This article provides an up-to-date survey of hybrid fiber-wireless (FiWi) access networks that leverage on the respective strengths of optical and wireless. A definitive objective of Fiber-Wireless (FiWi) systems is the meeting of different optical and wireless innovations under a solitary base keeping in mind the end. Survey Smoothly Fiber-Wireless (FiWi) Accessing Wireless Networks: Convergence and Challenges. Naseer Hwaidi Alkhazaali, Raed Abduljabbar Aljiznawi.
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Fiber-wireless (FiWi) access networks: A survey
This paper has citations. The aggregation of multiple bandwidth request messages into a small number of REPORT messages helps reduce the signaling overhead and achieve an improved throughput-delay performance.
Due to the difficulty and prohibitive costs of supplying optical fiber to all end-user premises as well as the spectrum limitations of wireless access networks, bimodal FiWi access networks are more attractive than relying on either stand-alone access solution.
Whenever the wireless link conditions change, a WiMAX subscriber station sends a bandwidth request message to its associated ODU to update its service requirements. Furthermore, FiWi research also includes the study of different remodulation schemes for the design of colorless i.
To make sure that the resultant link state prediction LSP is accurate, the authors proposed to use weighted moving average WMA to estimate the traffic intensity of a given link between the current LSA message and the next LSA message. In the WMN, each mesh node has two radios with several orthogonal channels per radio.
At the end of each interval, the lightpaths may be dynamically reconfigured in response to varying traffic demands. Today, Internet technology and renewable energies are beginning to merge in order to create the nerworks for the TIR economy, which has been officially endorsed by the European Commission as economic neetworks roadmap toward a competitive fiber-wwireless carbon society by and has been implemented by several early adopting countries such as Germany, England, and Italy, as well as cities such as San Antonio, TX, USA, among others [ ].
According to recent market data by ABI Research, the number of fixed broadband subscribers will rise to million by the end ofof which million will subscribe to services delivered via fiber. In this section, we describe a number of algorithms that help solve important FiWi network planning problems related to the optimal placement of ONUs, mitigation of the detrimental impact of wireless interferences for peer-to-peer communications between wireless end-users, and architectural modifications for the support of direct inter-ONU communications.
Fiber-wireless FiWi access networks: Fiber to the x Network topology. While significant progress has been made at the PHY layer of FiWi and in particular RoF transmission systems, FiWi networking research on layer-2 and layer-3 related issues has begun only recently. For downstream data transmissions to a wireless destination node, the OLT selects a gateway such that data packets travel on the minimum delay path across the EPON and fiber-wireles mesh front-end.
It also improves the average hop count compared to the netaorks throughput routing algorithm. However, these data packets may arrive nteworks the OLT out of order due to the fact that each path in general has a different delay. Traditionally, wireless and optical fiber networks have been designed separately from each other.
The additional transceiver enables ONUs to send data directly to each other across the AWG rather than going through the OLT, resulting in an improved throughput-delay performance under peer-to-peer traffic.
Recall from above that beside reliability, latency is a key requirement of not only fiber-wireldss grid communications but netqorks LTE-A fiber backhaul infrastructures. At the downside, it must be mentioned that the proposed architecture is quite complex and costly.
Toward this end, in the central hub of the FiWi network a network terminal continually monitors the buffer depth of each OLT for the downstream traffic. Each receiving ONU determines to discard or forward the traffic according to the location of the destination mesh fober-wireless.
Optical fiber provides an unprecedented bandwidth potential that is far in excess of any other known transmission medium and offers significantly longer ranges without requiring any active devices.
In the second phase of the algorithm, for each primary ONU a set of wireless end-users is obtained such that the distances between the ONU and its wireless end-users are minimized. After describing recent progress, we elaborate on the role of FiWi access networks in the dawning age of convergence and outline some exciting research directions for future FiWi access networks.
In netwoeks past, WiFi and cellular radio access networks RANs have been in constant competition, until recently when tighter integration of both capacity-centric WLAN and coverage-centric mobile networks has emerged as a necessary paradigm [ 96 ].
Survey on Integrated Fiber-Wireless ( FiWi ) Access Network Architectures – Semantic Scholar
The proposed channel assignment scheme performs load balancing of traffic flows across different channels in order to maintain a similar level of contention on each channel.
In this approach, packets belonging to the same flow are sent to the OLT along multiple paths. Equipping some of the wireless mesh routers with an additional radio does not lead to an increased maximum throughput due to the fact that the bottleneck links remain the same; however, it helps reduce the average delay of the network to some extent.
However, availability-aware routing is less bandwidth-efficient than the shortest path routing due to an increased mean number of hops. Moreover, the dynamic allocation of radio resources enables cost-effective and simple handovers. The optical switches have full wavelength conversion capability and interconnect the APs and CO by means of shared point-to-point lightpaths. To measure the network throughput gain in FiWi networks, a linear programming based routing algorithm was proposed in [ 43 ].
In FiWi networks, traffic may go from wireless end-users to the Internet or from one wireless client to another wireless client. RoF networks have been studied for many years as an approach to integrate optical fiber and wireless networks.
View at Google Scholar Z. MuralidharanWeichao WangAlexander M. In the upstream direction, each optical terminal is made colorless by deploying a reflective semiconductor optical amplifier RSOA for remote modulation of a continuous wavelength signal sent by the central hub. More precisely, if the primary gateway fails, then all the paths to that gateway become stale and packets destined for the primary gateway are rerouted through live PGG paths.
Citations Publications citing this paper. Note, however, that unlike OWI networks, OW links and networks do not involve any wired fiber infrastructure. The resultant peer-to-peer traffic can be routed either through the multihop wireless path within the wireless subnetwork or through the wireless-optical-wireless path, whereby traffic is first sent from mesh client via its associated mesh router to its closest ONU 1 and is then forwarded upstream to the OLT.
To solve this optimization problem, the authors applied a tabu search based heuristic, a widely used metaheuristic algorithm for solving combinatorial problems.