Techniques for managing channel reservation on a shared communication medium are disclosed. An access point or an access terminal contending for access to a communication medium shared between a first Radio Access Technology (RAT) and a second RAT, for example, may encode a first portion of a channel reservation message defined by the first RAT with a transmission opportunity duration associated with the second RAT and also encode a second portion of the channel reservation message with the transmission opportunity duration. The access point or the access terminal may then transmit, over the communication medium, the channel reservation message including the first and second portions to reserve the communication medium based on the contending.