DOCSIS (Data over Cable Service Interface Specification), metro Ethernet and PON technologies share the remaining two million subscribers (15%). While the TRAI report doesn’t clearly identify wireline subscribers by technology, a rough indication tells us that DOCSIS contributes to half the remaining number, i.e. one million subscribers.
The top five wired broadband service providers are BSNL (9.97 million), Bharti Airtel (1.4 million), MTNL (1.13 million), Beam Telecom (0.43 million) and YOU Broadband (0.41 million).
The major MSOs are geared up to roll out wireline broadband on DOCSIS 3.0 technology and the potential market is huge. With the total cable subscriber base at 100 million homes and less than one million subscribers enjoying broadband on this cable infrastructure, there are a potential 99 million homes as total addressable market for DOCSIS. Even at a conservative estimate of 30% conversion ratio, this translates to 30 million broadband subscribers on DOCSIS technology. It is only a matter of time, before this deluge hits the wireline RF cable.
From a global perspective, the USA has the maximum conversion of cable video subscribers to broadband subscribers using DOCSIS technology. There are 48 million DOCSIS-based broadband subscribers as compared to 27 million broadband subscribers on all other wireline technologies combined (FTTH, MEN and DSL). In advanced countries like USA and Australia, DOCSIS has been successful because of the high bandwidth it can provide on an existing wired medium available on the ground in a cost effective manner.
The DOCSIS trends amongst Indian MSOs
Based on more detailed data from Media Partners Asia, as recently as September 2014, DOCSIS contributed only a small fraction (5.6%) of India’s wireline broadband subscribers. However, over the last few years, there has been a steady growth in the cable broadband subscriber penetration, as is clear from the graph below.
Recently, the MSO market is seeing more focus and traction from the MSOs as they have started upgrading their networks to DOCSIS 3.0 technology and offering higher speed internet plans. In 2014, we have seen Hathway, DEN and Siticable announcing commercial and soft launches of their DOCSIS 3.0-enabled broadband network Hathway Cable and Datacom Limited has started offering 50mbps broadband plan to users in South Mumbai, powered by DOCSIS 3.0.
This is just an example of how DOCSIS 3.0, as a technology of choice, can offer a differentiated product for MSO customers. DOCSIS 3.0 allows MSOs to roll out high speed broadband – 50-300 Mbps download speeds – to subscriber homes at an economical price, over the existing coaxial cable medium and in a much shorter time compared to other wireline technologies such as fiber, Metro Ethernet or DSL. A number of other leading regional and national coverage cable operators with ISP licenses have thus already chosen to deploy DOCSIS 3.0.
While investment into upgrading an existing infrastructure can be a challenge, the cost of network investments by MSOs could be recovered over longer periods. Moreover, with broadband offering per-subscriber revenues three to five times those of MSOs’ traditional broadcast services, this could be a significant game changer and revenue enhancer for MSOs in the long term. With such enhancement, a rollout of DOCSIS 3.0 broadband services to 25% of an ISP-licensed cable operator’s network and a 30% subscriber uptake of DOCSIS 3.0 services in those covered areas could lead to an overall 30% revenue increase for the cable operator.
With increasing penetration of broadband to their existing subscribers and increasing uptake by subscribers, MSOs could expect to raise their revenues still further.
DOCSIS 3.0 Technology
During the last couple of years, India has seen a wave of digitalization of cable television due to Government regulation and demand by the industry for fair and transparent accounting. As a result of this digitalisation, we have seen the conversion of analog signal transmission of broadcast video channels to digital signal transmission. Before digitalisation, with analog cable TV transmission, each 8 MHz radio frequency (RF) channel allocation was used for carrying one video channel. With a total spectrum of 800 MHz, the number of channels that could be transmitted on the coax cable was limited to approximately 100. The number of channels available in the country (approved by the Ministry of Information and Broadcasting) was much higher - 400. Hence there was scarcity of spectrum to carry the channels. The broadcasters ended up paying ‘carriage fee’ to the MSOs so that they would reserve and provide their TV channels to the subscribers – this was a significant source of revenue to the MSOs. DOCSIS (broadband over cable network) also needed radio frequency spectrum on the same coax cable. The MSOs would not sacrifice their fee revenue by reserving channels for DOCSIS, which had comparatively lower revenue-earning potential.
