電信認(rèn)證cdma原理基礎(chǔ)知識(shí)(1)-wenkub
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【正文】 y 1998) 11 5a: Review Questions 1. What is the purpose of power control? To maximize system capacity by minimizing noise/interference, and to increase battery life in the mobile stations. 2. What is the ideal situation at the base station regarding power level of the received 移動(dòng)臺(tái) station signals? To receive exactly the same (minimum) power level from every mobile station. 3. What happens during Reverse Open Loop Power Control? The mobile station makes an initial estimation of the power at which it should transmit the initial access probe based on the mean received power, the builtin turnaround constant, and some parameters received from the base station in the Access Parameters Message。 then it refines this estimate through successive probes at increased power until it receives acknowledgment from the base station (or gives up). Course 809 Lesson 5: Power Control, Registration, Handoffs Issue (January 1998) 12 5a: Review Questions (cont) 4. What happens during Reverse Closed Loop Power Control? The mobile station corrects its output power level based on power up/powerdown mands received from the base station on the power control subchannel. 5. What happens during Reverse Outer Loop Power Control? The BSC monitors, and adjusts if necessary, the Setpoint used by the BTS to generate the powerup/powerdown mands for the mobile stations. It does that based on the Frame Error Rate for that mobile station measured at the base station. Course 809 Lesson 5: Power Control, Registration, Handoffs Issue (January 1998) 13 CDMA概述 第五課：功率控制、登記和切換 5b: 登記 Course 809 Lesson 5: Power Control, Registration, Handoffs Issue (January 1998) 14 5b: 登記 課程目標(biāo) ? 復(fù)習(xí)漫游的概念并明確移動(dòng)臺(tái)可能的三種漫游狀態(tài) . ? 復(fù)習(xí) HLR和 VLR的區(qū)別 ? 說明 登記概念 . ? 論述登記和尋呼之間的平衡 . ? 明確并論述不同形式的 CDMA登記 . Course 809 Lesson 5: Power Control, Registration, Handoffs Issue (January 1998) 15 漫游 ? 移動(dòng)臺(tái)可能為以下漫游狀態(tài)： ? 歸屬 ：移動(dòng)臺(tái)在其歸屬地 (非漫游 ) ? NID漫游 ：移動(dòng)臺(tái)在一外部 NID范圍內(nèi)，但在其歸屬 SID的范圍內(nèi) ? SID漫游 ：移動(dòng)臺(tái)在外部 SID范圍內(nèi) ?移動(dòng)臺(tái)內(nèi)有一個(gè)歸屬對(duì)列表 ? 該列表內(nèi)是 SID/NID對(duì)，定義移動(dòng)臺(tái)的歸屬位置 ? 這些數(shù)據(jù)存儲(chǔ)在半永久性存儲(chǔ)器中 ?當(dāng)前的 SID/NID包含在 系統(tǒng)參數(shù)消息 (在尋呼信道中發(fā)送 )中 Home SID/NID List (2, 3) (2, 0) (3, 1) SID = 2 SID = 4 SID漫游 NID = 7 NID =3 NID = 0 NID漫游 非漫游 漫游狀態(tài) Course 809 Lesson 5: Power Control, Registration, Handoffs Issue (January 1998) 16 CDMA登記 ? 登記就是移動(dòng)臺(tái)通知蜂窩系統(tǒng)它的位置、狀態(tài)、標(biāo)識(shí)及其它特征的方式 ?尋呼和登記之間要保持平衡 ? 登記間隔太久會(huì)造成尋呼率過高 ? 頻繁登記會(huì)使接入信道的負(fù)荷過重 ?合理的系統(tǒng)設(shè)計(jì)可以使基站在建立移動(dòng)臺(tái)終接呼叫時(shí)有效地尋呼移動(dòng)臺(tái) ?登記還提供： ? 移動(dòng)臺(tái)的時(shí)隙周期索引和劃分時(shí)隙模式 ? 移動(dòng)臺(tái)類別碼（ SCM）和協(xié)議版本號(hào)以便基站可以知道移動(dòng)臺(tái)的性能 ?移動(dòng)臺(tái)登記的兩種類型 ? 非自主登記：基站明確要求登記或根據(jù)移動(dòng)臺(tái)接收到的其它類型的消息隱含請(qǐng)求登記 ? 自主登記：由一些事件觸發(fā)，而不是因?yàn)榻邮盏絹碜曰镜拿鞔_或隱含請(qǐng)求 Course 809 Lesson 5: Power Control, Registration, Handoffs Issue (January 1998) 17 CMDA登記形式 ? 開機(jī)登記 ?關(guān)機(jī)登記 ?基于定時(shí)器的登記 ?基于距離的登記 ?基于區(qū)域的登記 ? 參數(shù)變更登記 ?隱含登記 ?受命登記 ?業(yè)務(wù)信道登
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