裝置間/車間群集移動管理機制

Group-based Device-to-Device/Vehicle-to-Vehicle Mobility Management Scheme

10.6342/NTU201702541

靳亨立

裝置間通訊 ； 車間通訊 ； 群集 ； 移動管理 ； 換手 ； 服務延續性 ； D2D ； V2V ； Clustering ； Mobility Management ； Handover ； Service Continuity

臺灣大學電信工程學研究所學位論文

2017年

碩士

魏宏宇

英文

Device-to-Device (D2D) 和Vehicle-to-Vehicle (V2V) 通訊技術旨在使一定距離範圍之內用戶通信設備直接通訊。其應用情境之一的D2D/V2V 群集概念包含了D2D/V2V 群集的產生以及簇頭的選擇。其中，簇頭的主要功能為蒐集群集結點的數據，並且傳送至基地台端，使得群集結點不須和基地台端有直接連線。現有研究指出D2D/V2V 群集概念能有效增加頻譜效率、能源效率、公平性等。縱使D2D/V2V 群集概念已非新議題，移動性對於D2D/V2V 群集所造成的影響卻鮮少被討論。當D2D/V2V 群集移動至基地台邊緣，希望能藉由無縫換手技術來保持D2D/V2V 群集結點間溝通的延續性，同時，每當有群集結點要離開群集時，能透過適當的流程將此節點從D2D/V2V 溝通模式轉換成cellular 溝通模式。 在本篇論文中，我們提出了一個D2D/V2V 群集移動管理機制。此機制能的功能包括: 無縫換手技術使得換手過程中群集結點間D2D/V2V 連線的延續，和適當的流程使得群集結點在離開群集時能快速從D2D/V2V 溝通模式轉換成cellular 溝通模式。同時，我們也提出了簇頭重選機制，在現有簇頭與基地台連線狀況不佳時，能從D2D/V2V 群集節點中選出適當的新簇頭，藉此維持群集與基地台間的連線品質。模擬結果證明D2D/V2V 群集的移動管理機制能有效降低換手失敗率，提升D2D/V2V 連線的延續性，同時也降低換手和D2D/V2V 轉cellular 溝通模式時的總服務中斷時間，並且提升群集與基地台間的連線品質。

Device-to-Device (D2D) and Vehicle-to-Vehicle (V2V) are proximity-based techniques that allow nearby User Equipments (UE) or vehicles to communicate directly. The concept of D2D/V2V clustering is one of the usage scenarios that exploits D2D/V2V technique. It covers the formation of D2D/V2V clusters/group using D2D/V2V discovery and the selection of a cluster head/leader, which in turn serves as a communication relay between the group members and the network. D2D/V2V clustering improves spectral efficiency, energy efficiency, and fairness. However, despite having been proposed since Third Generation Partnership Project (3GPP) Rel-12, few research works have been focused on the mobility of D2D/V2V cluster/group. When a moving D2D/V2V cluster/group reaches the cell boundary, handover is expected to reliably switch the entire cluster/group to a suitable neighbouring BS. On the other hand, whenever a cluster member/follower moves away from the group, a procedure is needed to switch this cluster member/follower from D2D/V2V communication mode to cellular communication mode. To meet these requirements, a novel group-based D2D/V2V mobility management scheme is proposed. This scheme not only ensures service continuity of the D2D/V2V links of group during handover, but also covers connection transition procedure to reliably switch the cluster members/followers from D2D/V2V communication mode to cellular communication mode. Moreover, a swapping mechanism is proposed to maintain good cellular connection between the D2D/V2V cluster/group and the network. Simulation is conducted to compare the performance of the proposed scheme against the conventional Long Term Evolution (LTE) handover scheme. Results show that the proposed scheme can achieve lower handover failure rate, better D2D/V2V service continuity, lower total handover transition interruption time, and lower total transition interruption time.