GPRS, or General Packet Radio Service, was introduced (in the late 90's and early 2000's) to enhance data carrying capabilities of the basic GSM Network. Initially it used the conventional T1 E1 transport and frame relay protocol. As data traffic (IP) has steadily increased, the use of IP interface provides many advantages including increased throughput, capacity, and economy. Also as the wireless infrastructure evolves towards IP, the migration of 2G IP based systems to 3G and 4G is also more efficient and economical.
To permit our customers to emulate, test, and verify GPRS Gb functionality, GL has enhanced its MAPS™ (Message Automation & Protocol Simulation), a multi-protocol, multi-technology platform to emulate GPRS Gb Interface over IP. MAPS™ also supports many other protocol families including TDM, IP, ATM, and Wireless.
MAPS™ is designed to simulate GPRS Gb interface messages and signaling specification as defined by 3GPP standards. MAPS™ GPRS Gb currently supports Gb interface between the BSS (Base Station Subsystem) and the SGSN (Serving GPRS Support Node) over IP transmission protocol. Emulation over Frame Relay transmission protocol will be supported in future.
Besides testing network elements (SGSN and BSS), the tester also involves error tracking, regression testing, and load testing/call generation. MAPS™ GPRS Gb interface Emulator supports various procedures including Network Service Control, Identity Check, Combined GPRS / IMSI Attach, and Routing Area Update. It can run pre-defined test scenarios against the interface test objects in a controlled & deterministic manner.
MAPS™ GPRS Gb 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 as per the protocol standards listed in the table below.
GL's MAPS™ GPRS Gb software benefits Network Equipment Providers of SGSN, and BSS entities, with -
- Accelerated time to market
- Reduced development costs
- Reduced project risk of internally-developed applications
GL has enhanced its MAPS™ protocol emulation tool to simulate multi-protocol and multi-interface, offering a complete range of test solutions, covering the entire 2G, 3G, and 4G network.
By mimicking real-world customer behavior in lab environments, our solutions allow mobile operators and equipment manufacturers to verify their wireless networks before deployment. In other words, one can setup a virtual real-time network simulating all the network elements using “MAPS 2G Wireless Lab Suite”. The test suite supports simulation of Gprs Gb, Gn Gp, and other interfaces in GPRS network required to simulate PS data traffic.
MAPS™ GPRS Gb (PKS131) supports Mobile traffic simulation over Gb interface between BSC and SGSN. Currently, this module transmits the pre-canned HTTP file (*.txt) between BSC and SGSN nodes. It multiplexes both signaling and traffic over Gb interface. Additionally, this module requires ETH101 - Mobile Traffic Core – GTP module.
GL also provides an independent GUI based GPRS protocol analyzer (optional application – XX155) for online capture and decode of the signaling in real-time both during tests and as a stand-alone tracer for live systems.
- Setup a virtual real-time network simulating 2G-GSM GPRS network elements using ‘MAPS™ 2G Wireless Lab Suite’
- Simulates SGSN (Serving GPRS Support Node) and BSS (Base Station Subsystem) elements in GPRS Gb interface over IP.
- Simulates Control plane Gb mode.
- Generates hundreds of Control Signaling (Load Testing).
- Generates and processes NS (Network Service), BSSGP (Base Station Subsystem GPRS Protocol), and various GPRS session procedure messages.
- Supports Gb interface procedures including Network Service Control, Identity Check, Combined GPRS / IMSI Attach, and Routing Area Update
- Insertion of impairments to create invalid messages.
- Supports GTP Traffic (GTP User Plane Data) which includes: verification like BERT testing, HTTP traffic generation capability, GGSN can actually be connected to real IP network to simulate Gateway testing
- Supports customization of call flows and message templates using Script and Message editors.
- Supports scripted call generation and automated call reception.
- Provides Call Statistics and Events Status.
- Automation, Remote access, and Schedulers to run tests 24/7
- Complete analysis and simulation capability.
- Provides fault insertion, and erroneous call flows testing capability.
- Functional testing, Regression testing and Conformance testing of network elements.
- Ready scripts makes testing procedure simpler, less time consuming and hence time to market products.
- QoS requests for greater or lesser bandwidth.
- GSM GPRS lab setup can be used in educational institutions for training purposes
General MAPS™ Features
- Call Simulation
- Multi-protocol, Multi-interface Simulation
- Script based and protocol independent software architecture
- Auto generate and respond to signaling messages
- Traffic Handling Capabilities (requires additional license)
- Fault Insertion, and Erroneous Call Flows Testing
- Automated Load /Stress Testing
- Scheduler and pre-saved configuration files for automated testing
- Pre-processing tools
- Easy script builder for quick testing to advance testing
- Customization of test configuration profiles
- Unlimited ability to customize the protocol fields and call control scenarios
- Centralized Control and Remote Access
- Command Line Interface (requires additional license)
- Option to send reports to database accessible via web interface
- Centralized control of multiple MAPS™ applications remotely from single client application
- Reports and Statistics
- Call Status, Link Status, and Message Statistics
- User defined Statistics for RTP Traffic parameters
- Capture Events, and Error Events
Call Simulation and Control
The signaling and traffic simulation in a call is completely implemented using scripts. Commands in the scripts are executed in controlled way to simulate protocol and traffic behavior. Most of the commands used in the scripts are generic and independent of specific protocol.
