To understand what an unlocked cell phone is, it is important to first understand what a locked cell phone is. A locked cell phone is one that can only be used with one cellular service provider. In contrast, an unlocked cell phone can be used with any cellular service provider. When a cell phone is …
Dr. Martin Cooper is the person credited with both inventing the modern cell phone as well as making the first cell phone call in New York City, New York in April 1973. A related invention is the cave radio phone invented by Nathan Stubblefield who was awarded a patent for the idea in the early …
An IMEI, or International Mobile Equipment Identity, number is a number associated with a specific cell phone and can be used by authorities in a wide variety of countries to blacklist stolen cell phones, making them unusable to the thief, even if he/she replaces the phone’s SIM card. An IMEI number should not be confused …
Many of us have lost our cell phones from time to time but some may have a harder time than others in retrieving their phone. What is worse is when you lose your cell phone in the middle of a texting session or when you have an important phone call to make and the person’s …
Cell phone technology is based on radio technology that was developed from the 1940’s onward. For instance, the beginning of cell phones can be traced to the innovation in taxi cabs, police cars, and other service vehicles where two way radios allowed taxi drivers or police officers to communicate with one another or with a …
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 …
PCS (Personal Communications Service) is a set of standards. Most PCS standards are based on an existing standard. PCS is little more than the operation of these standards on the frequency bands of 1930-1990MHz for receiving and 1850-1910Mhz for transmitting. PCS StandardBase Standard PCS TDMA IS-136 PCS CDMA IS-95 PCS 1900 GSM PACS PHS cordless …
Each GSM and UMTS mobile phone has a unique IMEI (International Mobile Equipment Identity) number. An IMEI number facilitates an important function – it easily identifies a mobile phone being used on a GSM (Global System for Mobile Communications) network. The IMEI is a useful tool to stop a stolen phone from accessing a network …
As many people are fed up with their cell phone providers, a new trend has opened up for tracphones. A tracphone, or TracFone, is a prepaid phone that gives you the accessibility of a contract plan without the commitment. Tracphones have become much more popular in the past few months as more people are finally …
A PIN, or Personal Identification Number, is a number that is used on some SIM cards to prevent unauthorized use of the cell phone it is located in. PINs are not used by all SIM cards and may need to be setup before they can be used. A PIN is generally between 4 and 8 …