Naive-LSTM based services awareness of edge computing elastic optical networks

Great challenges and demands are presented by increasing edge computing services for current elastic optical networks(EONs) to deal with serious diversity and complexity of these services. To improve the match degree between edge computing and optical network, the services awareness function is necessary for EON. This article proposes a Naive long short-term memory(Naive-LSTM) based services awareness strategy of the EON, where the Naive-LSTM model makes full use of the most simplified structure...     

Dynamic fragments awareness based virtual network mapping strategy of elastic optical networks

As virtual networks services emerge increasingly with higher diversification, the issue of spectrum fragments presents great challenge to the elastic optical networks (EON), especially under heaven services burdens. Aimed to solve this problem, this article proposes a dynamic fragments awareness based virtual network mapping (DFA-VNM) strategy of elastic optical network. In this proposed approach, the dynamic fragments awareness model of it is established, which takes available bandwidth demand and spectrum fragment degree into consideration. Moreover, the dynamic fragments awareness based virtual network mapping strategy makes full advantage of real-time fragments awareness result to conduct virtual network service mapping operation with less fragments and lower blocking rate. Testing results show that the proposed approach is able to improved services supporting ability of EON.     

Light-weighted services awareness scheme of the IP and optical converged network

As internet services newly emerge with diversity and complexity, great challenges and demands are presented to both IP network and optical network to support various services. Aimed to solve this problem, this paper proposes a light-weighted echo-state-network (LW-ESN) based services awareness scheme of the software defined IP and optical converged network. This LW-ESN model adopts the ring topology structure inside and generates the probability output result to determine the quality of service policy of IP and optical converged network. Moreover, the LW-ESN based service awareness engine is also designed in controller node of IP and optical converged network to perform services awareness by obtaining service traffic parameters from IP and optical layers, together with necessary working procedure. Simulation results show that the proposed approach is able to improve the services-oriented supporting ability in terms of blocking rate and delay time.     

Physical impairments awareness based virtual network mapping strategy of elastic optical networks

As virtual networks services emerge increasingly with higher requirement of flexibility and robust, great complex challenges caused by physical-layer impairments are presented to the elastic optical networks(EON). Aimed to solve this problem, this paper proposes a physical impairment awareness based virtual network mapping stragegy of EON. The physical impairments awareness model is established, including both of linear factors and nonlinear ones. On this basis, this paper proposes a virtual network mapping strategy with detailed procedures, combined with node importance factors during the virtual network mapping procedure. Test results show that the proposed approach is able to reduce blocking rate and enhance services supporting ability of EON.     

Research on the multicast mechanism based on physical-layer-impairment awareness model for OpenFlow optical network

A physical-layer-impairment (PLI)-awareness based optical multicast mechanism is proposed for OpenFlow controlled optical networks. This proposed approach takes the PLI models including linear and non-linear factors into optical multicast controlled by OpenFlow protocol. Thus, the proposed scheme is able to cover nearly all PLI factors of each optical link and to conduct optical multicast with better communication quality. Simulation results show that the proposed scheme can obtain the better performance of OpenFlow controlled optical multicast services.     

“光进铜退”热潮中二层汇聚网与光接入网的融合

在基于PON的"光进铜退"建设热潮中,如何优化整个二层网络的结构是关系到投资效率、业务能力与质量、运维成本的重要问题.本文重点从技术能力、建网和维护成本、网络扁平化的发展趋势、网络可靠性等方面综合分析了光接入网与L2(二层)汇聚网络融合的必要性和可行性,并给出了将来光接入网与L2汇聚网络融合的路线.针对这种融合的趋势,结合当前OLT和汇聚交换机的发展现状,提出了OLT和汇聚交换机的发展方向和急需解决的问题.最后,结合当前的网络现状,从充分利用现网资源,节约近期投资的角度,提出了近期光接入网的OLT上联组网模式.     

Resilient burst ring: extend IEEE 802.17 to WDM networks

In this article, a novel network architecture called resilient burst ring is proposed to implement the next-generation WDM-supported ultrahigh- speed (100 gigabit or higher) carrier Ethernet. This architecture inherits all the best features of resilient packet ring (IEEE 802.17), provides a burst-mode data transmission scheme through a two-sublayer (optical and electronic) hierarchy, and realizes the WDM-supported ultra-high-speed Ethernet with scalability and reliability. RBR adopts a two-layer buffering scheme to resolve the contentions of optical burst packets and provides three different data transmission modes. With the proposed Priority- Only-Destination-Delay resource reservation control protocol, RBR can provide a flexible QoS strategy to implement the transmission of all of the applications and services in existing networks.     

Mobility management in heterogeneous wireless networks

In heterogeneous wireless networks, mobile users are able to move from their home networks to different foreign networks while maintaining access capability to their subscribed services, which refers to global mobility. One of the key challenges in global mobility management is intersystem location management, which consists of keeping track of mobile users who roam into foreign networks. This paper presents an overview of mobility management in heterogeneous wireless networks and introduces a scheme which improves location management efficiency in terms of total signaling costs and intersystem paging delay. More specifically, cost reduction reaches about 50% when comparing the proposed architecture with conventional architectures.     

