A survey of self organisation in future cellular networks

This article surveys the literature over the period of the last decade on the emerging field of self organisation as applied to wireless cellular communication networks. Self organisation has been extensively studied and applied in adhoc networks, wireless sensor networks and autonomic computer networks; however in the context of wireless cellular networks, this is the first attempt to put in perspective the various efforts in form of a tutorial/survey. We provide a comprehensive survey of the existing literature, projects and standards in self organising cellular networks. Additionally, we also aim to present a clear understanding of this active research area, identifying a clear taxonomy and guidelines for design of self organising mechanisms. We compare strength and weakness of existing solutions and highlight the key research areas for further development. This paper serves as a guide and a starting point for anyone willing to delve into research on self organisation in wireless cellular communication networks

A directionally based bandwidth reservation scheme for call admission control

This paper proposes a new advanced Call Admission Control(CAC) strategy involving for the first time, a bandwidth reservation scheme that is influenced by the direction attribute of a mobile terminal (MT). Aside from the Quality-of-Service (QoS) parameters, the direction attribute plays a key role in efficiently reserving resources for MTs supporting multimedia communications for different QoS classes. The framework for a direction-based CAC system is entirely distributed and may be viewed as a message passing system, where MTs inform their neighbouring base stations (BS) not only of their QoS requirements, but also of their mobility parameters. The base stations then predict future demand and reserve resources accordingly, only admitting those terminals that can be adequately supported. The bandwidth reservation scheme proposed in this paper, integrates the direction attribute into the conventional Guard Channel (GC) scheme. Simulation results prove that this new scheme offers significant improvements in both Call Blocking Probability (CBP) and bandwidth utilization, under a variety of differing traffic conditions

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)

Adaptive Predictive Handoff Scheme with Channel Borrowing in Cellular Network

Previously, we presented an extension of predictive channel reservation (PCR) scheme, called HPCR_CB, for handoff motivated by the rapid evolving technology of mobile positioning. In this thesis, the author proposes a new scheme, called adaptive PCR_CB (APCR_CB), which is an extension of HPCR_CB by incorporating the concept of adaptive guard channels. In APCR_CB, the number of guard channel(s) is adjusted automatically based on the average handoff blocking rate measured in the past certain time period. The handoff blocking rate is controlled under the designated threshold and the new call blocking rate is minimized. The performance evaluation of the APCR_CB scheme is done by simulation. The result shows the APCR_CB scheme outperforms the original PCR, GC, and HPCR_CB schemes by controlling a hard constraint on the handoff blocking probability. It is able to achieve the optimal performance by maximizing the resource utilization and by adapting to changing traffic conditions automatically

Adaptive Predictive Handoff Scheme with Channel Borrowing in Cellular Network

Previously, we presented an extension of predictive channel reservation (PCR) scheme, called HPCR_CB, for handoff motivated by the rapid evolving technology of mobile positioning. In this thesis, the author proposes a new scheme, called adaptive PCR_CB (APCR_CB), which is an extension of HPCR_CB by incorporating the concept of adaptive guard channels. In APCR_CB, the number of guard channel(s) is adjusted automatically based on the average handoff blocking rate measured in the past certain time period. The handoff blocking rate is controlled under the designated threshold and the new call blocking rate is minimized. The performance evaluation of the APCR_CB scheme is done by simulation. The result shows the APCR_CB scheme outperforms the original PCR, GC, and HPCR_CB schemes by controlling a hard constraint on the handoff blocking probability. It is able to achieve the optimal performance by maximizing the resource utilization and by adapting to changing traffic conditions automatically