Biological effects of mobile phone radiation

Many studies have been conducted on electromagnetic absorption of mobile phone radiation by human head and the industrial Specific Absorption Rate (SAR) standards have been introduced to regulate handsets radiation power levels. Some research results revealed that the thermal effects due to handsets radiation can be always negligible. However, few can deny the fact or puzzle that some people did suffer from such symptoms as headache during or after a long talk; and no convincing answer to the puzzle is in the literature. This paper provides an answer to the puzzle through analysis and understanding of the popular Time Division Multiple Access (TDMA) signal waveform. With this analysis and understanding, we predict that TDMA phones are more likely to cause headache than Code Division Multiple Access (CDMA) phones.