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.     

The Broadband Access Facility

The deployment of broadband access networks will revolutionise many aspects of society in the early years of the next millennium. Manufacturers, telecommunications providers and cable television operators world-wide are investing heavily on research into networks that provide broadband multimedia services to customers. BT has developed a prototype of a full service access network that can connect customers via optical fibre, digital subscriber line or radio technologies. This paper describes the physical implementation of the prototype network and the wide range of services that it can support.This prototype network, referred to as the 'broadband access facility' is enabling BT and its partners to understand the best access architectures for a given environment through practical testing. The network now serves as an experimental platform, that can be used for communicating broadband concepts, designing operational processes, developing management solutions and testing advanced applications.The full service access networks (FSAN) initiative is a collaboration involving fourteen of the world's leading telecommunications network operators and major equipment manufacturers. Its vision is to create a shared requirements specification for access systems supporting narrowband and broadband services. This common specification will mean that broadband network components can be developed for world markets, thus raising volumes and driving down unit costs. The common system specification is based around an ATM/SDH (asynchronous transfer mode/synchronous digital hierarchy) core network, with local optical fibre distribution via an ATM PON (passive optical network). DSL (digital subscriber line) systems maximise reuse of existing copper plant. The exact DSL system used depends upon where the optical system is terminated, e.g. in the local exchange, cabinet, kerb or home. Hence this broadband access system can support a range of access architectures — this flexibility is fundamental to the consensus achieved in FSAN.     

Enhanced Dynamic Bandwidth Allocation Algorithm in Ethernet Passive Optical Networks

As broadband access is evolving from digital subscriber lines to optical access networks, Ethernet passive optical networks (EPONs) are considered a promising solution for next generation broadband access. The point‐to‐multipoint topology of EPONs requires a time‐division multiple access MAC protocol for upstream transmission. In this paper, we propose a new enhanced dynamic bandwidth allocation algorithm with fairness called EFDBA for multiple services over EPONs. The proposed algorithm is composed of a fairness counter controller and a fairness system buffer in the optical line terminal. The EFDBA algorithm with fairness can provide increased capability and efficient resource allocation in an EPON system. In the proposed EFDBA algorithm, the optical line termination allocates bandwidth to the optical network units in proportion to the fairness weighting counter number associated with their class and queue length. The proposed algorithm provides efficient resource utilization by reducing the unused remaining bandwidth made by idle state optical network units.     

Design of Optical Content Distribution Networks for Video on Demand Services

This paper presents the design of optical content distribution networks for video on demand (VoD) services. The proposed Ethernet-based WDM network architecture is decentralized and consists of independent regional ring networks with locally deployed video servers. Based on an Integer Linear Programming (ILP) model, a network design tool, minimizing the total installation cost for optical network equipment on the metro and the Hybrid Fiber Coax (HFC) access network, has been developed. Unicast as well as broadcast VoD services are taken into account. The influence of different parameters in our traffic and content models on the network design is studied.     

Proposal of networking by PON technologies for full and ethernet services in FTTx

The construction of optical access networks is one of key issues to provide new broad-band services and emulation of legacy services. Passive optical network (PON) technologies realize sophisticated and economical optical access networks for these purposes. This paper summarizes requirements and technical and marketing trends for optical access networks. It also presents advantages of networking by PON technologies for optical access networks. Moreover, it clarifies issues to install and operate PON base optical access networks and proposes solutions for these issues.     

IPACT With Grant Estimation (IPACT-GE) Scheme for Ethernet Passive Optical Networks

Dynamic bandwidth allocation (DBA) is an open and hot topic in the Ethernet passive optical network (EPON), which is regarded as one of the best choices for next-generation access networks. This paper proposes an estimation-based scheme, interleaved polling with adaptive cycle time with grant estimation (IPACT-GE), for effective upstream channel sharing among multiple optical network units (ONUs) in EPONs. By estimating the amount of new packets arriving between two consecutive pollings and granting ONUs with extra estimated amount, the proposed IPACT-GE scheme can achieve shorter waiting delay and less buffer occupancy at the light load than IPACT, a significant DBA scheme in EPONs. Moreover, when combined with the strict priority queue (SPQ) mechanism to provide differentiated services, IPACT-GE can greatly mitigate the light load penalty that is obvious in the IPACT solution combined with SPQ.      

