Australian Journal of Telecommunications and the Digital Economy, 2017
All network traffic is a by-product of social networking behaviour. In this paper, Anonymized Int... more All network traffic is a by-product of social networking behaviour. In this paper, Anonymized Internet (IP) Trace Datasets obtained from the Center for Applied Internet Data Analysis (CAIDA) have been used to identify and estimate characteristics of the underlying social network from the overall traffic. The analysis methods used here fall into two groups, the first being based on frequency analysis and second method being based on the use of traffic matrices, with the later analysis method being further sub-divided into groups based on the traffic mean, variance and co-variance. The frequency analysis of origin (O), destination (D) and O-D Pair statistics exhibit heavy tailed behaviour. Because the large number of IP addresses contained in the CAIDA Datasets, only the most predominate IP Addresses are used when estimating all three sub-divided groups of traffic matrices. Principal Component Analysis (PCA) and related methods are applied to identify key features of each type of traf...
This mathematica notebook is based on the one called fBmShiftTransformation10b.nb, which was in t... more This mathematica notebook is based on the one called fBmShiftTransformation10b.nb, which was in turn based on animate/animate3.nb. Section 1 includes basic definitions, Section 2 defines a function which estimates exit probability, for a process with a given down-crossing, by simulation. Section 3 then estimates the last exit density, which is carried out in detail for the cases H=0.75, 0.5, 0.85, and 0.35. Relative finality is found by fitting to the simulations, and this is then used to estimate the last exit density.
This report contains the Mathematica code, used to implement the aggregate EMF spectral density d... more This report contains the Mathematica code, used to implement the aggregate EMF spectral density due to several nearby transmitters.
Role-based delegation model (RBDM) based on the role-based access control (RBAC) has proven to be... more Role-based delegation model (RBDM) based on the role-based access control (RBAC) has proven to be a flexible and useful access control model for infor- mation sharing in a distributed collaborative environ- ment. In today's highly dynamic distributed systems, a user often needs to ...
Abstract. We present the formal model for a collection of Universal Forms Servers which allow use... more Abstract. We present the formal model for a collection of Universal Forms Servers which allow users distributed over peers to create webbased forms, capture data for these forms, and re-use information associated to forms located at different peers. Access rules included in the form definitions regulate both read and write rights of end-users, and also impose an implicit workflow on the entry of data. Hence, whereas current Workflow systems require the explicit modelling of workflow processes before deployment, our system enables ...
Bi-Directional Grid Constrained (BGC) stochastic processes (BGCSPs) constrain the random movement... more Bi-Directional Grid Constrained (BGC) stochastic processes (BGCSPs) constrain the random movement toward the origin steadily more and more, the further they deviate from the origin, rather than all at once imposing reflective barriers, as does the well-established theory of Itô diffusions with such reflective barriers. We identify that BGCSPs are a variant rather than a special case of the multi-skew Brownian motion (M-SBM). This is because they have their own complexities, such as the barriers being hidden (not known in advance) and not necessarily constant over time. We provide a M-SBM theoretical framework and also a simulation framework to elaborate deeper properties of BGCSPs. The simulation framework is then applied by generating numerous simulations of the constrained paths and the results are analysed. BGCSPs have applications in finance and indeed many other fields requiring graduated constraining, from both above and below the initial position.
2016 26th International Telecommunication Networks and Applications Conference (ITNAC), 2016
In disasters and emergencies severity of trauma and loss of life can be reduced by more effective... more In disasters and emergencies severity of trauma and loss of life can be reduced by more effective communication between emergency workers, volunteers, and survivors. Typically, almost all of these parties will hold mobile phones (in addition to special purpose wireless communication devices, in the case of emergency workers), which are likely to be used intensively to seek and to provide aid to those in need. However, the utility of mobile phones may be limited by battery life. The usefulness of these mobile phones can therefore be enhanced by extending battery life. One way to extend battery life is to introduce a duty cycle, i.e. a pattern of use where the phone is alternately sleeping and active. It is shown below that under some broad assumptions about the type of emergency, it is best to introduce such a duty cycle straight away, and to start with quite short sleep cycles, which increase exponentially, but with a relatively slow rate of growth of the sleep cycle duration. Simul...
