The correct answer is A. Two times.
W-CDMA is a third-generation (3G) cellular technology that offers a significant increase in spectral efficiency over second-generation (2G) technologies such as GSM. W-CDMA uses a spread spectrum technique called code division multiple access (CDMA), which allows multiple users to share the same frequency band without interfering with each other. This is in contrast to GSM, which uses a time division multiple access (TDMA) technique, where each user is assigned a specific time slot to transmit data.
The use of CDMA allows W-CDMA to achieve a spectral efficiency that is two times higher than GSM. This means that W-CDMA can support twice as many users on the same frequency band as GSM.
In addition to its higher spectral efficiency, W-CDMA also offers a number of other advantages over GSM, such as higher data rates, better voice quality, and support for multimedia services. As a result, W-CDMA has become the dominant 3G technology in many parts of the world.
Here is a brief explanation of each option:
- Option A: Two times. This is the correct answer. W-CDMA offers a spectral efficiency that is two times higher than GSM.
- Option B: Three times. This is incorrect. W-CDMA offers a spectral efficiency that is two times higher than GSM, not three times higher.
- Option C: No increase. This is incorrect. W-CDMA offers a significant increase in spectral efficiency over GSM.
- Option D: Six times. This is incorrect. W-CDMA offers a spectral efficiency that is two times higher than GSM, not six times higher.