Throughput Network Performance Research Articles

Energy and performance-aware balancing in establishing an emergency wireless communication network

In a disaster situation, natural or human-made disasters, establishing an emergency wireless network in these circumstances is very important to save lives. It is imperative to ensure the network’s ability to connect all people in the disaster area, with an optimum capacity to handle the information traffic while consuming less power. These factors are critical when designing such a network. The clustering technique has improved wireless network performance in throughput and power consumption. However, there are still difficulties when applying this technique to such a situation, essentially selecting cluster heads (CHs) and connecting them to the nearby functional base station (BS). This paper devises an algorithm (CCaCH/SCH-S) to create clusters and select CHs appropriately. Once clusters are created and CHs are selected, the connection between CHs and the relay station (RN) is established using long-range links. CHs are responsible for aggregating data from their members and forward the information to RN. Each cluster consists of a main-cluster with its CH and a sub-cluster with its sub-cluster head (SCH); both use short-range links. In this approach, the selection of CH and SCH was determined by the residual battery power. The proposed approach was investigated against the system capacity, power consumption, and the required time to establish communication to the functional areas. Different network parameters and clustering approaches were simulated using MATLAB. The proposed approach minimized the users’ equipment (UEs) power consumption by 5.9% comparing to a multi-hop approach and 9.4% compared to the single-hop approach. Furthermore, the proposed approach improved the network capacity up to 7% and 32.6% better than multi-hop and single-hop approaches, respectively.

Short-term fairness in slotted WDM rings

Single-hop WDM ring networks are promising architectures for future broadband access and metro networks. However, ring networks exhibit significant fairness issues, which must be handled by a fairness enforcing protocol. Fairness is usually ensured over a time window of several network propagation delays. Thus, data flows might experience large access delays which might be not compatible to support time-sensitive applications. We solve this issue proposing the Multi-Fasnet protocol, which is able to enforce fairness in a relative short time scale, in the order of few propagation delays, without trading off the aggregated throughput network performance. We discuss Multi-Fasnet limitations and propose several novel strategies that achieve high and fair network throughput as well as low, bounded and fair access delays.

Modified Greedy Physical Link Scheduling Algorithm for Improving Wireless Mesh Network Performance

The algorithm to allocate mesh active link to radio resource timeslot in wireless mesh network (WMN) is investigated. This paper proposes the novel method to allocate multiple links in one timeslot for improving the wireless mesh network throughput via spatial time division multiple access (STDMA) protocol. The throughput improvement is obtained by modifying greedy based algorithm that is widely known as a low complexity algorithm. We propose and investigate new parameters in the greedy based algorithm that can be used as scheduling control parameters, i.e. interference weight, scheduling weight, and the sum of link’s degree. Simulation results indicate that this approximation increases network performance in throughput and length of scheduling performance closed to the upper bound performance that is achieved by the algorithm that uses the physical interference model.

Priority Parameter-based Analysis and Optimization for EDCA

This article aims at coming up the optimization of the throughput network performance in EDCA. At first, we observe in different network load conditions that the effect of each priority parameter has on the network transmission performance. Then we make a deep research about the EDCA mechanism and come up a new EDCA analysis model and there is a throughput analysis of this model and a optimization scheme of the priority business flows under different network loads. Finally, based on the mathematical analysis and NS2 simulation results, it can be observed from the new optimization scheme that it to some extent improves different priority services under different network loads.

The Modified Gaussian Function based RED (MGF-RED) Algorithm for Congestion Avoidance in Mobile Ad Hoc Networks

In this paper the idea is to rationale a new active queue management technique (MGF-RED) based on Random Early Detection (RED), a well known active queue management technique for congestion avoidance. The conventional RED uses the concept of minimum threshold, maximum threshold and average queue length. If the average queue length increases by minimum threshold then the algorithm start dropping the packets with some probability using linear function of average queue size. If the average queue size is greater than the maximum threshold then packets are dropped with 1 probability. The proposed algorithm will use Modified Gaussian function for calculating the likelihood of packet drop as the average queue length increases the minimum threshold. Simulation has been performed using NS-2.34. The simulation results show that the proposed algorithm will present better network performance in throughput, packet delivery fraction and number of dropped packets. General Terms MANET, RED, Gaussian Function.

Comparative Investigation on CSMA/CA-Based Opportunistic Random Access for Internet of Things

Wireless communication is indispensable to Internet of Things (IoT). Carrier sensing multiple access/collision avoidance (CSMA/CA) is a well-proven wireless random access protocol and allows each node of equal probability in accessing wireless channel, which incurs equal throughput in long term regardless of the channel conditions. To exploit node diversity that refers to the difference of channel condition among nodes, this paper proposes two opportunistic random access mechanisms: overlapped contention and segmented contention, to favor the node of the best channel condition. In the overlapped contention, the contention windows of all nodes share the same ground of zero, but have different upper bounds upon channel condition. In the segmented contention, the contention window upper bound of a better channel condition is smaller than the lower bound of a worse channel condition; namely, their contention windows are segmented without any overlapping. These algorithms are also polished to provide temporal fairness and avoid starving the nodes of poor channel conditions. The proposed mechanisms are analyzed, implemented, and evaluated on a Linux-based testbed and in the NS3 simulator. Extensive comparative experiments show that both opportunistic solutions can significantly improve the network performance in throughput, delay, and jitter over the current CSMA/CA protocol. In particular, the overlapped contention scheme can offer 73.3% and 37.5% throughput improvements in the infrastructure-based and ad hoc networks, respectively.

Performance Analyses of Adaptive Access Mechanism in IEEE 802.11 WLANs

The performance analyses of adaptive access mechanism have not been studied completely, especially in non-saturation conditions. By using feedback signal of channel, we propose an adaptive access mechanism, which adjusts parameters based on idle slot intervals between two data transmissions. Then, we analyze the network performance of throughput, media access delay and retransmission attempts of packets, which shows some main characteristics of adaptive access mechanism. The simulation results also demonstrate the validity and good scalability of the proposed access mechanism.