Long Term Evolution (LTE) Emulator for X2 Interface

Welcome to another May 2013 issue of GL's Newsletter providing information and insight into our latest MAPS™ LTE Emulator for X2 Interface. Long Term Evolution is the all packet architecture that mobile networks are in the process of transitioning. It will permit vastly higher data rates to mobile smartphones, making voice, video, and data truly integrated for the first time - thru a single access technology. This is yet to be accomplished over wired networks.

In simple terms, LTE consists of a "Packet Core" and a network of eNodeBs (as shown below). eNodeBs have two interfaces, the X2 interface permits eNodeBs to talk to each other directly, and the S1 interface permits talking to the "Packet Core".

MAPS™ LTE Emulator for X2 Interface Network

Overview

GL has introduced LTE X2 Interface Emulation to test and verify eNodeB implementations through its MAPS architecture. Message Automation & Protocol Simulation (MAPS™) is a multi-protocol, multi-technology platform used for the emulation of a variety of communication protocols over IP, TDM, and Wireless networks. MAPS™ can be used to test signaling over legacy networks (such as CAS, SS7, ISDN, PPP and more), IP networks (such as SIP, MGCP, MEGACO, SIGTRAN, Diameter...) and also Wireless technologies including GSM, UMTS, and LTE networks. Recently LTE X2-AP has been introduced.

MAPS™ X2 Application Protocol (X2-AP) Interface Emulator is used to co-ordinate handovers and perform load management between eNodeB (Evolved Node B) network elements - Source eNodeB and Target eNodeB. The MAPS™ X2-AP test tool is designed with specific test cases, as per LTE 3GPP mobile standards.

MAPS™ LTE X2-AP Interface Emulator supports powerful utilities like Message Editor, Script Editor, and Profile Editor which allow new scenarios to be created or existing scenarios to be modified using messages and parameters.

Possible applications include:

  • Simulate up to 500 Smartphones (UEs) powering up and down
  • Authenticate and confirm security procedures
  • QoS requests for greater or lesser bandwidth
  • Temporary addressing management for mobility and security

Call Generation

Call Generation option allows the user to simulate outgoing communications where an outgoing call is initiated by sending call control messages using proper scripts and profiles. The profile allows necessary parameters of call control messages to be changed during runtime.

Testing Target eNodeB in X2 interface 

Here, MAPS™ acts as Source eNodeB, and tests the DUT that is configured as Target eNodeB. MAPS™ initiates the messages towards the end-terminal and responds to messages from the DUT.

MAPS™ X2 configured as Source eNodeB

MAPS™ X2 configured as Source eNodeB 

The test is performed to ensure that the MAPS™ X2 configured as Source eNodeB initiates the procedure by sending the HANDOVER REQUEST message to the Target eNodeB. The Target eNodeB (DUT) shall reserve necessary resources, and send the HANDOVER REQUEST ACKNOWLEDGE message back to the Source eNodeB. The call generation screen shot depicting the Handover Procedure flow is as shown below.

MAPS™ LTE X2 AP handover procedure generation

Call Reception

Call generated from other entity can be automatically detected in call reception window by pre-setting the required scripts in the Incoming Call Handler window.

Testing Source eNodeB in X2 interface 

This test is performed to ensure that the MAPS™ X2 configured as Target eNodeB in order to receive and process the Handover Request message from the Source eNodeB (DUT) in the X2 interface.

MAPS™ X2 configured as Target eNodeB

MAPS™ X2 configured as Target eNodeB

Handover Procedure Reception at Target eNodeB

Handover Procedure Reception at Target eNodeB


Main Features

  • Simulate two eNodeB elements in LTE X2-AP interface
  • Supports LTE Control plane
  • Generates hundreds of UE Signaling (Load Testing)
  • Generates and process X2-AP (valid and invalid) messages
  • Supports Mobility Management, Load Management, Reporting of General Error Situations, Re-setting X2, Setting up the X2, and eNodeB Configuration Update procedures
  • Insertion of impairments to create invalid messages
  • Supports customization of call flow and message templates using Script and Message Editor
  • Ready-to-use scripts for quick testing
  • Supports scripted call generation and automated call reception
  • Script based & protocol independent software architecture
  • Provides Call Statistics and Events Status
  • Supported on Windows® XP and Windows® 7 (32 bit and 64 bit) operating systems

Call Statistics, Events, Link Status

By default, all call handling scripts (irrespective of the type of the functions) are assessed by MAPS™ LTE S1 to provide statistical information about total calls, active calls, completed calls, passed calls, and failed calls. It is also possible to characterize the statistical information under different groups of call handling scripts under a unique heading.

Call Statistics Status

For comprehensive information on the application, you can refer to the MAPS™ LTE for X2 Interface Emulator web page.


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