Frequently Asked Questions
https://www.qualcomm.com/cda/technology/faq/0,1602,00.html
FREQUENTLY ASKED QUESTIONS
> What is CDMA?
Code Division Multiple Access. A digital technology pioneered by QUALCOMM that provides crystal clear voice quality in an exciting new generation of wireless communications products and services. Using digital encoding "spread spectrum" radio frequency (RF) techniques, CDMA provides much better and cost effective voice quality, privacy, system capacity, and flexibility than other wireless technologies, along with enhanced services such as short messaging, e-mail and Internet access.
> What is cdmaOne™?
cdmaOne is a universal term for IS-95 based CDMA (Code Division Multiple Access) specifications established by the CDMA Development group (CDG).
> What is the CDMA Development Group (CDG)?
The CDMA Development Group (CDG) is an industry consortium of companies who have come together to develop the products and services necessary to lead the adoption of CDMA wireless systems around the world.
The CDG is comprised of the world’s leading service providers and manufacturers of subscriber and network infrastructure equipment. In working together, the members will help ensure interpretability among systems while expediting the availability of CDMA technology to consumers.
> How does CDMA work?
CDMA uses spread spectrum technology to break up speech into small, digitized segments and encode them to identify each call. A large number of users can thus share the same band of spectrum and greatly increase system capacity. In other words, CDMA allows cellular and PCS service providers to squeeze more digital signals into a particular slice of the radio network.
> What is GSM?
Global System for Mobile communications. A digital communications technology developed in the early 1980s to allow for roaming throughout Europe.
> What is TDMA?
Time Division Multiple Access. A digital wireless technology that divides a narrow radio channel into framed time slots (typically 3 or 8) and allocates a slot to each user.
> Which has better voice quality – Cellular/800 or PCS/1900 MHz?
CDMA digital makes the difference in voice quality, not the frequency. Both are equally clear.
> Why is CDMA better?
A few of the benefits of CDMA are wireline/clearer voice quality, better reception with less background noise, fewer dropped calls, enhanced security and greater reliability. Also, CDMA allows for more users to be on the system at once – greater network capacity, resulting in fewer blocked calls for the users of a CDMA network.
> Tell me about security with CDMA?
The transmissions of CDMA are encoded digitally. Conversations are broken up and each segment of conversation is assigned a code. On the receiving end, the conversation is reconstructed using the code.
> What’s the capacity of CDMA?
CDMA offers more than 10 times the capacity than the existing analog (AMPS) systems and 3 times the capacity of TDMA.
> Is all digital CDMA?
No, not all digital communications is the same. QUALCOMM uses CDMA digital technology.
> Who is Leap Wireless International, Inc.?
QUALCOMM completed the spin-off of Leap Wireless International, Inc. as an independent company in September 1998. Leap Wireless is a wireless communications carrier that deploys Code Division Multiple Access (CDMA) based networks. The company is listed on the NASDAQ national market under the symbol LWIN.
> Where is CDMA offered?
CDMA has a footprint covering most of the U.S. CDMA is also offered around the world.
> What is Cellular?
Cellular utilizes the 800 MHz frequency range.
> What is the actual frequency range of the cellular band?
824.01-848.97 MHz Transmitter/869.01-893.97 MHz Receiver.
> What is PCS?
PCS stands for Personal Communications Services. It uses a different radio frequency than the current cellular system. Basically, it utilizes the 1900 MHz frequency range, as opposed to the 800 MHz cellular band.
> What is the actual frequency range of the PCS band?
1850-1920 MHz Transmitter/1930-1990 MHz Receiver
> What was the purpose of the new PCS network?
The PCS frequency was auctioned by the FCC in response to capacity issues with cellular networks that would not allow for future desired growth.
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