Dynamic Slot Allocation Research Articles

Energy efficient optimal parent selection with Chameleon Swarm algorithm and non-overlapping backoff algorithm based dynamic slot allocation in wireless body area network

Energy efficient optimal parent selection with Chameleon Swarm algorithm and non-overlapping backoff algorithm based dynamic slot allocation in wireless body area network

Dynamic Slot Allocation Without Explicit Request Messages for Wireless Sensor Networks With Limited Resources

Dynamic Slot Allocation Without Explicit Request Messages for Wireless Sensor Networks With Limited Resources

A joint dynamic inventory-slot allocation model for liner shipping using revenue management concepts

In this article, we integrate dynamic slot allocation and inventory management to improve liner shipping decisions. Multi-leg revenue management concepts are used to model the problem of marine transporting full and empty containers. The model considers market distinctions, service diversity, and no-shows. The transportation of empty containers is planned to balance the inventory of empty containers in the ports. The problem is formulated as an integer program. Our objective is to maximize the total profit (revenue from shipping full containers minus the overall costs of transporting, leasing, and holding empty containers). An illustrative example based on Iranian liner shipping is solved, and the sensitivity of the results is analyzed. To evaluate the proposed deterministic model, we compare its results to those of the first come first serve (FCFS) method in a stochastic environment using simulation. A comparison between the proposed and traditional FCFS models shows a significant increase in profit.

An Energy-Efficient Clustering Routing for Wireless Sensor Networks Based on Energy Consumption Optimization

In order to alleviate energy consumption of wireless sensor networks (WSNs), energy consumption optimization-based clustering routing (ECOR) is proposed in this paper. In ECOR, network is gridding by hexagon. And there is only a cluster head (CH) in each hexagon, which makes the distribution of CHs more even. Residual energy of nodes and distance from the centroid of hexagon are used to elect CHs. For any a CH, dynamic time slot allocation strategy is adopted to allocate time slot for its cluster members. According to status of cluster members, the duration of time slot is dynamically adjusted. In intercluster communication, the Dijkstra algorithm is used to construct the shortest path between CHs in order to shorten the distance of transmitting data. Simulation results show that the ECOR algorithm outperforms the improved-Low Energy Adaptive Clustering Hierarchy (I-LEACH) algorithm in terms of distribution of CHs and energy consumption.

A Complexity Aware Scheduler With Dynamic Slot Allocation for Cloud Video Transcoding

For a multimedia cloud computing platform, it needs to perform video transcoding to provide bandwidth-compatible bit-streams for users. In configuring a MapReduce system, it allocates slots to workers with the assumption of homogeneous worker power and performs task scheduling by assuming equal task time complexity. However, the computing power of a practical cluster of workers and the time complexity of tasks is time-varying in any case. The task-scheduling algorithm has to well manipulate these heterogeneous cloud resources and task complexity. We first find a good partition size for a video transcoding job for efficient processing. We proposed a Complexity-Aware Scheduling (CAS) algorithm that reorders task assignment priorities according to task complexity to maintain load-balancing operations. By utilizing a Neural Network model to refine the task complexity estimation for the CAS(CASNN), the scheduling and transcoding speedup performances can further be improved. Based on the CASNN, we proposed a Dynamically Adjusting Slot number allocation (DAS) method, DASCASNN, to adjust the slots according to resource utilization status to improve the processing performance. Experimental results show the proposed DASCASNN can help reduce 30% of the transcoding time on average as compared to available schedulers and increase the resource utilization rates from 82.7% to 98%.

