1. September 2005
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Resource Allocation and Admission Control in Distributed MAC for Mesh WPAN]
Date Submitted: [16 September, 2005]
Source: [Young Ae Jeon, Seung Hyong Rhee, Byung Joo Lee, Sang Sung Choi]
Company [Electronics & Telecommunications Research Institute / Kwangwoon University]
Address [161 Gajeong-Dong, Yuseong-Gu, Daejeon, , Korea]
Voice:[ ], FAX: [ ],
Re: [Call for Proposal: IEEE P /0071]
Abstract: [This document suggests to adopt a distributed mechanism that achieves a fair resource allocation and admission control in the distributed MAC protocols which are designed for WPAN mesh networking. It also provides a distributed means for service differentiation.]
Purpose: [Providing technical contributions to IEEE TG5]
Notice: This document has been prepared to assist the IEEE P It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

2. September 2005
Resource Allocation & Admission Control in Distributed MAC for Mesh WPAN
September 2005
ETRI/KWU
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

3. Motivation No piconet controller in a distributed mesh WPAN
September 2005
Motivation
No piconet controller in a distributed mesh WPAN
We still need
Fair resource allocation
Decentralized admission control
Service differentiation
How can we achieve them in a distributed manner?
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

4. Considering Multimedia & Mobile Devices…
September 2005
Considering Multimedia & Mobile Devices…
Mesh WPANs will include mobile devices
The devices may join and leave a piconet frequently
It makes the resource allocation and admission control harder
Multimedia traffic
Usually has a minimum bandwidth requirement
Sometimes has a maximum requirement
They still need
Fair allocations
Differentiated services
Our proposal is designed based on the MPA MAC
However, the mechanism can be used for any distributed MAC
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

5. Review: Distributed Reservation Protocol (DRP)
September 2005
Review: Distributed Reservation Protocol (DRP)
Devices announce desired transmissions
Receiver & transmitter negotiate via beacon
Beacons carry information on other devices’ reservations
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

6. Distributed Resource Allocation: Superframe Structure
September 2005
Distributed Resource Allocation: Superframe Structure
DEV i reserves MAS (duration Ti) using DRP
Max size of DTP in a superframe is C (μsec)
Devices store neighborhood information
Reserved MAS and their durations C
beacon
period
reserved for DTP
(data transmit period)
CAP
(inactive period) T1 T2
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

7. Distributed Allocations
September 2005
Distributed Allocations
DEVs take turns to make reservations
DEV i , at its turn, first compute
Tothers = ∑j≠i Tj
Then it reserves its channel time Ti such that, for 0 < α < 1,
Ti = α (C – Tothers )
Computes T1
Computes T2
Computes Tn
▪ ▪ ▪ ▪ T T T
DEV1 beacon
DEV2 beacon
DEVn beacon
beacon period
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

8. Example: 2 Devices (1) DTP length: 100 MAS α = 0.5 September 2005
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

9. Example: 2 Devices (2) DTP length: 100 MAS DTP length: 100 MAS
September 2005
Example: 2 Devices (2)
DTP length: 100 MAS
α = 0.25
DTP length: 100 MAS
α = 0.75
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

10. Example: 3 Devices (1) DTP length: 100 MAS α = 0.5 September 2005
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

11. Example: 3 Devices (2) DTP length: 100 MAS DTP length: 100 MAS
September 2005
Example: 3 Devices (2)
DTP length: 100 MAS
α = 0.25
DTP length: 100 MAS
α = 0.75
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

12. Service Differentiation
September 2005
Service Differentiation
Service quality is differentiated by using different values of α :
0 < αi < 1 for DEV i
αi is a real number that is determined such that
Small values for lower classes
Larger values for better services
DEV i reserves its channel time Ti such that, for 0 < αi < 1,
Ti = αi (C – Tothers )
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

13. Example: Service Differentiation
September 2005
Example: Service Differentiation
α1 = 0.5
α2 = 0.66
α1 = 0.5
α2 = 0.75
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

14. Guaranteeing Minimum Requirements
September 2005
Guaranteeing Minimum Requirements
DEV i has an interval Si = [mi , Mi] , where
mi : Min requirement for the channel time
Mi : Max requirement for the channel time
DEV i reserves its channel time Ti such that mi ≤ Ti ≤ Mi
Ti = max { mi , αi (C – Tothers ) }
The bounds may or may not exist
mi : system parameter based on traffic types or QoS
Mi : set by each DEV
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

15. Example: Minimum Requirements (1)
September 2005
Example: Minimum Requirements (1)
DTP length: 100 MAS
α = 0.5
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

16. Example: Minimum Requirements (2)
September 2005
Example: Minimum Requirements (2)
DTP length: 100 MAS
α = 0.5
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

17. Guaranteed Convergence
September 2005
Guaranteed Convergence
All devices converge to their equilibrium values, regardless of
Number of devices
The values of αi
Min/max requirements [mi , Mi]
The problem can be mathematically modeled using a system of optimization equations
It can be proved that, using the model,
They always converge
They converge in a finite time
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

18. Distributed Admission Control
September 2005
Distributed Admission Control
mi is included in the beacon for the self-admission control of a new-comer
New DEV i joins the group if and only if
mi + ∑j mj < C
Computes T1
Computes T2
Computes Tn
▪ ▪ ▪ ▪ T m T m T m
DEV1 beacon
DEV2 beacon
DEVn beacon
beacon period
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

19. Join/Leave of DEVs DEVs dynamically join and leave the group
September 2005
Join/Leave of DEVs
DEVs dynamically join and leave the group
Number of devices is not a constant anymore
Tothers and ∑j mj need to be dynamically managed
Each device updates its neighborhood table
Dynamically reflects the devices’ join and leave
MAS reservation varies accordingly
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

20. Example: Join/Leave of DEVs
September 2005
Example: Join/Leave of DEVs
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

21. September 2005
Two Piconets Join
The intermediate (relay) device reserves a channel time that is common in both piconets
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

22. Example: Piconet’s Join
September 2005
Example: Piconet’s Join
Piconet 1
Piconet 2
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

23. Mesh WPAN Neighborhood table informs about occupied slots in DTP
September 2005
Mesh WPAN
Neighborhood table informs about occupied slots in DTP
Beacon carry information on neighbor’s neighbor
Each device computes its fair share based on
Others’ reservations whose are within 2-hop distance
Its minimum requirement and priority
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

24. Example: Mesh WPAN DTP length: 100 MAS α = 0.5 September 2005
Jeon, Rhee, Lee, and Choi <ETRI/KWU>

25. Conclusions Distributed resource allocation mechanism for mesh WPAN
September 2005
Conclusions
Distributed resource allocation mechanism for mesh WPAN
Fair allocation without PNC
Decentralized admission control
Service differentiation
Future work includes
Further details on syntax and semantics of the protocol
Mathematical modeling and analysis
More exhaustive simulations
Reducing the convergence time
Jeon, Rhee, Lee, and Choi <ETRI/KWU>