中圖分類號(hào)： TN929.5 文獻(xiàn)標(biāo)識(shí)碼： A DOI：10.16157/j.issn.0258-7998.200711 中文引用格式： 林平平,，張光輝，李皛. 5G SA網(wǎng)絡(luò)的移動(dòng)性管理研究[J].電子技術(shù)應(yīng)用,，2020,，46(9)：7-13. 英文引用格式： Lin Pingping，Zhang Guanghui,，Li Xiao. Research on the mobility management in 5G SA network[J]. Application of Electronic Technique,，2020,，46(9)：7-13.
Research on the mobility management in 5G SA network
Lin Pingping1，Zhang Guanghui2,，Li Xiao1
1.China Telecom Research Institute,，Beijing 102209，China,；2.China Telecom Group Co.,，Ltd.，Beijing 100033,，China
Abstract： SA is the final network architecture of 5G network evolution and development, which adopts a brand new network deployment. But it will coexist with current LTE networks for quite a long time. In order to ensure that UEs enjoy uninterrupted service in the mobile process, the network needs to provide efficient mobility management. Mobility management can be divided into cell reselection, handover, and redirection based on UE state. And it can be divided into intra-system mobility management and inter-system mobility management according to whether the service cells cross the system. To achieve the 0 ms interruption delay of handover, R16 had proposed several mobility management enhancement solutions. The paper mainly introduced the mobility management between NR cells, the interoperability between 4G/5G cells and the mobility management enhancement solutions in R16, which provided a reference for the mobility management optimization of 5G SA network.
Key words : SA,；mobility management；handover,；reselection,；mobility enhancement
0 引言
2019年工信部頒發(fā)5G商用牌照，開啟了國(guó)內(nèi)的5G商用元年,。為了滿足不同業(yè)務(wù)的需求,，5G接入網(wǎng)架構(gòu)需要支持不同的部署方式，初期網(wǎng)絡(luò)部署是基于NSA(Non-Stand Alone)方式,，到2020年演進(jìn)到基于SA(Stand Alone)方式的網(wǎng)絡(luò)架構(gòu),。非獨(dú)立部署(NSA)是利用現(xiàn)有4G網(wǎng)絡(luò)，快速使無(wú)線接入網(wǎng)具備5G網(wǎng)絡(luò)的全部或部分能力,，獨(dú)立部署(SA)則是從核心網(wǎng)到接入網(wǎng)均需新建,，構(gòu)成一套完全獨(dú)立的5G網(wǎng)絡(luò)[1]。5G系統(tǒng)既包括了NR(New Radio),，也包括了演進(jìn)版本的LTE(Long Term Evolution0[2-3],。5G網(wǎng)絡(luò)復(fù)雜多樣，終端要實(shí)現(xiàn)多網(wǎng)絡(luò)的無(wú)縫移動(dòng),，就需要高效的移動(dòng)性處理,。
移動(dòng)性管理是移動(dòng)網(wǎng)絡(luò)的一項(xiàng)基本功能，用于保證用戶在移動(dòng)的情況下享受無(wú)中斷的服務(wù),。高效的移動(dòng)性處理是任何一個(gè)移動(dòng)通信系統(tǒng)的關(guān)鍵部分[4],。由于NR建網(wǎng)初期難以形成連續(xù)覆蓋，NR就會(huì)發(fā)生與異系統(tǒng)尤其LTE系統(tǒng)頻繁的互操作,，以保障用戶業(yè)務(wù)體驗(yàn)的連續(xù)性,。因此，SA網(wǎng)絡(luò)的移動(dòng)性管理既包括NR小區(qū)之間的移動(dòng)性處理,，也包括NR與異系統(tǒng)之間的互操作,。此外，NR切換0 ms中斷時(shí)延也是IMT2020的性能需求之一,。諸如URLLC(Ultra-reliable and Low Latency Communications)這類業(yè)務(wù),，就需要實(shí)現(xiàn)0 ms的中斷時(shí)間。因此,，減少切換中斷時(shí)延是R16移動(dòng)管理性能增強(qiáng)的一個(gè)方向,。