Dynamic Slot Allocation Scheme in Tactical Multi-hop Networks for Future Soldier Systems

In this paper, we propose a dynamic slot allocation scheme to improve the slot utilization rate in tactical multi-hop networks in which the channel condition varies due to node movements. The proposed scheme takes advantage of the fact that nodes that are more than three hops apart can use the same slot simultaneously. The frame is divided into two parts: the control period and the data period. To know the available slot information within two-hop distance, the node exchanges a slot allocation information with one-hop neighbors during the control period. The node can get the information on idle slots that are not used within two-hop distance but assigned already to other nodes that are more than three-hop away. The identified idle slot can be used by the node, which increases the slot utilization rate. The performance analysis results of the proposed scheme show that it increases the slot utilization rate sufficiently despite the overhead of the control period in the multi-hop networks of the future soldier system. Keywords: ìŠ¬ë¡¯í• ë‹¹, ë™ì ì‹œë¶„í• ë‹¤ì¤‘ì ‘ì†, ì „ìˆ ë‹¤ì¤‘í™‰ 네트워크, ë§¤ì²´ì ‘ê·¼í†µì œ, ê°œì¸ì „íˆ¬ì²´ê³„ Keywords: Slot Allocation, Dynamic TDMA, Tactical Multi-hop Networks, MAC, Future Soldier System

Priority Enabled Grant-Free Access With Dynamic Slot Allocation for Heterogeneous mMTC Traffic in 5G NR Networks

Although grant-based mechanisms have been a predominant approach for wireless access for years, the additional latency required for initial handshake message exchange and the extra control overhead for packet transmissions have stimulated the emergence of grant-free (GF) transmission. GF access provides a promising mechanism for carrying low and moderate traffic with small data and fits especially well for massive machine type communications (mMTC) applications. Despite a surge of interest in GF access, how to handle heterogeneous mMTC traffic based on GF mechanisms has not been investigated in depth. In this paper, we propose a priority enabled GF access scheme which performs dynamic slot allocation in each 5G new radio subframe to devices with different priority levels on a subframe-by-subframe basis. While high priority traffic has access privilege for slot occupancy, the remaining slots in the same subframe will be allocated to low priority traffic. To evaluate the performance of the proposed scheme, we develop a two-dimensional Markov chain model which integrates these two types of traffic via a pseudo-aggregated process. Furthermore, the model is validated through simulations and the performance of the scheme is evaluated both analytically and by simulations and compared with two other GF access schemes.

Efficient Dynamic Resource Allocation in Hadoop Multiclusters for Load- Balancing Problem

Background: ‘Map-Reduce’ is the framework and its processing of data by rationalizing the distributed servers. also its running the various tasks in parallel way. The most important problem in map reduce environment is Resource Allocation in distributed environments and data locality to its corresponding slave nodes. If the applications are not scheduled properly then it leads to load unbalancing problems in the cloud environments. Objective: This Research suggests a new dynamic way of allocating the resources in hadoop multi cluster environment in order to effectively monitor the nodes for faster computation, load balancing and data locality issues. The dynamic slot allocation is explained theoretically in order to address the problems of pre configuration, speculative execution, delay in scheduling and pre slot allocation in hadoop environments. Experiment is done with Hadoop cluster which increases the efficiency of the nodes and solves the load balancing problem. Methods: The Current design of Map Reduce Hadoop systems are affected by underutilization of slots. The reason is the number of maps and reducer is allotted is smaller than the available number of maps and reducers. In Hadoop most of the times its noticed that dynamic slot allocation policy, the mapper or reducers are idle. So we can use those unused map tasks to overloaded reducer tasks in-order to increase the efficiency of MR jobs and vice versa. Results: The real time experiment was implemented with Multinode Hadoop cluster map reduce jobs of file size 1giga bytes to 5 giga bytes and various performance test has been taken. Conclusion: This paper focused on Hadoop map reduce resource allocation management techniques for multi cluster environments. It proposes a novel dynamic slot allocation policy to improve the performance of yarn scheduler and eliminates the load balancing problem. This work proves that dynamic slot allocation is outperforms more than yarn framework. In future it considered to concentrate on CPU bandwidth and processing time.

