Low energy indoor network : deployment optimisation

This article considers what the minimum energy indoor access point deployment is in order to achieve a certain downlink quality-of-service. The article investigates two conventional multiple-access technologies, namely: LTE-femtocells and 802.11n Wi-Fi. This is done in a dynamic multi-user and multi-cell interference network. Our baseline results are reinforced by novel theoretical expressions. Furthermore, the work underlines the importance of considering optimisation when accounting for the capacity saturation of realistic modulation and coding schemes. The results in this article show that optimising the location of access points both within a building and within the individual rooms is critical to minimise the energy consumption

Future Evolution of CSMA Protocols for the IEEE 802.11 Standard

In this paper a candidate protocol to replace the prevalent CSMA/CA medium access control in Wireless Local Area Networks is presented. The proposed protocol can achieve higher throughput than CSMA/CA, while maintaining fairness, and without additional implementation complexity. Under certain circumstances, it is able to reach and maintain collision-free operation, even when the number of contenders is variable and potentially large. It is backward compatible, allowing for new and legacy stations to coexist without degrading one another's performance, a property that can make the adoption process by future versions of the standard smooth and inexpensive.Comment: This paper has been accepted in the Second IEEE ICC Workshop 2013 on Telecommunication Standards: From Research to Standard

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

Performance analysis of the IEEE 802.11e block ACK scheme in a noisy channel

A block ACK (BTA) scheme has been proposed in IEEE 802.11e to improve medium access control (MAC) layer performance. It is also a promising technique for next-generation high-speed wireless LANs (WLANs) such as IEEE 802.11n. We present a theoretical model to evaluate MAC saturation throughput of this scheme. This model takes into account the effects of both collisions and transmission errors in a noisy channel. The accuracy of this model is validated by NS-2 simulations