Earth Stations: Scalability Is the Key

Earth Stations: Scalability Is the Key

Broadcasters are faced with the challenge of digitizing operations on the right satellite, with coverage of their choice, and broadcasting content to reach new audiences in an efficient, reliable, and cost-effective manner.

Earth stations host communication systems that provide mission-critical, high-bandwidth services to broadcasters. Within these earth stations are a number of frequency-based equipment that generate and convert carrier frequencies, and modulate and demodulate data.

The satellite broadcasting TV services are available in India through multiple distribution platforms. These services are mostly delivered through cable TV, DTH, and HITS networks. There are 700 MSOs providing digital TV services, more than 60,000 cable operators, 7 DTH operators, and 2 HITS operators.

Each distribution platform operator retransmits on an average 350 satellite TV channels along with other services that may be unique for that particular operator.For optimum utilization of available infrastructure, there is a need to examine technical and commercial issues in earth station facilities. It is expected that benefits of reduction in CapEx and OpEx of operators will ultimately be passed on to the subscribers.

Indian Scenario2015-16 did not see much procurement for earth station installations. A total of 96 new TV channel licenses were issued in 2015-16, which did not require new earth stations to be set up. The four leading vendors Indiasign, Decibel Technologies, Planetcast, and General Dynamics are finding leasing the preferred option.

Indiasign upgraded its teleport facility at Hyderabad valued at Rs. 4 crore.

Planetcast received orders from Asiasat-5 for setting up earth station at captive basis valued at Rs. 3.5 crore.

India has a high penetration of pay-TV households. The projected channel growth in India will result in a huge demand-supply gap in transponder capacity in future. As the nation moves ahead with Phase-III and Phase-IV of cable digitization, especially with the growth of television consumption outside the urban areas, the DTH share of Indian pay-TV subscribers is expected to increase to 41 percent by 2019. This expanding customer base along with the proliferation of HD channels will mean a large need for transponders. The transponder capacity requirement of the DTH industry has always been met by foreign satellite firms. Today, only 25 percent of India’s DTH transponder capacity is being served by Indian satellites; most DTH operators are able to carry only 50 percent of the total channels available through cable networks owing to the limited number of transponders that are available. This puts them in a disadvantageous position vis-a-vis cable operators. This gap will only widen going forward. Over the last three years, the number of transponders contracted by DTH operators has gone up from 73 to 78.20 The DTH industry will require 200 transponders in the next three years to carry channels.

Earth station operators have to meet the challenge of providing multiple services to a large number of customers at the highest data rates. The overall volume of data serving critical applications necessitates an infrastructure with a higher level of scalability and redundancy to meet customer requirements. Earth station quality-of-service is directly related to the frequencies used to carry the payloads through the modulators, demodulators, uplinks, and downlinks. So there is need for a solution that can increase satellite bandwidth capacity so that more channels could be accommodated.

Broadcasters have to lower the cost per megabit over satellite as much as possible to create new revenue streams and give customers better value. At the same time, they need controlled, manageable, and predictable CapEx. One way to address this is by making the equipment as scalable as possible. High-throughput satellites are going to put new demands on satellite networking platforms, throwing new issues that have not been at play before. One of the demands that will be placed on these satellite networking platforms is packet processing performance. Networks will become increasingly complex as a result of high-throughput satellite designs. Operators will need to be able to address those issues while providing benefits to their customers. In addition, many satellite networking customers have a global presence, and their global connectivity needs have to be addressed. They are likely to operate in more than one region of the world and they need to be able to have a platform that gives them connectivity where and when they need it and to be able to do so automatically and dynamically.

Transitioning from Single-Channel to Multi-Channel Modulators

Modulators perform an integral function in broadcast applications including DTH services, as well as TV content distribution. The modulator performs the 24×7 mission-critical operations of ingesting the input data stream bits, in the form of IP or MPEG packets, and then transforming the data into a radio-frequency (RF) waveform for transmission to the satellite.

The cable TV and other terrestrial markets formerly used single-channel modulators for their services, albeit using different RF transmission standards and data formats. Over the last few years, these industries have been transitioning to multi-channel modulators to replace single-channel modulators.

The primary reason for the transition is that multi-channel modulators have comparable signal fidelity and quality but provide significant cost savings in terms of CapEx and long-term OpEx. As technology has evolved, the satellite industry can now benefit from a similar movement toward multi-channel satellite modulators.

Time for better modulators. Customers are moving to IP-based equipment rather than the ASI connections found on previous-generation modulators. The IP-centric approach allows the data to be generated anywhere in the customer’s network and distributed through standard networking equipment to the uplink facility.

