A Novel Adaptive Channel Allocation Scheme to Handle Handoffs

Wireless networking is becoming an increasingly important and popular way of providing global information access to users on the move. One of the main challenges for seamless mobility is the availability of simple and robust handoff algorithms, which allow a mobile node to roam among heterogeneous wireless networks. In this paper, the authors devise a scheme, A Novel Adaptive Channel Allocation Scheme (ACAS) where the number of guard channel(s) is adjusted automatically based on the average handoff blocking rate measured in the past certain period of time. The handoff blocking rate is controlled under the designated threshold and the new call blocking rate is minimized. The performance evaluation of the ACAS is done through simulation of nodes. The result shows that the ACAS scheme outperforms the Static Channel Allocation Scheme by controlling a hard constraint on the handoff rejection probability. The proposed scheme achieves the optimal performance by maximizing the resource utilization and adapts itself to changing traffic conditions automatically.Comment: 9 Pages; in International Journal of Distributed and Parallel system

Characteristics of chicken slaughterhouse wastewater

The chicken slaughterhouse wastewater is a class of wastewater, which is heavily polluted with organic matters including proteins, blood residues, fats and lard. Therefore, the direct discharged of untreated chicken slaughterhouse wastewater into the environment is associated with the occurrence of eutrophication phenomenon. In the present study, the characteristics of chicken slaughterhouse wastewater were investigated to ascertain the role of these wastes in the adverse effect on the environment and natural water system. The parameter tested included biological oxygen demand (BOD), chemical oxygen demand (COD), total suspended solid (TSS), total nitrogen (TN), total organic carbon (TOC), orthophosphate (PO4 3-), temperature and pH. The results revealed available high concentrations of BOD (1,341 - 1,821 ± 242.7 mg L1 ), COD (3,154.19 - 7,719.3 ± 2,282.69 mg L-1), TSS (377.67 - 5,462 ± 2,696.1 mg L-1) which have exceeded the EQA1974 standard limits for disposal of wastewater into the environment. The concentrations of TN (162.6 -563.8 ± 215 mg L-1) and PO4 3- (7.047 - 17.111 ± 4.25 mg L-1) were within the range required for microalgae growth which confirm their role in the occurrence of eutrophication phenomenon. It can be concluded that the direct discharge of chicken slaughterhouse wastewater contributes negatively on the environmental biodiversity and thus they should be subjected for an effective treated before the final disposal

QoS Provisioning for Multi-Class Traffic in Wireless Networks

Physical constraints, bandwidth constraints and host mobility all contribute to the difficulty of providing Quality of Service (QoS) guarantees in wireless networks. There is a growing demand for wireless networks to support all the services that are available on wired networks. These diverse services, such as email, instant messaging, web browsing, video conferencing, telephony and paging all place different demands on the network, making QoS provisioning for wireless networks that carry multiple classes of traffic a complex problem. We have developed a set of admission control and resource reservation schemes for QoS provisioning in multi-class wireless networks. We present three variations of a novel resource borrowing scheme for cellular networks that exploits the ability of some multimedia applications to adapt to transient fluctuations in the supplied resources. The first of the schemes is shown to be proportionally fair: the second scheme is max-min fair. The third scheme for cellular networks uses knowledge about the relationship between streams that together comprise a multimedia session in order to further improve performance. We also present a predictive resource reservation scheme for LEO satellite networks that exploits the regularity of the movement patterns of mobile hosts in LEO satellite networks. We have developed the cellular network simulator (CNS) for evaluating call-level QoS provisioning schemes. QoS at the call-level is concerned with call blocking probability (CBP), call dropping probability (CDP), and supplied bandwidth. We introduce two novel QoS parameters that relate to supplied bandwidth—the average percent of desired bandwidth supplied (DBS), and the percent of time spent operating at the desired bandwidth level (DBT)

Design and analysis of scheduling algorithms for next generation broadband wireless access systems

Efficient utilization of network resources is a key goal for emerging Broadband Wireless Access Systems (BWAS). This is a complex goal to achieve due to the heterogeneous service nature and diverse Quality of Service (QoS) requirements of various applications that BWAS support. Packet scheduling is an important activity that affects BWAS QoS outcomes. This thesis proposes a new packet scheduling mechanism that improves QoS in mobile wireless networks which exploit IP as a transport technology for data transfer between BWAS base stations and mobile users at the radio transmission layer. In order to improve BWAS QoS the new packet algorithm makes changes at both the IP and the radio layers. The new packet scheduling algorithm exploits handoff priority scheduling principles and takes into account buffer occupancy and channel conditions. The packet scheduling mechanism also incorporates the concept of fairness. The algorithm also offers an opportunity to maximize the carriers’ revenue at various traffic situations. Performance results were obtained by computer simulation and compared to the well-known algorithms. Results show that by exploiting the new packet scheduling algorithm, the transport system is able to provide a low handoff packet drop rate, low packet forwarding rate, low packet delay, ensure fairness amongst the users of different services and generates higher revenue for the telecom carriers. Furthermore this research proposes a new and novel measure named “satisfaction factor to measure the efficacy of various scheduling schemes and finally this s research also proposes four performance measurements metric for NodeB’s of Next Generation Wireless Network

