Testing ArchitectureTest ManagementControl & LoggingAutomation FrameworkTCIETSI Test Scripts in TTCN-3UE Protocol StackTRIRRCPDCPRLCMACMAC-PhySRB Codec ASN.1DRB CodecCodec LayerPDCPRLCMACL2 Layer StubsMAC-PhySystem Adaption LayerUDP / IP
6ComponentsEncodes and decodes the RRC messages which are defined in EUTRA_RRC_ASN1_Definitions.The default technique for encoding and decoding is as per RRC standard is “PER-BASIC-UNALIGNED: 2002”.CodecPDCP, RLC and MAC header encapsulation and de-capsulation of messages and PDUs are some of the functionalities of this module.Other basic functionalities/procedures of PDCP, RLC and MAC, ex - RACH procedure, broadcast etc are also implemented.L2 Layer Stubsdefines the communication protocol between eNodeB and UE protocol stack.The function of MAC-Phy interface is for the synchronization of eNodeB with UE protocol stack on UDP/IP.System Adaptation LayerMAC-Phy layer encapsulates its header into the messages.Wireshark doesn’t support these headers, so required dissectors are implemented in wire-shark to dissect and understand the LTE messages sent via PHYSAP interface.Wireshark Dissection ImplementationConsists of test cases, templates, records, functions, interfaces and TTCN3 ports (TCI & TRI Ports).Additional test cases were also developed to improve the coverage.ETSI Test Script
8Test ExecutionTest case drives the specified procedures for validation of the stack.The Test Manager of IDE provides a GUI interface to run the test cases individually or in batches.The frame work provides log capturing and debugging mechanism both in text and graphical representation
9Our Value Adds on ETSI’s Solution ETSI Test suite provides TTCN-3 scripts for protocol conformance testing.It provides parallel test components and ports for seamless mapping of protocol layers for network side entities.Our Value AddsIn order to optimize the development cycle, we have utilized ETSI test suites, commercially available IDE and external plug ins.Adaptation layers were developedA pseudo MAC-Phy interface layer was implemented.
10ChallengesCodec’s and Adaptation Layers : Requires good understanding of protocol stack layers and specificationDebugging and classification of issues: Differencing between test framework and UE issuesConcurrent Development : Development of Test Framework (IDE), ETSI test cases and UE Protocol stackIdentification of suitable commercial IDE
11Thank You Our Business Knowledge, Experts in Test Automation Your Winning Edge.