DAS Implementation Scenario 2015
Cable TV Networks Regulation Act 1995 Amendment 2011 and its Rules 2012 implied, in letter and spirit, the following :-
(a) Mandated demise of Analog transmission, in a phased manner for different cities/localities as notified by the MIB, to be replaced by digital addressable transmission for both, FTA and PAY TV content, implying access to such content by the subscriber through an addressable set top box(STB) to be inserted between the subscriber drop wall outlet and the domestic TV receiver(coaxial input from cable operator into the STB and output of STB into the TV receiver).
(b)Subscriber to apply for the DAS service by filling up an application form( intimation identification and location details)provided that for existing subscribers on non-addressable networks details could be compiled on the application form as if it was for a new service, choice on mode of procurement of STB ( outright sale, leasing or hire purchase), selection of programs (NOT Channels since channels is a 7 or 8 MHz wide frequency band in 47-862 MHz spectrum wherein each program in analog transmission occupied one such channel while in DAS each such channel could contain 10 to 25 programs) at rates indicated in a rate card to be prepared by the HSP(Headend Service Provider ; a better term than MSO) and receive itemized monthly bills as per details filled in the application form with provision to make changes after initiation of service. Such application form was deemed to form a B2C agreement between the HSP and the Subscriber.
(c)Based upon receipt of application form, creation of a Subscriber ID and release of an STB from the HSP’s warehouse duly programmed as per choice in the application form and also linked with ID of the Cable Operator (registered with Department of Post and does NOT perform any technical functions of encoding, encryption, multiplexing, modulation and authorization in their network) for proximity based service activation and reliability to the subscriber on all matters, including but NOT limited to customer care, so that firstly the cable operator does not lose the ownership of the subscriber and secondly the SMS automatically appropriates Cable Operator’s share of the revenue as per B2B ICO between the HSP and the Cable Operator. Further at the time of activation of service a manual of operation, prepared by the HSP, was to be issued to the subscriber.
(d)To implement the above, HSP was required to install hardware enabling digitization of all content, including encoding + encryption+ compression+authorization messages amongst other functions through an SMS(Subscriber Management System), after seeking registration with the MIB.
If all that was intended in the statute, summarized above, got implemented and networks were up-graded to bi-directionality, such networks could graduate to interactivity leading to delivery of broadband in the spirit of the DIGITAL INDIA theme and paving way for VAS(Value Added Services) including, but NOT limited to, Internet on TV leading to enhancement in ARPU.
Digitization, therefore, involved seeding of addressable( facility to enable or disable viewing remotely and selectively from the Headend) digital and BIS compliant STBs into viewer homes, but was NOT the end of implementation.
Statute was meant to benefit( facility to select content at rates mentioned in a rate card first time through application form and subsequently through 18x365 Call centers and receive itemized monthly bills ) the subscribers who, till date, don’t understand DAS . Getting itemized bills as per selected programs as per rate card has remained a lip service stamping boldly a failure of DAS implementation.
Technicians, the immediate interface for service with the subscriber, were NOT briefed on the processes involved and hence, in absence of completion of details in the SMS, itemized billing cannot commence. Monthly charges are being collected as earlier without bills and receipts.
Govt has NOT registered intended increase in taxes on Cable TV subscriptions through revealed actual connectivity.
Cable Operators are being issued bulk bills, by HSPs based upon number of STBs issued to each Cable Operator.
Technicians were given to understand that DAS signal will be visible everywhere in the network and hence NOTHING is to be done to the network.
Hence revenue has remained, more or less, at the pre-DAS volume levels. Subscriber has NOT felt the impact of DAS. HSPs have incurred capital investments on hardware, CAS and SMS. Cheap and NOT necessarily BIS compliant STBs have been seeded whose fault rate is reportedly high.
With all round increase in cost of living, Cable Operator, despite improvement in visible quality of picture and sound, has NOT been able to raise the subscription which is within the capacity of subscriber subject to feeling the impact of DAS and pay for services. Subscribers have the capacity to pay but want to understand and feel the reasons for enhancements sought.
In such a scenario, with increasing prices and overheads, can the business be sustained over a protracted period? If NOT, and without much hope on voids in DAS implementation, delivery of broadband to residential segment, with higher penetration density of coaxial cable, can be a possibility. This would involve upgrading networks to bi-directionality and introduction of ‘On Demand’ services.
WHAT IS BROADBAND?
BROADBAND is the common term for a very fast connection to the Internet. It allows users to download online entertainment such as video clips and music, listen to digital radio, send e-mail faster and speeds up everything they do online connecting to a computer.A broadband service is always ‘ON’, users don't need to dial up every time they want to log on. Broadband ADSL also lets people surf the internet and use the telephone at the same time.
