Compounding the issue, vendors such as Huawei and ZTE continue to export low margin structures out of China.Wavelength-division multiplexing (WDM) is a technology which multiplexes a number of optical carrier signals onto a single optical fiber by using different wavelengths of laser light. [Related -Stocks End Higher Before Payrolls Data; Verifone Systems Inc. (PAY) Sinks]During the quarter, the