Call admission and preemption for multiple bit-rate applications
View Patent ↗Embodiments of the present invention are directed to providing a method and system for call admission control and preemption of multiple bit-rate applications in a digital communication system. Multiple bit-rate applications such as streaming video can specify a Quality of Service (QoS) profile having multiple levels. When there are insufficient resources in the network to support an incoming multiple bit-rate call, the system determines whether, by reducing the bit-rate of the incoming call or by preemption of lower priority components of existing calls, enough resources can be recovered to support the incoming call.
1. A method of providing call admission control of multiple bit-rate applications, the method comprising:
identifying, in a digital communication system, allowable bit-rate levels and associated priority levels of an incoming multiple bit-rate call;
determining if said incoming multiple bit-rate call can be admitted to the digital communication system, at a first, maximum requested bit-rate level and associated minimum priority level;
when said incoming multiple bit-rate call cannot be admitted at the first, maximum requested bit-rate level and associated minimum priority level, selecting a lower allowable bit-rate level and associated higher priority level for said incoming multiple bit-rate call;
repeating both said determining step, with the selected lower allowable bit-rate level and associated higher priority level in each iteration, and the selecting step, until said incoming multiple bit-rate call can be admitted; and
admitting said multiple bit-rate call at a last-selected lower allowable bit-rate level and associated higher priority level.
2. The method of claim 1 , wherein lower allowable bit-rate levels are respectively associated with corresponding higher priority levels.
3. The method of claim 1 , wherein said admitting step further comprises:
sending a signaling message to a User Equipment (UE) initiating said incoming multiple bit-rate call; and
indicating said last-selected lower allowable bit-rate.
4. The method of claim 2 , wherein said identifying step further comprises:
identifying individual call components, wherein each individual call component comprises a particular bit-rate level and an associated priority level.
5. The method of claim 4 , wherein said determining step further comprises:
preempting components of existing multiple bit-rate calls having a lower priority than a current priority level of said incoming call.
6. The method of claim 5 wherein said step of preempting components further comprises:
making said individual call components inactive.
7. The method of claim 6 , wherein if a call is dropped by said digital communication system, the method further comprises:
determining available bandwidth of said digital communication system;
compiling a candidate list of current inactive call components of active multiple bit-rate calls along with their associated bit-rate and priority level;
sorting said candidate list by priority level, higher priority level first;
selecting from said candidate list, in order, inactive call components whose bit-rate can be accommodated by said available bandwidth of said digital communication system;
activating the selected inactive call components in order to upgrade the service of the active calls associated with said selected inactive call components.
8. The method of claim 1 , wherein said digital communication system comprises a packet data network.
9. The method of claim 8 , wherein said digital communication system comprises a Long Term Evolution (LTE) packet data network.
10. The method of claim 9 , wherein said method occurs at an eNodeB of a Long Term Evolution (LTE) network.
11. A non-transitory storage medium encoded with instructions which when executed by a digital communication system perform the following:
identify allowable bit rate levels and associated priority levels of an incoming multiple bit-rate call;
determine if said incoming multiple bit-rate call can be admitted at a first maximum requested bit rate level and associated minimum priority level;
when said incoming multiple bit-rate call cannot be admitted at the first maximum requested bit-rate level and associated minimum priority level, select a lower bit-rate level and associated higher priority level for said incoming multiple bit-rate call;
repeat both said determining step with the selected lower allowable bit-rate level and associated higher priority level in each iteration, and the selecting step until said incoming multiple bit-rate call can be admitted; and
admit said multiple bit-rate call at a last-selected lower allowable bit-rate level and associated higher priority level.