Definitions Flashcards
What is GSM?
The Global System for Mobile Communications (GSM):
A standard developed by the European Telecommunications Standards Institute (ETSI) to describe the protocols for second-generation (2G) digital cellular networks used by mobile devices such as mobile phones and tablets.
What is UMTS?
UTMS (Universal Mobile Telecommunications System):
A 3G mobile cellular system for networks based on the GSM standard
Frequency was originally 2100 mhz
What is LTE?
LTE (Long Term Evolution Standard) and LTE+ are cellular networks. LTE (3.99G) / LTE+ (4G) are the standard & main technoogy for most 4G networks.
Has increased capacity and data rates.
Has decreased packet latency
LTE+ is faster than the original LTE
What is WAP?
Wireless Application Protocol (WAP):
a now obsolete technical standard for accessing information over a mobile cellular network. Introduced in 1999, WAP allowed users with compatible mobile devices to browse content such as news, weather and sports scores provided by mobile network operators, specially designed for the limited capabilities of a mobile device
What is GPRS?
GPRS (General Packet Radio Service):
An expansion of GSM (Global System for Mobile Communications) networks that offer packet-switched data services. The GPRS architecture consists of different network components and interfaces that work together to provide data services. Developed as part of 2.5G
What is EDGE?
The letter E represents the Enhanced Data rates for GSM Evolution (or EDGE) network. The network started to spread in popularity sometime in 2003 by offering speeds that were almost three times faster than any of its predecessors. Developed as part of 2.5G
What is CDMA?
CDMA = Code Division Multiple Access
CDMA is an example of multiple access, a technology used in mobile networks to allow multiple transmitters to send info on the same frequency band simultaneously over a single communication channel..
It was widely used in 3G but mostly replaced by more advanced technologies such as 4G LTE (Long-Term Evolution) and 5G
What is BFU?
BFU (Before First Unlock).
When device is powered on but has not yet been unlocked for the first time since last powering on, or last reboot or reset - restricted features / functionality usually available.
Phone in this state are considered more challenging for examiners because the file based encryption will have not loaded the required file decryption keys into memory.
What is AFU?
AFU - After First Unlock (when device is powered on and has already been unlocked one or more times since powering on or re-boot or reset). A more advantageous state for examination - more content likely to be available because the file decryption keys have been loaded into the device’s temporary memory and will remain there until the device is powered off
What is an ICC?
ICC - Integrated Circuit Card
A general term for a smart card (a micro-controller based access module) - not just for mobile communication purposes.
An ICC is a physical card embedded with an integrated circuit (IC) that can process and store data. These cards are used in a variety of applications, including telecommunications, banking, identity verification, and security. The ICC enables the card to perform functions like authentication, encryption, and secure storage
What is a SIM?
Subscriber Identity Module (SIM) is the ICC defined for 2G GSM networks including the PHYSICAL card & LOGICAL application. It is a mini computer
What is a UICC?
Universal Integrated Circuit Card (UICC) is the PHYSICAL card as defined by UMTS, LTE & 5G networks
What is a USIM?
Universal Subscriber Identity Module (USIM) is the LOGICAL application as designed for the UMTS, LTE & 5G networks.
It is possible to have a number of USIM applications installed on one UICC
What is an IMSI?
International Mobile Subscriber Identity (IMSI)
- 15 digit number
- Used to uniqiely identify a USER on a GSM based mobile network. So identifies the SUBSCRIBER on a network
- Electronically stored in the SIM / UICC in the memory area
- May be protected by PIN / CHV
- Requires electronic extraction from the SIM / UICC to determine and may require PIN or PUK to acquire
- Defined by ITU-T Recommendation E.212.
- gives name and country of service provider
inputting IMSI into tools like numbering plans might give the country and service provider that issued the IMSI.
What is an ICCID?
ICCID (Integrated Circuit Card ID).
Unique serial number usually printed on the SIM / UICC. Unique to that SIM or UICC.
Also known as SIM serial number.
Has a structure.
19 or 20 digits (ignore any digits or letters after this)
Electronically stored on the SIM / UICC on EFICCID
Service provider can ID phone number (& poss subscriber) from the ICCID
Reveals country of origin & service provider.