MAPS™ application acts as either the Caller or resides at the network terminal acting as Callee. The Call Generation feature simulates an outgoing call by sending call control messages to the DUT using scripts and profiles. The profiles allow necessary parameters of call control messages to be changed during runtime. Call generated from other entity can be automatically detected in call reception window by pre-setting the required answer scripts in the Incoming Call Handler.
The call control scripts can also automatically handle the traffic over the established call. MAPS™ supports transmission and detection of various traffic types over IP (RTP, GTP), ATM, & TDM - such as, digits, voice file, single tone, dual tones, fax, sms, email, http, ftp, IVR, audio and video quality. MAPS™ also includes support for wide range of codec rates – visit www.gl.com/traffic-simulation.html and www.gl.com/voice-codecs.html webpage for more details.
Message Sequence - Each call scenario provides the trace with full decoding of the messages exchanged between the MAPS™ and the DUT, and graphical ladder diagrams of the call flow with time stamp. Impairments can be applied to messages to simulate error conditions that occur in real-time networks.
Event-Driven Control - Scripts execution, being event-based, allows redirection of script execution on-the-go with user-defined events. The custom parameters in the events can also be changed during script execution using event profiles.
Script Contents & Script Flow - The script flow and the contents window displays the Script Name, Sub-script Name, Script line number, and script statements to be successfully executed, which help the users in troubleshooting a particular call scenario.
Bulk Call Simulation and Load Testing
MAPS™ supports automated stress/load testing capabilities through Load Generation and Bulk Call Simulation features. Bulk Call Simulation allows quick configurations to easily create multiple test entries with different scripts and profiles. Multiple tests can be run simultaneously or sequentially (queue up tasks in succession). Load generation feature further allows specifying the patterns with which the bulk calls can be generated. Load generation can be customized with different statistical distribution patterns such as Uniform, Ramp, Sawtooth, Fixed, Normal, Step, and Step-Sawtooth distribution. Call duration also can be randomized using similar statistical distribution. This feature also helps users configure Stress/Load Testing parameters such as Call per second (CPS), Max Active Call, Minimum and Maximum Call Rates, Start Call Rates, and other parameters.
Scheduler can be used to schedule the simulation of bulk calls or manual calls at a specific start time. The pre-saved master configuration files for test setup and call simulation are automatically loaded to automate the test procedure.
Customization of Test Setup Parameters
The test setup profiles (.xml files) allow users to configure the necessary parameters in order to establish communication between MAPS™ and the DUT. It includes configuring parameters of the network nodes, the network properties, and transport related configurations such as T1/E1 timeslots, IP Address and port numbers for both MAPS™ and the DUT.
Once the transport layer is configured properly, protocol specific signaling messages and traffic can be transmitted and received successfully. All parameters setup in test setup are global and are accessible to all scripts. These parameters initialize protocol engines and the transport modules specific to the protocol.
Customization of Test Parameters, Call Flow, and Protocol Messages Using Pre-Processing Tools
- Message Editor - The Message Templates (GL’s proprietary *.HDL files) 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.
- Profile Editor – Profiles (*.xml files) are used to change the values of the fields in the messages (i.e. Message Template in MAPS™) during the course of a call. The multiple profiles with varying parameter values that allow users to configure call instances in call generation and to receive calls.
- Script Editor - The script editor allows the user to create / edit scripts and to define variables for the fields in the messages. 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.
Command Line Interface
Supports scripting through a Command Line Interface (CLI) such as the Python, and TCL, using MAPS™ client-server functionality (requires additional license)
MAPS™ can be configured as server-side application, to enable remote controlling of the application through multiple command-line based clients. Supported clients include C++, TCL, Python and others. TCL provides a simple scripting language, with programming facilities such as looping, procedures, and variables. The TCL Client application includes a MapsTclIfc.dll file, a packaged library that enables communication with the Server from a TCL environment.
User can remotely perform all functions such as start test bed setup, load scripts and profiles, apply user events such as send digits/file/tones, detect digits/file/tones, dial, originate call, terminate call, start and stop traffic and so on. User can also generate and receive calls through commands. This client application is distributed along with MAPS™ Server application. Multiple MAPS™ CLI servers can be controlled remotely from single client application (such as TCL, Python, etc).
Call Statistics, Events, Link Status
Call Status & Message Statistics - By default, all call handling scripts (irrespective of the type of the functions) are assessed by MAPS™ to provide statistical information about Total Calls, Active Calls, Completed Calls, Passed Calls, Failed Calls, and Calls/Sec. It is also possible to categorize the statistical information as per the call handling scripts. In addition, Call Generation and Call Reception windows provide useful call status & script execution results.
In addition, Message Stats option for any specific protocol, logs number of times the messages are being transmitted (Tx Count) and received (Rx Count), thus allowing user to monitor the occurring events.
User Defined Statistics - Users can customize the global statistics for RTP audio and video traffic. These global parameters are defined in the call generation scripts, which are calculated and updated periodically on run time.
Events Reporting – MAPS™ provides Event Log, Error Events, and Captured Errors windows that log the captured events and errors encountered during the progress of the call.
- Link Status window indicates transport related information of the protocol, for example, if SCTP is used as transport, it indicates if the association is Up or Down in the Link Status window. MAPS™ IuCS ATM uses SSCOP transport and the associated link status is indicated as Up or Down in the Link Status window.