QoS provisioning and mobility management for IP-based wireless LAN

Today two major technological forces drive the telecommunication era: the wireless cellular systems and the Internet. As these forces converge, the demand for new services, increasing bandwidth and ubiquitous connectivity continuously grows. The next-generation mobile systems will be based solely or in a large extent, on the Internet Protocol (IP). This thesis begins by addressing the problems and challenges faced in a multimedia, IP-based Wireless LAN environment. The ETSI HiperLAN/2 system has been mainly selected as the test wireless network for our theoretical and simulation experiments. Apart from the simulations, measurements have been taken from real life test scenarios, where the IEEE 802.11 system was used (UniS Test-bed). Furthermore, a brief overview of the All-IP network infrastructure is presented. An extension to the conventional wireless (cellular) architecture, which takes advantage of the IP network characteristics, is considered. Some of the trends driving the 3G and WLANs developments are explored, while the provision of quality of service on the latter for real-time and non-real-time multimedia services is investigated, simulated and evaluated. Finally, an efficient and catholic Q0S framework is proposed. At the same time, the multimedia services should be offered in a seamless and uninterrupted manner to users who access the all-IP infrastructure via a WLAN, meeting the demands of both enterprise and public environments anywhere and anytime. Thus providing support for mobile communications not only in terms of terminal mobility, as is currently the case, but also for session, service and personal mobility. Furthermore, this mobility should be available over heterogeneous networks, such as WLANs, IJMTS, as well as fixed networks. Therefore, this work investigates issues such as, multilayer and multi-protocol (SIP-Mobile IP-Cellular IP) mobility management in wireless LAN and 3G domains. Several local and global mobility protocols and architectures have been tested and evaluated and a complete mobility management framework is proposed. Moreover, integration of simple yet efficient authentication, accounting and authorisation mechanisms with the multimedia service architecture is an important issue of IP-based WLANs. Without such integration providers will not have the necessary means to control their provided services and make revenue from the users. The proposed AAA architecture should support a robust AAA infrastructure providing secure, fast and seamless access granting to multimedia services. On the other hand, a user wishing a service from the All-IP WLAN infrastructure needs to be authenticated twice, once to get access to the network and the other one should be granted for the required service. Hence, we provide insights into these issues by simulating and evaluating pre-authentication techniques and other network authentication scenarios based on the wellknown IEEE 802.lx protocol for multimedia IP-based WLANs.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

3G migration in Pakistan

The telecommunication industry in Pakistan has come a long way since the country\u27s independence in 1947. The initial era could be fairly termed as the PTCL (Pakistan Telecommunication Company Limited) monopoly, for it was the sole provider of all telecommunication services across the country. It was not until four decades later that the region embarked into the new world of wireless communication, hence ending the decades old PTCL monopoly. By the end of the late 1990\u27s, government support and international investment in the region opened new doors to innovation and better quality, low cost, healthy competition. Wireless licenses for the private sector in the telecommunication industry triggered a promising chain of events that resulted in a drastic change in the telecommunication infrastructure and service profile. The newly introduced wireless (GSM) technology received enormous support from all stakeholders (consumers, regulatory body, and market) and caused a vital boost in Pakistan\u27s economy. Numerous tangential elements had triggered this vital move in the history of telecommunications in Pakistan. Entrepreneurs intended to test the idea of global joint ventures in the East and hence the idea of international business became a reality. The technology had proven to be a great success in the West, while Pakistan\u27s telecom consumer had lived under the shadow of PTCL dominance for decades and needed more flexibility. At last the world was moving from wired to wireless! Analysts termed this move as the beginning of a new era. The investors, telecommunication businesses, and Pakistani treasury prospered. It was a win-win situation for all involved. The learning curve was steep for both operators and consumers but certainly improved over time. In essence, the principle of deploying the right technology in the right market at the right time led to this remarkable success. The industry today stands on the brink of a similar crossroads via transition from second generation to something beyond. With the partial success of 3G in Europe and the USA, the government has announced the release of three 3G licenses by mid 2009. This decision is not yet fully supported by all but still initiated parallel efforts by the operators and the vendors to integrate this next move into their existing infrastructure

Fourth Generation Wireless Systems: Requirements and Challenges for the Next Frontier

Fourth generation wireless systems (4G) are likely to reach the consumer market in another 4-5 years. 4G comes with the promise of increased bandwidth, higher speeds, greater interoperability across communication protocols, and user friendly, innovative, and secure applications. In this article, I list the requirements of the 4G systems by considering the needs of the users in the future. These requirements can be met if technical and business challenges can be overcome. Technical challenges include mobility management, quality of service, interoperability, high data rate, security, survivability, spectrum, intelligent mobile devices, middleware, and network access. I discuss the most plausible solutions to these technical challenges in this paper. Business-related challenges include billing, payment methods, pricing, size of investments, content provision and mediation, and the trade-off between richness and reach. If these technical and business challenges can be met, then 4G will become the next frontier in data and voice communication infrastructure

Effective Handover Technique in Cluster Based MANET Using Cooperative Communication

Mobile ad hoc networks (MANETs) are becoming increasingly common now a days and typical network loads considered for MANETs are increasing as applications evolve. This increases the importance of bandwidth efficiency and requirements on energy consumption delay and jitter. Coordinated channel access protocols have been shown to be well suited for MANETs under uniform load distributions. However, these protocols are not well suited for non-uniform load distributions as uncoordinated channel access protocols due to the lack of on-demand dynamic channel allocation mechanisms that exist in infrastructure based coordinated protocols. We have considered a lightweight dynamic channel allocation algorithm and a cooperative load balancing strategy that are helpful for the cluster based MANETs and an effective handover technique to improve the increased packet transmission mechanism. This helps in reduce jitter, packet delay and packet transfer speed, we use a novel handover algorithm to address this problem We present protocols that utilize these mechanisms to improve performance in terms of throughput, energy consumption and inter-packet delay variation (IPDV)