Yinpeng Yu

Planning of survivable long-reach passive optical network (LR-PON) against single shared-risk link group (SRLG) failure

Long-Reach Passive Optical Network (LR-PON) is known as a promising and economical solution for Next-Generation PON (NG-PON). Survivability is one of the key issues in the planning of LR-PON because massive high-rate traffic flows may be interrupted in case of network component failure. However, the survivability issue for LR-PON is addressed in little works. More importantly, most of the previous works focus on single distribution fiber failure and remain untouched the simultaneous failure of multiple distribution fibers, which is a possible failure scenario in LR-PON. In this paper, we focus on the survivability of LR-PON against single Shared-Risk Link Group (SRLG) failure. A reliability model is proposed to represent the disconnection probability of the ONUs. Based on this reliability model, we propose a novel Backup Fibers Protection (BFP) scheme. In the BFP scheme, we deal with the optimization problem of allocating backup capacity and deploying backup fibers. Under the constraint of reliability requirement, our objective is to fully protect all traffic demand in the network with the minimum deployment cost of backup fibers. Both ILP-based approach and heuristic approach are proposed to solve the optimization problem in the BFP scheme. To the best of our knowledge, this paper is the first work regarding the survivability of LR-PON against single SRLG failure. Through extensive simulation, we investigate the performance of BFP and demonstrate its effectiveness in different scenarios.

Planning of survivable cloud-integrated Wireless-Optical Broadband Access Network against distribution fiber failure

Abstract Cloud-integrated Wireless-Optical Broadband Access Network (WOBAN), which combines the advantages of wireless access network and optical access network, is becoming a promising hybrid architecture for access networks. Although it has many significant advantages, survivability still plays an important role in the performance optimization of cloud-integrated WOBAN, because the network component failure will cause huge data loss. Meanwhile, users need ubiquitous broadband access for cloud services which can be provided by cloud-integrated WOBAN. Hence, this paper proposes an approach for the planning of survivable cloud-integrated WOBAN to support ubiquitous urban area cloud-integrated wireless-optical broadband access. By Integer Linear Programming (ILP) model and heuristic solution, the proposed approach aims at the maximal coverage under the survivability constraints on the connection of wireless routers. When a distribution fiber is broken, each ONU can transmit data to its backup ONU using wireless routers via the node-disjoint wireless paths with the constraints of transmission delay. Simulation results show the network coverage of user ends for different numbers of ONUs and wireless routers, and illustrate the relationship between network coverage and cost represented by the number wireless routers. At the same time, this approach demonstrates itself about the feasibility to the real urban area cloud-integrated wireless-optical broadband access.

Deployment of survivable fiber-wireless access for converged optical and data center networks

Abstract As a promising solution for the bandwidth bottleneck of Data Center (DC) network, the converged optical and DC networks have gained an increasing popularity due to their advantages in rich bandwidth and high reliability. Although the converged optical and DC networks bring the opportunity for high-speed transmission of DC traffic, they also impose more severe challenge on the survivability design, because the network component failure will cause greater data loss. Some works focus on the survivability of core network for the convergence of optical and DC networks and remain less touched on that of access network. In fact, access network plays an important role in the reliable transmission of the traffic between end-users and DC, which accounts for considerable portion of all DC traffic. However, since the vulnerability to component failure, the traditional Passive Optical Network (PON) may no longer satisfy the higher survivability requirement. As an emerging broadband access technology, Fiber-Wireless (FiWi) may be a preferable candidate for the survivable access of converged optical and DC networks. In FiWi access network, the Wireless Mesh Network (WMN) at front-end can protect the Passive Optical Network (PON) at back-end by wirelessly rerouting. This paper focuses on the deployment of survivable FiWi access network against single distribution fiber failure, which is a typical failure scenario in optical access network. We propose a new protection approach called Wireless Rerouting with Backup Radios (WRBR) for the deployment of survivable FiWi access network. In WRBR, we deal with the optimization of wireless routers placement and backup radios configuration. Both Integer Linear Programming (ILP) and heuristic approach are proposed, aiming to minimize the deployment cost. Simulation results demonstrate the advantage of WRBR in saving deployment cost of FiWi access for converged optical and DC networks over the previous works.

Hybrid fiber-wireless network: an optimization framework for survivable deployment

Abstract—Hybrid fiber-wireless (FiWi) networks, which benefit from high bandwidth and ubiquitous access of optical and wireless networks, have been identified as a promising technology candidate for next-generation broadband access. As various component/fiber failures may occur in hybrid FiWi networks, thus affecting huge numbers of end users, survivability has become one of the key important deployment considerations in such networks. This paper focuses on developing optimal network planning strategies to achieve survivable hybrid FiWi networks. In particular, to address the additional cost involved in deploying backup fibers in previously proposed redundancy strategies against distribution fiber failures, we propose the use of wireless routing through the ubiquitous wireless coverage of end users in a hybrid FiWi network. We present an optimization framework to optimally plan and deploy a survivable hybrid FiWi network, where traffic from an affected optical network unit (ONU) can be effectively rerouted to backup ONUs through wireless connections in the event of a distribution fiber failure. However, focusing only on the resilience of a network without considering its cost, and ignoring the resultant capacity, latency, and coverage under normal and protection operating conditions, is impractical. Our proposed framework therefore ensures maximum end-user coverage whilst satisfying survivability, connectivity, delay, and capacity constraints of the network, by optimizing the placement of passive optical splitters, ONUs, and wireless routers in conjunction with fiber and wireless connections. Moreover, we demonstrate the feasibility of our framework in the context of an urban deployment under different deployment scenarios. In particular, our results provide insight into how survivable FiWi networks can be deployed without compromising on the latency, coverage, and capacity requirements of such networks.

