臺灣博碩士論文加值系統

本論文針對GSM網路維運時，因基地台斷訊所造成的信號涵蓋缺口，以機動調整斷訊基地台於BSC內所設定之鄰近細胞的發射功率，若鄰近細胞其發射出的信號強度至斷訊基地臺處已大於-75dBm，則該鄰近細胞之功率不作調整(因為當戶外之收訊強度已為-75dBm時，大部份室內都可通訊。)。調整發射功率時，須一併考量同頻干擾C/I(Carrier to Interference)值之狀況(如：當有設定跳頻(Frequency Hopping)時，C/I值須大於9dB，無設定跳頻時，則C/I值須大於12dB。)，再將鄰近細胞之發射功率調至到達斷訊基地台時，信號強度為-75dBm，且被調整之鄰近細胞其有效等向輻射功率(EIRP)不得超過電信總局所規定之500W或57dBm。

調整鄰近細胞的發射功率，以補強斷訊基地台之信號涵蓋的方法，其效能取決於可調整之功率範圍的大小；例如：每一細胞皆以最大可允許的EIRP值發射功率時，此方法則無從發揮起。反以，則效果顯著。另外，如能再對’新鄰近細胞’，重新予於定義至BSC中，更可有效降低因斷訊基地台所帶來的斷話率(Call Dropped Rate)。

This study is aimed at the situation of covering up the area at an out-of-service RBS in the GSM network. We purpose to adjust the radio output power of the out-of-service RBS’s neighboring cells defined in the BSC. When the signal strength received from one of the neighboring cells to the out-of-service RBS is more than —75dBm, the output power of that neighboring cell does not need to be adjusted. (If the RF input of outdoors has been reached to —75dBm, the communication of indoors can be connected.) When adjust the output power, the status of the C/I value has to be well considered. (For example: when the Frequency Hopping has been set, the C/I value has to be more than 9dB. If there’s no Frequency Hopping has been set, the C/I value has to be more than 12dB.) Furthermore, adjusting the output power of neighboring cell and let the signal strength reaches to —75dBm when it arrives at the out-of-service RBS site, but the EIRP should never be more than 500W or 57dBm by the regulation of the Directorate General of Telecommunications.

The efficiency of the method which is adjusting output power among neighboring cells can depends on the range of output power, which can be adjusted. For example, when the output power of each neighboring cell reached the maximum of EIRP, this manner is invalid. When it is opposite, it will have remarkable effect. In addition, if the new neighborhood relation can be redefined in BSC, it could reduce the call dropped rate caused by an out-of-service RBS.

目 錄
　　　　　　　　　　　　　　　　　　　　　　
中文提要　 --------------------------------------------------------- i
英文提要 --------------------------------------------------------- ii
誌謝 --------------------------------------------------------- iii
目錄 --------------------------------------------------------- iv
表目錄 --------------------------------------------------------- v
圖目錄 --------------------------------------------------------- vi
符號說明 --------------------------------------------------------- vii
一、緒論 --------------------------------------------------------- 1
二、主要應用原理與說明 ------------------------------------ 2
2.1傳播模式Propagation Model ------------------------ 4
2.1.1Okumura Hata Model ------------------- 4
三、量測環境與應用之エ具 ------------------------------------ 6
3.1GSM 1800MHZ網路 ----------------------------------- 6
3.2網路品質的測試手機TEMS ----------------------- 8
3.3行動通訊的模擬系統TCP -------------------------- 11
四、程序與方法 -------------------------------------------------- 13
4.1演算法 - 鄰近細胞功率調整法 ---------------------- 13
4.2演算法之程式模擬 -------------------------------------- 15
4.3TCP模擬系統之參數校正程序 ---------------------- 19
4.4基地台信號涵蓋模擬------------------------------------- 29
五、效能分析 ----------------------------------------------------- 31
　六、結論 ----------------------------------------------------------- 32
參考文獻 ----------------------------------------------------------- 33
附錄一 GSM1800頻道號碼(ARFCN)與頻率對照表----- 34
　附錄二 鄰近細胞功率調整法之原始計算程式 ----------- 36
附錄三 指向性天線之規格與特性 ----------------------- 68
附錄四 TCP傳播估算模組之校正報告 -------------------- 70
附錄五 TCP估算室內涵蓋率之統計表 -------------------- 75
附錄六 TCP估算戶外涵蓋率之統計表 -------------------- 96
附錄七 TCP The Worst Interference估算統計表---------- 112

參　考　文　獻1. David J. Goodman, 1997, Wireless Personal Communications Systems, AddisonWesley Longman, California.2. 林仁政，翁芳標，1997，無線通訊系統，初版，全華著者發行。3. Y. Okumura, E. Ohmori, T. Kawano and K. Fukuda. “Field strength and itsvariability in the VHF and UHF land mobile radio service,” Review Elec. Commun., Lab., vol. 16, no. 9-10, pp. 825-873, 1968.4. M. Hata, “An empirical formula for propagation loss in mobile radio service,” IEEETrans. On Vehicular Tech., vol. VT-29, no. 3, pp. 317-325, 1980. 5. Espen Christensen and Stein Erik Paulsen. GSM Project Group, Telenor Mobil AS. “Improved Coverage and Interference Predictions Using Line-of-Sight Detection and Correction”, IEEE, pp. 1638-1642, 1996.6. Arturas Medeisis, Algimantas Kajackas. Telecommunications Department, Kaunas University of Technology. “On the Use of the Universal Okumura-Hata Propagation Prediction Model in Rural Areas”, IEEE, VTC2000, pp. 1815-1818, 2000.7. M. Al-Akaidi, D. AlNsour, *H. Hammuda, P. Urwin. De Monfort University,Leicester, UK. “CAPACITY EVALUATION IN CELLULAR SYSTEM”, IEEE, 3G Mobile Communication Technologies, 26-28 March 2001, Conference Publication No. 477, pp. 175-179, 2001.