Broadband has been identified, internationally, as a key enabler for economic growth and social transformation. As per World Bank studies on growth effects of ICT, in low and middle income economies, every 10 percent point increase in broadband penetration can lead to 1.38 percent point increase in economic growth There is an urgent need to boost the broadband growth in the country. Broadband infrastructure can be created though various wireline technologies based on optical fibre network, copper cable (telecom), cable TV network and wireless technologies based on satellite, 3G and beyond, Broadband Wireless Access, etc. All these technologies can co-exist and supplement each other to create a good broadband infrastructure.
Business and occupational connectivity is largely in enterprise sector along with voice. This sector is NOT video savy. As against this video penetration in residential sector through Cable TV network is over 80%. This is largely uni-directional with best effort, including but NOT limited to HFC, since RoW has never been questioned. 20 to 50 ft space above ground level has been encroached and hence practices of strand engineering (hangars, mounts, lashing, bonding etc) were neither demanded nor applied at any time. In fact these have NOT been taught to network technicians. There is total absence of consciousness about adherence to frequency spectrum discipline and radiation from copper loops in the HFC. Active components (amplifiers and power inserters) are NOT bonded. Hence there is heavy ingress of avoidable noise in the network. This, besides uni-directionality, is a major deficit in provision of broadband on cable networks. 15 The MSO and Cable Operator business matrimony has largely been strained. Hence Cable Operators preferred laying separate cable (Cat5e) from TELCOs rather than providing Broadband on Coaxial Cable from MSO/HSP.
The enterprise sector has adequate Broadband penetration in static and portable access terminals. Digital India, in spirit, addresses the residential segment, served by uni-directional HFC networks, to dilute and deflate the Digital Divide by delivery of Broadband on TV. And this sector is largely with Cable Operators with poorly constructed HFC uni-directional networks. With LMOs indifference on DAS implementation, the subscriber is NOT aware of the schedule of rates. They are getting better picture quality and more programs for the same amounts paid before DAS implementation
The convergence of a range of distinct applications and services, such as telephony, video, and data communications, on a single network, yields significant changes in the way networks are built and the way services delivered. The telecommunication and broadcasting convergence allows different types of content and communication services to be delivered through the same network and consumed over a variety of platforms and user devices. The television delivery on wireline medium is currently undergoing a complete revolution. Analog content delivery giving way to digital addressability, providing better quality and more choice to the viewer in the form of more programs in a given bandwidth.
Also interactivity is becoming important in cable television with needed advantage of accessing Broadband Internet. Interactive TV enables the end user to interact with the content owners. Applications such as quizzes, voting and red button applications (selecting a viewing angle in a match, obtaining more information) are becoming a distinct possibility. The primary limitation for offering these broadband-based services over the telco networks is that, to push them through, sufficient bandwidth is currently not available over the TELCO copper cables. Further TV over IP undergoes intense bandwidth crunch as number of TV sets are connected in the same dwelling unit.
In Cable Networks, the present uni-directional (i.e. downstream transportation of signals from Head end to tail end) networks need to be upgraded to bi-directionality (i.e. enabling return path for upstream signal transport from end viewer to the head end). Cable TV operators are apparently NOT aware of the bandwidth handling capacity of their coaxial copper as compared to Telcos Cat5e and hence implied advantage in delivering triple play services(if voice is allowed on Cable TV networks) though VOIP will be an automatic fallout when Cable Modem based Internet is adopted in Cable TV. Cable network is one of the most cost effective future proof technologies for very high bandwidth converged applications.
The cable and satellite broadcast business has undergone a continuous transformation. The entry of organized Multi System Operators (MSOs) had resulted in establishment of more than 6000 head ends in metros and major towns to cater services to cable operators. There are around 60,000 estimated cable operators serving 120 million subscribers.
The MSOs operate on a model of franchising of cable TV feed to cable operators, who in turn provide last mile connectivity to the subscribers. In Cable TV delivery chain there are three distinct entities. MSO/Headend Service Provider(registered with the MIB), Cable Operator (registered with the department of Posts) and the subscriber. In smaller towns the cable operators own head ends and also provide services to end subscribers. There are only about a dozen national Headend Service Providers administering Cable TV services at National Level in different states. The rest are local Headend Service Providers confined to municipal limits of operation.
