802.16m – Mixed-Mode Load Balancing
Document Number: IEEE C802.16m-09/1207
Date Submitted: 2009-07-02
Source:
Aran Bergman
aran.bergman@intel.com
Hujun Yin
hujun.yin@intel.com
Intel Corporation
Re:
Category: SDD-CRs / Area: Chapter 11.7.2.2 Superframe Header (SFH)
“Comments on SDD 11.7.2.2 Superframe Header (SFH)
”
Venue:
IEEE Session#62, San Francisco
Base Contribution: None
Purpose: Discussion by TGm
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Problem Description
– Mixed-mode ABSs need to support both 16e and 16m MSs (YMS and
AMS)
– The assumption is that as migrations proceed, more 16m MSs will join
the network, but 16e devices will still be available for a considerable
time. The mix of 16m and 16e devices in a sector cannot be reliably
predicted and the ratio may be highly dynamic
• If the BS sets a small 16e zone, legacy users will suffer lower peak and
average throughput and a smaller sector capacity.
• Conclusion 
– BS needs to dynamically control the available resources for 16m MSs
and 16e MSs
• Recall that all 16m devices can work on the 16e zone (but with reduced
spectral efficiency)
– Control over available resources for each zone should be per BS /
sector (as demand on each zone may be different for different sectors /
BSs
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Solution - Dynamic Switching Point
•Description
– Change the partition between LZone and MZone according to the zone loading
– Partition is signaled in SFH
•Pros
–
–
–
–
AMS will be on a single zone (MZone)
Dynamic (can change partitioning every ~20ms, assuming this is signaled in the SFH)
No need to sync all the network on the switching point
AMS and YMS peak and average rates determined by the instantaneous loading (measured across
20ms).
•
•
A cell with a single AMS can get close to 16m peak rate (Mzone increased to maximum)
A cell with a single YMS can get close to 16e peak rate (Lzone increased to maximum)
•Cons
– Not currently supported by the AWD text (?)
•
Need to have the preamble sent at the last DL subframe so that switching point will not move the preamble
– Requires the MS to support quick configuration changes (more complex than fixed partitioning)
– Interference effect has not been investigated yet
– Complex testing – requires many switching point changes to be sure there are no problems
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Supporting MBS in a Mixed-Mode BS
– AMS needs to be able to decode 16e MBS zone
•
•
SDD specifies that eMBS control signaling should include enough information for the
AMS to decode the 16e MBS zone
Service providers will probably be reluctant to transmit the same MBS content – once
in the 16e LZone to 16e MSs and then again in the 16m MBS zone to AMSs.
– This means that
•
•
Either the AMS can decode 16e (MBS) bursts in the same frame as 16m bursts in
the MZone, or
The Mixed-mode BS will not be allowed to allocate 16m bursts in the MZone to AMSs
that should listen to the 16e MBS zone.
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