[Resource Allocation for IEEE 802.22b Systems] September 2013 doc.: IEEE 802.22-12-0088-02-000b September 2013 [Resource Allocation for IEEE 802.22b Systems] IEEE P802.22 Wireless RANs Date: 2013-09-09 Authors: Notice: This document has been prepared to assist IEEE 802.22. 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 grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.22. Patent Policy and Procedures: The contributor is familiar with the IEEE 802 Patent Policy and Procedures http://standards.ieee.org/guides/bylaws/sb-bylaws.pdf including the statement "IEEE standards may include the known use of patent(s), including patent applications, provided the IEEE receives assurance from the patent holder or applicant with respect to patents essential for compliance with both mandatory and optional portions of the standard." Early disclosure to the Working Group of patent information that might be relevant to the standard is essential to reduce the possibility for delays in the development process and increase the likelihood that the draft publication will be approved for publication. Please notify the Chair Apurva Mody <apurva.mody@ieee.org> as early as possible, in written or electronic form, if patented technology (or technology under patent application) might be incorporated into a draft standard being developed within the IEEE 802.22 Working Group. If you have questions, contact the IEEE Patent Committee Administrator at patcom@iee.org. Sunghyun Hwang, ETRI Sunghyun Hwang, ETRI

Summary Classification Statement September 2013 doc.: IEEE 802.22-12-0088-02-000b September 2013 Summary Classification Statement It is a partial proposal regarding the resource allocation for 802.22b systems. Address the issues of resource allocation Propose the resource allocation and backup channel management on a group basis Compare the MAP overhead for group resource allocation Mainly consider the Smart Metering Model and Real-time/near real-time video Monitoring Model as described in the 802.22b Functional Requirements Document Sunghyun Hwang, ETRI Sunghyun Hwang, ETRI

September 2013 Technology Overview Very large number of devices, small burst transmissions It is a burden of MAP overhead to allocate the resources to all devices individually. It is also inefficient to use random-access fully. The solution is Group Resource Allocation (GRA) Allocate the resources to the Group using Bitmap format GRA is very useful for connections with a same PHY mode and with a fixed payload size Manage the backup channel on a Group basis Sunghyun Hwang, ETRI

How to make a group? (Hub-device vs. Nano-device) September 2013 How to make a group? (Hub-device vs. Nano-device) Hub-device is a controller of a group consisting of many Nano-devices Hub-device (only one): access to DB, network entry with BS, identify the Group ID(GID) Nano-device (multiple): Sync. to Hub-device and/or BS Hub-device is mode II or mode I device, but Nano-device is mode I device only Nano-devices has same GID, but different Device ID(DID) Hub-device and Nano-device are similar to H-CPE and L-CPE, respectively. Sunghyun Hwang, ETRI

Type of Group Fixed Group Mobile Group September 2013 Type of Group Fixed Group Hub-device is fixed (e.g., on the building, house, tower) Fixed group consisting of fixed Nano-devices (e.g., village, wind turbines) Fixed group consisting of nomadic Nano-devices (e.g., live stocks) Mobile Group Hub-device is mobile (e.g., on the vehicles) Mobile group consisting of mobile Nano-devices (e.g., vehicles, boats) Mobile group consisting of nomadic Nano-devices (e.g., rescue crew, firefighter) Sunghyun Hwang, ETRI

Transmission Example of 802.22b Resource Allocation Message September 2013 Transmission Example of 802.22b Resource Allocation Message BS DS-MAP including Legacy DS-MAP-IE US-MAP including Legacy US-MAP-IE L-CPE H-CPE H-CPE L-CPE DS-MAP including GRA DS-MAP-IE US-MAP including GRA US-MAP-IE L-CPE L-CPE L-CPE L-CPE Sunghyun Hwang, ETRI

DS/US-MAP IE for Individual RA (Legacy) September 2013 DS/US-MAP IE for Individual RA (Legacy) SID: 9bits DIUC or UIUC: 6bits Length or Duration: 12 bits Sunghyun Hwang, ETRI

DS/US-MAP IE for GRA September 2013 Parameter Size (bits) Description Resource Allocation Bitmap Variable (1 bits * number of devices in the group) Indicates whether the resources are allocated to the device in a group. The number of devices in the group is determined by the Device Bitmap Size in GRA Configuration Message. 0: not allocated in the frame 1: allocated in the frame Resource Starting Index 11 Indicates the starting index of resource in the unit of OFDMA slot. In the DS subframe, the index starts right after the frame preamble from 0. In the US subframe, the index 0 starts from the ranging/BW request/UCS notification contention windows (not including SCW) if it exists. Resource Size Bitmap (3 bits * number of devices in the group) Indicates the resource allocation size for the device in the unit of OFDMA slot. 000: 1 001: 2 010: 4 011: 8 100: 16 101: 32 110: 64 111: 128 Sunghyun Hwang, ETRI

(6 bits * number of devices in the group) September 2013 DS/US-MAP IE for GRA Parameter Size (bits) Description Group DIUC Flag 1 Indicates whether the DIUC is fixed within group. 0: not fixed within group 1: fixed within group If(Group DIUC Flag = 0) { Group DIUC Bitmap Variable (6 bits * number of devices in the group) } Else{ DIUC 6 Sunghyun Hwang, ETRI