Two technologies of delivering broadband through cable TV network, namely Data Over Cable Service Interface Specification Protocol (DOCSIS) and Ethernet over Cable (EOC), are in vogue. Cable Modem Based Broadband
The fibre networks that transports TV over cable at subscriber homes can be more than an addition to viewing options — it can also be the means to fast Internet access. HFC (hybrid fibre-coaxial) networks, that are used to carry cable TV images, are also capable of carrying data at very high rates
Once the cable is installed, subscribers need a cable modem to get connected. This modem connects at one end to the cable, and at the other end to PC, either through an Ethernet or a USB connection. Cable modems can transfer data at theoretical speeds of up to 3Mbps. However, because cable is a shared medium with many other users on the same line, performance varies with the amount of subscribers using that particular stretch of bandwidth, as well as the usage patterns.
Many operators use a cable modem that is compliant with the DOCSIS (Data Over Cable Service Interface Specification) standard, which is the most common standard used worldwide. DOCSIS is an open standard, and any manufacturer can make modems that support it.
Cable download speeds are very fast, but, as usual, this can depend a great deal on the source from which the files are being downloaded. Ping times are also very fast, which is a boon for online games. However, as with the rest of the Internet, performance varies depending on the time of day and several other factors, such as the number of subscribers on the specific bandwidth strand.
HSPs offer broadband service, most notably high-speed Internet access services using cable-modem technologies. Cable modems can offer speeds as high as 10 Mbps. Cable operators have been complacent in upgrading their networks since digital delivery improves visibility of more programs over the same shoddy networks.
There is near negligible thought on delivering internet on TV sets if Web became an household items. Cable operators need to take advantage of this opportunity to provide high-speed access, because once their network is upgraded, adding high-speed access would not be a large expense. Digital cable TV networks are able to offer bi-directional data transfer bandwidth in addition to voice and digital TV services. A schematic diagram of triple play over cable TV network is shown at Fig. 1.
DOCSIS for Broadband over Cable
Broadband over Cable TV Networks through modem has three major segmentss—the customer cable modem (which connects to the customers PC or laptop), the cable TV network (through which the signal flows) and the main cable router (which take the customer signal off the cable TV network and passes it on to the Internet). Using a Cable Modem (CM) in the customer premise and a Cable Modem Termination System (CMTS) at the network head-end, the well established Hybrid-Fiber/Coax (HFC) standard, Data-Over-Cable-Service Interface Specification (DOCSIS) 3.0 , provides for a data transmission service with speeds of up to 140 Mbps on one 7 or 8 MHz channel using Quadrature-Amplitude Modulation (QAM) techniques. Data transmission over Cable TV networks has the advantage that where the coaxial cable is in good condition and two way Radio Frequency (RF) amplifiers can be installed to extend the network reach, relatively high bandwidths can be provided to the end user without distance limitations. However, a cable TV broadband service relies on shared network architecture. This results in the limitation of the amount of bandwidth delivered to the customer and is dependant on how many people share the connection back to the head-end.
The DOCSIS service transfers Ethernet (used by most systems) or asynchronous transfer mode (ATM) traffic over coaxial or HFC cable bi-directional between the service providers head end and the cable modem at customer locations. The service is supported on a Cable TV (CATV) network with a tree-and-branch architecture. The DOCSIS system is composed of Downstream (DS) and Upstream (US) paths. The DS is the connection from the CMTS, located at the cable network head end, to the CM located in the subscribers home or business. This path is a wide-Bandwidth, high-data-rate connection. The US connection is the path from the subscriber back to the CMTS. This path is lower bandwidth and uses lower data rates than the DS. DOCSIS 3.0, can hit speeds of 160 Mbps, although the fastest speed currently available is a 50 Mbps system. The system is always on, it is not dependent on the distance you are from the exchange (unlike Asymmetric Digital Subscriber Line (ADSL)) and every person can receive the same speeds ± unlike ADSL. A simple architecture of DOCSIS is shown in Fig 2
System operates through a Cable Modem functioning as an interface between cable network and the computer. It performs both functions of modulation (upstream) and Demodulation downstream. Hence the name MODEM(Modulation-De-modulation). When switched ON, modem locates the RF channel in which data is transported in the entire RF transport stream, synchronizes QAM de-modulation, looks for upstream frequency in the DESCRIPTOR and starts sending QPSK modulated messages to headend varying the output levels in steps till the Headend hears these communications. Whemn presence is detected by CMTS at the Headend, the DHCP(Dynamic Host Configuration Protocol) server allocates a session IP address ToD (Time of Day) stamping/logging. The communication is then established and Internet can be accessed.
