Embed Size (px)
Citation preview
doc.: IEEE 15-08-0618-01-004e
Submission
Slide 1
Project: Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [beacon collision avoidance mechanism for TG4e MAC]Date Submitted: [September, 2008]Source: [ChangSub Shin, Wun-Cheol Jeong, Soyoung Hwang, Anseok Lee, Seong-Soon Joo] Company [ETRI]Address [161 Gajeong-dong Yuseong-gu, Daejeon, Korea]Voice:[+82-42-860-1668], FAX: [+82-42-869-1712], E-Mail:[[email protected]]
Re: [IEEE P802.15.4e call for proposal]Abstract: [This document proposes beacon collision avoidance solution for IEEE802.15.4e MAC]Purpose: [This document is a response to call for proposals]
Notice: This document has been prepared to assist the IEEE P802.15. 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 P802.15.
ChangSub Shin et al
September 2008
doc.: IEEE 15-08-0618-01-004e
Submission
ChangSub Shin et alSlide 2
Beacon Collision Avoidance mechanism for TG4e MAC
ChangSub Shin, Wun-Cheol Jeong
Anseok Lee, Seong-Soon Joo
ETRI
September 2008
This work has been supported by the Ministry of Knowledge Economy (MKE) of the Republic of Korea under Grants 2008-F-052.
doc.: IEEE 15-08-0618-01-004e
Submission
Deferred beacon method for collision avoidance
ChangSub Shin et alSlide 3
September 2008
doc.: IEEE 15-08-0618-01-004e
Submission
• Beacon collision problem in IEEE802.15.4 MAC• Beacon transmitted without back-off algorithm• Possible interfered in mesh topology• Unreliable wireless environment
• Without a beacon collision avoidance method• Beacon-enabled PAN with mutli-hop mesh topology
can not be operated with IEEE 802.15.4 MAC
Motivation
ChangSub Shin et alSlide 4
September 2008
doc.: IEEE 15-08-0618-01-004e
Submission
• Basic algorithm
1. Sender node uses CCA or back-off algorithm before sending a beacon frame
2. Sender node notifies the offset value between the start time of superframe and actual beacon transmitting time
3. Receiver node adjusts the next beacon receiving time using the offset value
Deferred beacon method (1/3)
ChangSub Shin et alSlide 5
September 2008
doc.: IEEE 15-08-0618-01-004e
Submission
• A node : proposed method installed• defer beacon transmission for collision avoidance• calculate offset value (CCA or CSMA-CA)
• B node : IEEE 802.15.4-2006• set the beacon receiving time to the start time of superframe• next beacon time : T + BI
• C node : proposed method installed• adjust the start time of superframe with offset value• next beacon time : T - + BI
Deferred beacon method (2/3)
ChangSub Shin et alSlide 6
September 2008
doc.: IEEE 15-08-0618-01-004e
Submission
• Maximum delay and loss• CCA approach
• max number of CCA detection for a deferred beacon : 5• max delay with CCA detection : 1,600 us
• CSMA-CA approach• macMinBE : 3• macMaxBE : 5• macMaxCSMABackoffs : 2• macMaxFrameRetries : 0• max delay with CSMA-CA : 8,320 us
Deferred beacon method (3/3)
ChangSub Shin et alSlide 7
September 2008
SO 0 5 10 14
SD (us) 15,360 491,520 15,728,640 251,658,240
CSMA-CA delay / SD (%) 54.167 1.693 0.053 0.003
CCA delay / SD (%) 10.417 0.326 0.010 0.001
doc.: IEEE 15-08-0618-01-004e
Submission
• 15.4 beacon frame• Deferred time fields : The number of aUnitBackoffPeriod
Proposals on Frame Format
ChangSub Shin et al
September 2008
Slide 8
Bits:0-3 4-7 8-11 12 13 14 15
Beacon Order
Superframe Order
Final CAP Slot
Battery Life Extension(BLE)
Deferred Beacon
Indication
PAN Coordinator
Association Permit
Octets: 2
1 4/10 0/5/6/10/14 2 variable variable variable 0/1 2
Frame Control
Sequence Number
Addressing fields
Auxiliary Security Header
Superframe Specification
GTS fields
Pending Address
fields
Beacon Payload
Deferred time
FCS
MHR MAC Payload MFR
doc.: IEEE 15-08-0618-01-004e
Submission
Bitmap assisted beacon scheduling method for collision avoidance
ChangSub Shin et alSlide 9
September 2008
doc.: IEEE 15-08-0618-01-004e
Submission
• Beacon contains information on superframe structure and is used for synchronizing all devices in beacon enabled network
• Beacon scheduling mechanism is indispensible for multi-hop mesh networks
• Current IEEE802.15.4 MAC supports beacon scheduling using StartTime• Limitation : supported only for tree topology • Beacon scheduling is not operated in MAC layer
=> Propose beacon scheduling method
Motivation
ChangSub Shin et alSlide 10
September 2008
doc.: IEEE 15-08-0618-01-004e
Submission
• Bitmap assisted beacon scheduling• Inform own neighbor’s allocated SD information with the
bitmap in a beacon frame
• New joining node shall listen neighbor’s beacon during maximum ScanDuration and select unallocated SD
• Tracking only neighbor’s SD
• May use BLE for energy saving
• Distributed scheduling method, not centralized
• Need superframe structure for beacon scheduling • Superframe is consisted of the number of slotted SDs
Bitmap assisted beacon scheduling method (1/3)
ChangSub Shin et alSlide 11
September 2008
doc.: IEEE 15-08-0618-01-004e
Submission
Bitmap assisted beacon scheduling method (2/3)
ChangSub Shin et alSlide 12
September 2008
• Initialization• Scan : listen neighbor’s beacon
• Select blank SD from two-hop neighbor’s bitmap information
• Transmit beacon in the selected SD
• If beacon collision happen, notify collision notification to it’s neighbor nodes
doc.: IEEE 15-08-0618-01-004e
Submission
Bitmap assisted beacon scheduling method (3/3)
ChangSub Shin et alSlide 13
September 2008
doc.: IEEE 15-08-0618-01-004e
Submission
• 15.4 beacon frame
Proposals on Frame Format
ChangSub Shin et al
September 2008
Slide 14
Octets: 2
1 4/10 0/5/6/10/14 2 variable variable variable variable 2
Frame Control
Sequence Number
Addressing fields
Auxiliary Security Header
Superframe Specification
GTS fields
Pending Address
fields
Beacon Bitmap fields
Beacon Payload
FCS
MHR MAC Payload MFR
Octets: 1 variable
Beacon bitmap Specification
Beacon bitmap
Bits: 0-1 2-6 7
The length of Bitmap (bytes)
Allocated number of SD
Reserved
doc.: IEEE 15-08-0618-01-004e
Submission
Thank you very much for your attention
Any Questions?
ChangSub Shin et alSlide 15
September 2008
![SubmissionSlide 1 Project: IEEE 802.15.7r1 Optical Wireless Communication Submission Title: [LED Tag Applications for OWC] Date Submitted: [10 th March,](https://img.pdfslide.us/doc/110x75/56649d975503460f94a80d2a/submissionslide-1-project-ieee-802157r1-optical-wireless-communication-submission.jpg)
