1. Access distribution for M2M devices Document Number: IEEE C802.16p-10_0028 Date Submitted: December 31, 2010 Source: Jin Lee, Youngsoo Yuk, Jeongki Kim, Giwon Park, Kiseon Ryu, JinSam Kwak LG Electronics E-mail : {jin1.lee, youngsoo.yuk, kiseon.ryu}@lge.comjin1.lee, youngsoo.yuk, kiseon.ryu}@lge.com * http://standards.ieee.org/faqs/affiliationFAQ.html Re: 802.16p amendment texts Base Contribution: Purpose: Discuss and adopt proposed texts Notice: This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants listed in the Source(s) field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material contained herein. Copyright Policy: The contributor is familiar with the IEEE-SA Copyright Policy. Patent Policy: The contributor is familiar with the IEEE-SA Patent Policy and Procedures: and..html#6sect6.html#6.3 Further information is located at and.http://standards.ieee.org/board/pat/pat-material.htmlhttp://standards.ieee.org/board/pat

2. Motivation In 802.16p SRD, the following requirements are agreed –6.2.7 The 802.16p system shall support efficient mechanisms for network access from large numbers of M2M devices. 6.2.7.1 The 802.16p system shall provide mechanisms to reduce access network congestion or overload from large numbers of M2M Devices. 6.2.7.2 The 802.16p system shall support network access, without incurring excessive delays for certain M2M application scenarios. –6.2.9 The 802.16p system shall provide mechanisms for allowing access with different levels of priority for M2M devices across different classes of M2M services. Current random access procedure shall be optimized –In order to avoid delay and collision from large numbers of devices –In order to provide access priorities based on M2M applications In this contribution, we propose prioritized access and M2M device access distribution.

3. Network Access Scenario M2M group re-entry after paging M2M Group report –In case network knows of transmission period of M2M groups, it may request M2M devices belonging to specific groups to report/send data. Fig 1. M2M Group paging

4. Remedy 1 Prioritized access –Some M2M devices can be configured as delay sensitive devices (e.g., remote diagnostics, surveillance, etc.) or others can be verified as delay insensitive (e.g., smart metering) devices. Based on M2M application characteristics, each M2M device can be categorized by priority level. –This remedy is suitable if access collision or network congestion is occurred. PriorityOffset 00 12 24 36 Table1. Example of priority level Fig2. Priority based random access Access Collision

5. Remedy 2 M2M device specific access opportunity –As you see several access scenarios (page 3), we can expect simultaneous network access(es) from massive M2M devices. If current random backoff mechanism is used for these cases, it may still lead excessive delay and access network congestion due to the enormous number of M2M devices. –Therefore, assigning access opportunity for each M2M device seems more preferable. Differentiated M2M Group access time –Considering mass of M2M devices, groping of M2M devices is recommended since each individual management of M2M device may lead excessive network /signaling overload. –Also, when several M2M groups are paged, network may be able to distribute access opportunity by adopting different waiting time per M2M group.

6. Conclusion Due to a large number of M2M devices, efficient radio access distribution and network load control seem indisputable. As we have shown three remedies, we would like to propose remedy1 when access collision or network congestion is occurred (Fig 3). Remedy2 is recommended no access collision or network congestion is occurred (Fig 4) Fig 4. Device specific access opportunity with differentiated group waiting time Fig 3. Priority based random access Access Collision

7. Proposed texts [Insert the following texts in 16p amendment document] : 16.2.29 MAC Support of M2M 16.2.29.x Network Re-entry 16.2.29.x.1 Ranging –16.2.29.x.1.1 Contention Resolution –Priority level is assigned to an M2M device and the priority level based waiting time should be applied when access collision or congestion is detected. –16.2.29.x.1.2 Group Congestion Control –The M2M device access opportunity should be considered in case of initial random access. Different waiting time per M2M group should be applied before start of M2M device access opportunity.