 traffic but in these advanced service offerings. In many countries, such as Finland, cellular voice traffic has already reached almost everybody, and there may be a leveling off of sub- scriber voice demand in favor of other uses of wireless communications. While an in- crease in data service or subscriber interest in multimedia message service (MMS) is good for the wireless provider's business, these increases do not require the addition of more transport from the MSC to the PSTN. We believe that there will be sustained growth in the voice market. Even as we read about cellular market saturation, more people are buying their first cell phones, and others are buying more than one. Developing countries are developing markets for voice, and wireless systems will see large gains in voice traffic over time as subscribers begin to rely on their cell phones as their primary telephones. The bottom line for MSC-to-PSTN transport is that it will continue to increase as voice traffic continues to increase. Our monitor systems will generate reports on voice call activity and transport utilization, and 3G CDMA planners should continue to read these reports, no matter how boring they may seem. Voice call service may not be glam- orous in the high-tech, 3G picture, but it is the bread and butter of the wireless tele- phony industry, it is likely to stay that way, and we should make sure that our trans- port facilities are supporting that voice call traffic. 44.4 Adding MSC-to-PPDN Capacity The big unknown in the wireless market at the time we are writing this book (2002) is the size of the wireless data market. The popularity of other new services is also in question. Multimedia message service (MMS) allows subscribers to send graphic im- 2We read sad reports that cellular service may grow at a rate of only 10 or 20 percent per year. It is easy to forget that adding 10 percent to the world's current cellular community is an addition of 100 million subscribers. Downloaded from Digital Engineering Library @ McGraw-Hill (www.dig