While CB radios and pagers provided some mobile communications solutions, what people really wanted was a completely mobile telephone.

Experiments with radio-telephones began as far back as the turn of the century, but most of these attempts required the transport of bulky radio transmitters or using long poles to tap into local overhead telephone wires.

The first practical mobile radio-telephone service, MTS (Mobile Telephone Service) was begun in 1946 in St. Louis. But this first system was more like a radio walkie-talkie – operators handled the calls and only one person at a time could talk.

The idea of permanent "cells" first was broached in 1947 by AT&T researcher D.H. Ring, the same year radio-telephone service was initiated between Boston and New York by AT&T. Automatic dialing – making the radio-telephone call without the use of an operator – began in 1948 in Indiana, but it would be 16 years before the innovation was adopted by the Bell system.

During the next 15 years, the transistor along with other technologies, and a steady increase in frequencies allotted to the new technology, continued to improve radio-telephone service.

In 1964, AT&T developed a second-generation cell phone system called Improved Mobile Telephone Service (IMTS), which had more of the hallmarks of a standard telephone but allowed only a limited number of subscribers and was used only in cars. In most metropolitan areas in which the service was available, there was a long waiting list.

The idea of a mobile phone was popularized by Secret Agent 86, Maxwell Smart, who used a shoe phone on the 1960s TV spy spoof series, "Get Smart". But by the late 1960s, there were far more consumer requests for IMTS car telephones than there were channels available. The IMTS industry, known as the Land Mobile Radio Service, led by AT&T and Motorola, lobbied the FCC for additional bandwidth in the 806-960 MHz frequency band. However, local VHF television stations were using much of this band. In May 1970, after a fierce battle with the broadcasting industry, the FCC assigned the frequencies to the land mobile industry.

While the battle raged with broadcasters over the 806-960 MHz band, AT&T, Motorola and several other companies made various proposals on how to carve up and most effectively utilize the new frequency bands. In mid-1968, the FCC opened the so-called "cellular docket", Docket 18262, to address the reallocation of these new frequencies. On December 20, 1971, AT&T submitted a proposal to the FCC for the use of these frequencies for a new type of radio-telephone system that used an alternative to the usual one-transmitter/many-receivers radio transmission model.

Instead, a team from AT&T, led by Dr. Joel Engel and Richard Frenkiel, proposed carving up a metropolitan area into adjoining hexagonal "cells", each with its own low-power transmitter. As a user drives from one cell to another, the system would "hand-off" the transmission from a transmitter in one cell to a new transmitter in the next cell. This "cellular" scheme allowed different users to use the same channels in different cells, so called frequency reuse, vastly expanding the number of possible channels available and number of users a system could support.

AT&T's revolutionary proposal, however, also suggested that Ma Bell gain a monopoly over the new frequencies. Motorola, the primary equipment supplier to the car phone market, made a counter proposal, illustrating that the frequencies could be used by more than just car phones and, therefore, a monopoly hold on the frequencies was unnecessary. Whether Motorola actually believed that there was a credible market for bulky radiophones outside the car was another matter.

In the fall of 1972, Motorola project manager Dr. Martin Cooper proposed a number of different communications systems using the new frequencies. In March and April 1973, Cooper and a development team led by Don Linder demonstrated several of these hand-built systems for Washington legislators, FCC commissioners and the press. One of these devices was a handheld radio-telephone system dubbed the DynaTAC (Dynamic Total Area Coverage), which used the 900-MHz bandwidth and a version of AT&T's cell scheme. While technically not a "cell phone" – the single base/handset DynaTAC system more closely resembled what eventually would become the cordless telephone – it was the first demonstration of a wireless portable telephone, the Rosetta Stone for what would become the cellular phone.

The suitability of the new frequencies beyond their use for car phones finally helped convince the FCC not to give AT&T a monopoly and to allow so-called "common carriers" to share the new spectrum. But it took until May 1981, after more than a decade of legal wrangling, for the FCC to finalize the rules and allocations for cellular spectrum.

