Meet the Science
of Forensic Mobile Network Analysis
Six areas of science must be considered during analysis of
Mobile Network Evidence including, among other evidence,
CDR/CSLI (Call Detail Records/Cell Site Location Information)
Radio Science (How Radio Signals Propagate or Travel between Cell Sites & Cell Phones)
Atmospheric Science (How Surface and Space Weather Affects Radio Signals)
Photonics Science (Photons or Light Particles are Over 95% of the Signal Path Between Cell Sites & Cell Phones)
Wave Propagation Science (Radio Wave Behavior Includes Reflection, Refraction, Diffraction, and Absorption of Radio Signals Traveling Between Cell Phones & Cell Sites)
Metrology Science (Measurements are Important in Forensics - Radio & Photonic Signal Measurements Matter)
Computer Science (All Mobile Network Traffic Flows Through the Internet, Using Internet or TCP/IP Packets)
Intellectual Property of John B. Minor © All Rights Reserved · Reproduction Prohibited
Learn About Antenna Basics
Learn About the History of Integrated Access & Backhaul - Fiber & Microwave
Learn About the History of Mobile Networks, Antenna Types & 5G UDN
Learn About 5G Cross-Haul
Learn about Mobile Network Backhaul
Radio science is central to forensic cell site analysis even though typically less than 5% of the communications path between subscriber device and mobile switching core consists of a radio connection.
Radio frequencies in use, communications technologies utilized, electromagnetic radiation physics, antenna radiation behaviors and other fundamental signal propagation issues must be considered during an analysis.
Atmospheric science impacts the airgap of mobile network linkage between subscriber device and cell site.
Antenna radiation pattern and coverage extents in mobile subscriber devices such as cell phones and mobile network access points (2G Base Transceiver Station, 3G NodeB, 4G eNodeB, 5G gNodeB) may be affected by heightened solar activity, certain precipitation events, lightning strikes or near strikes, and extremely high winds.
The impact of precipitation events on meteorological electromagnetic scattering can be inferred through modeling or viewed through real-time sensing to assist in analysis of radio frequency path loss prediction.
Space weather, including both pulsed and cyclical events, is often historically available to review for impactful measurement and determination of radio-wave impairments.
These factors commonly affect mobile network operation and radio-wave propagation. Atmospheric impact can reduce, block, destabilize or skew cell site coverage.
Photonic science is the foundation of the communications transportation infrastructure utilized in more than 95% of the communications path between subscriber device and mobile switching core.
Interruption or congestion in segments of the photonic network (the major component of the network of networks identified as the Internet) used as backhaul between cell sites and mobile switching core may disrupt or reroute communications, resulting in intermittent re-pathing, often manifested as slowdowns or interruptions in mobile communications that result in dropped calls, out of sequence communications events, or other anomalies.
Wave propagation science has a direct bearing on how radio signals propagate between subscriber device and cell site.
The wave function is a key feature of quantum mechanics and radio wave scintillations including reflection, diffraction, refraction, absorption, and other scattering of radio signal propagation at various frequencies, affected by objects in the path between a subscriber device and cell site, determine the extent and quality of cell coverage.
Defined as manmade or naturally occurring objects varying in density and height, morphologies include vegetal, geographic, buildings or other structures, streets, waterways, and much more. Morphologies impact wave propagation and thereby cell site coverage. Antenna wave propagation behaviors must be considered during an analysis.
Metrology, the science of measurement, is utilized in forensic cell site analysis to elevate the accuracy of analytical outcomes.
An obvious example is the use of time and frequency measurements in performing radio surveys for mobile network testing.
Conducted versus Over-the-Air metrology is crucial to understanding the quality and hardiness of base station installations and the likelihood that subscribers will experience stable performance.
Conducted measurements (wired/photonic) such as reflected power, transmitted power, insertion loss, gain, distance to fault, and cable loss power measurements are critical to determining the health of base station feeder and backhaul cables. These cable connections degrade with weather exposure and aging. Initial installation or upgrade issues raise the question of testing for crossed-feeder cable connections at base stations, which not only affect the performance of the mobile network but also result in erroneous Charging Data Record entries that, when used as evidence in civil or criminal litigation, may result in high human or financial cost.
OTA radio spectrum monitoring and interference detection, functional testing and antenna measurements are critical to the ability of cell phones to detect base station signals and connect to the mobile network. Degraded OTA performance will impact quality of service, handoff, dropped calls and detected service outages are critical to determining forensic analysis outcomes.
Examples of theoretical propagation and coverage calculations include use of several methodologies including Okumura–Hata Model, COST 231–Walﬁsh–Ikegami Model, COST 207 GSM Model, ITU-R Models, 3GPP Spatial Channel Model, ITU-Advanced Channel Model, and 802.15.4a UWB Channel Model.
Computer science is fundamental to how the network elements that comprise the mobile network function and how accurately the MNO/MVNO subscriber device activities are logged to eventually become evidence in criminal or civil litigation. A thorough understanding of the Transmission Control Protocol/Internet Protocol, addressing schemes, composition of the Internet including network elements, switched packet flow, and routing protocols is essential to understanding both computer and photonic sciences. An understanding of peering, transit and service level agreements enhances understanding and lucidity regarding potential pathing issues that sometimes result in communications session sequencing irregularities.
Intellectual Property of John B. Minor © All Rights Reserved