The CMTS transmits digitally modulated RF signals downstream, preferably, to the CMs in the 301 -to-862 MHz frequency range with a 8 MHz channel bandwidth.). The data information is vector-modulated onto the carrier with a quadrature-amplitude modulation (QAM) format. The Headend operator can select either 64QAM or 256QAM (64 states or 256 states respectively), depending on the network in the last mile. The 256QAM signal provides faster data rates of 43 Mbps compared to 30Mbps for 64QAM. A continuous data stream of 30 or 43 Mbps in MPEG-2 format is received by all CMs connected to the CMTS. The CM transmits a US signal that is a Time-Division Multiple-Access (TDMA), or bursted, format in the 5-40 MHz frequency range in India. The US bandwidth is narrower than the DS, and it varies from 200 kHz to 3.2 MHz in five steps. The US bandwidth setting is determined by the CMTS, and it is based upon the Quality of Service (QoS) selection made by the cable operator.
Reluctance of Cable Operators to let SMS in DAS activate can be a major behavioural obstacle in adoption of DOCSIS based broadband delivery. Cable Operators have to understand that while TV entertainment delivery is subscription based billing operation, broadband will essentially be usage based addressable system with very clean (noise free up and downstream communications without interruptions whatsoever) network and hence would require a more robust SMS. Provision of broadband on cable TV will automatically pave the way for ON DEMAND services leading to additional revenue.
CMTS, depending upon quality, may cost Rs 5.0 lacs to Rs 7.0 lacs and Cable Modem costs would be around Rs 2500/- each. ISP licence costs will be in addition.
The costs for a ‘state of the art’ last mile, if built new(since present networks cannot handle even 64 QAM to meet IS-13420 specifications) could be as under :-
• 3 Amplifiers in coax cascade after the node ( in each radial arm, 4 bridgers after No1 amplifier on sides, 2 bridgers after 2nd amplifier and no bridger after 3rd amplifier.- total 12 trunk amplifiers and 24 bridgers in a 1 km last mile coax network from any node)
• 4 radial arms per node
• Each radial arm will have 6 line extenders/bridgers
• Trunk Cable 500 Series – 4 Kms @ Rs 50/- per km Rs 200000/-
• Sub Trunk Cable RG-11 – 3.6 Kms @ Rs 25/-per km Rs 90000/-
•Drop Cable RG-6, 10 mtrs per house for 750 @ Rs15/-mtr Rs 75000/-
•Trunk Amplifiers 5-862 MHz indigenous- 12 Nos @ Rs 7000/- each Rs 84000/-
•Line Extenders/bridgers 5-862 MHz indigenous 24 Nos @ Rs 5000/- each Rs 120000/-
•Taps Off/Splitters 200 Nos @ Rs 100/- each Rs 20000/-
•Total Rs 589000/-
•AddMisc Rs 100000/-
•Cost estimate for Last Mile DOCSIS 3.0 Compliant Last Mile Network Rs 689000/
•Cost per household @ 250 homes past per km for 4 km radius Rs 700/-
However if last mile owner cable operators do NOT wish to integrate with HSPs SMS, i.e. desire to take feed from telcos then the technology available would be EoC.
EoC (Ethernet over Coaxial Cable) Technology for Delivering Broadband – HPNA System
The term Ethernet-over-Coax (EoC) is a generic term for Ethernet transport systems that use coaxial cables to transport the Ethernet signal between two or more sites. The first differentiator between available EoC systems is the method they use to transport data over the coaxial cable: either base band or modulated RF. Base band systems can be called passive systems while systems using modulated RF are active systems due to the fact that they require an active device on either side of the network but while a base band system is typically easy to setup and use, it does have the disadvantage of requiring a point-to-point connection between two sites in order to achieve suitable data rates >10Mbps needed for applications currently running over IP networks. Active systems in turn allow connecting multiple Customer Premise Devices to the same coaxial cable.
HPNA(Home Phone Networking Alliance) in its latest revision 3.1 uses the frequency range of 4 to 52 MHz and can therefore, due to the low loss over coaxial cable in that frequency range, bridge greater distances. When mixed with TV RF transport in 47-862 MHZ spectrum with circuit filters, does not cause interference to TV signals. However, such mixed signals have to be confined to passive segment of Cable Networks i.e. insertion/mixing of Broadband after the amplifier feeding the subscriber.
An HPNA system is comprised of a master unit (sometimes called a bridge device) that serves as BROADBAND GATEWAY between the coaxial network and the main IP connection, and multiple CPE devices as end-points. In an HPNA 3.1 based system, the master unit can support and control up to 32 CPE devices, which can all be connected to one coaxial cable in any mix of tree and branch, and/or star architecture. These Gateways may cost around Rs 20000/-.
