Article

A new access point selection policy for multi-rate IEEE 802.11 WLANs.

IJPEDS 01/2008; 23:291-307. DOI: 10.1080/17445760801930914
Source: DBLP

ABSTRACT In wireless local area networks often a station can potentially associate with more than one access point. Therefore, a relevant question is which access point to select \best" from a list of candidate ones. In IEEE 802.11, the user simply associates to the access point with the strongest received signal strength. However, this may result in a signican t load imbalance between several access points. Moreover, the multi-rate exibilit y provided by several IEEE 802.11 variants can cause low bit rate stations to negatively aect high bit rate ones and consequently degrade the overall network throughput. This paper investigates the various aspects of \best" access point selection for IEEE 802.11 systems. In detail, we rst derive a new decision metric which can be used for AP selection. Using this metric we propose two new selection mechanisms which are decentralized in the sense that the decision is performed by each station, given appropriate status information of each access point. In fact, only few bytes of status information have to be added to the beacon and probe response frames which does not impose signican t overhead. We show that our mechanism improves mean quality of service of all stations and better utilizes network resources compared to the conventional one implemented today in IEEE 802.11 devices. Also, the schemes are appealing in terms of stability and provide their performance improvement even for denser or lighter network congurations.

0 Bookmarks
 · 
126 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Network performance monitor has now become a central issue in network application and operation optimization. This article describes a detail introduction of data processing and analyzing model in passive network performance monitor system. Pretreatment technique is used for eliminating impulse point and zero point. KMP algorithm is used for string matching. The data processing and analyzing technique is a bran-new idea. Experiment results indicate this model is effective and of a definite practicability.
    01/2010;
  • [Show abstract] [Hide abstract]
    ABSTRACT: We consider the issues of mitigating interference and improving network capacity in wireless networks from the viewpoint of channel diversity. Multi-channel diversity allows multiple pairs to concurrently use the wireless medium, thus increasing the achievable capacity; this multi-channel diversity can then be fully utilized by enabling wireless nodes to dynamically switch their channels. However, the process of switching channels in a wireless transceiver incurs switching overhead, resulting in the degradation of the throughput performance. We propose a receiver-centric multi-channel MAC protocol (RcMAC) that allows nodes to efficiently utilize multiple channels by reducing unnecessary channel switching. Receiver-centric channel switching enables each sender node to asynchronously and independently switch channels to one where its intended receiver resides, without requiring explicit channel negotiation. Thus, the wait time at the control channel is reduced, in addition to the number of channel switchings, thereby improving channel utilization. As this scheme requires prior knowledge of which channel a node is switched to, each node cooperatively shares its channel usage information in order to recognize the channels that its neighboring nodes are using. Through extensive simulations, we show that the proposed MAC protocol significantly improves network throughput and reduces end-to-end delay compared with other multi-channel MAC protocols.
    Computer Communications. 02/2013; 36(4):431–444.
  • [Show abstract] [Hide abstract]
    ABSTRACT: In wireless mesh networks (WMNs), a station (STA) often has a group of candidate access points (APs) to be associated with. How to select the most appropriate AP has been an open problem. In IEEE 802.11 standards, the STA simply chooses the one with the strongest RSSI. Since this AP selection strategy can cause severe network load unbalance, many new methods have been proposed. However, these solutions mainly focus on the WLAN environment and are not applicable for WMNs. The unique wireless multi-hop backbone in WMN will introduce higher latency, which must be considered during the AP selection process. In this paper, we propose a cross-layer AP selection scheme based on the information of both link layer and routing layer aiming at reducing the network transmission delay. The problem is formulated as a nonlinear programming problem, and a heuristic search algorithm is given. Experiment results show that the cross-layer scheme can reduce the mean delay of the whole network by about 30% and can benefit real-time applications.
    01/2010;

Full-text (2 Sources)

Download
29 Downloads
Available from
May 29, 2014