Recent advances in Wireless Mesh Networks (WMNs) have overcome the drawbacks of traditional wired networks and wireless ad hoc networks. WMNs will play a leading role in the next generation of networks, and the question of how to provide smooth mobility for WMNs is the driving force behind the research. The inherent characteristics of WMNs, such as relatively static backbones and highly mobile clients, require new handoff management solutions to be designed and implemented. This thesis first presents our research work on handoff management schemes in traditional WMNs. In general, a handoff process includes two parts, the MAC layer handoff and the network layer handoff. For the MAC layer handoff, a self-configured handoff scheme with dynamic adaptation is presented. Before the mobile node starts the probe process, it configures parameters for each channel to optimize the scan process. Moreover, a fast authentication scheme to reduce authentication latency for WiFi-based mesh networks is introduced. A tunnel is introduced to forward data packets between the new access router and the original reliable access router to recover data communication before the complete authentication process is finished. To minimize the network layer handoff latency, a hybrid routing protocol for forwarding packets is proposed: this involves both the link layer routing and the network layer routing. Based on the hybrid routing protocol, both intra-domain and inter-domain handoff management have been designed to support smooth roaming in WMNs. In addition, we extend our work to Vehicular Mesh Networks (VMNs). Considering the characteristics of VMNs, a fast handoff scheme is introduced to reduce handoff latency by using a multi-hop clustering algorithm. Using this scheme, vehicle nodes are divided into different multi-hop clusters according to the relative mobility. Some vehicle nodes are selected as assistant nodes; and these assistant nodes will help the cluster head node to determine the next access router for minimizing handoff latency. Extensive simulation results demonstrate that the proposed scheme can reduce handoff latency significantly.

The past few years have seen great increases in the use of portable devices like laptops, palmtops, etc. This has also led to the dramatic increase demand on wireless local area networks (WLAN) due to the flexibility and ease of use that it offers. Mobile IP and handover are important issues to be considered as these devices move within and between different networks and still have to maintain connectivity. It is, therefore, imperative to ensure seamless mobile IP handover for these devices as they move about. In this thesis we undertake a survey to describe the real processes involved in mobile IP handover in WLAN environment for different scenarios. Our work also identifies individual sources of delay during the handoff process, the sum total of which makes up the total latency. Other factors that could militate against the aim of having a seamless handoff in an inter-subnet network roaming were also considered as well as some proposed solutions. These factors are security, packet loss and triangle routing.

A telephone questionnaire was developed to collect information on pet owners, cat ownership patterns, and people's opinions about homeless pets. A 7-day observation log was also developed to gather information about free-roaming cats in Caldwell, TX. The objectives of this research were: (1) to evaluate the reliability of the telephone questionnaire, (2) to assess general cat ownership patterns, (3) to evaluate attachment level of pet owners to their pets, (4) to determine general opinions about free-roaming cats, (5) to determine if demographics were associated with opinions about free-roaming cat and dog problems and (6) to investigate free-roaming cat activity in a community. Telephone questionnaire information collected from 100 subjects was tested for reliability. Reliability was fair to good for cat level questions (sex, age, breed, length of time owned, indoor/outdoor status, litter, number of vet visits, vaccinated). Reliability was good for questions concerning subjects' knowledge of cat and dog behavior and levels of attachment to their pets. Reliability was excellent for all household level (demographic) variables. Reliability was moderate for questions regarding subjects' opinions about homeless animals. Telephone questionnaire responses collected from 441 subjects were checked for associations using exploratory logistic and linear regression models. A cat's role as a pet, vaccination status, and the length of time owned were associated with a cat's sterilization status. A cat's role as a pet was associated with the cat's indoor/outdoor status. Household size, education level and ethnicity of the owner were associated with cat ownership. Having children was associated with a negative opinion about homeless cats. Education level was associated with subjects' knowledge about dog and cat behavior. Gender, household size, and knowledge score were associated with subjects' attachment to their pets. Descriptive information on free-roaming cat activity was collected from 21 subjects using the 7-day observation log. Subjects made 382 cat sightings during the study period. Slightly more cat sightings were made during the morning than in the evening and afternoon. Most cats were spotted in neighborhoods and were resting or eating. Most of these cats that were eating were seen during the morning or evening hours.

