- 著者
- OHZAHATA Satoshi KIMURA Shigetomo EBIHARA Yoshihiko
- 出版者
- 電子情報通信学会
- 雑誌
- IEICE transactions on communications (ISSN:09168516)
- 巻号頁・発行日
- vol.E84.B, no.4, pp.752-759, 2001-04
Mobile IP can provide macro mobility for a mobile node (MN) instead of the original IP communication. Since the orignal Mobile IP does not consider micro mobility, it can not avoid handoff latency. The latency causes packets loss or large variations of the delivery times. To prevent it, several methods are proposed to improve the orignal Mobile IP handoff method. In our previous work, we proposed the fast registration method which enabled an MN to have two communication routes from the home agent (HA), and realized lower latency in the handoff procedures by the doublecasting on the two communication routes. But, the simulation results also show that the proposed method still has large overhead. This paper presents a seamless handoff method, which improves the fast registration method. In the method, the MN can know the first and second suitable base stations for the communications through information from the MAC media. The control helps for seamless handoff in case that the MN must frequently change its current base station (BS). The computer simulations for Constant Bit Rate (CBR) over real-time transport protocol (RTP) flow shows that the proposed method provides no handoff latency with low overhead even if the MN must occur frequcnt handoffs in a second.
- 著者
- OHZAHATA Satoshi KIMURA Shigetomo EBIHARA Yoshihiko KAWASHIMA Konosuke
- 出版者
- 電子情報通信学会
- 雑誌
- IEICE transactions on communications (ISSN:09168516)
- 巻号頁・発行日
- vol.E90.B, no.8, pp.2070-2080, 2007-08
- 被引用文献数
- 1 2
In this paper we propose a cross-layer retransmission control for TCP communication over a wireless link. With our proposed control, a retransmission delay for lost packet is reduced, packet losses in the wireless link are eliminated and all packets are delivered in the correct order. No change is required to TCP itself or to the sender. Our proposed method is implemented in a queue between the media access control (MAC) layer and logical link layer in a base station, and is designed to assist local retransmission control in the MAC layer. Computer simulations show that our proposed method can maximally use the bandwidth of the wireless link under high bit error rates conditions with conventional TCP control. The fairness problem of TCP communication between connections with different bit error rates in a wireless link is also improved, and MAC level fairness is also controllable.