1. Cell Site Survey Case Study
Hardware and software for Law Enforcement, Government & State Security Organisations
• BTS and cell survey equipment
• BTS and cell survey services
• Consultancy
• Legal and evidential support
Case Study:
A UK Police Force deployed Delma’s Cell Seeker technology in a criminal case in order
to verify that two mobile phones belonging to the accused had been used in a series of
voice calls and SMS transmissions for which the date, time and cell information were
available.
The data connected with the voice calls and text messages had been obtained from the
mobile service provider. The data also contained Cell ID information relating to the
voice calls and text messages.
Verification that the mobile phones belonged to the accused was carried out by
confirmation that the mobile phone network cells providing the mobile phone service at
the home address of the accused, a public house frequented by the accused, the
workplace of the accused and on a section of motorway used by the accused were
exactly as those which appeared in the mobile phone records.
The cell verification was carried out using Delma Cell Seeker PDA based cell detection
systems at each of the desired locations. The Cell ID data obtained was collated and
mapped using Delma Cell Seeker Back Office software. The finished results were
compared to the Cell data obtained from the mobile service provider for each mobile
phone and found to be an exact match.
The mobile usage evidence was so compelling as to encourage the accused to plead
guilty to the charges thus saving the Police considerable further effort and avoiding
potentially lengthy and expensive court proceedings.
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2. Survey processes:
Cell Site Surveys The mapping process involves the following
The process of surveying the mobile phone • Measurement of RF transmission levels at
infrastructure is designed to produce an accurate various points within the area of interest.
mapping of the reception footprint of a particular The higher the number of points the more
BTS (Base Transceiver Station). All BTS have one accurate the cell footprint will be known
or more cells associated with them and cells can • GPS readings taken simultaneously with
be of a variety of shapes. each set of transmission level readings.
• Off air identification of the MNC (Mobile
Although intended to be of a regular geometric Network Code i.e the service provider),
shape the reception footprint of cells may be LAC (Location Area Code) and Cell ID (Cell
modified by the presence of buildings, structures identity) of the cell being mapped.
and topographical features. • Off air identification of the frequency of
transmissions (e.g. 900, 1800 or
The antenna utilised for the transmission and 2100MHz)
reception of the RF based mobile phone service • Processing of the data into a database
can give rise to anomalies. It is vital to know and digital mapping system to provide a
how these anomalies influence the reception graphical representation of the cell and its
footprint of a given cell. supporting data.
• Comparison with historical data to
The accurate mapping of a single BTS and its determine changes.
associated cells is often referred to as a Cell Site
Survey.
Cell coverage footprints can be of different shapes and sizes depending on the type and location of
BTS antennae:
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3. Survey equipment and systems:
Cell Seekertm System I & II
Delma provides two levels of Cell Survey
equipment.
In Cell Seeker System I the hardware comprises
a portable PDA loaded with software which
handles the taking of RF transmission readings,
cell data and GPS coordinates. The second part
of the system is a laptop based mapping
application which is responsible for download,
storage, mapping and reporting of the collected
data.
The features of this system are:
• The PDA is highly portable and can be
taken into the most inaccessible of areas
for the taking of readings.
• The PDA has an in-built camera for the
capture of possible additional
photographic data
• The PDA can act as a mobile phone
allowing data to be sent by SMS to the
laptop system.
• The PDA can access any 2G, 2.5G or 3G
network globally
• The PDA has in-built GPS (System II)
• The laptop may be vehicle based or office
based depending on tactical requirement
• The laptop is Windows based providing
the user with a variety of mapping options
(e.g. Mapinfo, Google Maps etc)
• The laptop has extensive storage
capabilities but can also be networked to
the organisation’s server network.
• The PDA and laptop can connect to each
other via BlueTooth or WiFi or direct cable
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4. Cell Seekertm Laptop System
In Cell Seeker System II the emphasis is on high
speed gathering of cell data from large numbers
of cells from a moving vehicle.
The hardware comprises a vehicle based laptop
fitted with multiple mobile network reception
units, a GPS receiver and roof mounted
antennae.
The laptop is loaded with software capable of
rapid multi-network sampling for RF transmission
readings, cell data and GPS coordinates for each
set of readings.
The features of this system are:
• All networks are handled simultaneously
• Large geographical areas can be covered
quickly.
• The PDA described in System I above can
be used by surveyors on foot to cover
areas inaccessible to the vehicle. SMS,
• The laptop combines the data capture and
mapping processes
• Data can be gathered at high speed (e,g
for Motorway cell mapping)
•
Cell Seeker back office system • enforcement evidencial purposes or
security mission purposes
Data collected from Cell Seeker systems, GSM • Reporting
interceptors and other devices may be securely
and efficiently uploaded to the Cell Seeker back
office system. A full suite of storage and analysis
programs provide access to then following
functions
• Storage of Base Transceiver Station (BTS)
data Storage of Cell information and BTS
cross referencing
• Auto upload of survey data with creation
of cell and BTS records as appropriate
• Screening and analysis of survey data
• Mapping of specific survey or mission data
to provide cell footprints for law
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5. Example Cell footprint map (O2 cell 30720)
Cell Survey Services
Delma employs experienced consultants who can be deployed with the required equipment to
perform training, independent cell mapping services in support of Law Enforcement and other
qualifying organisations. Professionally prepared training material, reports, presentations and other
supporting material are provided as part of the service. The same consultants are available for
advice and legal work.
For information contact: Email: info@delmamss.co.uk
Telephone: +44 1962 735859 Fax: +44 1962 735890
In writing to: Delma MSS Ltd., Newhouse Farm, Northington, Alresford, Hampshire SO24 9UB
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