Since Mobile network operator (MNO) relies on many Business Support Systems (BSS) and Operation Support Systems (OSS) it should be assured that operator’s systems supports the requirements of the future.This thesis shall focus on the “start-to-end” aspects that must be considered to ensure that International Roaming continues to operate flawless. The thesis experience Long Term Evolution (LTE) in case of international roaming by measuring the end to end location update delay.In order to evaluate the LTE performance of international roaming, the delay time has been measured by the means of tracing tools for several different international roamers and the results has been compared with the results achieved for local user. The outcome has been compared with the respecting results in 3G network the statistical results has been provided and the graphs has been plotted to study the performance.Based on the results obtain on this thesis, it has been concluded that local user acts more stable to get attach to the network, i.e. there are less fluctuation in delay times for local user. Also the delay time in 3G networks is more than the LTE networks, however 3G networks acts more stable and there are less fluctuation to get connects to 3G networks.

Recent advances in Wireless Mesh Networks (WMNs) have overcome the drawbacks of traditional wired networks and wireless ad hoc networks. WMNs will play a leading role in the next generation of networks, and the question of how to provide smooth mobility for WMNs is the driving force behind the research. The inherent characteristics of WMNs, such as relatively static backbones and highly mobile clients, require new handoff management solutions to be designed and implemented. This thesis first presents our research work on handoff management schemes in traditional WMNs. In general, a handoff process includes two parts, the MAC layer handoff and the network layer handoff. For the MAC layer handoff, a self-configured handoff scheme with dynamic adaptation is presented. Before the mobile node starts the probe process, it configures parameters for each channel to optimize the scan process. Moreover, a fast authentication scheme to reduce authentication latency for WiFi-based mesh networks is introduced. A tunnel is introduced to forward data packets between the new access router and the original reliable access router to recover data communication before the complete authentication process is finished. To minimize the network layer handoff latency, a hybrid routing protocol for forwarding packets is proposed: this involves both the link layer routing and the network layer routing. Based on the hybrid routing protocol, both intra-domain and inter-domain handoff management have been designed to support smooth roaming in WMNs. In addition, we extend our work to Vehicular Mesh Networks (VMNs). Considering the characteristics of VMNs, a fast handoff scheme is introduced to reduce handoff latency by using a multi-hop clustering algorithm. Using this scheme, vehicle nodes are divided into different multi-hop clusters according to the relative mobility. Some vehicle nodes are selected as assistant nodes; and these assistant nodes will help the cluster head node to determine the next access router for minimizing handoff latency. Extensive simulation results demonstrate that the proposed scheme can reduce handoff latency significantly.

This diploma thesis examines the issue of the roaming regulation. The goal was to find out whether it had been necessary to regulate roaming prices at the EU level and what consequences it has and will have for individuals in the market - especially consumers, mobile operators, politicians, and also for the single European market. The basic hypothesis is that the roaming regulation will ultimately lead to a reduction in consumer utility, and therefore there is no substantial improvement to the single European market. The first part describes current developments in the roaming regulation and presents arguments for and against regulation. The second part then discusses the presented arguments. The impact on various market players is examined using the available data.

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While the data traffic has increased through the years, the average revenue per user (ARPU) remains flat. Thus, mobile network operators need to find a solution for how to support the growing amounts of traffic at fixed revenue per user. Similarly, the number of roaming users has increased, but according to recent European Union (EU) regulations, mobile network operators have to lower their charges for roaming to zero by June 2017. While this decrease in roaming charges will benefit European roaming users, mobile network operators have to cover their expenses for their own roaming subscribers, thus they have to find a way to lower their operational expenses (OPEX). Additionally, it is important for operators to consider how they might actually benefit from the removal of roaming charges. This project will focus on roaming in 4th generation (4G) mobile networks. A common roaming scenario would include three different networks: the Home Public Land Mobile Network (HPLMN) a transit network, and a Visited Public Land Mobile Network (VPLMN). Normally, both the signaling traffic and the media payloads traverse these networks, thus causing additional latencies and increasing OPEX. However, in recent years, a new mechanism, called local breakout (LBO), was introduced that can lower the costs of roaming and avoid unnecessary traffic while meeting a roaming user's needs. The goal of LBO is to decrease the operator's OPEX when supporting roaming subscribers. A secondary goal of LBO is to reduce the latencies experienced by roaming subscribers during their sessions. Achieving both of these goals will satisfy both operators and consumers. This thesis project analyzes Voice over Long Term Evolution roaming with the aim of presenting the various alternative architectures for Voice over LTE roaming, compare them in different scenarios, and evaluating them based on criteria defined during this project. The conclusion is that the best solution that is applicable to all the mobile network operators for all the possible roaming scenarios does not exist yet. The various VoLTE roaming architectures can be chosen by the mobile network providers according to their needs. / Datatrafiken har ökat genom åren men den genomsnittliga intäkten per användare (ARPU) är fortfarande oförändrad. Mobilnätsoperatörer bör hitta en lösning för att kunna stödja den växande mängden trafik på fasta intäkter per användare. Samtidigt har antalet roaming användare ökat. Enligt de senaste reglerna från Europeiska unionen (EU) måste mobiloperatörer sänka sina roamingkostnader till noll senast juni 2017. Denna minskning av roamingavgifterna kommer att gynna europeiska roaminganvändare, men mobilnätoperatörer måste samtidigt täcka sina kostnader för sina egna roamingabonnenter. Detta medför att mobilnätoperatörer måste hitta ett sätt att sänka sina driftskostnader (OPEX). Dessutom är det viktigt för operatörerna att fundera över hur de faktiskt kan utnyttja denna uteslutning av roamingavgifter. Detta projekt kommer att fokusera på roaming i den 4:e generationens (4G) mobila nät. Ett vanligt roaming scenario skulle omfatta tre olika nätverk: Home Public Land Mobile Network (HPLMN), transitnätverk, och en Visited Public Land Mobile Network (VPLMN). Vanligen är det både signaleringstrafik och media som passerar dessa nätverk. Det leder till ytterligare latenstider och ökande driftskostnader. Under de senaste åren har en ny mekanism som kallas för Local BreakOut (LBO) införts. Detta används för att sänka kostnaderna för roaming och undvika onödig trafik, samtidigt som den bemöter roaming användarens behov. Målet med LBO är att minska Operatörens OPEX när den stödjer roaming abonnenter. Ett sekundärt mål av LBO är att minska latensen för roamingabonnenter under sina sessioner. Uppnående av båda dessa mål kommer att tillfredsställa både operatörer och konsumenter. Detta examensarbete analyserar Voice over Long Term Evolution roaming i syfte att presentera de olika alternativa arkitekturer för Voice over LTE roaming, jämföra dem i olika scenarier, och utvärdera dem utifrån kriterier som fastställs under detta projekt.

