TE is a pioneer of TDD DAS technology, having deployed a carrier-certified commercial WiMAX InterReach Fusion system in 2007 at Dulles and Reagan National airports in Washington, DC. Now, TE offers TDD-LTE versions of its InterReach Fusion and FlexWave Prism DAS products.
TDD is different from frequency division multiplexing (FDD) used by mobile services today because it uses the same frequency for both transmit (TX) and receive (RX) paths, making it more spectrally efficient. For example, an FDD band such as PCS Band 25 with a TX/RX bandwidth of 60 MHz, which will utilise a total of 140 MHz of bandwidth (1850 to 1915 MHz for RX, 1930 to 1995 MHz for TX or a total of 1995-1850 = 145 MHz). Comparatively, TDD (Band 40), which has a bandwidth of 100 MHz, will utilise only 100 MHz since the TX/RX paths use the same frequency. To manage this, the DAS are able to detect a downlink burst.
“Spectrum is a scarce commodity and huge investment for mobile operators. It’s important for operators to have access to all frequency bands in order to maximise service to their customers,” said Peter Wraight, president of TE’s Wireless business unit. “By supporting TDD-LTE, TE provides a range of new options for mobile operators as they search for spectrum to support their services.”
