System upgrades may consist of:

• capacity enlargement,
• hardware upgrades,
• software upgrades, with or without functional changes.

Capacity enlargement

System capacity enlargement is an upgrade without functional changes. It consists of delivery of additional equipment and installation works (installation of equipment and putting into operation).

Capacity enlargement is performed easily, if the preconditions are met (enough room, etc). Basically, engineering according to new requirements is performed, while taking into account the already available (previous) results. Afterwise, the installation of new equipment may be done without interruption of system operation, unless there are extremeley big or complex changes.

Hardware upgrades

Upgrades which make for changes in the hardware are rare, mostly because most volatile system requirements are, by desing, met in software. These upgrades mostly mean the use of new functionality of new hardware revisions (within the same system version). In majority of cases, this means that there has to be some system capacity enlargement. If some part of existing hardware is replaced, then the replacement is relatively simple, and it includes appropriate software upgrades.

Hardware upgrades may be:

• capacity enlargement - adding equipment which did not exist in the system,
• performance enhancement - replacement of some parts of hardware with equipment with enhanced perfomance,
• new functionality - new equpment, eihter replacing existing or added to the system, which performs some new functionality.

Software upgrades

Software upgrading is done by modern procedures, that is, by delivery of new version of software (as a whole) and its installation in the system by standard installation procedure. GVS software is not upgrade by patches.

GVS R&D center is constantly working on software:

• to make new system functions,
• to enhance existing functions,
• to ehnance system perfomance measures,
• to ehnance sysetm quality and reliability.

For a certain system generation, GVS produces approximately 2 to 4 upgrades per year, although this number is not artificially limited. GVS informs its customers of upgrades in a certain (new) software version, and the customer will decide whether to by the ugprade or not. Often the upgrades to subsequent versions are free of charge.

Software upgrade may contain new system functions, for example, new subscriber supplemental survices (in a public switching system). GVS informs its customers of technical characteristics of the new function and its price, and customer will decide whether to by it or not. Often, these new system functions will be offered free of charge, as part of regular software upgrades.

When software is upgraded, with or without new system functions, the old software version will be removed (deleted) from the system, leaving only the new, upgraded, version in the system. GVS obligations, including maintenance, technical support and other, are carried on to the new (upgraded) version, unless GVS and the customer come to some other agreement.