Dynamic Slot Allocation Using Non Overlapping Backoff Algorithm in IEEE 802.15.6 WBAN

A dynamic slot allocation scheme using non-overlapping contention windows is presented in this paper to improve the utilization of the IEEE 802.15.6 Wireless Body Area Network (WBAN) superframe. Firstly, a Non Overlapping Backoff Algorithm (NOBA) that avoids inter-priority collisions due to backoff is presented. The results of this scheme are compared with the standard Binary Exponential Backoff (BEB) and the Prioritized Fibonacci Backoff (PFB) schemes. The NOBA provides improvement in the sum throughput, individual throughputs and access delay. Secondly, to avoid the wastage due to fixed slot size, a Dynamic Slot Allocation (DSA) scheme is introduced. It assigns the dynamic slots and phases in a superframe depending on the traffic requirements. Thirdly, a DSA-NOBA scheme that combines both the DSA and the NOBA is presented. The performance of DSA-NOBA is compared against the standard IEEE 802.15.6 superframe (with BEB) and Dynamic Phase Allocation (DPA) schemes using the individual throughput, sum throughput, latency, energy, superframe time and superframe efficiency as performance metrics. Over a range of payload sizes, the DSA-NOBA makes the superframe 50% more efficient than the standard IEEE 802.15.6 superframe with BEB, consequently also providing improvement in all the performance metrics. The most notable among them is energy, whose consumption is reduced by half when compared with the standard.

Spectrum Sensing and Resource Allocation for Proficient Transmission in Cognitive Radio with 5G

In orthogonal frequency division multiplexing (OFDM)-based cognitive radio network–cooperative spectrum sensing (CRN-CSS), resource allocation is critical due to the introduction of interference during spectrum sensing and transmission. This paper resolves this problem of interference through proficient spectrum sensing and resource allocation to improve data transmission. CRN-CSS network is integrated with 5G supported by multiple-input–multiple-output equipped fusion center (FC) to handle massive number of users without loss in connectivity. OFDM-based data transmission is adapted in CRN-CSS to achieve a better transmission rate. In the integrated network, grouping process is initiated by a balanced K-means clustering algorithm to preserve cooperation among secondary users (SUs). Dynamic slot allocation scheme, two-stage multi-slot channel assignment method, is proposed to avoid interference during spectrum sensing. Sensing errors are minimized with the assistance of the energy spectral density-based energy detection spectrum sensing method. For global decision-making, the channel state weighted graph scheme is introduced in which spectrum agent plays a vital role. Finally, resource allocation is carried out by the FC by utilizing efficient Karush–Kuhn–Tucker (EKKT) conditions. Through EKKT method spectrum, transmission powers are allocated to SUs together in such a way that interference with primary user is avoided. Meanwhile, OFDM-based transmission with quadrature phase shift keying modulation scheme reduces peak-to-average-power ratio that leads to high transmission rate. The proposed network is extensively simulated in the NS-3.26 simulation tool and the performance is evaluated from the following performance metrics: throughput, capacity, network utility, transmission power, and transmission rate.

A data fusion privacy protection strategy with low energy consumption based on time slot allocation and relay in WBAN

Wireless body area network (WBAN) can collect and analyze human health signs data of various modes in real time by virtue of low-energy consumption high-precision sensing technology, and it needs to protect health sensitive data related to personal privacy in the process of data transmission. In order to solve the important problem of reliable data transmission in wireless body area network, a new strategy is proposed in this paper. From the two levels of single-hop communication and two-hop communication, the channel characteristics and node data rate in WBAN are fully considered. The reliable data transmission in wireless body area network is realized by using time slot allocation and relay strategy. The introduction of TDMA mechanism of dynamic time slot allocation improves the energy efficiency of strategy and avoids the energy consumption caused by competition, while dynamic time slot allocation satisfies the change of node flow. Time slot allocation strategy based on channel condition and data traffic, exist some nodes in the practical use of the status of the data transmission reliability not guaranteed, we use the relay for this strategy to improve its, meet the requirements of the reliability of data transmission in the network, to bring the additional energy consumption, and strategy information dynamic relay selection depend on the channel information and energy, so that improve the energy efficiency, its energy consumption is reduced. Simulation results show that our transmission strategy can significantly improve the transmission success rate and reduce packet loss, and can adjust the channel changes to improve the reliability of data transmission.

