1. Address [ 30 Xueyuan Road, Beijing 100083, China]
Project: IEEE P Working Group for Wireless Personal Area Networks (WPANs)
Submission Title: [Enhancement to for Process Aotumation]
Date Submitted: [10 Nov, 2008]
Source: [Qin Wang / Peng Zeng], Company [University of Science & Technology Beijing/ Shenyang Institute of Automation-Chinese Academy of Sciences /]
Address [ 30 Xueyuan Road, Beijing , China]
Phone: [ ], FAX: [ ], [
Re: [IEEE P e Call For proposal]
Abstract: []
Purpose: [This document is a response to Item a) better support the industrial markets in IEEE P SG4e Call for Application on 14 November, 2007]
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
10 November Qin Wang /Peng Zeng
IEEE e

2. Enhancement to 802.15.4-2006 for Process Automation
Qin Wang1) , Peng Zeng2)
1) University of Science & Technology Beijing
2) Shenyang Institute of Automation-Chinese Academy of Sciences
10 November 2008
In order to increase the reliability more, we develop a kind of adaptive frequency diversity (AFD). The technology can be used in our previous proposal, but not limited in that.
The proposal is also given by Peng Zeng and Qin Wang.
10 November Qin Wang /Peng Zeng
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3. Increase deterministic degree of end-to-end communication
Objective
Increase reliability
Increase deterministic degree of end-to-end communication
Balance the fast communication for emergency information and the very low duty cycle communication for regular information
Compatible with IEEE device
Generalized the application of wireless sensor network from the specific application, we think the design goal for the enhanced MAC protocol should include the four folds.
Reliability
Deterministic degree
Balance fast communication and low duty cycle communication
Compatible with IEEE device.
Our proposed scheme includes the following components.
Mesh+Star topology => reliability and deterministic
Extended superframe (compatible with 15.4e)
CSMA/TDMA+FDMA during active period (emergency data)
TDMA+FH/AFD during scheduled period (deterministic, low duty cycle of periodical data)
Two-stage allocation (flexibility and efficiency)
10 November Qin Wang /Peng Zeng
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4. Propose (reference #619, #620)
Mesh+Star topology
Extended superframe
Two-stage resource allocation
TDMA+FH/AFD during scheduled period, i.e. inactive period of
Note: Difference between Adaptive Frequency Diversity (AFD) with Frequency Hopping (FH)
FH: Change communication channel according to a scheduled frequency hopping pattern, regardless how the real channel condition is.
AFD: Change communication channel according to the real channel condition. In another word, bad channel condition, which can be measured with packet drop rate or resend time, triggers the operation of changing channel.
10 November Qin Wang /Peng Zeng
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5. Link Layer Reliability
Assume a complete communication includes transmitting a packet and receiving ACK. Then, the packet drop rate (PDR) measured at the transmitting side is used as the measurement of link layer reliability, i.e.
For channel characteristics , some researcher presume that radio connectivity is reasonably consistent over time, others presume that radio links are entirely unreliable and unpredicted. So first we should study radio connectivity under different environments and get the knowledge of what real radio connectivity is. Following is the test results, we define packet_loss_rate to describe channel reliability, the definition is here
Flowing is some radio channel reliability test on different environments.
10 November Qin Wang /Peng Zeng
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6. 10 November 2008 Qin Wang /Peng Zeng IEEE 802.15-08-0820-00-004e
Test 1
Test 2
Test 3 A B C
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7. 10 November 2008 Qin Wang /Peng Zeng IEEE 802.15-08-0820-00-004eC
Test 4 C B A
Test 5
10 November Qin Wang /Peng Zeng
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8. 10 November 2008 Qin Wang /Peng Zeng
IEEE e

