HFC Solutions for Network Evolution

COMTECH provides a wide spectrum of CATV transmission elements covering all the segments from the headend to the service access point. More than 1000 product types are available to serve the needs of the large as well as the small sevice providers. The user satisfaction is guaranted by the excellent quality materials, by the professional experience of almost 30 years and 2500000 sold network elements. All our products are developed regarding to the customer feedbacks - the result is an easy-to-use product family with the highest level compatibility with all network topologies.

Take a look at our offer with the unique automatic four-state ingress management solution, with the multiprotocol monitoring system and with the robust modular node/amplifier family designed for extreme environmental conditions, which are working among others in Switzerland, in Malta and of course in Hungary.

"The reason why we co-operate with COMTECH Ltd is because they give us competitive products which perfectly stand up to our requirements. The products’ operation safety and quality meet the highest requirements. COMTECH Ltd is a realible partner for us because of the good co-operation and service background."

(Gottfried Schaffelhofer; CEO; Schaffelhofer CATV-Service; Austria)

Headend optical products

A really modern CATV headend launches and terminates optical signals. COMTECH provides all the needed elements of the optical-RF border surface in both signal directions. The dual and the most recent quad housing fills the requirement of higher density and this is supported by the possibility of the choice from the two different sized mainframes. All our headend optical products are managed and remote controlled beside the standardized local user interface.

Optical nodes

Optical nodes are key elements of each HFC network independent from the practical topology. COMTECH sells solutions for all the popular technologies such as:

Classical HFC technology: Using the capabilities of the DOCSIS 3.1 system the existing hybride networks can provide data speeds of higher than 1000 Mbps. This fact makes the HFC technology competitive with the baseband digital optical services. As a benefit the working transmission network should not be changed with all it's elements (that could have really high expenses in particular if underground cables are used), only the return path or both communication directions of the coaxial site must be segmented if the subscriber demands make that necessary. The COMTECH modular nodes allow this step without significant cost by adding only a new module to the earlier mounted element.
Fiber Deep technology: Reducing the OPEX the optical-RF conversion should be realized closer to the subscriber than in case of the former networks. This can eliminate the use of the amplifiers after the node, but only if the output signal level is high enough. The COMTECH fiber deep nodes provide this required level with the prescribed distortion parameters. The corresponding electrical and mechanical parameters of these elements make them specifically suitable for using in rural environment.
FTTB technology: Technically the rural and urban networks can have the same structure, but at higher subscriber density it can be more economical to do the optical-RF conversion in each building or stairway. (This is Fiber To The Building i.e. FTTB.) In such a case the future segmentation will be not needed - the best solution is to place a compact node at the end of the fiber. The COMTECH compact nodes work with built in optical receiver and exchangeable return path, further they do not need setting modules thanks to the electronic setup. This means these instruments are small and ready-to-use.
Modular construction: This structure allows to reconfigure the network element very fast and comfortable. The forward and return path breakpoints, the transmitter and/or receiver numbers, the comfort services as well as the gain and tilt parameters can be changed without any difficulty. By using this construction CAPEX can be minimalized too, because the modules of the unneccessary services should not be bought. The COMTECH modular nodes are available with exchangeable tray. It is especially useful at mast mounted networks where flash bolts are not impossible: A flash damaged element can be changed very fast without cable mounting. First benefit is the lowest system-down time, second benefit is lower OPEX.
Compact construction: The compact nodes delivered by COMTECH contain all the main circuits on the motherboard and on the return path module. This allows to reach all the comfort functions and small spatial dimensions at the same time. To provide the highest flexibility the output splitter, the diplex filter and the monitoring transponder are exchangeable at this construction too. The compact devices are available with either local or remote powering and on demand special powering can be realized. (For details see Bespoke products.)
Network manegement: All the COMTECH nodes can be managed via the optional monitoring transponders. The devices are insertable into either a standard SNMP (HMS) or into the extremely robust ComMon network element management system. For modular devices DOCSIS transponders are available too.

Broadband Amplifiers

The hybride CATV networks contain broadband amplifiers after the optical node. Particularly in lower subscriber density areas more network layers are involved with these elements - this means a higher number of amplifiers with various roles. COMTECH sells different construction amplifiers for each network layers for the following functionalities:

Bridger amplifiers: This type works with two independent active output stages so it is suitable for splitting the RF power into two symmetrically e.g. feeding two equal lines. COMTECH provides bridger amplifiers in modular design with different gain values.
Trunk amplifiers: Trunk amplifiers realize asymmetrical splitting with active attenuation compensation in the coupled (bridge) branch. These elements are used for joining shorter side branches (for example street lines) to the main (trunk) line. The COMTECH trunk amplifiers are available in modular style.
Line amplifiers: Line amplifiers i. e. line extenders are used to compensate the cable attenuation on the line. COMTECH provides these elements with modular, compact and super compact construction too.
Distribution amplifiers: Compact and super compact devices from COMTECH that are able to feed shorter lines thanks to their high output level but the low power consumption makes them able to work as a house amplifier too.
House amplifiers: Devices for compensating the in-house cabling system. COMTECH offers very low cost house amplifiers which are suggestible not only for CATV operators but for private households too as a flat amplifier.
Modular construction: This structure allows the reconfiguring of network elements very fast and comfortable. The forward and return path breakpoints, the comfort services as well as the gain and tilt parameters can be changed without any difficulty. By using this construction CAPEX can be minimalized too, because the modules of the unneccessary services should not be bought. The COMTECH modular amplifiers are available with exchangeable tray. It is especially useful at mast mounted networks where flash bolts are not impossible: A flash damaged element can be very fast changed without cable mounting. First benefit is the lowest system-down time, second benefit is lower OPEX.
Compact construction: The compact amplifiers delivered by COMTECH have the main benefit of the small spatial dimensions. Beside this all the comfort functions and breakpoint determining circuits are as modules available - so this style has similar flexibility as the modular types except for the exchangeable tray. The compact mini versions are available with integrated tilt circuitry and standard JXP module set too.
Network manegement: All the modular and the most of the compact COMTECH amplifiers can be managed via the optional monitoring transponders. The devices are insertable into either a standard SNMP (HMS) or into the extremely robust ComMon network element management system. For modular devices DOCSIS transponders are available too.

Monitoring Products

In the most european countries regulations prescribe that CATV networks have to be at service in the 99,99 percent of an arbitrary time interval. Since the network elements work in 24 hours often under very extreme environmental conditions it is hard to operate larger systems without management but observing the regulations. To overcome this problem COMTECH provides complete network management solutions. All the service providers can choose the corresponding protocol, gateway, server and transponder set from our product spectrum that contains transponders for OEM nodes and amplifiers too.

Using a COMTECH network element management system the operator can receive instant e-mail notification if a parameter of any network element comes out from the allowed range. If this parameter is the measured noise the remote controlled return noise switch and the remote controlled filter help to find the source and the frequency range of the noise or ingress.
Our monitoring solution has a lot of advantages beside the failure localization: The ComMon software depicts all the measured and registrated parameters graphically in time. Based on this an eventual tendential service degradation can be recognized and the needed maintaining work or network segmentation can be done keeping off the system down. These parameters are available at the site too by using the IR1 wireless data reader unit.
Another function is the remote controlling of the network elements' gain and tilt values - this function is already available at all the compact nodes.
These features prove higher system reliability and lower OPEX. To make these advantages available in the most popular CATV systems, COMTECH offers flexible configurable elements with the following options:
Standard protocols (HMS and DOCSIS): Solutions with standard protocols have the benefit of interoperability with OEM network elements. This makes easy inserting a COMTECH element into an existing foreign network and vice versa. All of our transponder products are available with SNMP based HMS protocol and the modular network elements can be ordered with DOCSIS transponder too.
Special protocols: COMTECH has developed an own communication protocol with very high robustness, so it is especially proposed to use in older and/or larger CATV networks. The solution based on this protocol provides the comfort of the fully automatic tuning and leveling of the transponders. Before the standardization other manufacturers has introduced their own protocols too. One of the most popular from them is the SMC protocol that can be interpreted by our newest gateway device.
HMS - DOCSIS - Special protocols. Which to use? The HMS protocol as a standard solution has the main advantage of hardware and software side independency from the main service i.e. DOCSIS data traffic. The very robust FSK modulation in the physical layer warrants that the management is in working order even at such serious failures that traverse the work of the DOCSIS data traffic. The future proof DOCSIS 3.1 compatible HMS transponders for OEM network elements are already available in the COMTECH product range.
The DOCSIS monitoring solution can be inserted into the CATV spectrum seamless. Since the commercial data traffic and the monitoring signals form a homogeneous system, no gateway is needed at the headend. The expense of this is the lower robustness - if the DOCSIS data traffic is traversed, not even the element management system works.    To utilize the advantages one of the newest COMTECH products is the fully frequency agile DOCSIS transponder for the modular products.
The COMTECH special protocol has the benefit of extreme high interference-tolerance and full-automatic system configuration. To override the problem of the interoperability with other manufacturers' network elements COMTECH produces transponders with this protocol for C-COR, Harmonic, Kathrein and Motorola devices too.

Signal Organization

One of the largest challenge at building a headend is to realize a clear-cut and small sized RF connection network between the signal sources and the optical elements. COMTECH provides 1U sized active and passive signal organizers containing splitters, combiners and direction couplers with various coupling values optimized for optical or coaxial segments. As special products bandpassed and impedance matching types are developed too. For feeding this network high level amplifiers may be needed which are available in forward path and in return path. The amplifiers are insertable into the optical mainframes and can be managed by all COMTECH monitoring solutions.

Optical passives

The optical networks need by all splitters, combiners, couplers and depending on the used technology WDM filters, multiplexers and demultiplexers. COMTECH deals in these elements and for mounting them on a headend also an optical rack is offered.

Auxiliary Products

To achieve best performance precise gain and tilt set, cable simulation, automatic leveling and filtering could be needed. COMTECH produces these elements as modules insertable into the modular devices. Further auxiliary units are the remote powering transformer and the interactive subscriber connector realizing a well defined leadable service access point.