Very-high-speed fibre-optic networks for broadband communications

Single-mode optical fibres have an enormous transmission bandwidth which can support ultra-high-speed digital transmission and networking. The use of electrical signal-processing, however, ultimately limits the network capacity. To eliminate the throughput bottleneck, all-optical processing techniques should be employed in a fibre-optic network. This paper discusses several schemes for implementing optical time division multiple access (OTDMA) networks with the emphasis on optical clock distribution, synchronisation and all-optical detection. The use of a fast-switching bistable laser diode as an all-optical threshold detector and data regenerator is suggested. A dual-wavelength OTDMA technique is investigated, which can be used for digital TV or future HDTV distributions. Moreover, an efficient multiple access scheme, called wavelength division multiple access with optical time division multiplexing (WDMA-OTDM), is proposed for broadband communication services. It is shown that WDMA-OTDM has all the advantages possessed by the individual OTDMA and WDMA schemes but offers improved flexibility and capacity     

认知 mesh 网络服务区分的动态频谱接入策略

动态频谱接入策略是实现认知无线电网络高效利用频谱的关键。与传统认知无线电网络不同,认知mesh网络中不同QoS需求的多类型业务共同接入,为适应这一特点,提出服务区分的动态频谱接入策略。策略依据业务的QoS需求确立优先级,针对不同优先级业务采取不同的信道接入方案,实时业务依据最优传输延迟期望选择接入信道集合,在减小传输延迟的同时降低数据传输过程授权用户出现的概率,普通业务选择最优理想传输成功概率的信道,降低信道切换概率。理论与实验结果表明,与传统的认知网络频谱接入策略相比,提出的策略能提供不同业务的服务区分,满足实时业务的低延迟需求,降低数据传输的中断率,同时在授权信道空闲率与网络负载较大时吞吐量性能较优。     

Key Management in Secure Satellite Multicast Using Key Hypergraphs

Satellite networks play an important role in today’s information age because they can provide the global coverage services. Information security is an important concern in satellite multicast communications, where eavesdropping can be performed much easier than the fixed terrestrial networks. In this work, a novel multicast key management scheme based on key hypergraph for satellite networks on a predefined communication scenario is proposed. We use logical key hierarchy and distributed-logical key hierarchy as reference models for performance comparisons. It is shown that the proposed multicast key management scheme is scalable to large dynamic groups and minimizes satellite bandwidth usage.     

Routing and fast protection in networks of long-reach PONs

This paper reports on proposed solutions to the recovery from faults in a generic class of networks, where customer access is achieved via long-reach passive optical networks (LR-PONs), with the majority of customers enjoying protection in the backhaul regime to two separate metro nodes. Initial modelling studies suggest that in the event of a cable failure or single equipment element failure, redirected data will almost always leave the transmitting node in under 50 ms. For more catastrophic failures (such as router failure or loss of a metro node), recovery might take between 100–200 ms. Reachability information for each LR-PON is discovered over each area of the network, and used to inform the redirection of traffic via tunnels. The scheme uses IP signalling to enable traffic re-routing, although the underlying services may be of any type (e.g. private line) — making the scheme separate from the service, customer or provider.     

A provable and secure mobile user authentication scheme for mobile cloud computing services

The mobile cloud computing (MCC) has enriched the quality of services that the clients access from remote cloud‐based servers. The growth in the number of wireless users for MCC has further augmented the requirement for a robust and efficient authenticated key agreement mechanism. Formerly, the users would access cloud services from various cloud‐based service providers and authenticate one another only after communicating with the trusted third party (TTP). This requirement for the clients to access the TTP during each mutual authentication session, in earlier schemes, contributes to the redundant latency overheads for the protocol. Recently, Tsai et al have presented a bilinear pairing based multi‐server authentication (MSA) protocol, to bypass the TTP, at least during mutual authentication. The scheme construction works fine, as far as the elimination of TTP involvement for authentication has been concerned. However, Tsai et al scheme has been found vulnerable to server spoofing attack and desynchronization attack, and lacks smart card‐based user verification, which renders the protocol inapt for practical implementation in different access networks. Hence, we have proposed an improved model designed with bilinear pairing operations, countering the identified threats as posed to Tsai scheme. Additionally, the proposed scheme is backed up by performance evaluation and formal security analysis.     

Data dissemination with interoperability in IoT network

Internet of Things (IoT) is connected to heterogeneous devices. Efficient adaptive scheduling with encoding and decoding of data is an unaddressed issue in IoT. This paper processes the data under three major hierarchy: namely, adaptability, scheduling of data, and network coding for that data. The reliable access to the information is ensured by a device which is a primary eminence in IoT. Device must be able to adapt itself according to the changes in the network and to maintain its reliability as well as transparency and seamless access to the resources. To enhance the performance of the data dissemination, the scheduling process is investigated using the spatial grouping in IoT devices; this is achieved by joint spatial and code domain scheduling scheme, and the novel preconfigured access scheme is coined in order to minimize the collision rate of arbitrary access; during the data dissemination, the erasure coding scheme is used for the encoding and decoding of packets which provides optimal redundancy. We carried the simulation using Contiki and it shows the proposed Polymorphic Erasure Coding with Markov decision Adaptability and Neural networks (PECMAN) improves in terms of cost, overhead, and delay when compared with Multi‐user Shared Access (EMUSA), Polynomial‐time Optimal Storage Allocation (OSA) scheme, and Event‐Aware Back pressure Scheduling Scheme (EABS).