带有卸载压缩激励的云增强FiWi网络节能机制

针对云增强型光纤-无线(FiWi)网络能耗以及卸载的通信开销过大问题,该文提出一种自适应卸载压缩节能机制(ESAOC),针对不同类型的业务属性和最大的容忍时延,结合光网络单元的负载变化和无线网状网的流量情况,通过统计的方式获得不同优先级卸载数据的平均到达率,再结合各个节点的压缩时延,动态调整业务的卸载压缩比,以降低卸载的通信开销;同时,建立排队模型分析卸载业务在MEC服务器的排队时延,协同调度无线侧中继节点,进而对光网络单元和终端设备进行协同休眠调度,最大化休眠时长,提高系统能源效率。结果表明,所提方法在有效降低整个网络能耗的同时能够保证卸载业务的时延性能。     

带有上行数据帧聚合的光无线融合接入网络节能机制

光无线融合接入网存在光网络单元利用率低,数据传输过程中控制开销较大的问题。该文提出一种带有上行数据帧聚合的节能机制,建立M/G/1模型分析数据帧在无线域节点及光域节点的队列时延,结合不同优先级业务的最大容忍时延,推导各优先级聚合帧在不同网络状态下的最佳长度,进而根据所得到的最佳帧长对光域节点进行休眠调度,在保障业务时延的前提下,尽可能地延长节点休眠时间长度,提高网络能量效率。仿真结果表明,所提方法在有效降低整个网络能耗的同时能够保证业务的时延性能。     

基于联合控制的无线传感器网络MAC协议

以多通道的随机多址无线传感器网络为研究对象,通过划分信息分组发送时间为1＋a,1时间内以概率p检测,可侦听与控制信道节点数和休眠站点数,从而降低系统耗能,有效延长节点生命周期;a内用非坚持的控制方式,可减少信息分组发送的时延;通过负载均衡,保证系统的吞吐量;通过减少空闲检测时间和忙时发送的碰撞以节省能耗。由此,给出了一种新的随机多址无线传感器网络MAC协议。用平均周期法对系统进行建模,分析得到系统的吞吐量、多业务优先级的吞吐量以及信息分组发送时延等参数。计算机仿真实验结果与理论计算有较好一致性。     

5G边云协同分布式网络架构下任务卸载模型

自动驾驶、增强现实等5G新兴的应用对网络时延和可靠性提出更高的挑战,针对边缘协同框架负载均衡问题,提出一种大规模边云协同分布式网络架构下的任务卸载模型.该模型以最低能耗为目标,根据任务特性与现有网络资源、计算资源和存储资源自适应优化任务卸载决策,通过整合边缘计算与云计算处理能力的优势,保证时延敏感型任务的质量,提高整个...     

EPON中一种新型的ONU休眠节能机制研究

为实现以太网无源光网络(EPON)的能源节省,提出了一种新型的基于双向业务流量的光网络单元休眠节能的控制机制。该机制通过扩展多点控制协议,并根据业务汇聚到缓存的容量来进行ONU休眠节能的时隙安排。仿真结果表明,该机制在实现绿色节能的同时可有效保证EPON网络的性能。     

TWDM-PON中带有业务区分的混合资源调度算法

针对时分波分复用无源光网络长距离和广覆盖特性带来往返时延增大,造成高优先级业务时延性能严重恶化的问题,提出带有业务区分的混合资源调度算法.根据网络负载实时调整光网络单元组的波长数以实现资源共享,并动态划分子周期以对不同优先级业务进行区分服务;设计混合资源调度算法,以在线方式填充波长空隙,以离线方式保障资源高效调度.仿真结果表明,所提算法能够满足不同优先级业务的时延要求,保证服务质量,并提高信道利用率.     

应用于航空Ad Hoc网络的高负载优先级均衡MAC协议

针对航空Ad Hoc网络在高负载下的低时延信道接入问题,提出一种优先级与公平性协作的多信道MAC协议(PBLL/HL)。在多信道检测统计基础上加以改进,结合优先级机制,在高负载网络中适时截流低优先级业务,优化网络流量,保证高优先级业务低时延发送;设计公平性优先级阈值与冲突退避窗口算法(PCA),减小低优先级业务接入时延。仿真结果表明,PBLL/HL能够在高负载网络有效控制信道接入,维持良好的网络流量,降低网络平均接入时延(低优先级业务时延过载时降低10%以上),稳定高负载网络吞吐量(最大吞吐量88.1%,过载时吞吐量下滑平缓),解决了航空数据链高业务量带来的高时延和网络拥塞。     

