Project: IEEE 802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: [TG4b MAC backward compatibility] Date Submitted: [14Sep2004] Source: [Phil Beecher] Company [CompXs Ltd] Address [Robert Denholm House, Bletchingley Road, Nutfield, RH1 4HW, UK] Voice:[+44 1737 822509], E-Mail: [pbeecher@compxs.com] Re: [15-04-521-nn-4b] Abstract: [Requirements for backward compatibility] Purpose: [To focus resolutions for 802.15.4 MAC Issues.] Notice: This document has been prepared to assist the IEEE 802.15. 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 802.15. January 2004 Phil Beecher, CompXs Ltd Phil Beecher, CompXs Ltd

MAC Backward Compatibility January 2004 MAC Backward Compatibility Compatibility requirements: Over air compatibility MAC layer primitive compatibility Phil Beecher, CompXs Ltd Phil Beecher, CompXs Ltd

Over air compatibility Requirements At a minimum, a 802.15.4b network must coexist with a 802.15.4-2003 network This must include the following: The .4b specification shall ensure that .4 devices are able to correctly interpret or ignore frames from .4b network. .4b devices shall be capable of correctly interpreting frames from .4 networks for supported modes of operation. This implies frames over air must be "compatible” Current header field assignments must be the same. New uses of previously unused fields must not break .4 definitions/restrictions. Changes to Frame header fields must not break .4 definitions/restrictions MAC commands must retain the same values. The order of MAC command parameter fields must stay the same. Phil Beecher, CompXs Ltd

MAC Layer Primitive Compatibility Requirement: to minimise change to existing NHL designs and implementations. Implication: The functionality of primitives must either remain the same or be enhanced; it cannot be changed in a way which will necessitate structural design change in the NHL. Therefore we cannot remove parameters that will adversely affect the flow of the next higher layer. Cannot remove or reduce functionality of MAC primitives - any new parameter in .4b primitive must have a default value which retains the behaviour of .4 primitive. Phil Beecher, CompXs Ltd