In a message dated 97-08-04 Roger Magnuson writes: << I'm trying to determine if a US modem designed for Part 68 would be able to pass testing "as-is" in following countries: Japan, China, Hong Kong, Korea, Taiwan, Malaysia, Singapore >>
Roger: There is no requirement in FCC Part 68 that directly conflicts with the requirements in these countries. However, based on my experience, here are a few areas to check out before you waste money submitting for formal testing: 1) Out-of-band signal power requirements are fairly stringent in Japan, Korea, and China. Depending on your modem chip set, you might have trouble with this parameter. FCC Part 68 has fairly "easy" requirements for this parameter. 2) DC V-I requirements call for fairly low effective DC resistance in most of the countries on your list. FCC Part 68 has no explicit requirement on the value of this parameter. 3) Return loss requirements are stringent in Singapore, easy in Japan, and moderate in the remaining countries on your list. FCC Part 68 has no requirement at all for return loss of a conventional modem. 4) Ring detect voltage thresholds are specified for most of the countries on your list. FCC Part 68 has no requirement for this parameter. 5) Several software-defined parameters such as modem transmit levels, pulse dialing break/make ratios, and auto-redial limitations will have to be modified for some countries. Since these are usually simple software modifications that involve no hardware changes, I am not sure whether you would consider these to be problems or not. So, you might get "lucky" and find that your modem will pass in all of the countries on your list. However, chances are that modifications will be required in at some of the areas that I have listed. That being said, it is worth noting that with a little forethought, it is possible to use the same hardware design in the USA and all of the countries on your list. In general, the additional requirements that apply in the other countries are a superset of the requirements in FCC Part 68. With the exception of some minor software changes, the same design can then be used in each country. Joe Randolph Telecom Design Consultant Randolph Telecom, Inc.
