NAM: Number Assignment Module
The NAM (Number Assignment Module) is the EPROM (Erasable Programmable Read-Only Memory) in a mobile telephone which holds information such as the MIN (or MDN) and SIDH. The data fields stored in a phone’s NAM vary between the various mobile telephone specifications, such as AMPS/NAMPS, GSM, PCS, CMDA. In modern networks, NAMs can be reprogrammed Over-The-Air (OTA).
Dual and Multi-NAM Phones
Some mobile handsets are equipped with NAM’s which can hold multiple telephone numbers. This enables the phone to have multiple telephone numbers from one carrier or telephone numbers from multiple carriers.
NAM Fraud
Cellular fraud in the AMPS/NAMPS system often involved modifying the information stored in the NAM.
- AMPS (EIA/TIA-553) and NAMPS (IS-91)
Mobile Frequency Range Rx: 869-894; Tx 824-849 Multiple Access Method FDM Duplex Method FDD Number of Channels 832 Channel Spacing 30kHz Modulation FM AMPS AMPS (Advanced Mobile Phone Service) was the first cellular mobile system in the United States. AMPS operates as an analog system using 30 kHz wide channels. NAMPS AMPS was later enhanced [...]...
- Tumbling
Tumbling exploits a weakness in the AMPS/NAMPS roaming system. In tumbling, you first configure the SIDH in your mobile telephone to pretend to be from another cellular carrier. If you are in Colorado, for example, you would configure your mobile telephone as if it were subscribed to a cellular carrier in Texas. Next, you modify [...]...
- ESN (Electronic Serial Number)
ESN (Electronic Serial Number) An Electronic Serial Number is a code created to identify mobile devices. An ESN is 32 bits long, and the distribution of information in those bits has changed as the standard has evolved. The first 8 bits originally represented the manufacturer code, leaving 24 bits for the manufacturer to assign codes [...]...
- MIN (Mobile Identification Number)
The MIN (Mobile Identification Number) is a number that uniquely identifies a mobile telephone subscriber. MINs are 34-bits in length. The first 10 bits are sometimes known as MIN2, while the last 24 bits are referred to as MIN1. Together they are simply known as the MIN. In the United States, the MIN is derived [...]...
- Types of Mobile Telephone Systems
The main mobile telephone systems in the last twenty five years have been: YearMobile Telephone System 1981 Nordic Mobile Telephone (NMT) 1983 Advanced Mobile Phone System (AMPS) 1985 Total Access Communication Systems (TACS) 1986 Nordic Mobile Telephony (NMT) 1991 American Digital Cellular (ADC) 1991 Global System for Mobile Communication (GSM) 1992 Digital Cellular System (DCS) [...]...




