Term: Cell Site Analysis
Also known as: cellsite analysis, CSA, cell mast analysis, mobile phone analysis, call record analysis, CDR analysis, mobile phone tracking.

Pronunciation: \'sel\ \'site\ \a-'na-la-ses\

Definition: The analysis of electronic data records originating from a mobile telephone operator to ascertain the location of a mobile telephone SIM card and/or handset at the time calls, short messages (SMS), multi-media messages (MMS) or data connections occurred.

Example of Use: 'In order to identify whether an individual could have been located near the scene of the crime, the engineer performed cell site analysis on the records for the subject's mobile phone'.

Further Information:

Cell site analysis (CSA) is a forensic technique performed by an experienced engineer or analyst using call data stored by a mobile network operator (i.e. Orange, Vodafone, O2, T-Mobile or 3 in the UK). The information, known as the Call Data Records (CDRs) and Cell Configuration Data, can be analysed to investigate where a mobile phone handset or SIM card could have been located in relation to a past call event.

Cell site analysis can be performed for a Pay-As-You-Go (i.e. prepay) account to the same level of detail as can be performed using the records for a Contract Account (i.e. pay monthly).

Figure 2. Map showing the extent of cell coverage

Since a mobile phone and SIM card are exactly that, mobile, even if a named subscriber is recorded by the network as being the owner of the account, this does not necessarily mean that they were the user of the equipment at a particular date and time. Detailed analysis of the call data records over an extended period of time can help to establish who could have been the user of the handset or SIM at a particular time.

The analysis of mobile telephone records is typically addressed in two stages:

1) a paper based study of the call data records to ascertain the general areas involved and establish 'normal calling patterns' (i.e. the subscribers normal usage/movement pattern),

2) to perform radio measurement surveys in the areas of interest to investigate radio coverage to ascertain the extent of the locations from which calls or short messages could have been made.