IPTV and OTT project architecture

Middleware: IPTV/OTT service management

At the heart of every video service is its middleware.

It is a server-side piece of software that coordinates the operation of other project components, e.g., transcoders, content protection systems, storage, streamers, CDN, and client devices.

Middleware determines which services you can offer, on which devices, and how you will manage content, user accounts, price plans, and stats. UI and scalability of the project also depend on the middleware.

A state-of-the-art IPTV/OTT service is impossible without middleware. Middleware is an essential part of the service and therefore needs to be selected first. It’s akin to a foundation, without which no house can be built.

Billing: receiving payments

The Billing system deals with everything from receiving subscribers' payments and managing price plans, to blocking non-payers.

It holds all the information about the subscriber, including their account balance and the list of available channels and movies.

Middleware is directly tied to billing. The billing system sets permissions for subscribers to receive content under their plan. If the account balance runs out, it suspends the service, and the subscriber will receive a reminder to top up their account.

Middleware vendors usually don’t integrate billing out of the box. Every country has its own currency and legislation, which makes universal billing solutions virtually impossible. Therefore, operators have to integrate the middleware of their choice with local billing services via an API.

For an in-depth look into middleware and billing, see resource 3:
Middleware and billing: the basis for your video service.

Headend: receiving content

The headend receives content and prepares it for delivery.

The signals are received via the internet, satellites, or radio stations — the headend system collects and relays them for further processing.

Satellite signals are received by an antenna station, which is equipped with antennas sized in proportion to consumer solutions because the requirements for the quality of reception are much higher. Bad weather, e.g., rain, may affect signal quality. For home satellite TV users, it may result in a distorted picture at the most, but for an operator, it would mean service disruptions and complaints from subscribers. The size of the antennas helps offset such adverse effects.

Signals from different sources are processed by receivers, multiplexors (switches), encoders/transcoders, and other headend components. They need to receive and decrypt the content, and then convert it into a format suitable for further processing.

The signal received by the headend needs to be made into an IP stream with the required bit rate and codec. This is where transcoders come in.

Transcoders convert content from one codec to another, limit bitrate, create multi-bitrate streams, and convert variable bitrate to constant and vice versa.

The solution enables bandwidth savings on both the subscriber and operator side as well as the standardization of content format for compatibility with all consumer devices. With transcoders, the bandwidth required to deliver 4K video to viewers can be reduced to 15–25 Mbps*.

*For HEVC-encoded content.

CAS/DRM: content protection

Copyright holders entrust their content only to those who can protect it from piracy.

CAS/DRM solutions encrypt the content you have been entrusted with so that it can be viewed only on your subscribers’ devices. The system receives unencrypted content from the transcoder and outputs the encrypted one into the network.

The CAS (Conditional Access System) manages access to IPTV/OTT content. It has a hardware and a software side.
The DRM (Digital Rights Management) encompasses software and hybrid content protection solutions. They limit access and protect the content from being illegally copied and played back.

CAS/DRM adds invisible watermarks to content. This isn’t noticeable if you are viewing content legitimately. However, these watermarks help track which operator dropped the ball if any content was illegally copied.

When an operator approaches copyright holders for content, they voice their protection requirements that cover middleware, DRM, infrastructure, and even client devices.

Servers: content storage

If an operator offers TV archive and VoD services, they will need storage.

When a user requests to view a movie or a TV show from the catalog, its stream is relayed to the streamer and then ends up on the client device. This process is controlled by middleware, too.

If the operator offers no such services, content storage becomes optional. In this case, the TV channel stream goes to the streamers with CAS/DRM already.

Streamers: content delivery

Streamers provide on-demand delivery of encrypted TV channels and VoD to client devices.

In fact, it is these components that distribute content streams to end-users. Streamers can be software as well as hardware.

When the user selects a piece of content in their set-top box interface, middleware receives the request and lets the streamer begin streaming it to the subscriber’s device.

CDN: content delivery

OTT operators serve customers all over the world, so they need a CDN (content delivery network) for that.

CDNs guarantee that subscribers in different regions get content in the quality they want. For this, servers are set up closer to subscribers. This way, a set-top box in the US can’t request content from Europe.

CDNs work closely with middleware. Depending on subscriber location, middleware provides links to streams from the closest storage available.

But you don’t have to establish a CDN of your own. Instead of investing in expensive infrastructure, OTT operators often prefer to use readily available solutions, e.g., from Amazon and Akamai. The operator pays the CDN owner for traffic to deliver content to subscribers without delays.

Client devices: content playback

The content sent from the streamer over CDNs ends up on client devices.

To play it, subscribers need a smart TV, set-top box, PC, tablet, or smartphone.

The consumer device plays back content. Therefore, it needs a CAS/DRM system client to be able to decrypt it. For this, the device contacts the operator’s key server. This process is controlled by middleware, too.

Multi-screen services support all kinds of devices. Viewers will be able to watch content from any device wherever they are: at home, on a trip, or on their way to work.

Client devices are key components of the system in that they have a crucial impact on customer satisfaction as well as on the selection of services the operator can offer.

Project architecture summary

Before designing an IPTV/OTT service, decide how you will receive content and choose your system integrator and middleware vendor. And don’t forget about load balancing—choose only easily scalable solutions.

In the next lesson, we will take a closer look at middleware and billing to learn how these core project components determine the success of your business.