Optimization and Deployment of Survivable Fiber-Wireless (FiWi) Access Networks with Integrated Small Cell and WiFi

Fiber-Wireless (FiWi) access network as a small cell backhaul is now becoming a promising architecture to satisfy the rapid growth of demand for mobile data traffic. With increasing amount of network traffic, the failure of network components such as distribution fiber link failure may lead to unpredictable service outages. The network survivability through protection and restoration has become a critical requirement. Thus, in this paper, we explore the protection mechanism for small cells by integrating WiFi and rerouting of data traffic over WiFi to offer some restoration of backhaul capacity. Using this architecture, we propose a novel method to optimize the deployment and maximize the coverage of survivable FiWi access network, with appropriate constraints from connectivity, survivability, capacity and delay perspectives. Our simulation results show the successful reconfiguration of survivable FiWi access networks with integrated small cell and WiFi under different simulated network failure scenarios and we demonstrate feasibility of the proposed optimization method.

Joint wireless and optical resources allocation for availability-guaranteed service in survivable fiber-wireless access network

The fiber-wireless (FIWi) access network not only leverages the technical merits of wireless and optical access networks, but also provides a potential opportunity for the design of survivable access networks. Previous works have studied the survivability of FiWi access network against network component failure by means of backup fiber deployment and wireless rerouting. However, most of these works put less attention on the connection availability and ignore the joint allocation of wireless and optical resources, which plays an important role in improving the global network performance gain. In this paper, we consider a notable failure scenario in FiWi access network but less mentioned in previous works, i.e., single shared-risk link group failure. We first propose a model for FiWi network to estimate the connection availability of service demand. Then, a novel resource allocation approach is proposed to provide the availability-guaranteed service. Under the requirements of bandwidth and connection availability, we deal with the optimal allocation of joint wireless and optical resources with the objective of minimum resource consumption. Numerical results demonstrate that the proposed scheme can reduce the resource consumption significantly compared to the resource allocation without considering connection availability.

Survivable deployment of cloud-integrated fiber-wireless networks against multi-fiber failure

Cloud-integrated fiber-wireless (FiWi) networks inheriting advantages of optical and wireless access networks have a broad prospect in the future. As various component failures may occur in cloud-integrated FiWi networks, survivability is becoming one of the key important issues. It is necessary to provide survivability strategies for cloud-integrated FiWi networks. Hence, this paper mainly focuses on the survivability of cloud-integrated FiWi networks against multiple fibers failure. Firstly, in this paper, a novel integer linear programming (ILP) solution is proposed to tolerate the failure of multiple distribution fibers with capacity and coverage constraints in the context of urban area. Then, considering the complexity of ILP models, an efficient heuristic scheme is proposed, in order to get the approximate solutions of ILP. Simulation results and analysis give the configurations of optical network units (ONUs) and wireless routers with different constraints and show the network coverage of clients for different number of ONUs and wireless routers with ILP solution and heuristic approach, respectively.

Placement strategy for survivable hybrid WOBAN against multi-fibre failure

This paper focuses on the survivability of citywide hybrid Wireless-Optical Broadband Access Network (WOBAN). A protection scheme is proposed to tolerate the failure of multiple distribution fibers considering capacity and coverage problem. Simulation results show good performance of this scheme.

Connection availability based protection algorithm in wireless-optical broadband access network

The hybrid Wireless-Optical Broadband Access Network (WOBAN) provides a new and promising architecture for broadband access network by combining the beneficial properties of wireless and optical access technologies. To avoid huge data loss, WOBAN needs to be designed with a high availability guarantee. The purpose of this paper is to protect the Passive Optical Network at the back-end using the backup radios in Wireless Mesh Network at the front-end. The proposed protection scheme is based on a connection availability model. First, we assigned several backup Optical Network Units (ONUs) for each primary ONU not satisfying the availability requirement of primary optical connection. Under the availability requirement of backup optical connection, each backup ONU needed to reserve the residual capacity as the backup capacity to fully protect the traffic demand of its primary ONU. Then, we selectively deployed the additional radio interfaces as the backup radios for the wireless routers in the front-end under the availability requirement of backup wireless connection, in order to establish the wireless-backup-path between each pair of primary and backup ONUs. Each backup radio on the wireless-backup-path will retain the backup radio capacity for rerouting traffic, so as to decrease the possibility of traffic block in case of failure. We aimed to design efficient heuristic algorithms and yield suboptimal solutions for minimizing the consumption of backup ONU capacity and the cost of backup radios. Simulation results demonstrate the advantage of the proposed scheme compared to previous works.