How does a headend work?

A headend is a distribution center, basically. It works by distributing the signals so that receiving devices can pick them up.

A cable headend typically has satellite dishes that receive the signals from the satellite and redistribute them...

to the cable customers. This can be bounded (with a cable) or unbounded (wireless). The testing equipment that you use will be dependant upon which method you use. For instance, if you deploy IP video, there are a myriad of options for testing as SNMP is built in. For RF methods, an RF spectrometer may be used.

Much of the distribution equipment that you put in has complementary products for testing and it is recommended that you seek advice from your vendors and find a product that they will all will work with. We have an IP video white paper from http://www.siemon.com, that may be of help. There is also one there specifically on CCTV and surveillance. It lists all of the standards and who wrote them with links to the different organizations web sites for more information.

Your distribution equipment can take on a variety of faces. It can be multicast, unicast, CCTV, etc. The functionality however is basically the same. It takes in one signal and puts out another. Hope this helps, if you need further information, just let me know.