9. PDR over time in school factory (4 hours)
Different packet loss rate on different channels, low and high packet loss rate last for a relative long stable time on one channel
ch ch ch ch ch ch ch ch8
ch ch ch ch ch ch ch ch16
Packet loss rate
Packet loss rate
This test is hold on USTB school factory over 4 hours, from the test result we know that different channel have different packet lost rate, that is to say, frequency diversity is
very important . Also we can learn form the result that for an channel, low packet loss rate time last for a relative long time and also very high packet loss rate last for a relative long time too, channels between have middle packet loss rate have large variation such as ch2
time
time
10 November Qin Wang /Peng Zeng
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10. PDR over time in Irion and steel factory (9hours)
ch ch ch ch ch ch ch ch8
ch ch ch ch ch ch ch ch16
Packet loss rate
Packet loss rate
Another test was hold on a Irion and steel factory over 9 hours, we also found that high and low packet loss rate channels last stable for a relative long time, besides, there are correlations between channels, such as ch4 and ch5
time
time
10 November Qin Wang /Peng Zeng
IEEE e

11. PDR over time in lab (17 hours)
channels have correlations with each other, the same can be found at previous two tests
ch ch ch ch ch ch ch ch8
ch ch ch ch ch ch ch ch16
Packet loss rate
Packet loss rate
A 17 hours lab test result is shown here, we can find that some channels have positive correlations, such as ch13~ ch14 ; ch10~11; ch9,12 etc. that is to say these channels have same variation trends, and some have negative correlations such as ch12 and ch13,14, and others have no or little correlations.
channel correlation will effect the result of different frequency diversity method.
time
time
10 November Qin Wang /Peng Zeng
IEEE e

12. Link Layer Statistic Model
Divided channel condition into 5 state according PDR, and do statistic interference.
state
PDR,e.g.
notation
Excellent
<5% E
Good
5~25% G
Middle
25~50% M
Poor
50~80% P
Bad
80~100% B
10 November Qin Wang /Peng Zeng
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13. Link layer PDR Generation
10 November Qin Wang /Peng Zeng
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14. E-Superframe IEEE802.15.4 Superframe SD BI E-Superframe
Beacon of superframe
16 slot
CAP CFP
inactive SD BI
E-Superframe
Beacon of E-superframe
CAP CFP
Intra-cluster Inter-cluster sleep
16 slot
Schedule period
Extended superframe, i.e. E-superframe is shown here. T-superframe is slotted, and interval of slot equals to SD/16. E-superframe is a kind of extension of the superframe in IEEE 802,15.4e A E-superframe consists of three period, i.e.
active period, which is same as that in the superframe of ;
Scheduled period, which includes intra-cluster period, inter-cluster period, and manager period.
Sleeping period
Both scheduled period and sleeping period together are associated to the inactive period of
10 November Qin Wang /Peng Zeng
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15. TDMA+FH/AFD in scheduled period
Intra-cluster
Sleeping
Collect data from SNs
Inter cluster
& Manager period
sleeping
TDMA+
AFD
TDMA+ FH
Similar with the previous proposed scheme, the other parts of scheduled period are also arranged by system manager, while the AFD replaces FH during the intra-cluster period.
The Inter cluster period and manager period are scheduled by the system manager.
10 November Qin Wang /Peng Zeng
IEEE e

16. Channel change protocol
10 November Qin Wang /Peng Zeng
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17. 8 sensor node，1 cluster head;
Simulation setting：
OMNet++ simulator;
8 sensor node，1 cluster head;
PDR over time is generated according to the link layer statistic model
FH sequence: 5, 6, 2, 8, 4, 1, 3, 7, 14, 13, 11, 12, 16, 9, 15, 10
AFD: randomly choose the next channel while current channel PDR>15%
1-PDR
0.981
0.969
0.945
0.980
0.954
1.000
0.984
channel selection 8
6,8 12 9 15
11,16,13
10 November Qin Wang /Peng Zeng
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18. Summary Increase reliability
Increase deterministic degree of end-to-end communication
Balance the fast communication for emergency information and the very low duty cycle communication for regular information
Compatible with IEEE device
Link Layer Statistic Model
Mesh+ Star topology
Extended Superframe
Two-stage resource allocation
Adaptive Frequency Diversity
10 November Qin Wang /Peng Zeng
IEEE e

19. Thanks! 10 November 2008 Qin Wang /Peng Zeng
IEEE e