Important note: References to any products in this tutorial should not be taken as recommendations for or against those products. There are a lot of suitable products in this area, and you should choose the ones that suit you best.
As you will notice when you start seriously looking, head-end equipment can be extremely expensive. Modulators can cost several thousand euros, and other head-end equipment can cost well in to five figures. Building a head-end can cost a great deal of money if you're not careful. Luckily, if all you want to do is test applications or run simple demos then you don't need a complicated solution. Most of the basic process of producing and playing out a transport stream can be done on a standard PC with an add-in modulator card. While this is still not a cheap solution (the modulator card and software for producing a transport stream is still quite expensive), it's an awful lot cheaper than buying a set of standalone components for generating the transport stream and playing it out. Solutions such as the Tektronix AD-952 system include almost everything that you need to record, create, analyse, and play out a transport stream, and these can be ideal for a test environment.
Solutions based around a standard PC chassis such as the AD-952 have a number of advantages in terms of saving space, flexibility and overall cost, but they do have some disadvantages as well. They are designed as test equipment, and are not really designed for use in a real head-end. Despite the fact that many of the standalone head-end devices are based around a PC, there are a number of significant differences in the way that they are designed and put together. The main differences in the requirements between a test setup and a head-end are:
This doesn't mean that a cheaper solution designed for lab use is the wrong choice - that depends entirely on your needs. If you are doing application or middleware development, or even testing g applications before rolling them out on a real network, then equipment designed for lab use will probably suit your needs better than equipment designed for a full head-end. Some vendors will sell either a software package for test systems, or a software/hardware package for real head ends: in this case you can get the best of both worlds.
To make things even cheaper, some open-source software may provide you with some of the tools that you need. One thing to be careful of, however, is that this may not be as compliant with the standards as commercial software. When dealing with complex standards like DSM-CC, this is an important consideration. Similarly, open-source software has often not been as reliably tested as commercial solutions, simply due to the size of the market and the number of different combinations of equipment, parameters, and streams that are possible. Between these factors and the lack of integration between the various open-source solutions on the marketplace, we do not recommend that anyone looks at open-source software for building a complete head-end system any time soon.
If you're interested in the open-source software that is available to see which parts may be useful to you, take a look at the section on generating a transport stream.