Adaptive Sending Rate Over Wireless Mesh Networks Using SNR

Author(s):  
Scott Fowler ◽  
Marc Eberhard ◽  
Keith Blow ◽  
Ahmed Shaikh

Wireless Mesh Networks (WMNs) have emerged as a key technology for the next generation of wireless networking. Instead of being another type of ad-hoc networking, WMNs diversify the capabilities of ad-hoc networks. Several protocols that work over WMNs include IEEE 802.11a/b/g, 802.15, 802.16 and LTE-Advanced. To bring about a high throughput under varying conditions, these protocols have to adapt their transmission rate. This paper proposes a scheme to improve channel conditions by performing rate adaptation along with multiple packet transmission using packet loss and physical layer condition. Dynamic monitoring, multiple packet transmission and adaptation to changes in channel quality by adjusting the packet transmission rates according to certain optimization criteria provided greater throughput. The key feature of the proposed method is the combination of the following two factors: 1) detection of intrinsic channel conditions by measuring the fluctuation of noise to signal ratio via the standard deviation, and 2) the detection of packet loss induced through congestion. The authors show that the use of such techniques in a WMN can significantly improve performance in terms of the packet sending rate. The effectiveness of the proposed method was demonstrated in a simulated wireless network testbed via packet-level simulation.

Author(s):  
Scott Fowler ◽  
Marc Eberhard ◽  
Keith Blow ◽  
Ahmed Shaikh

Wireless Mesh Networks (WMNs) have emerged as a key technology for the next generation of wireless networking. Instead of being another type of ad-hoc networking, WMNs diversify the capabilities of ad-hoc networks. Several protocols that work over WMNs include IEEE 802.11a/b/g, 802.15, 802.16 and LTE-Advanced. To bring about a high throughput under varying conditions, these protocols have to adapt their transmission rate. This paper proposes a scheme to improve channel conditions by performing rate adaptation along with multiple packet transmission using packet loss and physical layer condition. Dynamic monitoring, multiple packet transmission and adaptation to changes in channel quality by adjusting the packet transmission rates according to certain optimization criteria provided greater throughput. The key feature of the proposed method is the combination of the following two factors: 1) detection of intrinsic channel conditions by measuring the fluctuation of noise to signal ratio via the standard deviation, and 2) the detection of packet loss induced through congestion. The authors show that the use of such techniques in a WMN can significantly improve performance in terms of the packet sending rate. The effectiveness of the proposed method was demonstrated in a simulated wireless network testbed via packet-level simulation.


Author(s):  
Juan C. Guerri ◽  
Pau Arce ◽  
Patricia Acelas ◽  
Wilder E. Castellanos ◽  
Francisco Fraile

Video services are much demanded nowadays but bandwidth and delay requirements of this kind of services are very restrictive. Offering real-time video services in wireless ad-hoc networks is not an easy task because of the difficulty of guaranteeing certain quality in a shared medium. Practical solutions should try to improve communications at (and gathering information from) several layers of the protocol stack. Mobile Ad-hoc Networks are infrastructure-less wireless networks characterized by being very versatile, dynamic and self-organized but also by the difficulty to achieve a good Quality of Service in video transmissions due to packet losses and node mobility. On the other hand, the Wireless Mesh Network is presented as the next step in wireless networks. Wireless Mesh Networks have a hierarchical topology, clustered structure and static backbone, which all help to improve the network stability. In the way towards Wireless Mesh Networks, hierarchical routing protocols could transform an ad-hoc network in a more robust wireless network. Therefore, in this chapter, hierarchical routing protocols have been studied, particularly Hierarchical Optimized Link State Routing Protocol, and compared with a traditional flat routing protocol named Optimized Link State Routing. Furthermore, additional video coding techniques have been used in order to improve video quality in reception. At application layer, results show that Multi-description Coding achieves better quality on video transmissions when nodes have medium or high mobility, especially when using multipoint-to-point transmission or disjoint paths in a hierarchical structure. Video trace simulations have allowed us to perform subjective quality tests to assert the Quality of Experience improvements in video transmissions.


Sign in / Sign up

Export Citation Format

Share Document