SINR-based Network Selection for Optimization in Heterogeneous Wireless Networks (HWNs)

To guarantee the phenomenon of "Always Best Connection" in heterogeneous wireless networks, a vertical handover optimization is necessary to realize seamless mobility. Received signal strength (RSS) from the user equipment (UE) contains interference from surrounding base stations, which happens to be a function of the network load of the nearby cells. An expression is derived for the received SINR (signal to interference and noise ratio) as a function of traffic load in interfering cells of data networks. A better estimate of the UE SINR is achieved by taking into account the contribution of inter-cell interference. The proposed scheme affords UE to receive high throughput with less data rate, and hence benefits users who are located far from the base station. The proposed scheme demonstrates an improved throughput between the serving base station and the cell boundary

Vertical Handover Management for VoIP Session over Brodband Wireless Networks

Today, wireless LAN (IEEE802.11g/n) has been the dominant wireless network that can provide high data rates in a \ud limited coverage area. While emerging mobile WiMAX (IEEE802.16e) can provide a wireless broadband access to \ud mobile users in a wide coverage area. These two different technolgies will co-exist while complementing each other in \ud some regions, hence, a mobile node (MN) with dual interfaces traverses and executes many handovers (HOs) between \ud 802.11g and 802.16e. Meanwhile, there is a huge demand for Voice over IP (VoIP) service over wireless networks. \ud However, VoIP is a delay and loss sensitive application, hence, VoIP session is more likely to be deteriorated during \ud HO between 802.11g and 802.16e. In order to maintain quality of VoIP session during HO, we proposed Vertical \ud Handover Management (VHM) for VoIP session that focuses on HO initiation and decision strategy according to the \ud wireless link condition and congestion state of wireless networks. The VHM exploits request to send (RTS) retries and \ud round trip time (RTT) between an MN and an access point in an 802.11g interface as well as a carrier to interference \ud noise ration (CINR) level and MN???s queue length of an 802.16e interface as HO triggers. We then conducted simulation \ud experiments to evaluate the effectiveness of our proposed VHM using QualNet 4.5. Our simulation results show that \ud our proposed VHM can preserve the quality of VoIP session during such HO

Context-aware multi-attribute decision multi - attribute decision making for radio access technology selection in ultra dense network

Ultra Dense Network (UDN) is the extreme densification of heterogeneous Radio Access Technology (RAT) that is deployed closely in coordinated or uncoordinated manner. The densification of RAT forms an overlapping zone of signal coverage leading to the frequent service handovers among the RAT, thus degrading overall system performance. The current RAT selection approach is biased towards network-centric criteria pertaining to signal strength. However, the paradigm shift from network-centric to user-centric approach necessitates a multi-criteria selection process, with methodology relating to both network and user preferences in the context of future generation networks. Hence, an effective selection approach is required to avoid unnecessary handovers in RAT. The main aim of this study is to propose the Context-aware Multiattribute decision making for RAT (CMRAT) selection for investigating the need to choose a new RAT and further determine the best amongst the available methods. The CMRAT consists of two mechanisms, namely the Context-aware Analytical Hierarchy Process (CAHP) and Context-aware Technique for Order Preference by Similarity to an Ideal Solution (CTOPSIS). The CAHP mechanism measures the need to switch from the current RAT, while CTOPSIS aids in decision making to choose the best target RAT. A series of experimental studies were conducted to validate the effectiveness of CMRAT for achieving improved system performance. The investigation utilises shopping mall and urban dense network scenarios to evaluate the performance of RAT selection through simulation. The findings demonstrated that the CMRAT approach reduces delay and the number of handovers leading to an improvement of throughput and packet delivery ratio when compared to that of the commonly used A2A4-RSRQ approach. The CMRAT approach is effective in the RAT selection within UDN environment, thus supporting heterogeneous RAT deployment in future 5G networks. With context-aware selection, the user-centric feature is also emphasized

IP-Based Mobility Management and Handover Latency Measurement in heterogeneous environments

One serious concern in the ubiquitous networks is the seamless vertical handover management between different wireless technologies. To meet this challenge, many standardization organizations proposed different protocols at different layers of the protocol stack. The Internet Engineering Task Force (IETF) has different groups working on mobility at IP level in order to enhance mobile IPv4 and mobile IPv6 with different variants: HMIPv6 (Hierarchical Mobile IPv6), FMIPv6 (Fast Mobile IPv6) and PMIPv6 (Proxy Mobile IPv6) for seamless handover. Moreover, the IEEE 802.21 standard provides another framework for seamless handover. The 3GPP standard provides the Access Network and Selection Function (ANDSF) to support seamless handover between 3GPP – non 3GPP networks like Wi-Fi, considered as untrusted, and WIMAX considered as trusted networks. In this paper, we present an in-depth analysis of seamless vertical handover protocols and a handover latency comparison of the main mobility management approaches in the literature. The comparison shows the advantages and drawbacks of every mechanism in order to facilitate the adoption of the convenient one for vertical handover within Next Generation Network (NGN) environments. Keywords: Seamless vertical handover, mobility management protocols, IEEE 802.21 MIH, handover latenc

Specification of Cooperative Access Points Functionalities version 1

The What to do With the Wi-Fi Wild West H2020 project (Wi-5) combines research and innovation to propose an architecture based on an integrated and coordinated set of smart Wi-Fi networking solutions. The resulting system will be able to efficiently reduce interference between neighbouring Access Points (APs) and provide optimised connectivity for new and emerging services. The project approach is expected to develop and incorporate a variety of different solutions, which will be made available through academic publications, in addition to other dissemination channels. The present document includes the specification of the first version of the Cooperative AP Functionalities, which are being defined within Work Package (WP) 4 of the Wi-5 project. In this deliverable after the Executive Summary and the literature review, the first version of the Cooperative Access Point Solutions are illustrated. In particular, a section with a general cooperative framework that jointly includes functionalities for an optimized AP channel assignment, Radio Resource Management (RRM) and smart AP allocation is presented. The optimized APs channel assignment enables an important improvement of the network performance in terms of SINR. Furthermore, the results analysed in this deliverable validate the flexibility and practicality of the proposed algorithm in different scenarios. The smart AP allocation solution introduces the innovative Fittingness Factor (FF) concept that efficiently matches the suitability of the available spectrum resource to the application requirements. Moreover, the basis required for a seamless mobility functionality in the framework is also included in the section. Next, a first assessment of the algorithms proposed in this deliverable is presented through the analysis of several performance results in a simulated environment. In detail, the AP channel assignment and the smart AP allocation algorithms are assessed and compared against other strategies found in the literature. Finally, a set of monitoring procedures to be conducted on the Wi-5 APs and on the Wi-5 controller are presented. These procedures will allow the correct deployment of the cooperative APs functionalities proposed in this deliverable. After summarising the main conclusions, the document ends with future work