【正文】 關(guān)后，基站轉(zhuǎn)發(fā)器需要經(jīng)過較短的脫網(wǎng)時(shí)間(~1s) ，才釋放所占用的信道，若在脫網(wǎng)時(shí)間內(nèi)，通話一方繼續(xù)按下PTT開關(guān)， 則仍保持原信道通 話。用戶按下PTT開關(guān)，系統(tǒng)就為其分配一條空閑話音信道；用戶釋放PTT開關(guān)，系統(tǒng)立即釋放所占用的信道，該信道又可被再分配。用戶釋放PTT(發(fā) 射開關(guān)) 后，基站 轉(zhuǎn)發(fā)器需要經(jīng)過較長的脫網(wǎng)時(shí)間(6~10s)，才釋放所占用的信道。2 術(shù)語(trunking munication system)指由多個(gè)用戶共用一組無線信道，并動態(tài)地使用這些信道的通信系統(tǒng)，主要用于調(diào)度通信。、規(guī)范相矛盾時(shí)，應(yīng)以國家標(biāo)準(zhǔn)、規(guī)范為準(zhǔn)。，未經(jīng)鑒定合格的設(shè)備不得在工程中使用。，充分考慮使用、維護(hù)及施工的要求，確保通信質(zhì)量，做到技術(shù)先進(jìn)，經(jīng)濟(jì)合理、安全可靠。，結(jié)合我國集群通信發(fā)展實(shí)際情況，勤儉建國，合理利用頻率資源，重 視環(huán) 境保護(hù)。中華人民共和國郵電部一九九七年二月十四日目 次1總則 ............................................................................................................12術(shù)語 ............................................................................................................23設(shè)計(jì)要求及服務(wù)質(zhì)量指標(biāo) ........................................................................4 ...............................................................................................................4 .......................................................................................................4 ...............................................................................................................5 ...............................................................................................................64網(wǎng)路設(shè)計(jì) ....................................................................................................8 ...............................................................................................................8 .............................................................................................10 .............................................................................................................115無線覆蓋區(qū)設(shè)計(jì) ......................................................................................146頻率配置及復(fù)用 ......................................................................................16 .............................................................................................................16 .............................................................................................................167集群通信網(wǎng)接入有線電話網(wǎng)的方式 ......................................................188中繼線路、信令方式及摟口要求 ..........................................................20 .............................................................................................................20 .............................................................................................................20 .............................................................................................................219編號與計(jì)費(fèi) ..............................................................................................22 .............................................................................................................22 .....................................................................................................................2210設(shè)備選型 ................................................................................................2411站址選擇 ................................................................................................25 ...........................................................................................................25 ...................................................................................................................2512局站設(shè)計(jì)要求 ........................................................................................27 ...........................................................................................................2饋線及天線塔 .......................................................................................29 ...........................................................................................................30 ...........................................................................................................32附錄A800MHZ頻段的頻道分組 ..............................................................33附錄B本規(guī)定用詞說明 .............................................................................35附加說明 ....................................................................................................361總則 ..........................................................................................................383設(shè)計(jì)要求及服務(wù)質(zhì)量指標(biāo) ......................................................................394網(wǎng)路設(shè)計(jì) ..................................................................................................405 無線覆蓋區(qū)設(shè)計(jì) ...................................................................................416頻率配置及復(fù)用 ......................................................................................427集群通信網(wǎng)接入有線電話網(wǎng)的方式 ......................................................438中繼線路、信令方式及接入要求 ..........................................................449編號與計(jì)費(fèi) ..............................................................................................4510設(shè)備選型 ................................................................................................4611站址選擇 .................................................