tailieunhanh - AD HOC NETWORKS Technologies and Protocols phần 6

. Giao thức định tuyến được phát triển cho các mạng có dây như Internet có dây là không đủ khi họ không chỉ giả định cấu trúc liên kết chủ yếu là cố định nhưng cũng có overheads1 cao. Điều này đã dẫn đến một số đề xuất định tuyến cụ thể nhắm mục tiêu cho các mạng ad hoc. | 122 Multicasting in Ad Hoc Networks 34 K. Tang and M. Gerla. Random access MAC for efficient broadcast support in ad hoc networks. In Proc. of IEEE WCNC 2000. 35 P. Mohapatra J. Li and C. Gui. QoS in mobile ad hoc networks. Special Issue on Next-Generation Wireless Multimedia Communications Systems in IEEE Wireless Communications Magazine June 2003. Chapter 5 TRANSPORT LAYER PROTOCOLS IN AD HOC NETWORKS Karthikeyan Sundaresan Georgia Institute of Technology Atlanta Georgia sk@ Seung-Jong Park Georgia Institute of Technology Atlanta Georgia sjpark@ Raghupathy Sivakumar Georgia Institute of Technology Atlanta Georgia siva@ Abstract The Transmission Control Protocol TCP is by far the most dominant transport protocol in the Internet and is the protocol of choice for most network applications. The focus of this chapter is to present approaches for ad-hoc networks that provide the same end-to-end semantics as TCP. In this regard we first investigate the different problems experienced by TCP in ad-hoc networks and provide insights into how the different design components of TCP relate to the characteristics of such networks. We then identify three major classes of approaches to improve the transport layer performance in ad-hoc networks. We present a protocol instance for each of the three approaches in detail and highlight the specific problems it addresses. We also discuss the trade-offs stemming from the adoption of each of the protocols considered. Keywords Ad-hoc networks TCP 124 Transport Layer Protocols in Ad Hoc Networks Introduction The Open Systems Interconnection OSI reference model s fourth layer is the transport layer which is responsible for reliable end-to-end communication and flow control functionalities. The TCP IP protocol suite consists of the Transmission Control Protocol TCP and User Datagram Protocol UDP as the transport protocols1. UDP is a simplistic transport layer solution that merely provides .