Tracking The Location Of A Cell Phone


To make wireless communications possible, a network knows the general location of your phone or wireless device whenever it is turned on.

Cell Phone Tower Expert Witness Tracking The Location Of A Cell Phone

Typical Cell Phone Tower: Subpoenas have successfully been used to retrieve this data for litigation cases.

Your wireless device sends out a periodic signal to the nearest radio tower/cell site so that a network will know where to route an incoming communication and how to properly bill for the service. This is necessary to make wireless communications possible. Location information derived from providing voice service is CPNI (customer proprietary network information).

When you make a cell phone call, your cell phone transmits a very short message (about 1/4 second) that contains the MIN (Mobile Identification Number, aka your cell phone number), its ESN (Electronic Serial Number), and the number you just dialed. T-Mobile, as an example, retains all of the information it collects under this Policy for as long as there is a business need for it. In addition, they have a record retention policy that generally implements the broad range of regulatory requirements imposed on service providers for record keeping.

The mobile phone records that one has access to via internet accounts, paper statements, etc., generally are available for 12-18 months. I have recently accessed an individuals account records from August 2005. These records show phone calls made, calls received and the time & date of the call. In general, they DO NOT show the location of where the call was made. Although, some companies do include code letters / numbers that can correlate to a cell tower location.


The cell phone companies have been able to estimate the location of a cell phone for many years using triangulation information from the towers receiving the signal. This information is in general not easily available to the public, but in several cases that I am aware of was retrieved via subpoenas as part of the litigation process. Mobile phone service providers are storing records of location and social network data for one out of three people on Earth – some records are available for up to 3 years.

The process I would use is as follows:

  1. From the individual’s personal data, I can obtain the general information of phone calls made, calls received and the time and date of the call. Establish that a call was indeed made / received.

  1. By knowing the general area (city / state / ZIP) where the calls were made, I can attempt to retrieve the cell tower locations for that area (generally successful) by doing a cell tower search.

  1. By citing appropriate similar court cases where subpoenas have successfully been used to retrieve this data for litigation cases, I can attempt to locate that location where a call originated – this would put the location within a several mile radius of a cell tower location.

  1. Would rely on Title II of the ECPA (codified at 18 U.S.C. § 2701 et seq) for performing transaction surveillance. This article relates to stored communications and subscriber records.

  1. There are other legal methods that can also be attempted to retrieve this personal information.

  1. Some mobile phones also store via the SIM card or local memory card, calls made & received – this may be of help – I would download this call list information.

  1. Carriers are selling real-time location information to companies who use this information to extrapolate the location and speed of the individual and use this data to offer road traffic updates and forecasts. Could be in public domain and available.

  1. Write a document report with appropriate information for this case.

  1. Provide expert testimony.

    Written by: Telecommunications Engineer & Patents Expert Witness No. 1612

About the Author:
Telecommunications Engineer & Patents Expert Witness No. 1612 is an expert witness for telecommunications, electrical engineering, patent infringement, claims review & communications. He has had over 30 cases serving as an expert or expert witness, with affidavit, deposition & testifying experience. Expert in patent infringement cases, claims review & analysis, cellular network architectures, cell phone configurations (hardware / mechanical / keypad design & applications and cell phone tower records review and analysis.