Guest Editorial: Advances in Wireless Mobile and Sensor Technologies

The advance and wide deployment of wireless communication technologies lay the foundation stone of mobile communications in which a mobile node changes its point of attachment during communications with other nodes. However, due to limited resources provided by wireless communication technologies, advanced protocol and architecture for efficient IP mobility management are required to be developed. In this issue, four papers address recent approaches for IP mobility management. The invited paper “Locator ID Separation for Mobility Management in New Generation Networks” by Ved P. Kafle and Masugi Inoue introduces the recently proposed locator ID separation-based network architectures while providing the outlines of limitations and possible extensions to the locator ID separation-based network architectures. Because the approach of the locator ID separation will bring significant changes to the current Internet architecture, this approach is carefully considered as part of Future Network Design. Other three papers are regarding Proxy Mobile IPv6 (PMIPv6), which is the recently developed IP mobility management protocol by the IETF. The paper “Network-based Localized IP mobility Management: Proxy Mobile IPv6 and Current Trends in Standardization” by Carlos J. Bernardos, Marco Gramaglia, Luis M. Contreras, and Maria Calderon provides an overview of PMIPv6 and introduces being developed and required extensions for better performance such as flow mobility, multicast, and network mobility (NEMO) support. The next paper “Context Reflector for Proxy Mobile IPv6” by Sawako Kiriyama, Ryuji Wakikawa, Jinwei Xia, Fumio Teraoka tackles a limitation of the context transfer in the basic PMIPv6 protocol. In the paper, a context transfer mechanism in which the context of a mobile node is transferred from a previous network to a new network before the mobile node changes its attachment point to the new network is introduced to reduce handover latency and packet loss. This mechanism can be compared to the fast handover extension to PMIPv6 that is recently standardized by the IETF. Because PMIPv6 is an IP mobility management protocol, a combination with NEMO is expected. In the paper “N-NEMO: A Comprehensive Network Mobility Solution in Proxy Mobile IPv6 Network” presented by Zhiwei Yan, Huachun Zhou, and Ilsun You, a mechanism for enabling network mobility support in PMIPv6 is introduced with its performance analysis results. While IP mobility management focuses on location and handover functionalities at the network level, it is still needed to explore handover performance at the wireless radio level as well as human mobility patterns. The paper “Handoff in Radio over Fiber Indoor Networks at 60 GHz” by Van Quang Bien, R.Venkatesha Prasad, and Ignas Niemegeers presents a new algorithm in which the motion direction of a mobile node is considered for improving handover performance at 60 GHz wireless radio networks. The paper “Aggregate Human Mobility Modeling Using Principal Component Analysis” by Jingbo SUN, Yue WANG, Hongbo SI, Jian YUAN, and Xiuming SHAN introduces a model to explore the space-time structure of aggregate human mobility. In the proposed model, principal component analysis is utilized to find the low intrinsic dimensionality from collected real data in a southern city of China. Wireless communication technologies also facilitate sensors deployed in various application areas to construct wireless network structures in which monitored data is transmitted via wireless radio networks. In this issue, two papers introduce new research results on wireless sensor networks. The first paper “A Greedy Algorithm for Target Coverage Scheduling in Directional Sensor Networks” by Youn-Hee Han, Chan-Myung Kim, and Joon-Min Gil presents a new scheduling scheme aiming at solving the