Fuzzy-Based Dynamic Time Slot Allocation forWireless Body Area Networks.

With the advancement in networking, information and communication technologies, wireless body area networks (WBANs) are becoming more popular in the field of medical and non-medical applications. Real-time patient monitoring applications generate periodic data in a short time period. In the case of life-critical applications, the data may be bursty. Hence the system needs a reliable energy efficient communication technique which has a limited delay. In such cases the fixed time slot assignment in medium access control standards results in low system performance. This paper deals with a dynamic time slot allocation scheme in a fog-assisted network for a real-time remote patient monitoring system. Fog computing is an extended version of the cloud computing paradigm, which is suitable for reliable, delay-sensitive life-critical applications. In addition, to enhance the performance of the network, an energy-efficient minimum cost parent selection algorithm has been proposed for routing data packets. The dynamic time slot allocation uses fuzzy logic with input variables as energy ratio, buffer ratio, and packet arrival rate. Dynamic slot allocation eliminates the time slot wastage, excess delay in the network and attributes a high level of reliability to the network with maximum channel utilization. The efficacy of the proposed scheme is proved in terms of packet delivery ratio, average end to end delay, and average energy consumption when compared with the conventional IEEE 802.15.4 standard and the tele-medicine protocol.

Reliability and Energy Efficiency Enhancement for Emergency-Aware Wireless Body Area Networks (WBANs)

Medium access control protocols based on time division multiple access (TDMA) can improve the reliability and efficiency of wireless body area network (WBAN). However, traditional static TDMA techniques adopted by IEEE 802.15.4 and IEEE 802.15.6 do not sufficiently consider the channel status or the buffer requirements of the nodes within heterogeneous contexts. Although there are some solutions that have been proposed to alleviate the effect of the deep fade in WBAN channel by adopting dynamic slot allocation, these solutions still suffer from some reliability and energy efficiency issues and they do not avoid channel deep fading. This paper presents two novel and generic TDMA based techniques to improve WBAN reliability and energy efficiency. Both techniques synchronize nodes adaptively while tackling their channel and buffer status in normal and emergency contexts. Extensive simulation experiments using various traffic rates and time slot lengths demonstrate that the proposed techniques improve the reliability and the energy efficiency compared to IEEE 802.15.4 and IEEE 802.15.6 in both situations, the normal and emergency contexts. This improvement has been achieved in terms of packet loss, up to 90%, and energy consumption, up to 13%, confirming the significant enhancements made by the developed scheduling techniques.

Dynamic time slot allocation and stream control for MIMO STDMA in ad hoc networks

Multiple-input multiple-output (MIMO) technologies have been shown to potentially improve the performance of network. Many traditional medium access control (MAC) protocols, such as spatial time division multiple access (STDMA), may not support MIMO technologies directly and not make full use of the feature of MIMO, which may be a limitation in the practical application in ad hoc networks. Therefore, in this paper, we propose a dynamic time slot allocation and stream control for MIMO STDMA (DTSMS) protocol to improve STDMA in performance. Utilizing stream control technology of MIMO and reservation scheme, DTSMS makes improvement on network throughput and avoids the mutual interference of neighbor links. Thus, DTSMS can support both unicast and multicast simultaneously. Moreover, we implement the dynamic time slot allocation scheme in DTSMS to guarantee the transmission efficiency of packets with high cross-layer transmission parameters, such as the packet priority, neighbor node density, or link quality. Utilizing the collected cross-layer information, the proposed scheme allocates time slots for all nodes dynamically according to the changes of network topology and nodes’ transmission parameters. Finally, the effectiveness of the protocol is demonstrated by numerical analysis and simulations. The results show that DTSMS outperforms STDMA in terms of network throughput and delay. Furthermore, compared to our previous TTS-MIMO, DTSMS can decrease the delay of packets with high transmission parameters and improve the quality of service (QoS).

