Improving Bluetooth EDR Data Improving Bluetooth EDR Data Throughput Using FEC and Throughput Using FEC and InterleavingInterleaving

Ling-Jyh ChenLing-Jyh Chen**, Tony Sun**, Yung-Chih Chen*, Tony Sun**, Yung-Chih Chen**Institute of Information Science, Academia Sinica*Institute of Information Science, Academia Sinica

**Dept. of Computer Science, UCLA**Dept. of Computer Science, UCLA

IntroductionIntroduction

Wireless communication is inherently vulnerable to errors.

Wireless channel errors are usually bursty and dependent in occurrences rather than independently/ identically distributed.

Some robust link layer transmission schemes are required.

ContributionContribution

We propose three link layer enhancements for Bluetooth v2.0

Adaptive Packet Type (APT) FEC coding Interleaving FEC (IFEC)

The proposed solutions are applicable to other wireless technologies.

OutlineOutline

Bluetooth Overview Proposed Link Layer Enhancements Simulation Results Conclusion

The “enabler” of Personal Area Network (PAN) Low power, low cost, and smaller chips

Mode FEC

Packet AsymmetricThroughput

(kbps)Size

(bytes)Length(slots)

DM1 yes 17 1 108.8 108.8

DM3 yes 121 3 387.2 54.4

DM5 yes 227 5 477.8 36.3

DH1 no 27 1 172.8 172.8

DH3 no 183 3 585.6 86.4

DH5 no 339 5 723.2 57.6

BluetoothBluetooth OverviewOverview

Bluetooth packet typesBluetooth packet types

DH: Stop and Wait ARQ

DM: ARQ as well as FEC codes

FEC coding scheme: (15, 10) Shortened Hamming code Able to correct single bit error in each block.

EDR does not provide FEC enabled packet types (ie., no DM series types)

Bluetooth Enhanced Data Rate Bluetooth Enhanced Data Rate (EDR)(EDR)

Proposed Link Layer Proposed Link Layer EnhancementsEnhancements

1. Adaptive Packet Type (APT)

2. FEC coding

3. Interleaving FEC (IFEC)

Enhancement (I): APTEnhancement (I): APT

Adaptive Packet Type (APT)Determine optimal packet typeT: Theoretical Data throughput

s: packet size/bits b: bit error rate p: packet error rate n: packet length in Bluetooth slots

Enhancement (I): APT Enhancement (I): APT (Con’t) (Con’t)

Enhancement (II) : FECEnhancement (II) : FEC

Propose to apply FEC to Bluetooth EDRCalled 2DM1/3/5 & 3DM1/3/5(15,10) shortened Hamming code that is

able to correct single bit error Packet Error Rate :

( p: packet error rate, b: bit error rate s: packet size/bits )

Enhancement (II) : FEC Enhancement (II) : FEC (Con’t)(Con’t)

Enhancement (III) – IFECEnhancement (III) – IFEC

Wireless errors are mostly bursty in presence, previous techniques should be modified.

Propose Interleaved FEC (IFEC) coding Called DMI 1/3/5, 2DMI 1/3/5, and 3DMI 1/3/5

Good Bad Pbb

Pbg

Pgb

Pgg

gbbb

bbg PP

PP

1

1

gbbb

gbb PP

PP

1

Burst Error Model (aka Burst Error Model (aka Gilbert-Elliott model)Gilbert-Elliott model)

Enhancement (III) – IFEC Enhancement (III) – IFEC (Con’t)(Con’t)

FEC coding Interleaved FEC coding

Simulation ResultsSimulation Results Gilbert-Elliott model: Pgb= 0.005, Pbb from 0.9 to

0.9999

FEC coding IFEC coding

Conclusion Conclusion

We proposed three link layer enhancement techniques (APT/FEC/IFEC) for BT EDR.

We verified the proposed techniques using simulation.

The proposed solutions are applicable to other wireless technologies.

Thank you !Thank you !