After digitalisation, each of these 8 MHz RF channel allocations can now carry 10-12 TV channels. Hence, there is no dearth of frequency availability to carry the TV channels. Even after accommodating all the TV channels, there is still frequency spectrum left to offer more services like broadband, using DOCSIS technology. Adding broadband services to the same frequency spectrum only adds to the revenues of the MSOs, although at the cost of converting the cable plant to 2-way. DOCSIS requires QAM channels on the RF medium to transmit and receive internet data from the subscribers. The data download from the internet to the user is considered the downstream while the data requests and uploads are considered upstream data. DOCSIS reserves channels and frequencies for both the upstream and the downstream direction.
MSOs can decide their own spectrum utilization in the above 5 MHz to 1 GHz spectrum. The 5 MHz to 65 MHz (or up to 85 MHz, as decided by the MSO) spectrum is used for the upstream traffic from the subscriber modems towards the internet and the 86 MHz (or 106 MHz, as decided by the MSO) to 1 GHz spectrum can be used for the downstream traffic and broadcast TV channels.
The MSOs can also decide their MPEG framing format as per Annexure A (8 MHz – Euro-DOCSIS) or Annexure B (6 MHz – North American DOCSIS) channels. Each of the 8 MHz Euro-DOCSIS RF channels is capable of providing up to 50 Mbps of data rates while each 6 MHz DOCSIS RF channel is capable of providing up to 38 Mbps.
DOCSIS 3.0 technology enables multiple (greater than eight) QAM (Quadrature Amplitude Multiplexing) channels to be ‘bonded’ and shared for data transfer between the Cable Modem Termination System (CMTS)and the Cable Modem (CM), providing a ‘fat pipe’ to the end users for internet usage.
A DOCSIS 3.0 next-generation cable access network is one of the key components of the Cisco IP NGN. DOCSIS 3.0 is a cable standard developed by CableLabs that enables high-bandwidth access networks. DOCSIS 3.0 enables operators to increase upstream and downstream speeds to 120 Mbps and 400 Mbps respectively from DOCSIS 2.0 data rates of 20 and 50 Mbps respectively. To achieve these ultra-high speeds and help cable operators deliver more content over their existing networks, DOCSIS 3.0-compliant channel-bonding technology from Cisco uses multiple channels to deliver more packets simultaneously, providing high-speed data rates several times faster than existing ADSL and DOCSIS 2.0 equipment.
Cisco offers both integrated and modular cable modem termination systems (I-CMTS and M-CMTS) DOCSIS 3.0 solutions. M-CMTS is an accompanying standard that allows separation of the downstream and upstream processing plant, enabling the number of DOCSIS downstream channels to be scaled without changing the media access control (MAC) domain or the number of DOCSIS upstream channels. It also lowers the cost of delivery of video over DOCSIS channels by enabling DOCSIS downstream-only cards to be used with existing CMTS units, rather than combined upstream and downstream channel cards.
Network Upgrade Required
Deployment of DOCSIS 3.0 technology requires a network upgrade from traditional 1-way networks (which deliver broadcast TV content) to 2-way networks in order to serve broadband to the subscribers over the same coaxial cable.
An important aspect of the field upgrade is appropriate design of the forward as well as reverse path so that noise levels can be contained and all subscribers continue to receive uninterrupted high speed services. This is equivalent to building large scale infrastructure projects like roads, buildings, dams etc. with correct architecture and design.
India has a very low broadband penetration and is sitting on the verge of the broadband explosion. Cable, being a mass media with wide reach across the geography, can be a strong medium of this broadband revolution. MSOs, with their strength of carrying video to the homes through this RF cable medium, are uniquely positioned to provide the internet bandwidth pipe as well as next-generation video services to their subscribers. They must plan and build their two-way networks such that they are ready to carry the load of not just linear broadcast TV channels but also next-generation video services. DOCSIS is the natural technology of choice with worldwide deployment and standardization helping to keep pace with future trends and a standards body (CableLabs) ratifying standards and interoperability.