2 research outputs found
Attention to Wi-Fi Diversity: Resource Management in WLANs with Heterogeneous APs
Many home networks integrate a small number (typically 2-4) of Wi-Fi Access Points (APs), with heterogeneous characteristics: different 802.11 variants, capabilities and security schemes. This paper proposes the consideration of these specific characteristics in order to improve the management of network resources. Three use cases are presented in order to showcase the potential benefits. By the use of a user-space AP, which works in coordination with a controller, the network is able to assign each connected station to the AP that best fits with its characteristics. The system also manages security, avoiding the need of adding specific elements for authentication, encryption or decryption. Extensions are proposed to an existing protocol that defines the communication between the AP and the controller, in order to communicate and store the specific characteristics of each AP and end device. This includes new association and handoff schemes that do not introduce any additional delay. The system has been implemented in a real environment, and a battery of tests has been run using three hardware platforms of different characteristics. The results show that handoffs between bands are possible, and estimate the processing delays, the Round-Trip Time and the handoff delay, which is small enough in order not to produce any significant disruption to the user (10-50 ms). Finally, the scenarios of interest have been replicated in a simulation environment, showing that significant benefits can be achieved if the specific characteristics of each AP and station are considered
SOSW: Scalable and optimal nearsighted location selection for fog node deployment and routing in SDN-based wireless networks for IoT systems
In a fog computing (FC) architecture, cloud services migrate towards the network
edge and operate via edge devices such as access points (AP), routers, and switches. These
devices become part of a virtualization infrastructure and are referred to as āfog nodesā.
Recently, software-defined networking (SDN) has been used in FC to improve its control
and manageability. The current SDN-based FC literature has overlooked two issues: (a) fog
nodesā deployment at optimal locations and (b) SDN best path computation for data flows
based on constraints (i.e., end-to-end delay and link utilization). To solve these optimization
problems, this paper suggests a novel approach, called scalable and optimal near-sighted
location selection for fog node deployment and routing in SDN-based wireless networks
for IoT systems (SOSW). First, the SOSW model uses singular-value decomposition (SVD)
and QR factorization with column pivoting linear algebra methods on the traffic matrix of
the network to compute the optimal locations for fog nodes, and second, it introduces a
new heuristic-based traffic engineering algorithm, called the constraint-based shortest path
algorithm (CSPA), which uses ant colony optimization (ACO) to optimize the path computation process for task offloading. The results show that our proposed approach significantly
reduces average latency and energy consumption in comparison with existing approaches