1. 3GPP2 A30-20110907-009r0 3GPP2 C20-20110926-xxxr0 TSG-A WG3 and TSG-C WG2 Title: M2M Congestion Control in the RAN Source: Mike Dolan Dave Rossetti Satish Kanugovi Abstract: This contribution proposes a means of controlling congestion at the RAN level by use of a “Low Priority Indication” from the AT, and by obtaining the subscription priority from the AN-AAA. In support of Work Item 3GPP2-00269. Recommendation: Review and Approve in concept. © 2011 Alcatel-Lucent Alcatel-Lucent grants a free, irrevocable license to 3GPP2 and its Organizational Partners to incorporate text or other copyrightable material contained in the contribution and any modifications thereof in the creation of 3GPP2 publications; to copyright and sell in Organizational Partner's name any Organizational Partner's standards publication even though it may include all or portions of this contribution; and at the Organizational Partner's sole discretion to permit others to reproduce in whole or in part such contribution or the resulting Organizational Partner's standards publication. Alcatel-Lucent is also willing to grant licenses under such contributor copyrights to third parties on reasonable, non-discriminatory terms and conditions for purpose of practicing an Organizational Partner's standard which incorporates this contribution. This document has been prepared by Alcatel-Lucent to assist the development of specifications by 3GPP2. It is proposed to the Committee as a basis for discussion and is not to be construed as a binding proposal on Alcatel-Lucent. Alcatel-Lucent specifically reserves the right to amend or modify the material contained herein and to any intellectual property of Alcatel-Lucent other than provided in the copyright statement above.

2. 2 COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED. Work on congestion caused by M2M activity has been going on in several places around the world for some time, and in 3GPP2 for over a year. One area that needs to be handled is throttling traffic into the core network at the RAN level. One area of throttling that can occur is at the air interface, preventing the device from sending signaling to the network. This is already under the area of TSG-C and is not the concern of this contribution. This contribution addresses signaling that has reached the RAN from the device, and that may need to be throttled due to network congestion. M2M Congestion Background

3. 3 COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED. To provide throttling, we need: Some notification from the core network (e.g., PDSN/HSGW) that throttling is needed, and some threshold to apply to accomplish that throttling. ­Throttling can occur based on priority level. Some way to know the subscription priority level of the device at the RAN without having to involve the PDSN/HSGW in signaling. ­Use the A12 interface to get the subscription priority along with the IMSI. Some way for the RAN to provide a back-off timer to devices whose priority is less than the threshold priority of the PDSN/HSGW. ­Add a cause and a back-off timer to ConnectionDeny, ConnectionClose and ReservationReject. Some way for the device to indicate a specific priority for its request. ­Add a requested priority to ConnectionRequest and ReservationOnRequest. Some Important Aspects A synopsis of the proposal.

4. 4 COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED. How it might work A threshold is provided by the PDSN/HSGW

5. 5 COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED. How it might work A priority is requested by the device *There is no need to the AN to validate a requested priority that is lower than the priority threshold.

6. 6 COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED. How it might work A threshold is provided by the PDSN/HSGW. The AT requests a specific priority.

7. 7 COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED. How it might work A threshold is provided by the PDSN/HSGW

8. 8 COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED. How it might work A lower threshold is provided by the PDSN/HSGW *Please note that ReservationReject can also be sent to indicate which reservations are allowed the state change in place of ReservationAccept based on admission control

9. 9 COPYRIGHT © 2011 ALCATEL-LUCENT. ALL RIGHTS RESERVED. Proposal Accept the set of basic concepts of this contribution. The PDSN(HSGW) can notify the AN/PCF(eAN/ePCF) of the priority threshold it wants to impose on new connections from ATs(eATs). The RAN can retrieve the subscription priority via A12 for comparison with the priority threshold. The device can request a specific priority that the RAN can compare to the threshold priority and to the subscription priority. The RAN can send a cause and a back-off timer to the device to indicate that delayed re-attempts are allowed after the timer expires. expires. The RAN can reject requests for a higher priority than that allowed by the subscription.