Handover mechanisms in next generation heterogeneous wireless networks

University of Technology, Sydney. Faculty of Engineering.New access technologies such as IEEE 802.11 Wireless LAN are emerging as a new means of public wireless access. Working on public unlicensed bands, they are capable of providing high speed data services, but small radio coverage. The third generation cellular networks such as Universal Mobile Telecommunications System (UMTS) provide wide radio coverage, but have limited data rates. An integration of these heterogeneous wireless networks is expected to be an effective means of providing high speed data access in wide radio coverage in the Next Generation (NG) wireless networks. When a mobile user moves across these networks, it has to perform handover to maintain its services. During a handover, it is pivotal to guarantee both service continuity and service quality, which ensure that handover can be made seamlessly. To provide ubiquitous services, an extensive collaboration between network operators is anticipated to be an economic solution. Providing seamless handover and ubiquitous services in heterogeneous wireless networks presents many new research challenges. The objective of this thesis is to develop new handover management techniques for supporting seamless handover and facilitating ubiquitous services in heterogeneous wireless networks. More specifically, new techniques for dealing with the extensive collaboration of NG network operators, and new techniques that enable the interworking of heterogeneous wireless technologies. Regarding the extensive collaboration of network operators, a neighbour network trust information retrieval scheme is proposed for global roaming. With this scheme, an access network can obtain network trust information of its nearby access networks without relying on direct links with them. The retrieved trust information can be provided to an attached mobile user later to assist it with global roaming. Next, a handover decision algorithm that uses network trust information is presented. The proposed algorithm guarantees much more reliable handover in a multiple-operator environment. It is demonstrated how quality of service is maintained and overall network load is balanced using the proposed handover algorithm. The thesis moves further to a proxy based authentication localisation scheme that focuses on the handover across two networks without a trust relation. The proposed scheme provides a secure and effective method of localising authentication at a third-party entity during a handover. This avoids resorting to a mobile’s home network for identity verification in a handover, and thus, greatly reduces handover latency. In terms of the interworking of heterogeneous wireless technologies, the thesis presents a multi-interface mobile terminal model for media independent handover. The presented model addresses the challenge of working with heterogeneous wireless technologies from the perspective of a mobile terminal. Under the proposed multi-interface architecture, a mobile terminal can work with multiple network interfaces, and still uses common upper layer protocols such as Mobile IPv4. Being compatible with IEEE 802.21 framework, it uses a cross-layer design approach

Motorized cart

Motorized cart is known as an effective tool and timeless that help people carry heavy loads. For farmers, it has an especially vital tool for moving goods. Oil palm farmers typically uses the wheelbarrow to move the oil palm fruit (Figure 10.1). However, there is a lack of equipment that should be further enhanced in capabilities. Motorized carts that seek to add automation to wheelbarrow as it is to help people save manpower while using it. At present, oil palm plantation industry is among the largest in Malaysia. However, in an effort to increase the prestige of the industry to a higher level there are challenges to be faced. Shortage of workers willing to work the farm for harvesting oil palm has given pain to manage oil palm plantations. Many have complained about the difficulty of hiring foreign workers and a high cost. Although there are tools that can be used to collect or transfer the proceeds of oil palm fruits such as carts available. However, these tools still have the disadvantage that requires high manpower to operate. Moreover, it is not suitable for all land surfaces and limited cargo space. Workload and manpower dependence has an impact on farmers' income

Separation Framework: An Enabler for Cooperative and D2D Communication for Future 5G Networks

Soaring capacity and coverage demands dictate that future cellular networks need to soon migrate towards ultra-dense networks. However, network densification comes with a host of challenges that include compromised energy efficiency, complex interference management, cumbersome mobility management, burdensome signaling overheads and higher backhaul costs. Interestingly, most of the problems, that beleaguer network densification, stem from legacy networks' one common feature i.e., tight coupling between the control and data planes regardless of their degree of heterogeneity and cell density. Consequently, in wake of 5G, control and data planes separation architecture (SARC) has recently been conceived as a promising paradigm that has potential to address most of aforementioned challenges. In this article, we review various proposals that have been presented in literature so far to enable SARC. More specifically, we analyze how and to what degree various SARC proposals address the four main challenges in network densification namely: energy efficiency, system level capacity maximization, interference management and mobility management. We then focus on two salient features of future cellular networks that have not yet been adapted in legacy networks at wide scale and thus remain a hallmark of 5G, i.e., coordinated multipoint (CoMP), and device-to-device (D2D) communications. After providing necessary background on CoMP and D2D, we analyze how SARC can particularly act as a major enabler for CoMP and D2D in context of 5G. This article thus serves as both a tutorial as well as an up to date survey on SARC, CoMP and D2D. Most importantly, the article provides an extensive outlook of challenges and opportunities that lie at the crossroads of these three mutually entangled emerging technologies.Comment: 28 pages, 11 figures, IEEE Communications Surveys & Tutorials 201