Ieee p802. 15 Wireless Personal Area Networks

July, 2005 15-05-0485-00-003b

IEEE P802.15

Wireless Personal Area Networks

Project	IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs)
Title	Propose a Revisions for 802.15.3 – Modify Stream At PM
Date Submitted	[July 26, 2005]
Source	[Chieh-Ying Kan] [ITRI] [M100/CCL, Bldg 14, 195-11 Sec. 4, Chung Hsing Rd. Chutung, Hsinchu, Taiwan R.O.C.]	Voice: [[phone] ] Fax: [[phone]] E-mail: [ [e-mail] ]
Re:	15-05-0249-00-003b-TG3b-Create-Stream-At-PM.doc, 15-05-0380-00-003b-CreateStreaminPSmode.ppt
Abstract	Proposing a change request to the IEEE Standard 802.15.3. Because, it neglects to specify the procedure of modify the isochronous stream for devices in the same set of DSPS mode.
Purpose	The change request documents the specification of the procedure of modifying the isochronous stream for devices in the same set of DSPS mode. The new procedure is distinguished in red color.
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.

8.5.1.2 Isochronous stream modification
Only the originating DEV or the PNC may modify an established isochronous stream. The originating DEV that is requesting a modification of the channel time allocated to one of its streams shall send the PNC a Channel Time Request command with these parameter values:

• 
  Target ID List field is set to the DEVID with which the originating DEV has an established stream.
  
• 
  Stream Request ID field set to zero.
  
• 
  Stream Index field set to the index of the stream to be modified.
  
• 
  The CTA Type field shall be set to the same value as in the original request for that stream index.
  
• 
  If the originating DEV is in a DSPS mode, the DSPS Set Index field shall be set to the DSPS Set Index of the stream to be modified.
  
• 
  All the other Channel Time Request command parameters are set to appropriate values as defined in 7.5.6.1.
  

The PNC upon receiving the Channel Time Request command shall check to see if the requested resources are available. If the requested channel time is not available the PNC shall:

• 
  Send a Channel Time Response command with the Available Number Of TUs equal to the previously assigned Available Number Of TUs.
  
• 
  The Stream Request ID field set to zero.
  
• 
  The Reason Code field set to ‘channel time unavailable’.
  
• 
  Await an Imm-ACK from the requesting DEV.
  
• 
  Make no modification to the existing beacon CTA blocks for the DEV requesting the modification.
  

If the requested channel time is available, the PNC shall:

• 
  Reserve the requested channel time.
  
• 
  Send a Channel Time Response Command where:
  

the “new" Available Number Of TUs field is greater than the "previous" Available Number Of TUs field and is less than or equal to the Desired Number Of TUs (for a requested an increase in channel time),

or

the "new" Available Number Of TUs field less than or equal to the Desired Number Of TUs field (for a requested decrease in channel time).

• 
  The Stream Request ID field set to zero.
  
• 
  If the originating and destination DEVs are in the same set of DSPS mode, the Reason Code field set to the value: 1 -> Success, DEV in PS mode. Otherwise, the Reason Code field set to the value: 0 -> success.
  
• 
  Await an ACK from the requesting DEV.
  
• 
  Build a new beacon with the modified CTA.
  

The PNC shall announce the modification of those streams for which the destination DEV, or any intended destination DEV in the case of broadcast and multicast streams, is in power save mode. The PNC shall announce the modification of those streams for which one or more of the PM CTRq Type, CTA Rate Type, and the CTA Rate Factor fields are modified. The PNC shall make the announcement with the CTA Status IE, as described in 7.4.10, using the beacon information announcement mechanism, as described in 8.6.4. If the destination and originating DEVs are in the same set of DSPS mode, the PNC shall announce the modification as indicated by Wake Beacon Interval of the DSPS set. The PNC shall issue the first modified CTA for the stream in the superframe indicated in that IE.

If the destination and originating DEVs are either:

in the same set of DSPS mode, the PNC shall allocate for the target DEV an uplink MCTA in the same superframe as when the CTA is first allocated with the DSPS DEV as the source and the PNC as the destination that is long enough to handle the Channel Time Request command with 4 isochronous CTRqBs, and the associated Imm-ACKs and SIFSs.

or

not in the same set of DSPS mode, the PNC shall allocate for the target DEV an uplink MCTA in the same superframe as when the CTA is first allocated with the DSPS DEV as the source and the PNC as the destination that is long enough to handle a PM Change command, a Channel Time Request command with 4 isochronous CTRqBs, and the associated Imm-ACKs and SIFSs.

A dependent PNC, the originator DEV, may handover control of the dependent piconet’s CTA to another DEV, the target DEV, in the parent piconet. The target DEV shall be either a member of the piconet or a DEV that has associated as a neighbor PNC, as described in 8.2.6. To handover control of the dependent piconet’s CTA, the originator DEV shall send a Channel Time Request command to the parent PNC with the following parameters:

• 
  The Num Targets field set to one.
  
• 
  The Target ID List field containing the DEVID of the target DEV that is to receive control of the CTA
  
• 
  The Stream Request ID field set to zero.
  
• 
  The Stream Index field set to the stream index of a CTA that has already been allocated to the dependent PNC as a private, pseudo-static CTA.
  
• 
  All other fields set to the same values as in the last successful Channel Time Request for this Stream Index.