1. doc.: IEEE 802.15- Submission Chongqing University of Posts and Telecommunications Slide 1 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:[023liyong@163.com] 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.

2. doc.: IEEE 802.15- Submission 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

3. doc.: IEEE 802.15- Submission CQUPTSlide 3 1. Motivation A flexible MAC scheme is proposed to meet potential requirements of LECIM.

4. doc.: IEEE 802.15- Submission CQUPTSlide 4 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

5. doc.: IEEE 802.15- Submission CQUPTSlide 5 3. Superframe structure Beacon enabled TG4k star network End Device Coordinator

6. doc.: IEEE 802.15- Submission 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

7. doc.: IEEE 802.15- Submission CQUPTSlide 7 3. Superframe structure:continued Beacon time slot Beacon is used to synchronize the nodes and transmit superframe information, number of management time slots, and time slot allocation. Management time slots For joining network, management of endpoints; The presence information and number of management timeslots are included in beacon frame.

8. doc.: IEEE 802.15- Submission CQUPTSlide 8 3. Superframe structure:continued Allocated time slot time slot which is allocated by coordinator and used to transmit scheduled data communication. CSMA time slot contention access time slot which is preserved for urgent packet.

9. doc.: IEEE 802.15- SubmissionChongqing 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. Beacon time slotManagement time slotAllocated time slotCSMA time slot Superframe

10. doc.: IEEE 802.15- Submission 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 D1D1 D2D2 D3D3 D4D4 D5D5 D6D6 D1D1 D2D2 D1 D2 D6 Beacon time slotManagement time slot Allocated time slot Sleep slot Upstream slot CSMA time slot

11. doc.: IEEE 802.15- Submission 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 D6D6 D2D2 D3D3 D4D4 D5D5 D6D6 D1D1 D2D2 D1 D2 D6 Beacon time slotManagement time slot Allocated time slotSleep slotUpstream slot D6D6 D6D6 CSMA time slot

12. doc.: IEEE 802.15- Submission 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.

13. doc.: IEEE 802.15- Submission CQUPTSlide 13 4.Time Slot Allocation: Urgent Data communication Urgent situation of LECIM network Normal Device Coordinator Alarming Device

14. doc.: IEEE 802.15- Submission CQUPTSlide 14 4.Time Slot Allocation: Urgent Data communication 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 D1D1 D2D2 D3D3 D4D4 D5D5 D6D6 D1D1 D2D2 D1 Beacon time slotManagement time slot Allocated time slotSleep slot Current superframeSuperframe 1Superframe 2 Buffer Upstream slot Alarming state detected

15. doc.: IEEE 802.15- Submission CQUPTSlide 15 4.Time Slot Allocation: Urgent Data communication 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 D1D1 D2D2 D3D3 D4D4 D5D5 D6D6 D1D1 D2D2 D1 D2 Beacon time slotManagement time slot Allocated time slotSleep slot Current superframeSuperframe 1Superframe 2 Buffer D1D1 D1D1 Upstream slot

16. doc.: IEEE 802.15- Submission 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. 4.Time Slot Allocation: Urgent Data communication Coordinator D1D1 D2D2 D1D1 D2D2 D2D2 D6D6 D1D1 D2D2 D1 D2 Beacon time slotManagement time slotAllocated time slotSleep slot Current superframeSuperframe 1Superframe 2 Buffer D1D1 D1D1 D1D1 D1D1 D2D2 D2D2 D2D2 Alarming state detected Upstream slot

17. doc.: IEEE 802.15- Submission CQUPTSlide 17 5. Comparsion Coordinator Current superframeSuperframe 1Superframe 2 D1 Buffer Alarming state detected D2 Buffer Alarming state detected Proposed Mac Coordinator 15.4 Superframe D3 Buffer Alarming state detected CAPCFP

18. doc.: IEEE 802.15- Submission 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

19. doc.: IEEE 802.15- Submission CQUPTSlide 19 Thank you for your attention Any Questions ?