an integrated wimax/wifi architecture with qos consistency over broadband wireless networks...
TRANSCRIPT
An Integrated WiMAX/WiFi Architecture with QoS Consistency over Broadband Wireless Networks
報告者 : 李宗穎
IEEE Consumer Communications and Networking Conference 2009
Hui-Tang Lin, Ying-You Lin, Wang-Rong Chang, and Rung-Shiang Cheng
Outline
Introduction Description of Network Model Bandwidth Allocation and Management Performance Evaluation Conclusions
Introduction
WiMAX and WiFi have emerged as promising broadband access solutions for the latest generation of wireless MANs and LANs
an integrated architecture utilizing a novel WiMAX/WiFi Access Point (W2-AP) device to effectively combine the WiMAX and WiFi technologies
Integrated WiMAX/Wifi System
a single WiMAX BS, operating in a licensed band, serves both multiple WiMAX Subscriber Stations (SSs) and multiple W2-APs
Proposed MAC Layer Module
MultiMAC dynamic switching between different MAC protocols ex: adding a byte to the header of the frame for identification purp
oses SoftMAC
encapsulate a WiMAX PDU into a single WiFi PDU over 802.11a OFDM PHY or to decapsulate a single WiFi PDU into its WiMAX PDU.
MAC Module in W2-AP Device
UL Aggregator/Classfier Packet Classification
temporarily buffer the UL data packets based on their corresponding priority
BW-REQ Aggregation aggregate all bandwidth demands at
the same QoS level from WiFi nodes into a single bandwidth request
MAC Module in W2-AP Device
The UL and DL bandwidth information is passed down to the DL/UL-MAP Generator
MAC Module in WiFi Node/WiMAX BS
WiFi Node modified by adding MultiMAC, SoftMAC and
802.16 SS-MAC functions WiMAX BS
the MAC layer is the same as that defined in the IEEE 802.16 standard
Two-Level Hierarchical Bandwidth Allocation (THBA)
W2-AP attempts to aggregate bandwidth demands having the same level of QoS
Frame Operation in Level A/B
WiFi and WiMAX networks use different frequency bands, and thus the problem of interference is neglected
Second-Hop Frame Gap
Simulation Model
Traffic Type CBR (kbps) Interval (ms)
VoIP (UGS) 64 20
Video (rtPS) 128 10
Web (BE) 64 12.5
Total Bandwidth 64Mbps TDD
DL/UL Ratio 1:1
three specific bandwidth allocation protocols THBA scheme
Each W2-AP aggregates all the bandwidth demands with the same QoS level received from its WiFi nodes
Independent bandwidth allocation control The W2-AP directly allocates its own bandwidth to its
WiFi nodes based on their bandwidth requirements and buffers the packets sent from the WiFi nodes
WiMAX with EDCA control IEEE 802.11e NIC card to employ a priority-based ED
CA bandwidth contention protocol for accessing the channel
Mean end-to-end delay of various traffic classes for various network offered loads
Mean end-to-end delay of various traffic classes for the number of VoIP connections within the network
Mean end-to-end delay versus number of WiFi nodes per WiFi hotspot
Conclusion
By using the W2-AP and modify 802.11 NIC card, the integrated architecture enables the use of a common protocol operation between the WiMAX and WiFi components of the network
THBA mechanism can reduces the end-to-end delays of high priority traffic
Comment
英文寫的很難懂 沒有較詳細的頻寬分配方法 雖然只要軟體升級,但要修改到 WiFi 節點會比較造成支援度便利性不足