MAPS™ LTE for S1 Interface Emulator
(Scripted LTE S1 Interface Emulation)
Background
The above diagram depicts some of the internals of the Long Term Evolution (LTE) network. The user (UE) has very high speed
RF connection to the nearest local tower. This high speed connection is always ON, as long as the mobile is powered up. LTE is an
all IP infrastructure with service priority built in – audio and video are given priority. All necessities like IP address, authentication,
and security are validated. Instant resources over RF (the air) and IP (internal network) are made available depending on what the
user is attempting to do. Also, LTE is designed for compatibility with older 2G and 3G mobile systems.
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eNode B is the base station in the LTE/SAE S1 interface and also includes MME (to handle signaling of control plane)as shown
in the network diagram above.
Overview
GL’s Message Automation & Protocol Simulation (MAPS™) designed for testing LTE – S1 interface (any interface
excluding Air interface) can simulate eNodeB (Evolved Node B), and MME (Mobility Management Entity).
The application is available as
- MAPS™ - LTE-S1 (Item # PKS140) for S1-MME interface
MAPS™ is also capable of simulating S11 and S5/S8 (LTE-eGTP) interfaces. Refer to MAPS™ LTE eGTP
(S3, S4, S5, S8, S10, S11 and S16 ) webpage for more details. Other interfaces such as S4, S11, and S12 will also be supported by the application
in near future.
The application gives the users the unlimited ability to edit S1-AP/NAS messages and call scenarios (message sequences).
"Message sequences" are generated through scripts. "Messages" are created using message templates.
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
GL also provides a GUI based LTE Analyzer for on-line capture and decode of the signaling in
real-time both during tests and as a stand-alone tracer for live systems.
Main Features
- Simulates eNodeB, and MME elements in S1 interface.
- Supports LTE control plane.
- Generates and responds to hundreds of UE Signaling (Load testing)
- Generates and process S1/NAS messages (valid and invalid).
- Impairments can be applied to messages to simulate error conditions
- Supports customization of call flows and message templates using Script editor and Message editor.
- Ready-to-use scripts for quick testing
- Supports scripted call generation and automated call reception.
- Provides protocol trace with full message decoding, and graphical ladder diagrams of call flow with time stamp
- Script based & protocol independent software architecture.
- Provides call statistics and associated captured events and error events during call simulation.
Supported Protocol Standards
Control Plane for S1-MME Interface
- S1 Application Protocol (S1-AP): Application Layer Protocol between the eNodeB and the MME.
- SCTP for the control plane (SCTP): This protocol guarantees delivery of signaling messages between MME and eNodeB (S1).
SCTP is defined in RFC 2960 [35].
| Supported Protocols |
Standard / Specification Used |
| S1 Interface |
|
| S1 Application Protocol (S1-AP) |
3GPP 36.413 9.0.0 (2009-09) |
| Non-Access-Stratum (NAS) |
3GPP TS 24.301 V9.0.0 (2009-09) |
Test Configuration
This feature allows users to configure the necessary parameters to establish communication between
MAPS™ LTE S1 and the DUT. S1 interface supports SCTP configuration.
Screen Shot of LTE-S1 Testbed Setup Configuration
Typical Call Flow Scenario
LTE-S1 signaling scenario (messages between eNodeB (eNB) and MME (Mobility Management Entity))
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 MME in S1 interface
Here, MAPS™ acts as eNodeB, and tests the DUT that is configured as MME. MAPS™ initiates the messages
towards MME and responds to messages from MME (DUT).
MAPS as eNodeB
The test is performed to ensure that the MAPS™ (eNodeB) sends Attach Request to DUT (MME) in order to
attach an EPC for packet services. The DUT (MME) responds by initiating Authentication procedure and sending
Authentication Request towards UE (User Equipment). MAPS™ (eNodeB) receives Authentication Request message
as depicted in the figure.
Call Generation at eNodeB Node
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 eNodeB in S1 interface
This test is performed to ensure that the MAPS™ (MME) in order to initiate Authentication process, sends
Authentication Request message as response to Attach Request from eNodeB (DUT).
MAPS as MME
Call Reception at MME
Bulk Call Simulation
MAPS™ supports Bulk Call Simulation and Stress/Load Testing capabilities through Load Generation feature.
Load Generation window helps users configure Stress/Load Testing parameters such as Call per second (CPS) or
Busy hour call attempts (BHCA), Max Simultaneous Calls and Burst parameters.
Screen Shot of Load Generation Parameters
Customization of Call Flow and Messages Using Pre-Processing Tools
- Script Editor - The script editor allows the user to create / edit scripts and to define variables for the
protocol fields. The script uses pre-defined message templates to build call flow and perform send and receive actions.
Script editor provides options to run the test for multiple iterations in sequential or random flow. Commands allow
retransmission of messages with specific interval
Screen Shot of Script Editor
- Profile Editor - Profiles are used to provide the user configured values to the fields in the Messages
(i.e Message Template in MAPS™ LTE S1) through variables which are going to change during the course of a call.
Screen Shot of Profile Editor
- Message Editor - The Message Template is a *.HDL file that comprises of protocol encoding parameters with
preset values. It is required to create a message template for every message in a protocol. The message templates are
called within the scripts to perform scenario based testing.
Screen Shot of Message Editor
Call Flow & Script Execution Control
Message Sequence - MAPS™ LTE S1 provides protocol trace with full message decoding, custom trace,
and graphical ladder diagrams of call flow with time stamp while simulation is running. Call flow graph allows to easily
verifying the messages exchanged between MAPS™ LTE S1 and DUT. See Call Generation
and Call Reception for details.
Script Contents & Script Flow - The Scripts Contents window displays the contents of the script selected for
call generation or reception. The Script Flow window displays the set of statements successfully executed by MAPS™ - LTE
S1 to help users in troubleshooting a particular the call scenario.
Events & Event Profile Editor - User-defined events allow redirection of script execution on-the-go. The custom parameters
in the events can also be changed during script execution using Event Profiles
Screen Shot of Script Contents and Script Flow
Screen Shot of Event Config
Call Statistics, Events, Link Status
Call Statistics & 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.
In addition, Call Generation and Call Reception windows provide useful call status & script execution results.
Screen Shot of Call Statistics and Status
Events Reporting – MAPS™ LTE S1 provides Event Log, Error Events, and Captured Errors windows that log the captured events and
errors encountered during the progress of the call.
Screen Shot of Events Log
Buyer's Guide:
Specifications are subject to change without notice.
Back to Message Automation & Protocol Simulation (MAPS™) Index Page
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