�3���� Reverse Charging (REV)
������� 3.1���� Introduction
������� 3.2���� Description
������� 3.3���� Operational requirements
������� 3.4���� Coding requirements
������� 3.5���� Signalling requirements
������� 3.6���� Interaction with other supplementary services
������� 3.7���� Interactions with other networks
������� 3.8���� Signalling flows
������� 3.9���� Parameter values (Timers)