31.5.02 10-S46 FDA.fm i 37 Am Engl, A31008-H4600-A2-1-19

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People who must conduct extended conversations in their cars every day could switch to a type of mobile phone that places more distance between their bodies and the source of the RF, since the exposure level drops off dramatically with distance. For example, they could switch to:

•a mobile phone in which the antenna is located outside the vehicle,

•a hand-held phone with a built-in antenna connected to a different antenna mounted on the outside of the car or built into a separate package, or

•a headset with a remote antenna to a mobile phone carried at the waist.

Where can I find additional information?

For additional information, see the following websites:

•Federal Communications Commission (FCC) RF Safety Program (select “Information on Human Exposure to RF Fields from Cellular and PCS Radio Transmitters”): http://www.fcc.gov/oet/rfsafety.

•World Health Organization (WHO) International Commission on Non- Ionizing Radiation Protection (select Qs & As): http://www.who.int/emf

•United Kingdom, National Radiological Protection Board: http:// www.nrpb.org.uk

•Cellular Telecommunications Industry Association (CTIA): http:// www.wow-com.com

•U.S. Food and Drug Administration (FDA) Center for devices and Radiological Health: Http://www.fda.gov/cdhr/consumer/

1Muscat et al. Epidemiological Study of Cellular Telephone Use and Malignant Brain Tumors. In: State of the Science Symposium; 1999 June 20; Long Beach, California.

2Tice et al. Tests of mobile phone signals for activity in genotoxicity and other laboratory assays. In: Annual Meeting of the Environmental Mutagen Society; March 29, 1999, Washington, DC; and personal communication, unpublished results.

3Preece, AW, Iwi, G, Davies-Smith, A, Wesnes, K, Butler, S, Lim, E, and Varey, A. Effect of a 915- MHz simulated mobile phone signal on cognitive function in man. Int. J. Radiat. Biol., April 8, 1999.

4Hardell, L, Nasman, A, Pahlson, A, Hallquist, A and Mild, KH. Use of cellular telephones and the risk for brain tumors; a case-control study. Int. J. Oncol, 15: 113-116, 1999.

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Siemens GSM 900, GSM 1900, TDMA 800, TDMA 1900 manual 103, Where can I find additional information?
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GSM 900, GSM 1900, TDMA 1900, TDMA 800 specifications

Siemens is a renowned telecommunications equipment manufacturer known for its innovative solutions in mobile communication. Among its notable contributions are the TDMA 800, TDMA 1900, GSM 900, and GSM 1900 systems. These technologies have played a significant role in shaping mobile telephony, particularly during the late 20th century.

TDMA, or Time Division Multiple Access, is a digital transmission protocol that allows multiple users to share the same frequency channel by dividing the signal into time slots. The Siemens TDMA 800 operates in the 800 MHz frequency band, which is ideal for regional mobile communication. Its main features include improved call quality, greater capacity, and effective handover capabilities. This system was particularly popular in the United States, where it formed the backbone of early digital cellular networks.

On the other hand, the TDMA 1900 operates in the 1900 MHz band, catering to urban areas with higher population densities. This system further enhances voice clarity and offers faster data transmission speeds. Its key characteristics include support for features such as call waiting, caller ID, and enhanced voice privacy, making it suitable for modern telecommunication needs.

GSM, or Global System for Mobile Communications, is another critical technology developed by Siemens. The GSM 900 operates at 900 MHz and is one of the most widely adopted mobile standards globally. Its contributions to the communication landscape include superior frequency reuse, allowing for a greater number of simultaneous calls. The GSM 900 also supports various services beyond voice calls, including SMS (Short Message Service) and basic data transmission.

Meanwhile, GSM 1900, which functions in the 1900 MHz frequency band, is predominantly used in North America. This technology shares many features with GSM 900, but it accommodates a larger number of channels per frequency unit due to its higher frequency. The GSM 1900 system has been critical in facilitating the growth of mobile data services, providing a solid foundation for the evolution of mobile internet access.

Overall, Siemens' TDMA and GSM technologies have significantly influenced the development of mobile telecommunications. With features focused on capacity, flexibility, and quality, these systems established the groundwork for the advanced mobile networks we rely on today. Their legacy continues to be seen in the current generation of wireless technologies, highlighting the importance of innovation in the telecommunications industry.
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