Some time ago I happened to be on an interview with the local telecom company. They were exploring my understanding of the industry specifics and I based my answer on what I experienced in telecom audits. It looked to me that they approved those answers at that time.
The major field is billing. This stage of revenue generation process is extremely important for telecoms. Billing involves significant number of transactions and is managed by automated IT systems. Finance professionals should make significant efforts to manage the system otherwise the system will manage on its own.
Property plant and equipment is the major part of a telecom company assets and depreciation is the major part of their costs. Application of finance: significant accounting resources for tracking of PPE and profitability analyses.