車用WiFi網路中的碰撞分析

Analysis of Collision Probability in Vehicular WiFi Networks

林正平(Cheng-ping Lin)

指導教授 ： 孫敏德

國立中央大學/資訊電機學院/資訊工程學系/碩士(2012年)

摘要

機率性轉傳的技術提昇了車用 WiFi 網路的效能，使得資料能夠在短暫且斷斷續續的通訊品質下順利地送達目的地。然而，過多的轉送卻增加了碰撞的發生，降低網路的傳輸效能。因此，分析車用 WiFi 網路中的碰撞機率，可以使轉送效率最大化，進而增進車用 WiFi 網路的連線品質。

關鍵字

車載網路 ； WiFi ； ViFi ； 碰撞 ； 轉傳

並列摘要

Opportunistic relay improves the performance of transmissions in vehicular WiFi networks, which make data transmitted more effectively in the fleeting and intermittent vehicular networks. However, too many relays may reduce the quality of connections due to the increasing collisions. In this thesis, we analyze the collisions in vehicular WiFi networks and compute the probability of collisions in the network by two different schemes. Besides, we derive the optimal relay probability for an existing relay algorithm to minimize the redundant retransmission with the consideration of collisions.

並列關鍵字

collision ； relay ； VANET ； ViFi ； WiFi

參考文獻

[1] http://en.wikipedia.org/wiki/Carrier sense multiple access

[3] Jakob Eriksson, Hari Balakrishnan, Samuel Madden, “Cabernet: Vehicular Content

September 2008.

802.11 Protocol to Achieve a Theoretical Throughput Limit,” IEEE/ACM Transac-tions on Networking, vol. 8, no. 6, December 2000.

[5] Raffaele Bruno, Marco Conti, and Enrico Gregori, “Optimal Capacity of p-Persistent