The modulator transforms the data into the waveform required by the uplink and uses the DVB-S2 standard or the more recently introduced DVB-S2X (extensions) standard to maximize the efficiency of the satellite transponder or channel with regard to the number of bits/Hertz transmitted.

The waveform is upconverted by a frequency translator to Ku-or Ka-band for transmission to the satellite. The high-frequency signal is then amplified by a TWTA or SSPA prior to uplink by the station antenna. For a wideband system with many channels, the output of several single channel modulators is combined to form an aggregate signal for upconversion and amplification.

Because the data being uplinked by the gateway or teleport is mission critical, redundancy  is incorporated into the uplink chain to ensure that equipment failures do not interrupt the signal transmission. Many service providers also incorporate site diversity because signal fade due to highly variable weather conditions, particularly at Ka-band and higher frequencies, can interrupt the uplink signal.

Availability is a critical aspect of the transmission system. Unlike the original one uplink chain for one-channel architecture that was common in the early days of broadcast, more and more items in the uplink chain handle multiple channels in a single device.

Data playout sources aggregate many channels and multi-cast this data to the rest of the transmission chain. Wideband amplifiers and frequency converters handle many channels. The multi-channel modulator continues this trend. When combined with a suitable redundancy switch, the multi-channel modulator can be used in the uplink chain.

Cost effectiveness is the primary reason for the selection of the multi-channel modulator. With the current technology available in the market, one multi-channel modulator can replace as many as 16 traditional modulators. This corresponds to a significant reduction in rack space populating the equipment room where space is often at a premium.

The initial CapEx to procure multi-channel modulators is much lower when eight multi-channel modulators are purchased instead of 128 single-channel modulators. Although the components used within the multi-channel modulator are more technologically advanced and likely to be more expensive than the single-channel units, savings can be realized from the reduction of similar components within the modulator like the power supplies and chassis. This leads to an overall lower price per channel in terms of procurement.

Along with the CapEx savings and the reduction in space required for the modulators in the equipment room, there are also other important savings in operating expenses – electricity and HVAC costs. A multi-channel modulator draws roughly the same amount of power as a single-channel modulator.

Many applications are suitable for the inclusion of a multi-channel modulator. A new uplink site build-out is but one example. For a new facility under construction, the savings in initial purchase price coupled with the reduced equipment room size and ongoing operational savings lead to an attractive business case when compared to the single-channel modulator architecture.

Another suitable application is a diversity site build-out, which is becoming more important as climate change is causing modified weather patterns. Existing uplink facilities are experiencing more rain-fade outages, which are triggering the need for backup facilities to be put into place to handle these outages. The diversity site advantages are similar to a new uplink site build-out and also provide a way for an operator to become familiar with and comfortable with the multi-channel technology prior to use in the main facility.

Apt for 4K broadcasting. The multi-channel modulator also has advantages for transmissions of 4K or ultra-high-definition (UHD) video. These emerging applications over satellite require high bandwidths to be transmitted over the satellite and can benefit from the channel-bonding features available in the DVB-S2X standards.

Multi-channel modulators are uniquely suitable for UHD because the delay between the bonded channels can be tightly controlled in transmission from a single source. Single-channel modulators cannot achieve the same level of synchronization and they can cause higher levels of skew between channels. This, in turn, can complicate set-top box design.

The multi-channel modulator is also uniquely able to bond together portions of a transponder and make use of underutilized bandwidth on a transponder to generate additional revenue. The S2X channel-bonding can be used in conjunction with the multi-channel modulator to enable this new application and remove the need for the satellite operator to move around customer bandwidth as leases expire, in order to tightly pack together customer bandwidth.In this application, the multi-channel modulator, along with a complementary multi-channel receiver, provides a way for this fragmented bandwidth to be consolidated into a usable virtually contiguous bandwidth that can more readily be commercialized with minimal impact to operations.

The advantages of the multi-channel modulator are clear for broadcast applications. The new technology is a viable fit for new uplink site build-out, diversity sites, aging facility refurbishment, new applications based on channel bonding such as UHD/4K video, and increasing bandwidth efficiency on existing transponders.The compelling advantages of this technology make a strong case that it is ready for broad-based adoption. The time for the multi-channel modulator has arrived.

Share this:

Leave a Reply

Your email address will not be published. Required fields are marked *

88 − 82 =

Stay Updated on Broadcast and CableSat.
Receive our Daily Newsletter.