Proceedings of ICC'97 - International Conference on Communications
The paper provides insight into the performance of a candidate IEEE 802.14 MAC protocol for hybri... more The paper provides insight into the performance of a candidate IEEE 802.14 MAC protocol for hybrid fibre/coax (HFC) networks, by simulation. The simulations make use of two types of input traffic: measured traffic traces, and randomly generated memoryless traffic. It is confirmed that the protocol does not reach congestion collapse under any traffic load, and this is found to hold regardless of traffic type. The paper demonstrates that memoryless traffic streams cannot be used for dimensioning guidelines as they underestimate delay as compared to real traffic traces. The paper also compares between the performance of the protocol loaded by traffic traces with that of a benchmark based on an ideal multiplexer under the same traffic conditions. It is demonstrated that both the throughput and delay performance of the protocol converge to that of an ideal multiplexer, with an increasing number of active stations
Proceedings of INFOCOM '94 Conference on Computer Communications
... The traffic models amenable to analysis that have been Moshe Zukerman ... Let D, be the net o... more ... The traffic models amenable to analysis that have been Moshe Zukerman ... Let D, be the net output process; ie for all n D, = 0, - r . Clearly, for the case of infinite buffer E{A,} = E{O,} . Also, from Daley [8], for the case of an infinite buffer queue: ...
Abstract—In this paper, the results and analysis of the measured data for multiple-input multiple... more Abstract—In this paper, the results and analysis of the measured data for multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) channels in indoor environment, in presence of pedestrian, are reported. The experiment used 4 sending and 4 receiving antennas and 114 OFDM sub-carriers for each transmission. The mean channel capacity and the dynamic range of the received power increased with the number of pedestrians present within the indoor environment. Each transmitter-to-sender sub-channel had a Signal to Noise Ration (SNR) of 15 db. With three pedestrians, the mean channel capacity rose by up to 2 bps/Hz compared to the vacant room scenario due to the increase in multipath conditions caused by body-shadowing effects. This demonstrates that the use of MIMO in the indoor environment is effective in compensating for the presence of pedestrians. Keywords- multiple-input multiple-output (MIMO), channel capacity, multipath channels. I.
2019 29th International Telecommunication Networks and Applications Conference (ITNAC)
The concept that cybersecurity architecture is the discovery, definition and validation of rules ... more The concept that cybersecurity architecture is the discovery, definition and validation of rules is introduced. The new concept of inference graphs for illustrating the relationship between cybersecurity rules is defined. Three increasingly complex examples of inference graphs for systems needing cybersecurity architecture are presented, including the detailed proofs which form the basis of these inference graphs, in some cases. The software which has been developed to support the development and use of cybersecurity inference graphs is described including details of the public server where it can be used. It is shown that cybersecurity inference graphs can significantly contribute to development of, and validation of cybersecurity and also that rigorous validation of cybersecurity is not necessarily as difficult as previously thought.
Comparison between alternative technologies for switching and routing is difficult for several re... more Comparison between alternative technologies for switching and routing is difficult for several reasons: (i) the range of options is quite large and appears to demand knowledge over a very wide range – wider than we can reasonably expect to find in any one individual; (ii) in addition, each of the alternative technical solutions can potentially be used in combination with one of more of its competitors; (iii) the impact on the traffic being handled is difficult to model, and therefore it is almost inconceivable that we can predict the performance which can be delivered by complex configurations. In this paper we propose and develop a unified framework for multiple technologies that interwork together. To do this we adopt a simple model based on the principle that (i) technologies can be modelled as layers; (ii) traffic can be modelled as a Poisson stream of flows; and (iii) the dynamic (and static) choice between layers can be modelled by a strategy for splitting traffic between laye...
