Cell Site Analysis Truths & Myths

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Cell Site Analysis Truths & Myths

Transcript of Cell Site Analysis Truths & Myths

Cell Site Analysis Truths & Myths

What is CSA?

• Likely location of mobile phone(s) through examination of call data records, with or without radio frequency surveys

• Presented by expert witness, evidence being both relevant and reliable

• Introduced by Crown or defence in support of their case

Do cell sites cover 35Km?

How Many Cell Sites?

Where could this happen?

Data Retention

• Operators by law have to retain call data records for a minimum of 12 months

No Calls – No Data

• Operators will in general only retain records relating to call activity

• GPRS Data is frequently available, giving data without call activity

• There are several exceptions including Home Location Register updates

Does your phone use nearest Cell Site?

• Not always, topography and local building clutter, may cause a distant site to provide a better service than the nearest site

• Also variable in the use of GPRS sites

• May vary with the hardware design

Can cell site pinpoint exact location?

• Cell Site Analysis cannot pinpoint precise locations of a mobile phone

• However, depending upon call data analysis, it may be possible to locate a mobile to within a few hundred metres

Is CSA an exact science?• The data we work with is

precise and therefore fact based and can be relied upon for accuracy

• It is often used to prove or disprove an inference and may be supported by other evidence i.e. ANPR, CCTV etc…

Does a Bus or Lorry Driving Past Affect Cell Site Signals?

• This generally does not apply as network operators employ techniques to avoid unnecessary handover between cells

• In certain situations however, if in close proximity to a stationary large vehicle, this could instigate handover

Directed Retry(Network Busy)

Could it be that the network was busy at the time of the call and a different cell site was used because of this?

•This can and does happen but only on certain networks, in busy areas at busy times!

Does the weather affect network readings?

• Very limited effects due to frequency of signals and low power cell sites

• Severe weather will affect all local cell sites equally

When are Temporary Cell Sites Used?

• To provide coverage or additional capacity at a specific event

• A common event for temporary cells is Glastonbury due to volume of people and rural setting which is not well covered.

How many SMS (text messages) are sent across all UK networks

each month?

• Over 12.5 BILLION!