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IEEE C802.16m-08/016r2. Long HO Interruption Time in Conventional HHO. Difficulty for meeting HO interruption time below 30 msec. Attempt of Optimized HHO (1/4). Attempt of Optimized HHO (2/4). Attempt of Optimized HHO (3/4). MS initiated HO process block diagram
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Long HO Interruption Time in Conventional HHO • Difficulty for meeting HO interruption time below 30 msec
Attempt of Optimized HHO (3/4) MS initiated HO process block diagram as seen by MS (in 802.16e)
Attempt of Optimized HHO (4/4) BS initiated HO process block diagram as seen by MS (in 802.16e)
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.
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
Problem with Optimized HHO (3/4) • Optimized HHO may incur even longer interruption time than conventional HHO does
Proposed Expedited HHO (2/5) Table 2- OFDMA Fast_First_Ranging_IE() format
Proposed Expedited HHO (3/5) MS initiated HO process block diagram as seen by MS (in 802.16m)
Proposed Expedited HHO (4/5) BS initiated HO process block diagram as seen by MS (in 802.16m)
Proposed Expedited HHO (5/5) Table 3 (modified Table 290a) Extended UIUC Code Assignment for UIUC = 15
Conclusions • Enhanced Handoff procedures and Messaging should be taken into 802.16m systems as a new discussion feature, because • Conventional HHO cannot meet 802.16m 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 802.16m requirements