Heuristic Approach to Select Opportunistic Routing Forwarders (HASORF) to Enhance Throughput for Wireless Sensor Networks

Biological schemes provide useful resources for designing adaptive routing protocols for wireless sensor networks (WSNs). The key idea behind using bioinspired routing is to find the optimal path to the destination. Similarly, the idea of opportunistic routing (OR) is to find the least number of hops to deliver the data to the destination. Numerous routing schemes have been proposed in WSNs while targeting various performance goals, such as throughput, delay, and link quality. Recently, OR schemes have come onto the scene in comparison with the traditional routing algorithms. The performance of OR schemes, however, highly depends on the selection of forwarder nodes. In this paper, we consider a chain network topology, where nodes are separated by an equal distance. The throughput of the chain network is analyzed mathematically, and based on the analysis results, a heuristic algorithm is proposed to choose the forwarder nodes. We evaluate the performance of the proposed Heuristic Approach to Select Opportunistic Routing Forwarders (HASORF) by using the ns-2 simulator and compare it with previous schemes, such as random routing, Extremely Opportunistic Routing (ExOR), and Simple Opportunistic Adaptive Routing (SOAR). The empirical results show that our proposed scheme achieves the best performance among them

Cell-Throughput Analysis of the Proportional Fair Scheduler in the Single-Cell Environment

Abstract. The fairness concept has been widely studied in the area of data networks. The most well-known fairness criterion, max-min fairness, gives priority to the minimum rate session. Kelly questioned its appropriateness in his works on the bandwidth sharing among the end-to-end flows and proposed another fairness criterion preferring short distance flows to enhance the overall throughput, which is called the proportional fairness (PF). A simple scheduler achieving this objective was introduced in wireless access networks and revealed that it can achieve a good compromise between cell throughput and user fairness. Though it has received much attention for some time, research on its performance mainly depended on computer simulations. In this paper, we analyze the PF scheduler to obtain the cell throughput which is a primary performance metric

Optimal CSMA scheduling with dual access probability for wireless networks

Recently optimal Carrier Sense Multiple Access (CSMA) scheduling schemes have attracted much attention in wireless networks due to their low complexity and provably optimal throughput. However, in practice, the schemes incur strong positive correlations between consecutive link schedules and let a scheduled link likely remain scheduled in the next time slot, which leads to poor delay performance. In this paper, we revise the original optimal CSMA algorithm for discrete-time systems, the Queue-length based CSMA (Q-CSMA), and substantially improve its delay performance. In our proposed algorithm, called Dual Access Probability CSMA (DAP-CSMA), each link has two state-dependent access probabilities depending on the link activity of the previous time, which allow us to accelerate the turn-off of previously scheduled links. This rapid activity transition reduces the correlation of the link service process and thereby improves the delay performance. We show that our DAP-CSMA is provably efficient and attains the optimal throughput. The simulation results demonstrate that our proposed scheduling significantly outperforms Q-CSMA in various scenarios and can be combined with a recent variant of Q-CSMA for better delay performance, Delayed-CSMA

Adapting TCP Segment Size in Cellular Networks

Abstract. In cellular networks, a frame size is generally made small to reduce the impact of errors. Thus, a segment of transport layer is splitted into multiple frames before transmission. A problem is that the whole segment is lost when a frame of a segment is lost. So, the segment error rate tends to be high even though the cellular network provides relatively the low frame error rate, which drops TCP performance. However, the relation between the frame size, the segment size and the error rate has not been closely investigated. In this paper, we analyze the impact of the segment size on TCP performance in cellular networks and propose a scheme alleviating the performance drop of TCP. Our result shows that our scheme reduces the drop by 82%.

An ID/Locator Separation Based Group Mobility Management in Wireless Body Area Network

Mobility management in wireless sensor network is the most important factor to be considered for applications such as healthcare system. Recently, Identifier (ID)/Locator (LOC) separation based mobility management scheme has been proposed for wireless sensor network. However, it does not perform well in group-based mobility management in wireless body area network, and thus it tends to induce large registration, packet delivery, and handover delays. To overcome these limitations, we propose a group-based mobility management scheme based on ID/LOC separation concept for ID-based communications with location-based routing to reduce the number of control messages. In the proposed scheme, each sensor device has a globally unique device identifier (GDID) which contains the information of its home network domain. For handover support, each access gateway maintains its home GDID register (HGR) and visiting GDID register (VGR) which are used to keep the GDID-locator (LOC) mappings for primary mobile devices in the distributed manner. Besides, in the proposed scheme, only the coordinator will send Router Solicitation and Router Advertisement messages to reduce the control messages further. By numerical analysis, we show that the proposed scheme can significantly reduce the registration, packet delivery, and handover delays, compared to the existing schemes

Utility Maximization for Arbitrary Traffic in Communication Networks

MaxWeight-based throughput-optimal link scheduling schemes have been shown to attain the maximum utility in communication networks for any feasible input traffic. However, for input traffic outside the capacity region, they fail to achieve the maximum utility. Although a joint solution with admission controller has been recently developed to address the problem, it requires additional structural complexity with non-intuitive state variables, which further complicates the already complex MaxWeight-based schemes. In this paper, we take more direct control of the arrivals, and develop a new joint solution with simpler admission controller and less structural complexity. Our scheme provably achieves the maximum utility, and empirically outperforms the previous solution in terms of delay.close1