08/20/01 1 IS-2000 Sync Channel Issue The IS95 Sync Channel Message length is increased in IS2000 Release 0 (11 bits) and Release A (14 to 81 bits) Legacy IS95 mobiles from more than one manufacturer (Including Motorola and Nokia) experience problems when Sync Channel Message length is extended beyond 27 octets (IS95 length) –Problems differ depending on manufacturer & message length There are two issues associated with Motorola IS95 CDMA mobiles (to be summarized in following slides) –All currently shipping product has the issues corrected

08/20/01 2 Motorola “28 octet” Issue Experienced when Sync Channel Message exceeds 27 octets (i.e. IS2000 Release 0 and beyond) –Can result in mobile failing to acquire Paging Channel of preferred system (acquires service on “less preferred” system): 4% of time –Can result in delay in acquiring Paging Channel of preferred system: 30% of time Expected behavior of affected Motorola mobiles –66%No impact (PCH/BCCH acquired immediately after Sync Channel) –22%About 4sec delay to acquire PCH/BCCH after acquiring Sync –8%About 7sec delay to acquire PCH/BCCH after acquiring Sync –4%PCH/BCCH of most preferred channel not acquired, acquires next channel in PRL

08/20/01 3 Motorola “32 octet” Issue Experienced when Sync Channel Message exceeds 31 octets (i.e. IS2000 Release A) –Sync Channel Message exceeds 31 octets ONLY in networks that support Transmit Diversity (TD) and/or 3X channels. –When 31 octets is exceeded, the problem Motorola mobile will reject the Sync Channel Message as too long Expected behavior of affected Motorola mobiles –100%Release A CDMA channel never acquired, less preferred IS95 CDMA channel or AMPS channel acquired instead (based on channels in the PRL)

08/20/01 4 Standards-based Solution Problem affects a “significant” number of legacy mobiles –Recall would impact smooth evolution to IS2000 –Standards fix desirable, if there are not “significant’ performance trade-offs Standards-based solution developed jointly between Motorola and Qualcomm, and supported by Nokia, includes 3 “scenarios” 1.No problem mobiles 2.“32-octet” problem mobiles AND TD/3X deployed 3.“28-octet” problem mobiles

08/20/01 5 Impacts Proposed standards changes –Add new BCCH Channel List Message to both BCCH and PCH –Allow MS to go directly to Idle State from Traffic Channel, after successful release of traffic channel (and SID, Band Class have not changed) –Other minor changes and bug fixes In the short-term (where “workarounds” are needed) –Extra “hop” needed to go from Sync to appropriate CDMA Channel –Average worst case delay is 640ms to reach PCH/F-CCCH for pages –0.7% to 2% increase in PCH/BCCH loading In the long-term (or where “workarounds” NOT needed) –Standard is improved (Sync acquisition success rate improved, time away from PCH/F-CCCH reduced) –BCCH Channel List Message obsoleted on PCH