Another scenario for the use of EoC is for network demarcation. Builders may like to own the CATV and IP data distribution service, as they want to offer these services as part of the package. Here the cable modem installation in the basement of the MDU building can act as a demarcation point between CATV MSO and the owner of the MDU building. At this point, the MSO hands over the CATV and Ethernet signal to the building owner. The builder can then use an HPNA-EoC system to distribute the CATV and IP service via the existing coaxial distribution system while having full control over the connected subscribers. Fig. 6 shows a typical network layout in an Multi-Dwelling Unit (MDU) environment.
At the receiving end of the HPNA based EoC, is a typlical diplexer type device to which the Coaxial drop is connected at the input and at the output are two connectors i.e. F connector for connecting the TV set or the STB ans RJ-11 socket for connecting to the computer. These sockets cost approximately Rs 500/-.
The range of an HomePNA (version 2.0) phoneline network is about 1000 feet (300 m). The maximum bandwidth of an HomePNA 2.0 network is 10 Mbps, while an HomePNA 3.0 network supports more than 100 Mbps. The speed of phoneline networking can suffer depending on the quality of phone cables installed in the residence.
Using HPNA based EoC in HFC Networks modern HFC networks that use DOCSIS to offer High Speed Data (HSD) services by MSOs may cause someone to question the need for EoC systems, as each customer can have its own cable modem. But the coaxial in-building installations in large MDU buildings and townships, which can be found in most big cities all across India, are often the source for severe ingress. If a number of MDU buildings are connected to one optical node, which is often the case in suburbs with MDU structure, the ingress coming from these in-building networks accumulate and can force a DOCSIS system to switch back to low upstream bandwidth or even fail to operate. In these critical environments EoC offers the ability to terminate the DOCSIS system at the access point to the in building coax system and then use the ruggedness of HPNA in the existing RF distribution to overcome the many issues with existing old coaxial in-building distribution systems while keeping the data throughput at maximum level. The basic network layout will be to use a cable modem in the basement and then use an HPNA-based EoC to distribute IP connectivity throughout the building via the coaxial distribution system, which is at the same time used for distribution of TV signals. As the throughput of the cable modem is shared among the number of subscribers connected to the HPNA EoC system, most preferably the cable modem should be a wideband or DOCSIS 3.0 type to maximize the available bandwidth in downstream and upstream by the use of channel bonding technology. A typical network layout of such a system is shown in
43.Additional key benefits include:
- Broadband access networks in multi-dwelling environments typically have lower signal quality and higher noise and attenuation than home networks - making it a more challenging environment. The new standard increases transmission power and adds enhancements that make MDU operation robust and reliable.
- Fast EoC's enhanced mode uses bonded channels that provide up to 640 Mega bits per second (Mbps) data rate, which, combined with guaranteed QoS and true multicast capability, can enable the delivery of triple play services to MDU residents over the existing coax cables.
- Fast EoC delivers the highest security and privacy by adding encryption capability and a unique MAC architecture to prevent endpoints from becoming aware of or communicating with each other.
- Fast EoC enables control of up to 126 endpoints supporting the large number of living units in an MDU. The implementation enables the addition of these endpoints with almost no change in the total throughput, ensuring stable predictable performance.
- Network management in MDUs is important and the endpoints must be managed effectively. Fast EoC features capabilities that enable vendors to supply powerful network management tools.
HPNA offers high bandwidth, guaranteed QoS, remote management, and diagnostic capabilities that facilitate the installation and maintenance of the home entertainment network. The technology provides flexible solutions capable of servicing MDUs, hotels, single-family homes, and large and small network operators enabling service providers to deploy reliable cutting-edge services, like triple-play, in a variety of environments, while minimizing operation expenditures.
With the development of technologies, it is now possible to provide broadband internet services using cable TV network at high quality and affordable costs. This is definitely going to revolutionize broadband growth in the Indian scenario. The existing cable network has a reach of more than 120 million homes, which can be utilized as a potential means to increase broadband penetration in the country. While the Broadband on cable system using DOCSIS standard can be used by bigger cable operators and MSOs whose cable infrastructure has already been upgraded, the EoC technology can be used by the smaller cable operators for supplementing the growth of Broadband in the country. Both the technologies can also be used simultaneously in the same network and at times, using a combination of both the technologies is more efficient.
The impending changes will result in big opportunities especially for Cable operators. They are OWNERS of the Last Mile. They are optimally located to provide these much in demand technologies to the end consumer. The Indian government is directly indicating interest in this network transformation, and the time is NOW, for Cable operators in India to realize substantial gain and increased market importance, something that DTH seemed to have taken away.