MAP Overhead as Percentage of Frame September 2013 MAP Overhead as Percentage of Frame Individual RA (Legacy) vs. Group RA (Proposed) Considered Network Model Smart Metering Model 1 BS, 25 H-CPEs, 2500 L-CPEs (100 L-CPEs per H-CPE) Max. simultaneous communication L-CPEs: 2500 (H-CPEs: 25) Real-time/near real-time video Monitoring Model 1 BS, 250 H-CPEs, 2500 L-CPEs (10 L-CPEs per H-CPE) Max. simultaneous communication H-CPEs: 100 Total bits per frame: 24*1440=34,560 Assuming 6 MHz BW, ¼ CP, and QPSK-1/2 Sunghyun Hwang, ETRI

MAP Overhead as Percentage of Frame September 2013 MAP Overhead as Percentage of Frame Sunghyun Hwang, ETRI

Management Message for GRA Configuration: GRA-CFG September 2013 Management Message for GRA Configuration: GRA-CFG New Message Type 41 in IEEE 802.22 - Table 19 Management Message This message is carried in the payload of a MAC PDU This message is used for GRA configuration Create new group Indicate the devices that is included to a group Define the characteristics of group Sunghyun Hwang, ETRI

Management Message for GRA Configuration: GRA-CFG September 2013 Management Message for GRA Configuration: GRA-CFG Parameter Size (bits) Description Device Bitmap Size 4 Maximum number of devices that are included to a new group. 0000: 1 0001: 2 0010: 4 0011: 8 0100: 16 0101: 32 0110: 64 0111: 128 SID Bitmap Variable (9 bits * number of devices) The bitmap of station ID that is included to a new group. GID 12 Group ID to which the device is included to a group. Group Type 1 0: Fixed Group 1: Mobile Group Group Location 48 Latitude and longitude of a new group Sunghyun Hwang, ETRI

Management Message for GRA Update: GRA-UPD September 2013 Management Message for GRA Update: GRA-UPD New Message Type 42 in IEEE 802.22 - Table 19 Management Message This message is carried in the payload of a MAC PDU This message is used to update the GRA configuration The device can be added to or deleted from a group Sunghyun Hwang, ETRI

Management Message for GRA Update: GRA-UPD September 2013 Management Message for GRA Update: GRA-UPD Parameter Size (bits) Description Deletion Flag 1 Flag to indicate whether the device is added to or deleted from a group. 0: Added to a group 1: Deleted from a group SID 9 Station ID that is added to or deleted from a group. GID 12 Group ID to which the device is added to or deleted from a group. If(Deletion Flag = 0) { Device Bitmap Index 7 Indicates the index of the device in a group’s device bitmap. } Sunghyun Hwang, ETRI

How to Manage the Backup Channel of Group? September 2013 doc.: IEEE 802.22-12-0088-02-000b September 2013 How to Manage the Backup Channel of Group? All devices within group share the same backup channel information. Control all devices with one message simultaneously Type of group is determined according to the mobility of Hub-device. Using the location information from the Hub-device, the BS can identify whether the group could overlap with other group. Sunghyun Hwang, ETRI Sunghyun Hwang, ETRI

How to Manage the Backup Channel? September 2013 How to Manage the Backup Channel? Fixed vs. Fixed In principle, allocate same backup channel to each group (e.g., farmhouse vs. wind turbine) But, if they could overlap, the allocated backup channel shall be different to avoid interference among groups (e.g., farmhouse vs. village). Fixed vs. Mobile or Mobile vs. Mobile In principle, allocate different backup channel to each group (e.g., wind turbines vs. vehicles) But, if they could not overlap, the allocated backup channel could be same for frequency reuse (village vs. vehicles) Periodic monitoring to check whether groups could overlap each other The backup channel of each group shall be updated according to the monitoring result Sunghyun Hwang, ETRI

Example of Backup Channel Management September 2013 Example of Backup Channel Management Sunghyun Hwang, ETRI

Backup Channel Decision Process (@BS) September 2013 Backup Channel Decision Process (@BS) Start Are there any idle backup channels which are not being allocated to other groups? Are there any backup channels which are being allocated to mobile groups? No Yes ⑤ Allocate some of backup channels which are being allocated to BS ① Allocate the idle backup channels to target group No Yes Are there any backup channels which are being allocated to fixed groups? Do they overlap each other? No No Yes Yes ③ Allocate some of backup channels which are being allocated to mobile groups Do they overlap each other? ④ Allocate some of backup channels which are being allocated to fixed and/or mobile groups No ② Allocate some of backup channels which are being allocated to fixed groups Yes End Slide 19 Sunghyun Hwang, ETRI Sunghyun Hwang, ETRI

Management Message for Backup Channel September 2013 Management Message for Backup Channel Modified Backup and Candidate Channel List (Table 22 of 802.22-2011 Standard) Syntax Size Notes Backup_and_candidate_channel_list_IE_Format() { Element ID = 10 8 bits Length Number of Channels in the list For (i=0; i < Number of Channels in the list; i++) { List of backup channels in order of priority to be used by CPEs in case of loss of communication with the BS due to incumbents. This list may also include candidate channels, in which case they will follow the backup channels in the list, and will also be included in order of priority. The number of backup channels in the list is indicated in DCD Element ID 9 (see Table 21). The list shall be a disjoint set with the current operating channel. Channel Number [i] GID [i] 12 bits } Sunghyun Hwang, ETRI

September 2013 Conclusions Reduction of the MAP overhead using group resource allocation: MAP overhead assuming 1000 devices Individual RA(802.22-2011): 78% of frame GRA (Resource size=12bits, Individual DIUC/UIUC): 55% of frame GRA (Resource size=3bits, Group DIUC/UIUC): 11% of frame As new group or new incumbent user appears, or mobile group moves into other group, we can avoid frequent channel switching Reduce the signaling overhead Prevent QoS degradation due to frequent channel switching Sunghyun Hwang, ETRI