Question: In mission critical services, as per 3GPP specifications, what media characteristics may need to be modified by the MC service server for an already established communication?
Option 1: Only activation and deactivation of the bearer
Option 2: Modification of QoS characteristics (e.g., bearer priority adjustment) and modification of GBR due to media codec change, but not activation/deactivation
Option 3: Activation and deactivation of the bearer, and modification of GBR due to media codec change, excluding QoS characteristic modifications
Option 4: Activation and deactivation of the bearer, modification of QoS characteristics (e.g., bearer priority adjustment), and modification of GBR due to media codec change
Explanation: According to the specifications for mission critical services in 3GPP, the MC service server may need to modify various media characteristics for an ongoing communication. These modifications are not limited to a single aspect but can include activating or deactivating the bearer (to manage resource allocation), adjusting QoS (Quality of Service) characteristics (like changing the bearer priority to ensure timely delivery of critical communications), and modifying the Guaranteed Bit Rate (GBR) in response to changes in media codec (to maintain optimal service quality based on the new codec requirements). Thus, all these aspects are crucial for effective resource management in mission-critical communications.