HANDOVER MANAGEABILITY AND PERFORMANCE MODELING IN MOBILE COMMUNICATION NETWORKS

In cellular Networks, a mobile station (MS’s) move from one cell region to another on seamless Communicationscheduling.. Handoff or Handover is an essential issue for the seamless communication. Several approaches havebeen proposed for handoff performance analysis in mobile communication systems. In Code-Division Multiple-Access (CDMA) systems with soft handoff, mobile stations (MS’s) within a soft-handoff region (SR) use multipleradio channels and receive their signals from multiple base stations (BS’s) simultaneously. Consequently, SR’sshould be investigated for handoff analysis in CDMA systems. In this paper, a model for soft handoff in CDMAnetworks is developed by initiating an overlap region between adjacent cells facilitating the derivation of handoffmanageability performance model. We employed an empirical modelling approach to support our analyticalfindings, measure and investigated the performance characteristics of typical communication network over a specificperiod from March to June, 2013 in an established cellular communication network operator in Nigeria. Theobserved data parameters were used as model predictors during the simulation phase. Simulation results revealedthat increased system capacity degrades the performance of the network due to congestion, dropping and callblocking, which the system is most likely to experience, but the rate of those factors could be minimized by properlyconsidering the handoff probabilities level. Comparing our results, we determined the effective and efficientperformance model and recommend it to network operators for an enhanced Quality of Service (QoS), which willpotentially improve the cost-value ratio for mobile users and thus confirmed that Soft Handoff (SH) performancemodel should be carefully implemented to minimize cellular communication system defects.Keywords: CDMA, QoS, optimization, Handoff Manageability, Congestion, Call Blocking and Call Dropping,

Performance measurements and analysis of the existing wireless communication technology in Iraq.

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel UniversityIraq may be considered as the largest wireless market in the Gulf region. A key driving factor in the market of wireless communication, it has seen enormous growth in the mobile phone market over the last five years leading to almost 24 million subscribers in 2011. Moreover, there are several technologies and services working in Iraq; three GSM Operators, three CDMA national operators and three CDMA provinces operators. The recent growth in the mobile phone market is based on the Global System for Mobile (GSM) communications and Code Division Multiple Access (CDMA) standards creating the next-generation wireless technologies in the Iraqi Wireless Communication market. One of the essential issues of this research is to investigate the performance of the decreased Quality Of Service (QoS) caused by interferences in the services on GSM/CDMA operators in Iraq. Many issues should be studied and taken into consideration, such as; does the Multi-Coalition Forces cause the interferences, jamming, higher rate of calls drop and false ringing; or are they caused by bad design and planning? Do we need to optimise our network due to the large number of users? All these factors are investigated and the measurements of most service providers and government agencies will be gathered. A detailed analysis was included from the providers with measurements of performance and the reasons for the deterioration of wireless services. The novel contributions of this thesis is the extensive radio measurement campaign over the three mobile an CDMA operator networks and the analysis and recommendations that were drawn to suggest the best approach to improve the QoS of Wireless communication technologies. Awareness of actual reasons behind the deterioration of services will be raised to the Iraqi Government, CMC and the wireless service providers

A New Analysis of the DS-CDMA Cellular Uplink Under Spatial Constraints

A new analysis is presented for the direct-sequence code-division multiple access (DS-CDMA) cellular uplink. For a given network topology, closed-form expressions are found for the outage probability and rate of each uplink in the presence of path-dependent Nakagami fading and log-normal shadowing. The topology may be arbitrary or modeled by a random spatial distribution for a fixed number of base stations and mobiles placed over a finite area with the separations among them constrained to exceed a minimum distance. The analysis is more detailed and accurate than existing ones and facilitates the resolution of network design issues, including the influence of the minimum base-station separation, the role of the spreading factor, and the impact of various power-control and rate-control policies. It is shown that once power control is established, the rate can be allocated according to a fixed-rate or variable-rate policy with the objective of either meeting an outage constraint or maximizing throughput. An advantage of the variable-rate policy is that it allows an outage constraint to be enforced on every uplink, whereas the fixed-rate policy can only meet an average outage constraint.Comment: 6 pages, 6 figures, to appear at International Conference on Communications (ICC) 201