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Customer Installs: HFC Extensions

All Digital Wireless HFC Extension Spans 35 Miles

13 and 18 GHz Antennas at Guthrie Peak repeater site.
The town of Morenci, AZ, served by an all-digital Wireless HFC System.

A dual-band, two-way microwave system was recently installed by MSO Cable One in Morenci, Arizona, providing an all-digital wireless HFC extension capable of delivering the same Digital TV and DOCSIS cable modem services offered in the nearby Safford, Arizona system.

The wireless HFC system was selected over the two other possible alternatives: a fiber link from the Safford headend or a stand-alone headend. The main reason is that it is much more cost effective, which is a significant consideration when providing service for areas with under one thousand subscribers.

The Morenci system had previously received off-air broadcast signals from Safford via a two-hop FM microwave system. The links are 23.3 and 11.7 miles long respectively, for a total of 35 line-of-sight miles.

Cable One decided to implement an all-digital service. The microwave system operates with multiple carriers, all with 256-QAM modulation. The initial 13 GHz downstream transmission rate is 814 Mbps, but the system has capacity to transmit upwards of 3 Gbps.

The 18 GHz upstream was designed to accommodate multiple 16-QAM signals from each of the four nodes. With the increasingly symmetrical nature of subscriber data traffic, more than one upstream channel was required. Cable AML developed a synchronized, block-conversion system to transport four independent upstream channels (each from 5 to 42 MHz) through the two-hop microwave system back to Safford for integration into the CATV return network.

In order to minimize the cost and reduce cut over issues, the existing 13 GHz antennas and waveguides were used for downstream 13 GHz transmission of the 256-QAM digital signals within the 54 to 550 MHz spectrum.

The upstream service in the 18GHz band required the installation of new antennas and waveguide jumpers at the transmitter site at Morenci, the repeater at Guthrie Peak and the receiver at Safford.


Cable One Upgrades Two-Way AML

Kenny Wright, system engineer for Cable One of Natchez MS, at the Vidalia site in Louisiana.

Cable AML has concluded an upgrade of an existing bi-directional AML system linking the towns of Natchez (Mississippi) and Vidalia (Louisiana) across the Mississippi River.

Cable operator Cable One wanted to improve the reliability of the link to provide better upstream DOCSIS modem service to Vidalia subscribers from the existing Headend at Natchez.

The improvements required eliminating a tower-mounted LNA which was prone to failures due to the high frequency of lightning strikes on the tower. To compensate the losses through a long run of elliptical waveguide, a high power upstream transmitter was installed and integrated with the existing broadband downlink used for analog and digital video transmission. 

An extra benefit of the upgrade was to improve clear-weather carrier-to-noise and also fade margin.


Wireless HFC Best Solution for Comcast System

Aerial view of ACOM’s headend and transmit tower in Manaus, Brazil

Comcast, the leading cable operator in the US, has selected a two-way CABLE AML link to provide full HFC service in the small community of Rio Vista, California. The link provides transport of 54 to 870 MHz downstream signals and 5 to 42 MHz upstream signals.

There were three available alternatives to provide full two-way service to Rio Vista: building a new 110 channel headend, Interconnecting to the existing Headend with 30 miles of fiber or interconnecting to the existing Headend with a 21 mile Cable AML link.

Comcast chose the Cable AML wireless solution based on cost and performance considerations: “the performance of the link is equal to fiber and the cost is several times less”, said Butch Robertson of COMCAST.


Upstream Wireless HFC Upgrade For Leading Cable Operator in Arizona

Cable AML has implemented a full digital upstream upgrade to an existing 54 to 550 MHz downstream AML System.

The upgrade allows full bi-directional cable service in areas that are expected to generate significant income growth, because marketing studies showed that DOCSIS Modem service and Set Top Box interactivity were important issues for increasing revenue.

The existing downstream system consisted of a transmitter at Sedona ( Arizona) delivering signals to five remote sites via a repeater array at Mingus Mountain. Cable AML designed the upgrade and assisted in the installation and turn-on.

Upstream capability was implemented without the need to change or add to the existing antennas. Local and remote transceivers were implemented by using existing receivers, originally purchased form another company, thus saving NPG tens of thousands of dollars.

Repeater tower at Mingus Mountain Installing the Return Path Receiver at the Sedona Headend site

Adelphia Ready For Wireless HFC Extension In Hemet, CA

Engineering team from Adephia’s Hemet during system training.

The 16 mile AML link to the isolated mountain community of Idyllwild has been providing reliable signal delivery for years, but until August of this year it was a one way link limited to 54 MHz - 550MHz transmission. Fiber was not a viable alternative due both to cost and exposure to forest fire damage.

A pair of Cable AML transceivers was added to the existing link, expanding DownStream carriage to 54 – 860 MHz and Upstream 5 – 42 MHz... a full wireless HFC extension, installed with virtually no interruption to the 54 – 550 MHz service.

Now subscribers in Idyllwild have the same HSD and digital video services that other Adelphia subscribers enjoy.


Wireless HFC Extension Provides Cable Return Path

Cable AML has delivered a Wireless HFC Extension to provide 54 to 870 MHz downstream service plus 5 to 42 MHz return for Cable Modems and Interactive Set-top boxes (STBs) between the master headend and a subscriber pocket at a distance of 14 miles (22.4 Kms).

Cable operators are selecting two-way AML microwave links for two-way plant upgrades because in many situations microwave has significantly lower cost than fiber. For example, the system recently delivered by Cable AML has a LOS (line of sight) distance of 14 miles, which is equivalent on the average to twenty miles (32 Kms) of fiber. Depending on terrain and other factors, fiber can cost more than twice the cost of the two-way AML link. link.


AML Cable Modem Return System Delivered

Cable AML has delivered an AML Cable Modem Return system to serve a single remote service area. The AML return system is a cost-effective method of providing cable modem service to small pockets of subscribers already served by microwave.

The AML return system was implemented in an existing link providing the full 54 to 550 MHz downstream and it covers the complete 5 to 42 MHz bandwidth used by DOCSIS modems in the upstream. The system design allows for future expansion of the downstream carriage from 550 to 870 MHz.


Wireless HFC Extension Product Family Expanded

Cable operators utilizing wireless links to reach subscriber pockets too difficult or too expensive to serve via HFC will be pleased to learn of Cable AML's new line of wireless extension products. These products enable operators to:

(1) Provide a wireless return path for the latest bi-directional services such as high-speed internet access, video-conferencing, Voice-over-IP, etc;

(2) Add downstream capacity for more video as well as data; and

(3) Achieve these goals cost-effectively, without sacrificing existing bandwidth.


Cable AML Offers 54 to 750 MHz AML Backbone System

Cable AML has manufactured and delivered a broadband AML system with a contiguous channel input and output covering the full 54 to 750 MHz band. The system provides seamless transmission of the whole band without loss of channels because it does not rely on guard-bands for crossover.

Cable Operators can now use an AML trunking solution for advanced broadband cable plants. The able AML solution multiplexes the input VHF signals into the two available CARS (Community Antenna Relay System) Bands, one centered at 13 GHz and one centered at 18 GHz, to provide 700 MHz total bandwidth capability. Like all P-T-P (Point to Point) systems from Cable AML, the system accepts analog (AM or FM), digital (QAM) or any mixture of both types of channels.