Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [Emergent Modification for Wireless Industry Control] Date Submitted: [May 2008 ] Source: [Ping Wang, Q. Wang, Liang Li ] Company: [Chongqing university of Posts and Telecommunications, Vinno Technologies Inc. ] Address: [College of Automation, Chongqing University of Posts and Telecommunications,2 Chongwen Rd, Nan an District, Chongqing,China ] Voice:[+86 23 62461061], E-Mail:[wangping@cqupt.edu.cn, liang_1@vinnotech.com] Re: [ IEEE 802.15.4e ] Abstract: [This document proposes an improvement to IEEE 802.15.4-2006 MAC Layer for Wireless Industry Communication] Purpose: [This document is a response to better support the industrial markets in IEEE P802.15.SG4e Call for Application on 14 November, 2007] Notice: This document has been prepared to Make the improvement on the IEEE Std 802.15.4-2006, satisfying the following key requirements of the wireless industry communication: (1) reliability; (2) deterministic Scheduling; (3) real time; (4) low power consumption.. Release: The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15. Submission Ping Wang, Liang Li
Supported topology architecture The improvements of this proposal for PHY and MAC layer can support multiple network topologies, such as star networks, tree networks etc., which are adaptive to industrial control, as shown in above Figure. Cluster-tree MESH networks is also supported in Control network. Submission Ping Wang, Liang Li
GTS mechanism While industrial communication has a high require for reliability, this proposal improved the original superframe. The superframe has an enhanced GTS mechanism, which can satisfy the requirement for industrial communication and keep the activity for transmitting data. The superframe we adopted have such characters: (1) the period of each slot in the same superframe is identical; (2)the superframe have a 250ms period , which is consider for industrial control. Submission Ping Wang, Liang Li
GTS mechanism CAP: This period is used for network managing and is suit for dynamic network changing. CSMA-CA algorithm with priority support is used when transmitting beacon frame and command frame. P-GTS: contention-free, for transmitting periodical data. T-GTS: contention-free, for transmitting temporary periodical data or non-periodical critical data. Sleep period: used for save power. Submission Ping Wang, Liang Li
Adaptive channel hopping Generation of channel hopping sequence Assignment of channel hopping sequence Black list Submission Ping Wang, Liang Li
Precise clock synchronization The synchronization technology is based on the MAC timestamps, the mechanism is shown in the Figure. The timestamp is captured in SFD interruption. The timestamp is added at the end of the message when it is send. The synchronization error is within a tick in the star network. Submission Ping Wang, Liang Li