Method and system for determining deterioration in the quality of a mobile telephony network

A system for determining deteriorations in the quality of a mobile telephony network on a day D, at an hour H or a minute M, implementing one or more items of special equipment of the network, characterised in that the system comprises at least:

• a device for the acquisition, at the Mobile Services Switching
• Centres (MSCs, commutation switches) (b) of the network or any other point in a network (fixed or mobile), of Usage Messages (UMs) (1) corresponding to each call by recording the UM data in a storage means,
• a device for transmitting the recorded data of the UMs (1) from
• the MSCs to a centralised unit (c),
• a selection device (c1) of the centralised unit (c) comprising a comparison means and a storage means in which a value of the “call date” field is recorded for selecting the UMs (1) on day D, at hour H or minute M (2a),
• a device for filtering the UMs (4), comprising a means for comparing the values of the “caller” fields associated with each UM with values of the “caller” fields recorded in a storage means, and a means for separating the UMs called “incoming-outgoing” (5) from the UMs called “return incoming” (6) and the UMs called “return outgoing” (7) based on the “type of UM” fields,
• a device for characterising the callbacks for selecting the UMs to be considered as callbacks from among the UMs (4) of the group having identical “client”, “caller” (or APN for UMs of the DATA type) and “call date” fields, wherein the device comprises a comparison and a storage means in which a value of the “previous call time difference” field is recorded,
• a device for determining at least one type of tester, wherein this device is connected to a storage means which records the newly recognised testers (11) and wherein the storage means is itself connected to a selection device which deletes the UMs deriving from callers recognised as testers,
• a device for determining the fields supplying geographical and technical information as a function of the “cell code” field of the UMs (12) connected to a device for recovering (d) at least one list containing at least one reference for each value of the “cell code” field, wherein the determination device comprises a means for comparing the “cell code” field associated with each UM (12) with the values displayed by the loaded list,
• a device for calculating at least one indicator by grouping the UMs (15) as a function of several common data fields,
• a device for transmitting the calculated indicators to a server (e) to which local units (f1, f2, f3, f4) have access,
• a device for calculating the callback rate by applying an algorithm executing the following operation
• Callback
• 
• 
• Rate
• =
• Number
• 
• 
• of
• 
• 
• Calls
• (
• Number
• 
• 
• of
• 
• 
• Calls
• -
• Number
• 
• 
• of
• 
• 
• Callbacks
• )
• signaling device enabling an intervention to be initiated to restore or improve the quality of the call in a section of the network linked to the calculated callback rate.