Doc.: IEEE 802.15- Submission Chongqing University of Posts and Telecommunications Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area.

doc.: IEEE 802.15-<doc#>

Submission

<September, 2011>

Chongqing University of Posts and TelecommunicationsSlide 1

Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)

Submission Title: [A Flexible MAC Proposal for TG4k Networks]Date Submitted: [16 Sept., 2011]Source: [Yong Li, Ping Wang, Heng Wang]Company [Chongqing University of Posts and Telecommunications]Address [2 Chongwen Road, Nan an District, Chongqing 400065, China]Voice:[+86-159522723680], FAX: [+86-23-62461061], E-Mail:[[email protected]]

Re: [802.15.4K final proposal Call]

Abstract: [A Flexible MAC Proposals for TG4k Networks]

Purpose: [Presented to the IEEE 802.15.4k LECIM task group for consideration]

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.


Submission

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CQUPTSlide 2

Outline 1. Motivation

2. TG4K MAC requirement

3. Superframe structure

4. Timeslote allocation Fast Network Forming Data communication procedure Urgent Data communication

5. Comparsion

6. Advantages


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CQUPTSlide 3

1. Motivation

A flexible MAC scheme is proposed to meet

potential requirements of LECIM.


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2. TG4K MAC Requirement

Communication between main-powered coordinator and large number of endpoints,>1000 endpoints.

Scheduled and Urgent event data.

Fragmentation of 4K packets

Ultra-low maintenance traffic


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CQUPTSlide 5

3. Superframe structure

Beacon enabled TG4k star network

End Device

Coordinator


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CQUPTSlide 6

3. Superframe structure:continued

•Superframe contains N time slots N<<number of endpoints•Superframe timeslot has 3 types. -Beacon time slot -Management time slots: when they exists, they follows beacon time slot. -Data communication time slots allocated time slots CSMA time slots

Beacon time slot Management time slot Allocated time slot CSMA time slot

Superframe


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CQUPTSlide 7


•Beacon time slotBeacon is used to synchronize the nodes and transmit superframe information, number of management time slots, and time slot allocation.•Management time slotsFor joining network, management of endpoints; The presence information and number of management timeslots are included in beacon frame.


Superframe


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CQUPTSlide 8


•Allocated time slot time slot which is allocated by coordinator and used to transmit scheduled data communication.• CSMA time slotcontention access time slot which is preserved for urgent packet.


Superframe


Submission

Chongqing University of Posts and TelecommunicationsSlide 9

4.Time Slot Allocation: Fast Network Forming

Since there may be more than hundreds of endpoints waiting for joining 4k network, most of time slots of early superframe can be configured as management time slot. During the process of joining network, network address, and a time slot is allocated to every 4k device.(although a time slot is allocated when it joins network, this allocation can be cancelled by coordinator temporarily) After most of endpoints have joined network, the number of management time slots can be decreased.


Superframe


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CQUPTSlide 10

4.Time Slot Allocation: Data communication procedure

1. Coordinator sends beacon frame.2. Device 1 wakes up at beacon timeslot, and synchronizes to current

superframe.3. If regular data communication of D1 is scheduled in current

superframe, and allocated time slot is not reallocated to another device with urgent message, D1 send its packet with that time slot. After the transmission, it goes to sleep state.

Coordinator

D1

D2

D3

D4

D5

D6

D1

D2

D1

D2

D6

Beacon time slot Management time slot Allocated time slot

Sleep slot Upstream slot

CSMA time slot


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CQUPTSlide 11

4.Time Slot Allocation: Data communication procedure

4. In the case of urgent situation, for example D6 has high priority packet, current superframe can be reallocated to D6 as shown in this slide.5. D1 has to send its packet in one CSMA time slot.(time slot

13 of current superframe is used to transfer scheduled packet. )

Coordinator

D6

D2

D3

D4

D5

D6

D1

D2

D1

D2

D6

Beacon time slot Management time slot Allocated time slot Sleep slot Upstream slot

D6

D6

CSMA time slot


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CQUPTSlide 12

4.Time Slot Allocation: Urgent Data communication

1. Since low energy critical infrastructure monitoring network, event information is more important than periodic data;

2. Urgent messages may burst in a very short time duration from several endpoints;

3. Urgent message including more information than regular message and fragmentation may be used.


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CQUPTSlide 13


Urgent situation of LECIM network

Normal Device

Coordinator

Alarming Device


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CQUPTSlide 14


1. Coordinator broadcast beacon at the beginning of current superframe. Time slots 6 and 10 are allocated to D1 &D2;

2. Given an alarming state is detected at time slot 7, D1 needs to send a alarming message, and 4 time slots is needed to transmit the 4 fragments of this message;

Coordinator

D1

D2

D3

D4

D5

D6

D1

D2

D1

Beacon time slot Management time slot Allocated time slot Sleep slot

Current superframe Superframe 1 Superframe 2

Buffer

Upstream slot

Alarming state detected


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CQUPTSlide 15


3. Each fragment is sent with CSMA in current superframe, and has the information about how many packets need to sending in current burst transmission.4. Coordinator calculates the time slots needed for the left fragments

of D1 and allocates needed time slots for D1 in the next superframe and broadcast time slots information in the next beacon.

Coordinator

D1

D2

D3

D4

D5

D6

D1

D2

D1

D2



Buffer

D1

D1

Upstream slot


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CQUPTSlide 16

5. If several endpoints (such as D1&D2) use CSMA time slots in current superframe to transmit pack, all time slots of next superframe can be allocated to these urgent endpoints.


Coordinator

D1

D2

D1

D2

D2

D6

D1

D2

D1

D2



Buffer

D1D1

Buffer

D1

D1

D2

D2

D2



Upstream slot


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5. Comparsion

Coordinator


D1

BufferAlarming state detected

D2


Proposed Mac

Coordinator 15.4 Superframe

D3


CAP CFP


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CQUPTSlide 18

6. Advantages

1. Minimized network maintenance message: No time slot requirement message sequence.2. Support shorter superframe which can increase

the response speed for alarming requirement of 4K network.

3. Dynamic time slot allocation scheme make 4k MAC flexible and efficient to packet fragmentation and burst packets


Submission

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CQUPTSlide 19

Thank you for your attention

Any Questions ?

Doc.: IEEE 802.15- Submission Chongqing University of Posts and Telecommunications Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area.

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