Media Access Control in Wireless Sensor Networks using Priority Index

As the nodes in Wireless Sensor Networks (WSNs) have limited power, energy conservation is essential at different layers of the protocol stack to prolong lifetime. In our previous work, ”Priority based slot allocation for media access in wireless sensor networks” (PSAWSN), probability based priority scheme is used to allocate slots to competing nodes. Limitations of this work include 1) It does not handle dynamic and variable slot allocation based on varying requirements of nodes. 2) Error control is not taken into account. To overcome these limitations, we propose a Medium Access Control scheme using Priority Index (MACPI) that generates Priority Index (PI) to allocate varying slots based on parameters: message length (ML), node energy (NE), number of requests (NR) and message urgency (MU). Models have been de- signed for all these parameters and an expert system is proposed that makes decisions based on collective knowledge of these parameters. Analysis and simulation results for various message sizes and error conditions show that there is an improvement in terms of energy efficiency, optimal message length and throughput compared to the ”Reliable data deliveries using packet optimization in multi-hop underwater sensor networks”(RDPSN).

Dynamic Channel Slot Allocation Scheme and Performance Analysis of Cyclic Quorum Multichannel MAC Protocol

In high diversity node situation, multichannel MAC protocol can improve the frequency efficiency, owing to fewer collisions compared with single-channel MAC protocol. And the performance of cyclic quorum-based multichannel (CQM) MAC protocol is outstanding. Based on cyclic quorum system and channel slot allocation, it can avoid the bottleneck that others suffered from and can be easily realized with only one transceiver. To obtain the accurate performance of CQM MAC protocol, a Markov chain model, which combines the channel-hopping strategy of CQM protocol and IEEE 802.11 distributed coordination function (DCF), is proposed. The results of numerical analysis show that the optimal performance of CQM protocol can be obtained in saturation bound situation. And then we obtain the saturation bound of CQM system by bird swarm algorithm. In addition, to improve the performance of CQM protocol in unsaturation situation, a dynamic channel slot allocation of CQM (DCQM) protocol is proposed, based on wavelet neural network. Finally, the performance of CQM protocol and DCQM protocol is simulated by Qualnet platform. And the simulation results show that the analytic and simulation results match very well; the DCQM performs better in unsaturation situation.

공중 전술 데이터링크에서 상황인식 공유를 위한 우선순위 기반 매체접속제어와 부하분산 기법

현대전이 네트워크 중심전으로 변화함에 따라 아군 플랫폼끼리 상황인식 정보를 공유하는 능력은 작전임무 수행을 위한 핵심 능력이 되었다. 공중 환경에서 상황인식 공유를 위하여 Link-16과 같은 전술 데이터링크를 이용하는데, 슬롯 할당이 동적으로 되지 않거나 동적으로 할당된 슬롯의 개수를 변경하지 못하는 문제가 존재하였다. 또한 슬롯할당을 받지 못한 노드가 있는 경우 상황인식 공유의 필요에도 불구하고 유한한 타임 슬롯 자원의 한계로 이를 공유하지 못하여 상황인식 능력을 향상시키지 못하는 문제가 존재하였다. 본 논문에서는 TDMA (time division multiple access)와 랜덤액세스가 혼합된 구조를 활용하여 동적인 슬롯할당 및 할당 슬롯의 변화를 수용하며, 사용 가능한 슬롯이 소진된 경우에도 일부 상황인식 공유가 가능한 기법 및 슬롯 요청이나 메시지 전송 집중에 다른 슬롯 할당 지연시간을 감소를 위한 서브프레임간 부하 분산 기법을 제안한다. As modern warfare has changed into network centered, the ability to share situational awareness among allies become a core competency for performing operational missions. In an airborne environment, it uses a tactical data link such as Link-16 for shared situational awareness. There exist problems when it shares situational awareness over the existing data link that can not allocate slots dynamically or that can not change the number of a slot to be allocated. In addition, there was a problem that can not share this failure so that failed to improves situation awareness because of finite time slot resources. In this paper, we accommodate dynamic slot allocation and changes of slot allocation with mixed structure of TDMA (time division multiple access) and random access. We propose a technique that can be used when available slots are exhausted, and a load balancing method to prevent slot allocation delay when slot requesting or message sending is concentrated on a single subframe.

