Class-Based Weighted Window for TCP Fairness in WLANs

The explosive growth of the Internet has extended to the wireless domain. The number of Internet users and mobile devices with wireless Internet access is continuously increasing. However, the network resource is essentially limited, and fair service is a key issue in bandwidth allocation. In this research, the focus is on the issue of fairness among wireless stations having different number and direction of flows for different required bandwidth to ensure that fair channel is fairly shared between wireless stations in the same class of bandwidth. It is shown that the current WLANs allocate bandwidth unfairly. It is also identified that the cause of this problem of unfairness is the TCP cumulative ACK mechanism combined with the packet dropping mechanism of AP queue and the irregular space for each wireless station in AP queue. The proposed method allocate converged bandwidth by introducing a Class-Based Weighted Window method which adjusts the TCP window size based on the current conditions of the network and according to the network’s requirements. This method works in wireless stations without requiring any modification in MAC. It can guarantee fair service in terms of throughput among wireless users whether they require the same or different bandwidth.Wireless LAN, TCP, Fairness

IEEE 802.16: WiMAX overview, WiMAX architecture

WiMax, the Worldwide Interoperability for Microwave Access is a new technology dealing with provision of data over long distance using wireless communication method in many different ways. Based on IEEE 802.16 WiMax is claimed as an alternative broadband rather than cable and DSL. This paper is a quick technical overview and covers:WiMAX overview(Fundamental Concept; Technology; Standard update) andWiMAX architecture(Network and Node Architectures; Physical Layer; MAC Layer)

Weighted Window for TCP Fair Bandwidth Allocation in Wireless Lans

The explosive growth of the Internet has extended to the wireless domain. The number of Internet users and mobile devices with wireless Internet access is continuously increasing. However, the network resource is essentially limited, and fair service is a key issue in bandwidth allocation. The main objective of this research is to provide fair service in terms of throughput among wireless stations using the TCP window size according to Access Point (AP) queue size for fair bandwidth allocation in wireless LANs. In the first part of this research the focus is on the issue of fairness among stations having different numbers and directions of flow. It is shown in this part that the current WLANs allocate bandwidth unfairly. It is also identified that the cause of this unfairness problem is TCP cumulative ACK mechanism combined with the packet dropping mechanism of AP queue and the irregular space for each station in AP queue. The proposed method allocates converged bandwidth by introducing weighted window method which adjusts the TCP window size based on the current conditions of the network. Therefore, this method works in wireless nodes without requiring any modification in MAC. The second part dealt with the fair bandwidth allocation problem for different required bandwidth which aims to improve weighted window method to assure fair channel is fairly shared between wireless nodes in the same class of bandwidth. The proposed class-based weighted window method adjusts the TCP window size of each station according to their weights. So the stations share the wireless channel fairly in terms of throughput. The proposed methods can guarantee fair service in terms of throughput among wireless users either they require the same or different bandwidth

Weighted window method for TCP fairness in WLANs

Distributed Coordination Function (DCF) in IEEE 802.11 WLANs cannot guarantee per-station TCP fairness among wireless stations. In order to satisfy users, and guarantee to allocate fair bandwidth among wireless users regardless of the number and direction of flows, the Weighted Window method is proposed. This method can be simply implemented in mobile stations without having to modify the MAC layer. In this paper, the proposed method and its properties will be presented in detail using ns2 simulation tool under various network conditions. The simulation results are shown that the proposed method achieves fair throughput among stations as compared with previous methods

Zero-degree algorithm for internet GateWay placement in backbone wireless mesh networks

Internet GateWays (IGWs) are responsible for connecting the backbone wireless mesh networks (BWMNs) to the Internet/wired backbone. An IGW has more capabilities than a simple wireless mesh router (WMR) but is more expensive. Strategically placing the IGWs in a BWMN is critical to the Wireless Mesh Network (WMN) architecture. In order to solve the problem of IGWs placement in BWMNs, a novel algorithm is proposed in this paper. The new algorithm is involved in placing a minimum number of IGWs so that the Quality of Service (QoS) requirements are satisfied. Different from existing algorithms, this new algorithm incrementally identifies IGWs and prioritively assigns wireless mesh routers (WMRs) based on the computed degree of WMRs to identified IGWs. Performance evaluation results show that proposed algorithm outperforms other alternative algorithms by comparing the number of gateways placed in different scenarios. Furthermore, having control of the distribution of IGWs in order to locate them closest to available Internet/wired network connection points is an added advantage of this algorithm

Weighted window and class-based weighted window methods for per-station TCP fairness in IEEE 802.11 WLANs.

TCP unfairness problem in access networks using the 802.11 has been studied by many researchers. Their solutions required that the existing MAC protocol be modified. However, since they did not consider the case when each wireless node has a different number of flows, they cannot provide fairness among wireless nodes having different numbers of flow in both directions. In order to resolve this problem, Weighted Window and Class-Based Weighted Window methods are proposed. In the Weighted Window method, each wireless node can control the rate of TCP flows based on TCP window size. By applying this method, per-station fairness can be achieved, regardless of the number and direction of flows in each wireless node. Furthermore, to improve and to provide fair bandwidth allocation in the Weighted Window method when the users have different requirements, the Class-Based Weighted Window method is proposed. Therefore, for wireless nodes with different requirements, fair allocation bandwidth between wireless nodes in the same class of bandwidth is achieved

Class-based weighted window for TCP fairness in WLANs

The explosive growth of the Internet has extended to the wireless domain. The number of Internet users and mobile devices with wireless Internet access is continuously increasing. However, the network resource is essentially limited, and fair service is a key issue in bandwidth allocation. In this research, the focus is on the issue of fairness among wireless stations having different number and direction of flows for different required bandwidth to ensure that fair channel is fairly shared between wireless stations in the same class of bandwidth. It is shown that the current WLANs allocate bandwidth unfairly. It is also identified that the cause of this problem of unfairness is the TCP cumulative ACK mechanism combined with the packet dropping mechanism of AP queue and the irregular space for each wireless station in AP queue. The proposed method allocate converged bandwidth by introducing a Class-Based Weighted Window method which adjusts the TCP window size based on the current conditions of the network and according to the network’s requirements. This method works in wireless stations without requiring any modification in MAC. It can guarantee fair service in terms of throughput among wireless users whether they require the same or different bandwidth