Nowadays, broadband access network has obtained increasing attention among Internet users. High bandwidth demands and the need on mobility of the network are factors for the network design and architectures to be part of the hot topics in... more
Nowadays, broadband access network has obtained increasing attention among Internet users. High bandwidth demands and the need on mobility of the network are factors for the network design and architectures to be part of the hot topics in the research area. Wireline optical and wireless networks are two different architectures of broadband access network which offer advantages over each other. Quality of services (QoS) in telecommunication network has significant role in the flow of data in the network, particularly in data scheduling. This paper defines integrated optical wireless broadband access network, describes QoS focusing on integrated network and reviews some previous work on scheduling algorithms.
Completely GPS-free positioning systems for wireless, mobile, ad-hoc networks typically stress on building a network-wide coordinate system. Such systems suffer from lack of mobility and high computational overhead. On the other hand,... more
Completely GPS-free positioning systems for wireless, mobile, ad-hoc networks typically stress on building a network-wide coordinate system. Such systems suffer from lack of mobility and high computational overhead. On the other hand, specialized hardware in GPS-enabled ...
Optical technologies allow the end-user to take advantage of a very high bitrate access. This in turn modifies traffic patterns to be supported by access and aggregation (metro) networks. The present paper first proposes tentative traffic... more
Optical technologies allow the end-user to take advantage of a very high bitrate access. This in turn modifies traffic patterns to be supported by access and aggregation (metro) networks. The present paper first proposes tentative traffic scenarios to assess future capacity requirements for these networks. It is shown that the current aggregation architecture based on primary and secondary aggregation rings should be reconsidered to limit potential bottlenecks and to take account of both infrastructure costs and potential energy savings. The paper then presents alternative architectures to revise and move the boundaries existing today between access and aggregation networks. A first alternative architecture is fully centralized and performs traffic aggregation in a central location. The second alternative architecture proposes to locate the first aggregation points (called “Next Generation Points of Presence”) on the primary aggregation ring and to centralize control functions.
Completely GPS-free positioning systems for wireless, mobile, ad-hoc networks typically stress on building a network-wide coordinate system. Such systems suffer from lack of mobility and high computational overhead. On the other hand,... more
Completely GPS-free positioning systems for wireless, mobile, ad-hoc networks typically stress on building a network-wide coordinate system. Such systems suffer from lack of mobility and high computational overhead. On the other hand, specialized hardware in GPS-enabled nodes tends to increase the solution cost. A number of GPS free position based routing algorithms have been studied by the authors before proposing a new positioning framework in this paper. The proposed positioning framework is characterized by using only a handful of GPS enabled nodes. Lower dependence on specialized GPS hardware reduces the total cost of implementing the framework. A new location aided routing protocol called Location Aided Cluster Based Energy-efficient Routing (LACBER) has been proposed in the paper. Simulation results show that using the proposed positioning framework, LACBER turns out to be efficient in lowering mean hop and hence in utilizing the limited energy of mobile nodes
In elastic optical networks, a wavelength is divided into frequency slots (FS) and optical signals are switched at multiple FS intervals. On the other hand, network virtualization manages network resources by efficiently mapping virtual... more
In elastic optical networks, a wavelength is divided into frequency slots (FS) and optical signals are switched at multiple FS intervals. On the other hand, network virtualization manages network resources by efficiently mapping virtual nodes and links to physical ones (virtual network embedding). In this paper, we propose a dynamic virtual network embedding algorithm to decrease the rejection rate of virtual optical network requests. We define four schemes for node mapping. For link mapping, the primary path, which is the shortest path between the mapped nodes, is computed. If there are no available FSs, path splitting is performed and FSs are assigned at links in primary and alternatives paths. By simulation, we evaluate the effectiveness of path splitting for NSFNET and ARPA2. Numerical results show that path splitting is effective in decreasing the rejection rate. Finally, LLNL scheme, which considers both node and link resources, has the smallest rejection rate.
