1. Header Compression Date: 2012-05-13 Authors: May 2012 Month Year
doc.: IEEE yy/XXXXr0
May 2012
Header Compression
Date:
Authors:
Shoukang Zheng et. al, I2R, Singapore
Shoukang ZHENG et. al, I2R, Singapore

2. Month Year
doc.: IEEE yy/XXXXr0
May 2012
Abstract
In this contribution, we present the scheme to compress the dynamic fields in MAC header in ah.
Shoukang Zheng et. al, I2R, Singapore
Shoukang ZHENG et. al, I2R, Singapore

3. May 2012
Motivation
In ah use cases, low data rate requires header compression for efficient transmission.
Constant fields in MAC header can be compressed
MAC address
Constant in the Control fields
Dynamic fields in the header may be also compressed
Sequence number
PN (packet number) in CCMP header
Shoukang Zheng et. al, I2R, Singapore

4. May 2012
Problems
Header compression protocol must be simple with small overhead
Proposed scheme [1] uses some management exchange to set up the context for compression. Other method is suitable as well.
How to compress the dynamic field compression efficiently?
Shoukang Zheng et. al, I2R, Singapore

5. Suggested Solution Compression/Decompression Context Setup Compression
May 2012
Suggested Solution
Compression/Decompression Context Setup
Initial value as the base for dynamic field
The range of compressed value is [0,Vmax]
Compression
Use fewer bits
Only compressed value (bits) is transmitted after context setup
# of compressed bits: log2(Vmax+1)
Decompression
Compressed value + Initial value
Context Update
Re-synchronize the initial value of dynamic field
Shoukang Zheng et. al, I2R, Singapore

6. Dynamic Field Compression
May 2012
Dynamic Field Compression
Sequence Number (12 bits)
Use fewer bits (e.g. 4 bits) for low data rate
PN0-5 fields in CCMP header
Use fewer bits (e.g. 4 bits)
PN incremental value fixed as 1 (highest compression ratio)
Shoukang Zheng et. al, I2R, Singapore

7. Synchronizing Context
May 2012
Synchronizing Context
When compression side detects that decompression is out of synchronization on initial value of dynamic field, compression side can update the context
When decompression side detects that it is out of synchronization on initial value of dynamic field, decompression side can request to update the context
Shoukang Zheng et. al, I2R, Singapore

8. May 2012
Conclusions
We propose to support dynamic field compression for MAC header
Shoukang Zheng et. al, I2R, Singapore

9. May 2012
References
[1] “Frame Header Compression”, ah-frame-headercompression.pptx
[2] “MAC Header Compression”, ah-mac-headercompression.pptx
Shoukang Zheng et. al, I2R, Singapore

10. May 2012
Straw Poll (1)
Do you agree that dynamic field (sequence number and PN0-5 fields) can be compressed as in slide 5? Y: N: A:
Shoukang Zheng et. al, I2R, Singapore

11. May 2012
Straw Poll (2)
Do you agree that sequence number field can be compressed as in slide 6? Y: N: A:
Shoukang Zheng et. al, I2R, Singapore

12. May 2012
Straw Poll (3)
Do you agree that PN (packet number) in CCMP header can be compressed as in slide 6? Y: N: A:
Shoukang Zheng et. al, I2R, Singapore