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

1. Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Consideration on MAC enhancement of IEEE 802.15.4-2006] Date Submitted: [6th July, 2007] Source: [Yongjun Liu, Yongfeng Zhong, Paul Dixon, Pei Liu, Liang Li] Company [Huawei Technologies Co., Ltd, Vinno Technologies Inc.] Address [No.3 Xinxi Road, Shangdi Information Industry Base, Haidian District, Beijing, P.R.China] Voice:[+86 10 82836430], FAX: [+86 82836920], E-Mail:[yongjunliu@huawei.com, liangli@vinnotech.com] Abstract: [Analyses the MAC enhancement issue existing in IEEE 802.15.4-2006.] Purpose: [For discussion and to make a motion.] 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. Huawei

2. Consideration on MAC enhancement of IEEE 802.15.4-2006 Yongjun Liu Yongfeng Zhong Paul Dixon Pei Liu Huawei Technologies Co., Ltd Liang Li Vinno Technologies Inc. Huawei

3. Content • Some Issues Related to IEEE 802.15.4-2006. • Possible Problems • GTS problems • Enhancement on service performanc • RFDs’ direct link communication issue • Power Saving and Service Qualities for Various Devices • Summary Huawei

4. Issues of IEEE 802.15.4-2006 • IEEE 802.15.4-2006 is designed for the low rate WPAN, but… • GTS is not designed so well for applications which demand more flexibility in latency or bandwidth requirements. • It lacks some interfaces and mechanisms for the higher layer to enhance the service performance • It is not necessary to restrict the direct link communication between two RFDs • Power saving strategies do not related to the service qualities of various devices in one WPAN Huawei

5. GTS problems • Low latency applications: control messages, emergency services, etc • GTS provides latency guarantee in a certain level, but • GTS can only be used in the communication between PAN coordinator and devices. There is no guarantee in multi-hop communication • GTS can only be managed and allocated by PAN coordinator • GTS cannot be shared by several devices. • Too large granularity of GTS so that the number of it is not enough sometimes – only 7 GTS can be allocated in maximum Huawei

6. Enhancement on service performance • There may be several types of services in the same WPAN. Some may require more on latency or bandwidth than others • Power control sometimes is needed to decrease interference and power consumption Lack some indicators for differentiated services and power control! Huawei

7. RFDs’ direct link communication issue • It is restricted currently that RFD can only talk to FFD • This restriction is not necessary and limit the network topology and performance • Direct link communication between two RFDs is more efficient than that with parent FFD’s help • Direct link communication between RFDs may be useful when the link to the parent FFD is broken The direct line is the shortest path! Some problems happen in the parent FFD FFD RFD Keep connecting with other nodes by RFDs’ P2P links Huawei

8. Power Saving and Service Qualities of Various Devices • In one WPAN, the various devices may implement the different tasks. So, • The service qualities for tasks are totally different • It is not smart to ask all of device in one WPAN to implement the same Power Saving • The Superframe may provide the solutions for both inquires. Huawei

9. Summary • IEEE 802.15.4-2006 still has some issues in MAC so as to limit the applications • Possible consideration on improvement to the specification • Possible solution : to form a new study group to investigate the improvement of low rate WPAN MAC layer Huawei