QoS 制御を考慮したＤＳＲプロトコル拡張の一考察

Abstract

This paper discusses some extensions of DSR (Dynamic Source Routing) protocol to consider QoS (Quality of Service) controls. IEEE 802.11e is wireless LAN standards for QoS. It specifies two functions, that is, EDCA (Enhanced Distributed Channel Access) and HCCA (Hybrid coordination function Controlled Channel Access). EDCA has two modes; one is an ad hoc mode and the other is an infrastructure mode. The proposed method focuses on the ad hoc mode in EDCA that classifies all data-frames into four access categories such as voice, video, text, or background. These access categories are indicated by AC VO, AC VI, AC BE, and AC BK, respectively. They are associated with contention windows that have an effect on setting a back-off time. So firstly, I propose a method for dynamically changing a range of contention windows after getting the number of neighbors of the node. Secondly, I propose three features adding to the original DSR protocol so as to consider QoS in the followings: 1) the first feature is to put an access category into an option field of control packets for DSR, 2) the second is to manage route-caches using only RREP packets, and 3) the last is to limit the hop-count metric.