Communication in London shouldn’t be too much of a problem as long as you have access to the technology to allow you to communicate with others. The UK has high speed broadband access, extensive phone connections, etc. The UK uses the GSM mobile phone system, which means that most visitors coming from the USA or Canada may find their mobile phones do not work in the country.
There are usually a lot of internet cafes in London, offering internet access, skype, etc. Some public libraries also offer internet access.