CDMA 3G1X切换流程.doc

3G1X Inter freq. hand down Settings 1. 结构:1X(201)1X/95 mix (283)95(283)2. 目标:a. 建立3G call 从201至283的切换。3. 步骤：a. 定义边界扇区b. 定义边界下切的邻区关系c. 确定切换的触发原则。d. 采用Multi-pilot inter frequency handoffe. 相应参数调整与优化以下就各个项目详细说明：A 定义边界扇区：具体的说就是定义进行下切的扇区，也就是201频点最外层的一圈扇区。注意以扇区为单位而非基站。B 定义边界扇区的邻区关系：最多可定义6个，注意次序，根据HOMAX的结果设置。因为排列次序越靠前，具有越高的优先级。通常情况下,应当将本扇区的283频点也列为可被切换的小区,以获取更好的切换效果。但在上海,因上下两载频分别为1X 和95,因此未将本扇区的非切换载频,加入邻区关系。填写cdhfl：1, 采用insert 的方式填写。2， Service cell site number +Serving Antenna Face Number = 定义的边界扇区。3， 检查CGSA form，确认201被定义为第二载频，因此在cdhfl Form中填写第二行。如果进行下切的载频在CGSA 表中被定义为第三载频，则需填写第三行，以此类推。4， 填写 Target channel number 和 Target Band class。上图中填写的意义即为：66号机站 alpha 扇区的第二载频（201）的下切目标载频为283。填写cdhnl：1， insert 方式填写。先填chdfl，再填chdnl。2， 注意邻区的关系的先后次序。参考HOMAX结果。3， Inter-ECP或Inter-DCS时需填写Extend_system_idC 确定切换触发原则：CDMA Direct Handoff 有两种触发机制：机制一： CDMA-to-CDMA Handdown threshold，（ceqface page10，item147，recommend value =-4）当符合下列条件时切换被触发： . All Active set Pilots are border sectors . IFHOTI is disabled on at least one of these border sectors . Call on Fn is in simplex or two-way soft/softer handoff state . Strength of each Active set Pilot is below TrCho thresholdServing carrier index for which target band-class/channelnumber is entered in the cdhfl form represents border carrierOnly the calls on the border carrier solicited for PSMMperiodically. The polling starts when a border cell becomesthe primary.Origination/termination attempts always on the underlyingcarrier. Assignments may be to any carrier decided byTCA.机制二： CDMA inter frequency handoff trigger improvement （CIFHOTI）当符合下列条件时切换被触发： If both border and non-border sectors present in theActive set, the receive Ec/Io of the strongest border Pilot must exceed that of the strongest non-border Pilot by at least the Border_Vs_Interior Pilot comparison threshold (BPIP). If all Active set Pilots are border sectors, this metric is not computed. The Ec/Io loss metric exceeds the Border Sector Loss threshold. The loss metric is defined as the difference in cell site Transmit pilot Ec/Io for the strongest receive Active set border Pilot and the aggregate strength of all Active set pilots (border or non-border) reported on the PSMM . Number of CE used by call on Fn is 3 or less The serving primary obtains target band-class/frequency channel information from the cdhfl form of a border cell based on the serving carrier (Fn) . Using the band-class/frequency channel, the serving primary obtains neighbor list entries from the border cell cdhnl form to build a list of target pilots If multiple border pilots present in the Active set, a combined target pilot list is constructed and rank-ordered using the neighbor list selection algorithm . The 7 minus CE_on_Fn 1 strongest pilots in the target list are selected for transition to Fi if CMPIFHO enabled on all Fn Active set border sectors as well as on （该FEATURE在ECQFACE）其中最重要的的参数就是：1， Border Sector Loss threshold for inter frequency handoff：（ceqface，page 10， item 152，default=3.5）(系统当前值为2)Border Sector Loss根据手机接收Ec/Io和机站的负荷计算而得,一旦大于上述阈值,则触发切换。2， Border_Vs_Interior Pilot comparison threshold (BPIP)(ceqface, page 10, item 154, default =3)（系统当前值为2）优化过程中，通过上述两个参数的调整，并配合机站功率的调整，第二载频的覆盖范围和切换发生的位置。上述两种机制的差别在于：在第一种机制下仅手机接收的Ec/Io，当基站的符合发生变化时，切换点发生较大的变化。而第二种机制因考虑了基站负荷的因素，切换点较少受到基站负荷的影响。触发机制的选择： （cell2 form，page 11，Item 203/4）对于设置的边界扇区（基站）当CDMA IFHO TI 设为“Y”时，采用机制二。参数：Border Sector Loss threshold for inter frequency handoff和Border_Vs_Interior Pilot comparison threshold (BPIP)起作用。如设为“n”，则意味着采用“机制一”。参数“CDMA-to-CDMA Handdown threshold” 发生作用。D 激活CDMA multi-pilot inter frequency handoff：cell2 form page 11， 设为yes。注意：打开feature之前，须得到TD的认可。仅在设置的边界扇区打开feature。E 相应参数调整与优化1， 一旦某个扇区的某个载频被设置为边界小区， 在channel_list_message,中将不再出现这个载频,意味着,手机在空闲模式下将停留在该扇区的非切换载频上(283)。为使3G手机在边界站上仍在201频点(1X频点)上起呼,需作下列设置:对于边界扇区，在Ceqface form 中，将Carrier Assignment Algorithm:设为 ”rf”，对于其它的非边界扇区，在ECP form 中，将Carrier Assignment Algorithm一项设为“OC