1. doc.: 15-08-0605-01-004e Submission Huawei Technologies Co., Ltd.Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Enhancing reliability of data transmission in GTS] Date Submitted: [1 September, 2008] Source: [Betty Zhao, Yongjun Liu, Yong Xu] Company [Huawei Technologies, Co., Ltd.] Address [Kuike Building, 9 Shangdi Xinxi Road, Haidian District, Beijing 100085] Voice: [86 10 82836033], Fax: [86 10 82836920], E-Mail: [betty.zhao@huawei.com] Re: [15-08-0373-01-004e-call-for-proposals] Abstract:[This document proposes an enhancement for IEEE 802.15.4-2006 MAC to increase reliability of data transmission by frequency hopping GTS.] 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.

2. doc.: 15-08-0605-01-004e Submission Huawei Technologies Co., Ltd.Slide 2 Enhancing reliability of data transmission in GTS Yongjun Liu, Yong Xu, Betty Zhao Huawei Technologies Co., Ltd.

3. doc.: 15-08-0605-01-004e Submission Huawei Technologies Co., Ltd.Slide 3 Outline Reliability problem in GTS Frequency hopping in GTS Modifications to current Std Things about time synchronization Summary

4. doc.: 15-08-0605-01-004e Submission Huawei Technologies Co., Ltd.Slide 4 Reliability problem in GTS GTS is used for exclusive communication between device and PAN coordinator on one channel all the time. Its possible that packet collisions happen in GTS. Moreover, outside interference and environment changing havent been considered in current GTS mechanism. Frequency hopping in GTS is introduced to meet the higher requirement of reliability of data transmission, especially for the important data such as control messages and emergency data.

5. doc.: 15-08-0605-01-004e Submission Huawei Technologies Co., Ltd.Slide 5 Frequency hopping in GTS FH-GTS is to employ the GTS to transmit data by hopping on a sequence of chosen channels, while in the normal GTS data are transmitted on one channel all the time. - Coordinator selects a group of channels based on its previous channel scan. Frequency hopping can avoid severe transmission interference on one channel and resist the channel fading. Keep non-hopping at other time in the superframe to maintain the virtues of fast (re-)association

6. doc.: 15-08-0605-01-004e Submission Huawei Technologies Co., Ltd.Slide 6 Frequency hopping in GTS FH-GTS allocation and usage 1.Device requests the coordinator for FH-GTS allocation; 2.The coordinator arranges an FH-GTS, and responses with hopping information; 3.Device gets synchronization and FH-GTS descriptor with beacon frame; 4.FH-GTS is used by the device and coordinator.

7. doc.: 15-08-0605-01-004e Submission Huawei Technologies Co., Ltd.Slide 7 Modifications to current Std Add FH-GTS request command and its descriptions as requesting for the FH-GTS.

8. doc.: 15-08-0605-01-004e Submission Huawei Technologies Co., Ltd.Slide 8 Modifications to current Std (cont.) Add FH-GTS response command and its descriptions as transmitting hopping information from the coordinator to the device. Channel mask means the channels that can be used for hopping. E.g. in 2.4GHz band, 0x0842 indicates channel 15, 20, 25 to be used; Hopping mode describes the frequency hopping interval that FH-GTS chooses. The value n means the hopping dwell time is aBaseSlotDuration * 2 n symbols. Initial channel is the first channel for FH-GTS working on;

9. doc.: 15-08-0605-01-004e Submission Huawei Technologies Co., Ltd.Slide 9 Time synchronization in FH-GTS Synchronization can be fulfilled by beacon frame. Lost beacon issue can be overcome by resynchronization in CAP between the coordinator and the device

10. doc.: 15-08-0605-01-004e Submission Huawei Technologies Co., Ltd.Slide 10 Summary FH-GTS is a simple solution for increase transmission reliability of important data communication; Its compatible with current std and the virtue of fast (re- )association is kept. Add FH-GTS request and FH-GTS response commands to apply frequency hopping GTS. Add resynchronization method to enhance synchronization of data transmitting.

11. doc.: 15-08-0605-01-004e Submission Huawei Technologies Co., Ltd.Slide 11 Thank you!