Many communications companies are small ones.
So, you may not always see advertisements in newspapers for the available jobs. This be because of lack of access to work experience, and can be compounded by mobility difficulties, or by issues such as lack of minicoms excluding Deaf people from speculative calling, or a whole host of other potential barriers. In addition, companies without formal application procedures will often lack equal opportunities policies, recruiters trained in disability awareness, or the facilities and expertise to offer to make appropriate interview arrangements that you often find in large organisations. The more you find out about where, how and when employers in the industry that you want to go into tend to recruit, the better. A good way to get the information you need is to identify companies within your chosen occupation and contact them speculatively.