Continuous Progress In Dynamic Slot Allocation In Mapreduce Clusters In Cloud Environment

For large data processing in the cloud, MapReduce is a process that can split the data into multiple parts and make a processing slot. The slot based MapReduce is not too effective as it gives the poor performance because of the unoptimized resource allocation and it has the various challenges. The MapReduce job task executions have two unique features. The map slot allocation, only allocates the map task before allocating reduce task to process. The data locality maximization for the efficiency and utilization is required to improve the quality of the system. The modified DynamicMR is a dynamic slot allocation framework to improve the performance of MapReduce. The modified DynamicMR focuses on Hadoop Fair Scheduler (HFS). The Dynamic scheduler consist of three optimization techniques Modified Dynamic Hadoop Slot Allocation (MDHSA), Speculative Execution performance Balancing (SEPB) and Slot Pre-scheduling. Thus the modified DynamicMR provides the effective results compared to the existing system.

A Traffic Adaptive Multi-Channel MAC Protocol with Dynamic Slot Allocation for WSNs

Using low duty-cycle is the most common technique to extend the system lifetime in WSNs. However, it also implies limited throughput and long delay and the penalty is even higher under variable traffic patterns. In this paper, we present iQueue-MAC, a hybrid CSMA/TDMA MAC that adapts to variable/bursty traffic. With light load, iQueue-MAC uses a contention-based CSMA mechanism that provides low delay with scattered transmissions. When traffic increases, detected by a forming backlog in the sender, iQueue-MAC changes to a contention-free TDMA mechanism allocating transmission slots. Thus, iQueue-MAC mitigates packet buffering and reduces packet delay, combining the best of TDMA and CSMA. In this paper we also show how iQueue-MAC can operate in both single and multi channel modes. We implemented it on SIM32W108 chips together with other reference WSN protocols for comparison. iQueue-MAC exhibits similar figures during light traffic. However, with bursty traffic its throughput can be five times that of CoSenS and Ri-MAC-MC and its delay 20 times lower. Finally, iQueue-MAC is able to effectively use multiple channels, duplicating its throughput when compared to single channel operation.

DynamicMR: A Dynamic Slot Allocation Optimization Framework for MapReduce Clusters

MapReduce is a popular computing paradigm for large-scale data processing in cloud computing. However, the slot-based MapReduce system (e.g., Hadoop MRv1) can suffer from poor performance due to its unoptimized resource allocation. To address it, this paper identifies and optimizes the resource allocation from three key aspects. First, due to the pre-configuration of distinct map slots and reduce slots which are not fungible, slots can be severely under-utilized. Because map slots might be fully utilized while reduce slots are empty, and vice-versa. We propose an alternative technique called Dynamic Hadoop Slot Allocation by keeping the slot-based model. It relaxes the slot allocation constraint to allow slots to be reallocated to either map or reduce tasks depending on their needs. Second, the speculative execution can tackle the straggler problem, which has shown to improve the performance for a single job but at the expense of the cluster efficiency. In view of this, we propose Speculative Execution Performance Balancing to balance the performance tradeoff between a single job and a batch of jobs. Third, delay scheduling has shown to improve the data locality but at the cost of fairness. Alternatively, we propose a technique called Slot PreScheduling that can improve the data locality but with no impact on fairness. Finally, by combining these techniques together, we form a step-by-step slot allocation system called DynamicMR that can improve the performance of MapReduce workloads substantially. The experimental results show that our DynamicMR can improve the performance of Hadoop MRv1 significantly while maintaining the fairness, by up to $46 \sim 115$ percent for single jobs and $49\sim 112$ percent for multiple jobs. Moreover, we make a comparison with YARN experimentally, showing that DynamicMR outperforms YARN by about $2 \sim 9$ percent for multiple jobs due to its ratio control mechanism of running map/reduce tasks.