What is a PTMSI?
PTMSI = Packet Temporary Mobile Subscriber Identity.
P-TMSI Is a temporary identity issued to a GPRS enabled mobile device to track its location within in a GSM or a UMTS network, and is unique within a given Routing Area (RA). The location update procedure allows a mobile device to inform the cellular network, whenever it moves from one location area to the next.
The P-TMSI is used by the GPRS network to page the specified mobile device
What is an MSISDN
MSISDN (Mobile Station International Subscriber Directory Number)
i.e the TELEPHONE NUMBER
Can be stored on SIM as ‘own dialling number’ but this is user edited so is not reliable. Only reliable source is a request to the SP (using the ICCID or IMSI)
Length of MSISDN is county specific but max is 15.
What is the CHV?
CHV (Card Holder Verification)
- Commonly known as a PIN but now correctly known as CHV
- 2 user editable locks are available. Usually PIN1 is used.
- 4 to 8 digits in length
- 3 incorrect attempts usually require an unblocking key or PUK to unlock
- Some providers use default values
What is the UCHV?
UCHV (Unblock Card Holder Verification)
- Commonly called PIN unblocking key (PUK). Correct name is Unblock Card Holder Verification (UCHV)
- 8 digit code to unblock SIM/ UICC
- Set by and can be requested from the CSP. Cannot be edited by user.
- 10 failed PUK / UCHV attempts permanently destroys data on the SIM UICC. Important because SP sometimes give incorrect codes due to wrong database, or people may deliberately enter it wrong 9 times to leave only 1.
UCHV can be input on the handset or cardreader by the forensic tool (preferred method)
What is a TMSI?
TMSI - Temporary Mobile Subscriber Identity.
TMSI is a temporary identifier used in mobile networks to protect the privacy and security of a subscriber. It helps mobile network operators manage and secure communication between a mobile device and the network without revealing the permanent identity of the subscriber (such as the IMSI International Mobile Subscriber Identity)
Prevents user ID by eavesdropping.
Subscriber uses same TMSI until the network location update occurs when a new one is issued
What is a PCB?
A PCB (Printed Circuit Board) is a flat, typically rigid board that holds and connects electronic components using conductive tracks, pads, and other features etched from one or more layers of copper laminated onto or between sheets of non-conductive material.
What is an IMEI?
IMEI (International Mobile Equipment Identity)
It is the ‘serial number’ of a mobile device handset. 15 or 16 digit number.
Used by the network operator to ensure the device is a valid piece of equipment to be allowed on the mobile network.
Identifes the device make, model & manufacturer
What is a TAC?
TAC is a Type Allocation Code.
- Unique identifier that represents the first 8 digits of the device’s IMEI number.
- Identifies the make, model, and country of origin - agency that issued the IMEI e.g Britsh Approvals Board for Telecommunications (BABT) - not necessarily where it was manufactured.
- The first 2 digits are the reporting body identifier (e.g 35 = BABT)
35 = BABT
01 = CTIA
86 = TAF
91 = MSAI
00 = Test
98 = Reserved for future use
99 = GHA
- Digits 3 to 8 are the Mobile Equipment Model Identifier - allocated to the device manufacturer for a specific model (e.g 195000 = Siemens MC60)
What is a CD (in terms of the IMEI)?
CD (Check Digit)
- 15th digit of an IMEI is a check digit (CD). Used to check the validity of the IMEI.
- Check digit is calculated with the ‘Luhn’ formula (open source). This is a checksum formula used to check the first 14 digits of the IMEI
- Early handsets this was always a value of zero. Now can be anything up from 0 to 9
- The CD is NOT transmitted on the network so WILL NOT have a value on call / charge data records (CDR) obtained. On CDR it will always show a zero.
What is a Cell (in terms of wireless communication)
A Cell is a specific geographic area covered by a cell tower (or base station) in a cellular network. Each cell is assigned a cell ID. Cells vary in size.
Each cell is covered by a BTS
A cell provides network coverage to mobile devices within its area, enabling seamless wireless communication. This web of cells forms the backbone of our daily communication, allowing us to stay connected as we move about.
