Case Studies

The Challenge

leading Network Infrastructure provider approached Cell Telecom for assistance in migrating large amounts of subscriber data from a number of operational local telephone exchanges to state-of-the-art Softswitch i-Nodes. The migration process was required to be able to handle ongoing subscriber data changes (churn) and have no impact on the operational performance of the live switches in a major UK operators Network upgrade.

How We Met the Challenge:

• Capturing of requirements from the client and their end customer
• Create XML schema for Subscriber data
• Develop Java application to create XML from Subscriber data
• Transform XML to MML using XSL/XSLT
• Develop Java wrapper application for testing of XSL/XSLT
• Participate in demos to the client’s end customer
• Automate the various stages using Robotask

Competencies deployed to this task:

• Project Management
• Requirement Management/Capture
• JAVA
• NetBeans
• XML
• XSL/XSLT/XPath/XQuery
• Access
• Robotask

The Challenge

Cell Telecom was asked by a leading Network Infrastructure provider to provide the resources and expertise for the development of the Home Location Register (HLR) in a major Mobile Development Project.

How We Met the Challenge:

Cell Telecom supplied a team of 12 Telecoms experts to assist in the development and test of the new HLR Front End node as part of the Project. The team worked in the customer’s offices in Madrid and remotely for the duration of the 8 month assignment. The project involved a major functional change of the HLR software for it to operate in a Layered Architecture environment where the HLR data is stored on a separate commercially available database solution.

The work was required to be completed within extremely tight timescales and this required the adoption of radical design and development methods where coding was undertaken directly from high level design documents. The Cell Telecom team were able to work with these new methods and tight timescales where they designed and implemented a number of functions that included:

• MAP Operation Handling
• Common GAS Handling
• Control of Traffic and Provisioning Processes in Database Blocks

Additionally, Cell Telecom provided test resources that were responsible for the development and execution of Location Based Services (LBS) tests, and also to assist in System Test trouble shooting.

Competencies deployed to this task:

• AXE Systems
• HLR Architecture
• MAP Signalling
• Clearcase
• Location Based Services
• Proprietary Design Environment
• Adoption of the client’s radical Design Methodology

The Challenge

Cell Telecom has been approached on numerous occasions by a leading Network Infrastructure provider to provide expertise and resources in the Testing of its Softswitch. Cell Telecom have provided Project management, Test management and test teams, ranging from 3 to 12 test resources, working remotely from our Brighton Office.

How We Met the Challenge:

Below are details of some of the key project which we have run or been involved in, giving a glimpse of the range of knowledge and expertise we can bring to test projects:

• Setting up of a remote test environment from our offices in Brighton and Stockholm to access a grid of servers located at the client’s offices in Brazil. Driving changes to the remote grid to improve the way the servers and required tools were accessed.
• Planned and executed a test project for the client’s Softswitch project in France.

The size of the test project was 4000 mh.

• Planned and executed a large test project for the client’s Softswitch project in Croatia. This included working alongside a local Ericsson company, to support their testing effort and environment by delivering TTCN courses and providing technical support and configuration management.
• Produced Test Specifications from both Functional and Requirement specifications. Reviewing the documentation and progressing the documentation status according to the client’s processes.
• Developed fully automated test scripts for TTCN. Including the creation of a protocol test suite according to specification.
• Building test builds from a reference build, maintaining the build in terms of data, software level and status. Making built test beds available to other sites and incorporating any requested changes to the build or data.
• Executing TTCN tests. Reporting test progress and raising and tracking defects according to Ericsson processes.

Competencies deployed to this task:

• Project management
• Team leading
• Configuration management
• Corporate course delivery
• TTCN
• Test case design
• Test execution
• Defect investigation and resolution
• Corporate course delivery

The Challenge

Cell Telecom were requested by a major Network Infrastructure provider to produce for their end customer, a comprehensive subset of the Use Cases as Message Sequence Charts; that would imply the total behaviour of the customers UK Softswitch based network in terms of the networks logical and physical standards components.

The Network is based on current standards specifications, in particular ITU-T and UK NICC specifications for SIP-I networking and TISPAN specifications for AGW, BGW, TGW and MS control via the relevant H.248 standards for each node. All the related IETF RFCs were also applicable.

The produced call flows show the behaviour of the various interfaces for basic calls and the related to type network supplementary services.

The call flows include the following interfaces:

• POTS / DSS1 / DASS2 / DPNSS access
• DSS1 / DASS2 / DPNSS signalling via IUA and DUA
• SIP-I Intra Operator network signalling
• SIP-I Inter Operator network signalling

As well as providing access to the next Generation of voice protocols, the Softswitch was also required to provide access to legacy services for all UK subscribers and interface with all other UK operators.

How We Met the Challenge:

Cell Telecom provided an autonomous skilled team, to work directly with client’s end customer, taking responsibility for producing and delivering the Network Use Case Descriptions to the end customer.

Cell Telecom took responsibility for ensuring that the end customer’s requirements were fulfilled, from initial development through to system test; the charts were taken as the ‘de facto standard’ for Message sequences within the multi-vendor project. The descriptions were provided as Call flows, structured as use cases with use case parts. Common use case parts were defined once only, allowing their re-use. Thereby, a structured set of call flows was produced with cross referencing.

The Challenge

A major Network Infrastructure provider approached Cell Telecom to provide resources and expertise to perform a feasibility study (for design and test) for the delivery of the Voice Group Call Service (VGCS), specified through 3GPP, intended for the German subsidiary of a large global operator as a solution for Professional Mobile Radio (PMR) also known as Private Mobile Radio.

How We Met the Challenge:

Cell Telecom performed an analysis of the 3GPP specifications for the VGCS and Voice Broadcast Service (VBS) and from them produced design proposals for implementation in the client’s Core Network products.

The feasibility activities produced the following documentation for the client:

• 3 Implementation Proposals ready for review by the client’s Product Committee.
• Test study and test strategy reports for the services.

Expertise in the AXE system and PLEX language was used in conjunction with an analysis of the 3GPP specifications in order to produce the feasibility studies. The feasibility study documentation was delivered to the client within an aggressive time plan necessitated by the end customer.

Competencies deployed to this task:

• Mobile Switching Centre (MSC) (Anchor and Relay nodes for the services)
• Base Station Controller (BSC)
• 3GPP specifications
• Signalling protocols: MAP, BSSAP and ISUP
• AXE system and the PLEX language.