1. Expedited Hard Handover
IEEE Presentation Submission Template (Rev. 9)
Document Number: IEEE S802.16m-08/016
Date Submitted: January 16, 2008
Source:
Baowei Ji, Changhoi Koo
Samsung Telecommunications America
Venue: Levi, Finland
Base Contribution: TGm Call for comments on SDD, IEEE m-07/040
Purpose:
Discuss the problem with Optimized Handover, and propose Expedited HHO to meet the requirement in m
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2. Long HO Interruption Time in Conventional HHO
Difficulty for meeting HO interruption time below 30 msec

3. Attempt of Optimized HHO (1/4)

4. Attempt of Optimized HHO (2/4)

5. Attempt of Optimized HHO (3/4)
MS initiated HO process block diagram
as seen by MS (in e)

6. Attempt of Optimized HHO (4/4)
BS initiated HO process block diagram
as seen by MS (in e)

7. Problem with Optimized HHO (1/4)
Without parameter adjustment, especially timing adjustment, RNG-REQ might arrive outside of the guard interval, fails to be detected by the target BS.

8. Problem with Optimized HHO (2/4)
Initial ranging shall use an initial ranging code in an initial ranging slot
TDD: power and frequency could be adjusted autonomously after downlink synchronization
Timing may not be adjusted without handshaking

9. Problem with Optimized HHO (3/4)
Optimized HHO may incur even longer interruption time than conventional HHO does

10. Problem with Optimized HHO (4/4)

11. Proposed Expedited HHO (1/5)

12. Proposed Expedited HHO (2/5)
Table 2- OFDMA Fast_First_Ranging_IE() format
Syntax
Size
Notes
Fast_First_Ranging_IE{
Extended UIUC
4 bits
Fast_First_Ranging_IE() = 0x0B
HO ID
8 bits
Assigned by the targeting BS
OFDMA symbol offset
Subchannel offset
7 bits
No. OFDMA symbols
No. subchannels
Ranging method
1 bit
0- Ranging over 2 symbols
1- Ranging over 4 symbols
reserved
6 bits
Shall be set to zero }

13. Proposed Expedited HHO (3/5)
MS initiated HO process block diagram
as seen by MS (in m)

14. Proposed Expedited HHO (4/5)
BS initiated HO process block diagram
as seen by MS (in m)

15. Proposed Expedited HHO (5/5)
Table 3 (modified Table 290a) Extended UIUC Code Assignment for UIUC = 15
Extended UIUC
(hexadecimal)
Usage 00
Power_control_IE 01
reserved 02
AAS_UL_IE 03
CQICH_Alloc_IE 04
UL_Zone_IE 05
PHYMOD_UL_IE 06
Reserved 07
UL-MAP_Fast_Tracking_IE 08
UL_PUSC_Burst_Allocation_in_Other_Segment_IE 09
Fast_Ranging_IE 0A
UL_Allcoation_Start_IE 0B
Fast_First_Ranging_IE
0C … 0F

16. Conclusions
Enhanced Handoff procedures and Messaging should be taken into m systems as a new discussion feature, because
Conventional HHO cannot meet m requirement
Optimized HHO may not function
We propose to add a new section and/or description for the enhanced handoff operation in SDD
The proposed Expedited HHO in this proposal could be one of solutions for meeting m requirements