SchedulerΒΆ
Components:
- General purpose & technology specific parts
- Strategy: How to schedule the PDUs
- Queue: What PDUs are available for scheduling
- RegistryProxy: Provide system specific information:
- Callback: System specific interpretation of schedule
Timing:
- Start Collection: Ask upper FUs (Buffers) to pass PDUs to Queue
- Schedule: Let the Strategy analyze queued data and create a schedule
- Finish Scheduling: Pass the schedule and scheduled data to the Callback
- Deliver Schedule: Pass the technology specific schedule and the PDUs to the PhyUser and on to layer 1
Scheduler Spots:
- Three scheduler spots:
- Downlink Master: Create DL schedule, all information is available
- Uplink Master: Create UL schedule, needs information about queued bit in UT
- Uplink Slave: Read the MAP and schedule queued PDUs in the granted resources
Queue:
- Internally one queue per connection ID (CID)
- Single QoS class: One CID per UT per direction
- Multiple QoS classes: One CID per UT per direction per QoS class
SimpleQueue: Retrieve head of queue PDU
SegmentingQueue: Obtain a segment with given size in bit fitting a resource block
- QueueProxy: Virtual queue holding a copy of all UT queues
- Used in the UL Master Scheduler
- Could alternatively process system specific bandwidth requests
Strategy: Two Stage Static Priority Scheduling Strategy:
Two tasks: Resource and packet scheduling
Schedule highest priority which has data queued (stage 1, packet scheduling)
Use sub-strategy to determine which UT should be scheduled (stage 2, resource scheduling)
- DynamicSubchannelAssignment (DSA): Strategy to find frequency/time resource
- eg. for frequency selective fading or coexistence
AdaptivePowerControl (APC): Assign transmission power to each subchannel
RegistryProxy: Provide system specific information
Associated UTs
Channel quality
Available MCSs and switching points
QoS classes
- Can be extended to provide any information useful for scheduling
- eg. node positions
- Interfering system type
- ...