Australian Journal of Telecommunications and the Digital Economy, 2017
All network traffic is a by-product of social networking behaviour. In this paper, Anonymized Int... more All network traffic is a by-product of social networking behaviour. In this paper, Anonymized Internet (IP) Trace Datasets obtained from the Center for Applied Internet Data Analysis (CAIDA) have been used to identify and estimate characteristics of the underlying social network from the overall traffic. The analysis methods used here fall into two groups, the first being based on frequency analysis and second method being based on the use of traffic matrices, with the later analysis method being further sub-divided into groups based on the traffic mean, variance and co-variance. The frequency analysis of origin (O), destination (D) and O-D Pair statistics exhibit heavy tailed behaviour. Because the large number of IP addresses contained in the CAIDA Datasets, only the most predominate IP Addresses are used when estimating all three sub-divided groups of traffic matrices. Principal Component Analysis (PCA) and related methods are applied to identify key features of each type of traf...
This mathematica notebook is based on the one called fBmShiftTransformation10b.nb, which was in t... more This mathematica notebook is based on the one called fBmShiftTransformation10b.nb, which was in turn based on animate/animate3.nb. Section 1 includes basic definitions, Section 2 defines a function which estimates exit probability, for a process with a given down-crossing, by simulation. Section 3 then estimates the last exit density, which is carried out in detail for the cases H=0.75, 0.5, 0.85, and 0.35. Relative finality is found by fitting to the simulations, and this is then used to estimate the last exit density.
This report contains the Mathematica code, used to implement the aggregate EMF spectral density d... more This report contains the Mathematica code, used to implement the aggregate EMF spectral density due to several nearby transmitters.
Role-based delegation model (RBDM) based on the role-based access control (RBAC) has proven to be... more Role-based delegation model (RBDM) based on the role-based access control (RBAC) has proven to be a flexible and useful access control model for infor- mation sharing in a distributed collaborative environ- ment. In today's highly dynamic distributed systems, a user often needs to ...
Abstract. We present the formal model for a collection of Universal Forms Servers which allow use... more Abstract. We present the formal model for a collection of Universal Forms Servers which allow users distributed over peers to create webbased forms, capture data for these forms, and re-use information associated to forms located at different peers. Access rules included in the form definitions regulate both read and write rights of end-users, and also impose an implicit workflow on the entry of data. Hence, whereas current Workflow systems require the explicit modelling of workflow processes before deployment, our system enables ...
Bi-Directional Grid Constrained (BGC) stochastic processes (BGCSPs) constrain the random movement... more Bi-Directional Grid Constrained (BGC) stochastic processes (BGCSPs) constrain the random movement toward the origin steadily more and more, the further they deviate from the origin, rather than all at once imposing reflective barriers, as does the well-established theory of Itô diffusions with such reflective barriers. We identify that BGCSPs are a variant rather than a special case of the multi-skew Brownian motion (M-SBM). This is because they have their own complexities, such as the barriers being hidden (not known in advance) and not necessarily constant over time. We provide a M-SBM theoretical framework and also a simulation framework to elaborate deeper properties of BGCSPs. The simulation framework is then applied by generating numerous simulations of the constrained paths and the results are analysed. BGCSPs have applications in finance and indeed many other fields requiring graduated constraining, from both above and below the initial position.
2016 26th International Telecommunication Networks and Applications Conference (ITNAC), 2016
In disasters and emergencies severity of trauma and loss of life can be reduced by more effective... more In disasters and emergencies severity of trauma and loss of life can be reduced by more effective communication between emergency workers, volunteers, and survivors. Typically, almost all of these parties will hold mobile phones (in addition to special purpose wireless communication devices, in the case of emergency workers), which are likely to be used intensively to seek and to provide aid to those in need. However, the utility of mobile phones may be limited by battery life. The usefulness of these mobile phones can therefore be enhanced by extending battery life. One way to extend battery life is to introduce a duty cycle, i.e. a pattern of use where the phone is alternately sleeping and active. It is shown below that under some broad assumptions about the type of emergency, it is best to introduce such a duty cycle straight away, and to start with quite short sleep cycles, which increase exponentially, but with a relatively slow rate of growth of the sleep cycle duration. Simul...
