It’s a known fact, that one of the manufacturers of the most popular and prevalent HFC network elements was Scientific Atlanta i.e. Cisco in the last few years. Products of this firm are present in the CATV systems of the most European countries, their average age is quite low in many cases. Since the growth of the demand on high-speed services is accelerating more and more, the need for higher bandwidth devices presents itself significantly sooner, than the CAPEX of these active components returns.
Switching off the analog channels reduces this problem in the forward path, but introducing high-split diplex filters is necessary by all for improving the return path bandwidth. Although the Cisco return path gain stages and lasers make possible a bandwidth of 204 MHz, there is no available original diplexer for utilizing this capability. Regarding to our customers’ wish, COMTECH has developed DOCSIS 3.1 compatible (204/258 MHz) diplex filters for the Cisco 90100, 90300, 9007x, 9020x and 93xxx product families. The additional low-pass filter of 204 MHz is also available in the COMTECH portfolio with optional high-pass (e.g. of 15 MHz) and/or sloped frequency characteristic.
Using the above mentioned frequency ranges the formerly applied HMS and SMC transponders cannot be used, because their forward path receiver works only up to 162 MHz. That is the reason, why COMTECH has developed the NMT-CSC module with extended frequency range up to 300 MHz. The device is compatible with the original 91200 handheld terminal, software and polling machine. The headend controller can be the well-known and popular COMTECH HMTS-X2 with the new improved transmitter card of extended bandwidth, called HMTS-X2-TX-D3.1.

For more information check the following links:


Passives for Cisco

NMT-CSC monitoring transponder for Cisco

HMTS-X2 HMS/SMC monitoring gateway

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