EPON中节能动态带宽分配算法

结合光网络单元(ONU)休眠控制和动态带宽分配机制,提出一种节能的双向DBA算法。该算法根据上/下行业务量为每个ONU分配合适的上/下行授权带宽,保证每个ONU在上/下行方向都具有较低的传输时延,同时尽可能增加ONU的休眠时间来降低网络能耗。仿真结果表明,与已有算法相比,该算法具有较低的上/下行平均时延,并能减少ONU的能耗。     

新型随机多址接入无线传感器网络MAC控制协议与能量有效性分析

提出了一种新的随机多址接入无线传感器网络的MAC控制协议,在发送分组的时间1+a中,采用P概率检测与1-坚持的联合控制策略,并对多通道的随机多址接入无线传感器网络进行了分析,理论分析了系统的吞吐量和多通道中不同业务的吞吐量,以及信息分组的发送时延等参数,理论分析与仿真实验结果相一致.还结合无线传感器网络的能量有效性,通过对概率P值的选取,控制忙周期侦听信道的节点数和空闲期的休眠站点数,采用休眠技术实现了系统的节能效果.通过对2种无线传感器网络控制协议的能量有效性分析,证明了改进的控制协议其节点具有更长的生命周期,更适合作为无线传感器网络的MAC控制协议.     

太赫兹无线个域网公平高效的MAC层优化机制

针对太赫兹无线个域网双信道媒体访问控制(Medium Access Control, MAC)协议中存在的信道资源分配公平性差、数据帧重传效率低和控制开销较高的问题,提出了一种公平高效的MAC层优化机制。新机制采用基于历史时隙申请信息的信道资源分配策略优化时隙分配公平性,根据信道质量自适应选择数据帧重传机制,控制节点从申请时隙的节点发送的控制帧中的“duration”字段提取时隙申请信息,省略时隙申请帧的发送,从而降低数据帧排队时延和控制开销,提高吞吐量。仿真结果表明,与TAB-MAC和MDP-MAC协议的机制相比,所提机制的数据帧平均排队时延降低了15%,吞吐量提高了5%。     

QoS-aware energy-saving mechanism for hybrid optical-wireless broadband access networks

Hybrid optical-wireless broadband access network (HOWBAN) takes full advantage of the high capacity and reliability of the passive optical network and the flexibility, ubiquity of the wireless network. Similar to other access networks, the issue of high energy consumption is a great challenge for HOWBAN. In HOWBAN, optical network units (ONUs) consume a great amount of energy. The sleep of ONUs can greatly improve the energy efficiency of HOWBAN. However, the quality of service (QoS) will be decreased while the packets are waiting in ONUs and optical line terminal. In this paper, we propose a QoS-aware energy-saving mechanism. A dynamic bandwidth allocation mechanism is designed to guarantee the QoS, where different priorities are considered. Meanwhile, we employ different sleep strategies by taking different priorities’ tolerant delays into account to prolong the sleep time of ONUs. Then, based on the evaluation of packet delay, the optimal sleep parameter is derived to maximum the energy efficiency. In addition, a load balancing and resource allocation mechanism is adopted in the wireless domain to reduce the delay and congestion caused by ONUs’ sleep. Results show that the proposed mechanism can effectively improve the energy efficiency and meet the QoS requirements of packets.     

支持ONU模块独立不连续收发数据的节能方法

为有效解决绿色无源光网络中的节能效果与时延性能的矛盾,提出一种支持ONU模块独立不连续收发数据的节能方法。通过光网络单元的模块化,各能耗模块独立地切换睡眠或唤醒模式,从而在规定时隙内实现不连续地收发数据;通过子周期划分,将实时业务集中到第一个子周期内收发,提升了网络的总体服务质量;提出完全独立的上下行带宽分配算法,使所提方法在流量上下行不对称的应用场景更具优势。仿真表明,所提方法在保证业务时延性能的前提下,网络的能耗得到进一步降低。     

QoS‐aware cross‐domain collaborative energy‐saving mechanism for FiWi virtual networks

The fiber‐wireless (FiWi) access network is a very promising solution for next‐generation access networks. Because of the different protocols between its subnets, it is hard to globally optimize the operation of FiWi networks. Network virtualization technology is applied to FiWi networks to realize the coexistence of heterogeneous networks and centralized control of network resource. The existing virtual resource management methods always be designed to optimize virtual network (VN) request acceptance rate and survivability, but seldom consider energy consumption and varied requirements of quality of service (QoS) satisfaction, which is a hot and important topic in the industrial field. Therefore, this paper focuses on the QoS‐aware cross‐domain collaborative energy saving mechanism for FiWi virtual networks. First, the virtual network embedding (VNE) model, energy consumption model, and VNE profit model of FiWi networks are established. Then, a QoS‐aware in‐region VN embedding mechanism is proposed to guarantee service quality of different services. After that, an underlying resource updating mechanism based on energy efficiency awareness is designed to realize low‐load ONU and wireless routers co‐sleep in FiWi networks. Finally, a QoS‐aware re‐embedding mechanism is presented to allocate proper resource to the VNs affected by the sleeping mechanism. Especially for video VNs, a re‐embedding scheme which adopts traffic splitting and multipath route is introduced to meet resource limitation and low latency. Simulation results show that the proposed mechanism can reduce FiWi network's energy consumption, improve VNE profit, and ensure high embedding accepting rate and strict delay demand of high‐priority VNs.     