Proceedings of ICC'97 - International Conference on Communications
The paper provides insight into the performance of a candidate IEEE 802.14 MAC protocol for hybri... more The paper provides insight into the performance of a candidate IEEE 802.14 MAC protocol for hybrid fibre/coax (HFC) networks, by simulation. The simulations make use of two types of input traffic: measured traffic traces, and randomly generated memoryless traffic. It is confirmed that the protocol does not reach congestion collapse under any traffic load, and this is found to hold regardless of traffic type. The paper demonstrates that memoryless traffic streams cannot be used for dimensioning guidelines as they underestimate delay as compared to real traffic traces. The paper also compares between the performance of the protocol loaded by traffic traces with that of a benchmark based on an ideal multiplexer under the same traffic conditions. It is demonstrated that both the throughput and delay performance of the protocol converge to that of an ideal multiplexer, with an increasing number of active stations
Proceedings of INFOCOM '94 Conference on Computer Communications
... The traffic models amenable to analysis that have been Moshe Zukerman ... Let D, be the net o... more ... The traffic models amenable to analysis that have been Moshe Zukerman ... Let D, be the net output process; ie for all n D, = 0, - r . Clearly, for the case of infinite buffer E{A,} = E{O,} . Also, from Daley [8], for the case of an infinite buffer queue: ...
Abstract—In this paper, the results and analysis of the measured data for multiple-input multiple... more Abstract—In this paper, the results and analysis of the measured data for multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) channels in indoor environment, in presence of pedestrian, are reported. The experiment used 4 sending and 4 receiving antennas and 114 OFDM sub-carriers for each transmission. The mean channel capacity and the dynamic range of the received power increased with the number of pedestrians present within the indoor environment. Each transmitter-to-sender sub-channel had a Signal to Noise Ration (SNR) of 15 db. With three pedestrians, the mean channel capacity rose by up to 2 bps/Hz compared to the vacant room scenario due to the increase in multipath conditions caused by body-shadowing effects. This demonstrates that the use of MIMO in the indoor environment is effective in compensating for the presence of pedestrians. Keywords- multiple-input multiple-output (MIMO), channel capacity, multipath channels. I.
2019 29th International Telecommunication Networks and Applications Conference (ITNAC)
The concept that cybersecurity architecture is the discovery, definition and validation of rules ... more The concept that cybersecurity architecture is the discovery, definition and validation of rules is introduced. The new concept of inference graphs for illustrating the relationship between cybersecurity rules is defined. Three increasingly complex examples of inference graphs for systems needing cybersecurity architecture are presented, including the detailed proofs which form the basis of these inference graphs, in some cases. The software which has been developed to support the development and use of cybersecurity inference graphs is described including details of the public server where it can be used. It is shown that cybersecurity inference graphs can significantly contribute to development of, and validation of cybersecurity and also that rigorous validation of cybersecurity is not necessarily as difficult as previously thought.
Comparison between alternative technologies for switching and routing is difficult for several re... more Comparison between alternative technologies for switching and routing is difficult for several reasons: (i) the range of options is quite large and appears to demand knowledge over a very wide range – wider than we can reasonably expect to find in any one individual; (ii) in addition, each of the alternative technical solutions can potentially be used in combination with one of more of its competitors; (iii) the impact on the traffic being handled is difficult to model, and therefore it is almost inconceivable that we can predict the performance which can be delivered by complex configurations. In this paper we propose and develop a unified framework for multiple technologies that interwork together. To do this we adopt a simple model based on the principle that (i) technologies can be modelled as layers; (ii) traffic can be modelled as a Poisson stream of flows; and (iii) the dynamic (and static) choice between layers can be modelled by a strategy for splitting traffic between laye...
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