This thesis provides an insight into the biology and ecology of foxes Vulpes vulpes from a coastal habitat and free roaming dogs Canis lupus familiaris from an Aboriginal community, both in SE NSW. In particular, the study examines the home range and movement patterns of both canids from a view point of population and disease control. Additional base line information was collected for these species on diet, parasites and population biology. A total of 14 foxes and 10 dogs were collared and radio tracked to determine the home range and movement patterns of the animals. The data collected provides information on the behaviour of foxes in coastal habitat and represents the first detailed biological study of freeroaming dogs in Australia. The results provide a better understanding of dog movements, particularly the differences in behaviour between wandering and sedentary dogs. Home range sizes varied greatly between the dog groups from 1 ha to 2451 ha. There was evidence that dog forays were influenced by prey availability, particularly medium sized macropods. Occasional sallies, size and shape of fox and dog home range is discussed in relation to the richness of habitat at Jervis Bay with comparisons being made with other studies from the literature. Foxes in Jervis Bay had home ranges between 60-270 ha which is comparable to foxes living in the forests of Germany and in coastal habitat in the Netherlands This study also provides data on the diet of foxes and dogs presenting quantitative and qualitative data on food preferences. Foxes tended to be opportunistic in food selection although critical weight range mammals ie. ringtail possums were favoured. The high prevalence of the parasite Spirometra spp. in foxes indicated that considerable numbers of amphibians and reptiles are consumed by this species. A comprehensive inventory of the parasites of the two canid species showed a high proportion of hookworm in foxes and dogs and Spirometra spp in foxes. These results are discussed in light of the potential health implications for local Aboriginal people. Analysis of fox scats revealed that they have the potential to spread the seeds of bitou bush. A more detailed pilot study revealed the potential impact of foxes on the environment through the spread of weed seeds. Germination trials recorded high viability of seeds that were eaten and deposited by foxes. The management implications of this behaviour are discussed in context to weed control. This thesis has provided new information on foxes and dogs in Australia. Discussion on these species in the thesis has been framed around the benefits of this information for population and disease control.

The focus of this dissertation is to decipher the previously unknown reaction dynamics of NO3 photodissociation. Although the NO + O2 products are known to catalyze atmospheric ozone destruction, the mechanism by which these products are formed has remained a mystery, and no energetically accessible transition state has ever been calculated. Using velocity map ion imaging experiments to carefully study the stereochemistry of the product fragments combined with theoretical calculations performed by Drs. Xiao, Maeda, and Morokuma at Kyoto University, we have determined that the reaction proceeds exclusively via the unusual "roaming mechanism," with no evidence of a competing traditional transition state pathway. Within, the significance of this discovery is discussed in regards to both the NO3 system and roaming dynamics in general, for which this system has provided new insight.