What is a cellular network?
GSM UTMS LTE+ are cellular networks.
Cellular networks are made of a ajacent cells interlinked at a higher layer which controls all network activty.
What is a BTS?
A Base Transceiver Station (BTS)
A Base Transceiver Station (BTS) allows wireless communication between user equipment and the network
Typically contains several transievers operating on different frequencies
GSM uses the GAUSSIAN Minimum Shift Keying (GMSK) modulation technique
Edge uses Eight Phase Shift Keying modulation technique for greater data throughput
What is the MCC?
Mobile Country Code (MCC)
A three-digit code that identifies the country in which a mobile network operates.
What is the MNC?
The Mobile Network Code (MNC) is a two- or three-digit number used in mobile telecommunications to identify a specific mobile network operator within a country. Only unique within that country
The Mobile Network Code (MNC) is a critical identifier in mobile telecommunications, used alongside the Mobile Country Code (MCC) to uniquely identify mobile network operators. It ensures that mobile devices can connect to the correct network both at home and when roaming, allowing for proper authentication, service provision, and billing.
The MCC plus the MCC is unique.
What is a LAC?
LAC = Location Area Code.
What is a CI?
CI = Cell Identity.
A number assigned to a cell. Every individual cell has Cell Identity. Sometimes called CID
What is a LAI?
A group of cells form a Location Area and can be identified by the Location Area Identity (LAI). Can cover a wide area.
- The LAI is broadcast frequently by BTS’s on the broadcast channel on the network
- The LAI is served by one or (usually) more BTS’s.
- SIM card stores the LAI (the last group of cells used)
- MCC + MNC + LAC = LAI
What is a CGI?
The Cell Global Identity (CGI) is a unique identifier used in mobile networks to distinguish individual cells within a network. It helps identify the specific location of a mobile device by referring to the cell that the device is currently connected to.
The CGI is a vital component of location management, call routing, and mobility in cellular networks.
MCC + MNC + LAC + CI = CGI
What is frequency reuse?
Frequency reuse is the core of a cellular network concept.
- Allows users in different geographic cells can use the same frequencies simultaneously.
- It increases capacity & means more efficient radio spectrum use
- it does require spectrum management to minimise co-channel interefrence.
- A group of cells implementing the same frequency reuse plan is called a CELL CLUSTER
What is a Chipset?
A chipset refers to the collection of integrated circuits that manage and control the device’s core functions. It serves as the backbone of the device, handling communication between the processor, memory, storage, and other components. The chipset enables the device to perform tasks such as processing data, running applications, connecting to networks, and managing power consumption.
In mobile devices, chipsets are often referred to as SoCs (System on a Chip), as they integrate multiple components onto a single chip
What is Jailbreaking & Rooting?
Jailbroken and rooted refer to two similar processes used to gain privileged or unrestricted access to mobile devices’ file systems and operating systems, typically beyond what is allowed by default by the manufacturer.
This process is used on iOS (jailbreaking) and Android (rooting) devices, and it gives the user administrative rights, allowing them to bypass certain security mechanisms and restrictions put in place by the OS or manufacturer.
What is The FCC-ID?
Relevant to US markets.
The FCC-ID is the Federal Communications Commission Identification.
The first 3 or 5 characters represent the manufacturer (Grantee code)
The remaining characters are the equipment product code.
What is a Grantee Code?
Relevant to US markets and the FCC-ID. The Grantee code is the first 3 or 5 digits of the FCC-ID that represent the MANUFACTURER
What is a CSIM?
A CDMA Subscriber Identity module. This is the logical application providing service on a CDMA network
What is a RUIM?
The Removable User Identity Module is the ICC that allows a GSM subscriber to operate on a CDMA network.
It contains 2 logical applications: SIM and a CSIM
What is an eSIM or eUICC?
these are embedded SIMs or UICCs. Not removable (unless soldered out).. Built into the device.
What is EPROM?
EPROM, or erasable programmable read-only memory, is a type of programmable read-only memory chip that retains its data when its power supply is switched off.
Used to store data on a UICC / SIM
