AMG4.6 and LSF2.0

Status date

There are two separate development efforts for this project which are captured internally within Altobridge as AMG4.6 and LSF2.0.

AMG4.6 Project

AMG4.6: The main objectives of AMG4.6 are to satisfy requirements from our existing customer base to increase the value proposition of the AMG system. A number of features are being added to this release including Edge, AMR, Channel Quenching and enhancements to the current operation of the Bandwidth Manager functionality. This release will allow for a smarter internal method of managing the ever increasing number of terminals which our customer base chooses to deploy within their network. Coupled with this software development effort will be a comprehensive set of customer facing documentation which will clearly outline the benefits of the release and provide details on the upgrade and maintenance of their systems.

LSF2.0 Project

LSF 2.0 builds on our initial release of the Local Switching product by improving its functionality. Specifically in the areas of supporting Multiple PDCH channels for GPRS and Edge, Licensing, codec matching and the integration of the LS OMC with a Vendor Network Management System. In addition to the software development there will be a comprehensive set of customer facing documents and training materials.


The new suite of customer bandwidth terminals will need to be closely managed as each one is quite unique. This will be handled through regular communication with the customer from a project management perspective but also through rigorous onsite testing with the customer.

For LSF2.0 end to end System Test is only possible in the customer lab environment. As such we need to engage in a Joint System Test phase.


AMG4.6:- We have clearly demonstrated our ability to provide both single and multiple TRX remote system which generates a positive Return On Investment for GSM operators and helps them meet their universal Service Obligations for small communities (100 to 200 users) with a relatively high ARPU of 10$ to $20. With the release of AMG4.6, Altobridge will further enhance its product offering by enabling customers to use a wide variety of bandwidth terminals thereby allowing them to extend their market penetration as the end customer needs dictate. Altobridge will further refine and improve the existing backhaul bandwidth savings to be made through the implementation of the Channel Quenching feature.

LSF2.0:-This project has the following benefits:

  • LS supports the following standard GSM services: Mobile originated and mobile terminated voice services
  • Short Message Service (SMS)
  • General Packet Radio Service (GPRS) CS -1 to CS-4)
  • EDGE (Enhanced Data rates for GSM Evolution) (Multi Coding Scheme) MCS-1 to MCS-9
  • CSD (Circuit Switched Data) /Fax service.

The benefit for mobile subscribers in implementing LS is better voice quality for locally switched calls due to shorter delay.

The LS solution offers a significant reduction in operating expenditure of GSM sites as a percentage of calls are locally switched, reducing satellite and terrestrial bandwidth requirement. This results in extra savings for the operator. Satellite bandwidth requirements are further reduced by optimisation of the Abis over IP.

The following codecs are supported:

  • Full Rate (FR)
  • Half Rate (HR)
  • Enhanced Full Rate (EFR)
  • All AMR codecs

LS supports intra cell handover and Inter cell handover within the RGW. This means that the call remains locally switched after the handover. If one of the parties on a locally switched call requires handover to a cell outside of the RGW, the call is handed back to the network.


AMG4.6 Project

Architectural Diagram

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BTS: This element of the overall system shall consist of a standard low power pico-cell BTS (IP Access BTS, note that AMG5.0 will add support for the Ericsson PICO BTS).
Remote Gateway: The Altobridge Remote Gateway, in conjunction with the Altobridge Ground Gateway, shall enable the use of minimal bandwidth while providing ubiquitous GSM Voice and SMS services to mobile users. It essentially shall emulate the GSM function of a BSC in conjunction with the Altobridge Ground Gateway.

Remote Gateway Structure

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Satcom Terminal: This aspect of the overall solution provides connectivity between the Remote Gateway and the Ground Gateway.
Ground Earth Station (GES): This entity of the overall solution provides the connectivity between the satellite network and terrestrial telephony and packet data networks. It is the complimentary peer of the satellite terminal equipment.
Ground Gateway: The Ground Gateway shall provide the complementary peer of the Remote Gateway and this system shall provide a standard inter-connect to the Public Land Mobile Network (PLMN) this essential part of the Altobridge product offering shall enable multiple Remote Gateways to interact with standard GSM network through one interface.
MSC: The Mobile Services Switching Centre (MSC) is an integral part of an existing PLMN. It shall provide standard MSC and Visitor Location Register (VLR) functions for the subscribers at remote locations.

LSF2.0 Project

Architectural Diagram

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To integrate Local Switching into the customer product suite, two new network elements are integrated into the current BSS architecture:

  • RGW - remote Abis gateway located with the BTS
  • CGW - central Abis gateway located with the BSC

The RGW (Remote Gateway) and the CGW (Central Gateway) as seen in the figure above are the base components of Local Switching technology. The RGW is the interface between the remote BTS and the E1 or T1. The CGW is the interface between the BSC and the E1 or T1.

The other components (BSC, MSC etc) are independent of the Altobridge solution and not governed by our architecture in anyway. As such, their function remains the same as described previously in the AMG architectural description.


As this project encompasses two separate deliverables, there are two project plans as detailed below.

The implementation and execution of both projects will be achieved through feature assignments to key technical leads within Altobridge and validated through rigorous System Test phase.

The project plan is to deliver the software features on the AMG4.6 release in line with the planned timeline to exceed customer expectations.

Specifically, the features which will be developed and delivered include:

  • AMR
  • Edge
  • Enhanced Bandwidth Management
  • Extended Welcome Character Set
  • Channel Quenching
  • Optimised Long Signaling
  • Full Rate Calls
  • EP8 Features for Aero Market

Technical Writing updates to support the new software feature detail.


This project will deliver the following features;

  • Licensing
  • Codec Matching
  • Multiple PDCH Support for GPRS & EDGE
  • OMC to NMS Integration
  • Customer Document Set
  • Customer Training Materials
Current status

Specific details follow:-

AMG4.6 software has for the most part been developed and delivered. There is one remaining software component currently being worked (EP8) which is specifically for our Aero customer. In addition the Customer facing documentation and training materials are being drafted.

LSF 2.0 is now at pilot stage with a major customer. We continue to work the customer facing documentation as well as concluding the final features.