Meanwhile, several experimental licenses were granted for testing the new cellular systems. AT&T developed the advanced mobile phone system (AMPS), the first regular U.S. cellular phone system using microwave transmissions, which began trials in 1977 in Chicago. After five years of tests, full commercial AMPS service was officially initiated on October 12, 1983, in Chicago. In its first year, there were a half-million subscribers. By the end of the decade, there were two million.

But neither AT&T nor Motorola predicted the consumer desire for mobile phones; all the early cell phone companies believed the new technology would be used for emergency services, as land mobile car phones had been. But consumer demand soon far outstripped the supply of frequency bands and cell phone numbers, despite the fact that "portable" phones were barely that. These early cell phones were the size and weight of small bricks, required large and heavy batteries and often had to be carried in briefcases.

The analog systems could not contain the unexpected deluge of wireless customers. In 1990, the digital standard time division multiple access (TDMA) system was established and, when first introduced in 1992, tripled capacity and vastly improved sound quality.

In 1994, an alternative digital standard, code division multiple access (CDMA) technology was introduced by Qualcomm. In December of that year, the FCC began to auction off the 1900-MHz bands, so-called "PCS" (Personal Communications Service) bands, for digital cell phone use.

By 1996, thanks to single-chip digital signal processing (DSP) chips first unveiled in 1983 by Texas Instruments, cellular phones became pocket-sized and "wearable". Every major carrier was offering digital PCS, which allowed a raft of messaging and information services and features to be accessed in addition to voice calls.

Personal communications took to the skies in late 1998 when both satellite phones and satellite e-mail devices were introduced, the former from Iridium and Motorola, and Globalstar, and the latter from Magellan. Unfortunately, satellite phone service proved too costly for most consumers. Iridium ceased operation in March 2000 and the satellites for other proposed satellite phone providers were never launched. The military now is the primary user of heretofore consumer satellite phones.

In 1999, wireless phones converged with handheld personal computers, combining wireless phone service, Web access and personal digital assistant (PDA) capabilities in a single pocket-sized device. The first such device came from Qualcomm in 1999 with its pdQ 800, a cell phone with a built-in Palm Pilot. That same year, the Neopoint 1000, the first cell phone with wireless Web access, went on sale. In 2001, Samsung unveiled the SPH-i300, the first combined color Palm PDA cell phone.

In 2001, so-called "third-generation" (3G) digital cell phones – actually more like 2G and 2.5G since data transmission speeds did not reach broadband levels – started to appear. True 3G EDGE (Enhanced Data GSM Environment) and Ev-DO (Evolution Data Only) broadband networks capable of providing data transmission speeds in excess of 384 kbps became available in most metropolitan areas in late 2004.

Speedier broadband networks powering these phones allow the transmission of pictures, video and digital music as well as voice, have vastly speedier wireless Web access connections, and allow the cell phone to be used as a wireless modem when attached to a laptop computer, a digital music player or even a TV. Several carriers began transmitting both live and packaged TV clips through cell phones in late 2004, and the first true MP3 phones with multi-gigabyte memory, through which consumers could access and download tracks from cell carriers, began to appear in mid-2005.

Once consumers signed with a carrier, they were stuck with that carrier if they wanted to keep their phone number, which limited consumer choice. In September 2003, the FCC enacted Local Number Portability, which allowed consumers to take their cell phone number with them when they switched carriers, or even transfer their home landline phone number to a cell phone.

Competition from a wide variety of local, regional and national cell carriers has driven the price-per-minute down to the point that the cost of using a cell phone rivals or surpasses that of a home phone. These economics, combined with a cell phone's portability, have prompted many consumers to forego their home phones and opt simply for a cell phone. As of early 2006, there are more than 200 million cell phone users in the U.S. alone.