Sleep mode operation for IEEE 802.16e UGS based WiMAX

To solve the problem of energy efficiency drop in wireless metropolitan area network communication due to frequently sleep-awake transitions, the energy-saving mechanism of the sleep mode operation was researched in WMAN. In this paper we propose a dynamic algorithm to tune the ratio of the sleep windows and receive windows according to the real time load. Then, a Markov chain model was set up to analyze the energy efficiency and mean access delay. NS2 simulation results show that the proposed algorithm can achieve marked gain in energy efficiency compared to the traditional energy saving mechanism.     

利用用户移动提高WiFi业务分担能力的用户激励机制研究

WiFi网络可以分担蜂窝网络的通信业务压力,缓解其拥塞状况。然而,WiFi网络的业务分担只能在其覆盖范围内进行。由于用户具有移动性,如果通过提供一些奖励引导WiFi网络覆盖范围之外的用户延迟其在蜂窝网络中的业务、直至其进入WiFi覆盖区再接受服务,WiFi网络的业务分担能力将得到显著提升。该文探讨了运营商通过激励机制鼓励用户延迟其蜂窝网络业务转而接入WiFi网络的过程,并将其建模为两阶段斯塔克博格(Stackelberg)博弈。在该博弈中,运营商期望采取最优的奖励方案,能够兼顾蜂窝网络拥塞和付出的用户奖励。该文推导出了运营商的最优奖励方案。数值结果表明,所提激励机制可以有效降低包括蜂窝网络拥塞代价和奖励用户代价在内的运营商总代价。     

An Adaptive QoS Power Saving Scheme for Mobile WiMAX

With the rapid development of Internet and wireless communication technology, ubiquitous network services become more and more popular. WiMAX is widely used to solve the last mile in network deployment. To enhance the mobility, mobile WiMAX is launched to support the mobile usages. Due to the limited power of mobile devices, power saving becomes a key issue for mobile WiMAX applications. Though plenty of efforts have been proposed to save power on the mobile devices, the problems are partially solved. Among others, sleep mode operations are widely adopted to save power in wireless communications. Generally, longer sleep time can reduce power consumption at the cost of increased packet response delay. To improve the quality of services, an adaptive power saving scheme for mobile WiMAX is proposed in this paper. Parameters related to power management are dynamically set according to current network traffic load. The analyses and simulation results show that the proposed scheme presents superior power efficiency and packet response delay in the context of mobile WiMAX.     

V2X offloading and resource allocation under SDN and MEC architecture

To address the serious problem of delay and energy consumption increase and service quality degradation caused by complex network status and huge amounts of computing data in the scenario of vehicle-to-everything (V2X),a vehicular network architecture combining mobile edge computing (MEC) and software defined network (SDN) was constructed.MEC sinks cloud serviced to the edge of the wireless network to compensate for the delay fluctuation caused by remote cloud computing.The SDN controller could sense network information from a global perspective,flexibly schedule resources,and control offload traffic.To further reduce the system overhead,a joint task offloading and resource allocation scheme was proposed.By modeling the MEC-based V2X offloading and resource allocation,the optimal offloading decision,communication and computing resource allocation scheme were derived.Considering the NP-hard attribute of the problem,Agglomerative Clustering was used to select the initial offloading node,and Q-learning was used for resource allocation.The offloading decision was modeled as an exact potential game,and the existence of Nash equilibrium was proved by the potential function structure.The simulation results show that,as compared to other mechanisms,the proposed mechanism can effectively reduce the system overhead.     

RP-MAC: A Passive MAC Protocol with Frame Reordering for Wireless Sensor Networks

Idle listening is one of the main factors for energy consumption in wireless sensor networks, and the duty cycle mechanism is widely used to reduce idle listening. In this paper, we present a new receiver-initiated duty cycling MAC protocol for wireless sensor networks, called reordering-passive MAC (RP-MAC), which includes receiver wake-up time estimation scheme and frame reordering scheme. We evaluate the performance of RP-MAC in ns-2 network simulator, and the simulation results shows that RP-MAC achieves higher energy efficiency, higher network throughput and lower end-to-end delay compared to other passive protocols, especially in case of heavy traffic or low duty cycle.