A Brief History of CDMA<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
The second technology standard to consider is CDMA, which stands for Code Division Multiplex Access. When the world's first cellular networks were introduced using analog radio transmission technologies such as Advanced Mobile Phone System (AMPS) in the early eighties, it became clear that a higher level of network capacity required accommodating more user traffic within a tighter radio spectrum.
To accomplish that, the industry developed a new set of digital wireless technologies-Time Division Multiple Access (TDMA) and Global System for Mobile-that used a time-sharing protocol. In essence, these technologies allocated milliseconds of time to all users accessing the wireless network. The move to digital network access, though, made segmenting network usage by code rather than time feasible. Under CDMA, all mobile network users received a unique code that allowed them to access the network continuously rather than intermittent, timed access.
But CDMA's road was not a simple one. In fact, a panel of the world's leading engineers reportedly met in Japan in the early 1990s to discuss the development of wireless CDMA technology as a standard. They concluded, however, that it was impossible.
To the founders of Qualcomm, however, "impossible" simply meant that several thorny technical issues needed to be overcome. With unstoppable entrepreneurial spirit, Qualcomm's team solved them all, establishing CDMA as a legitimate wireless communications standard (and patenting it to ensure their ownership).
Launched commercially in 1995, the first CDMA networks provided roughly ten times more capacity than analog networks, and far more than TDMA or GSM. Besides supporting more traffic, CDMA brought mobile carriers and consumers better voice quality, broader coverage and stronger security, among other benefits. CDMA now has over a hundred million subscribers worldwide.
