Performance Comparison of Dynamic Guard Channel Assignment with Buffered Prioritized Scheme for Mobile WiMAX Network

Abstract—Priority is usually given to handover traffic in mobile communication but doing so has the tendency of increasing call blocking probability. It was said previously that non-prioritized call traffic channel assignment scheme reduces call blocking probability more than other basic channel assignment schemes at high handover traffic intensities. A comparison of channel assignment schemes by analysis and MATLAB simulation in this research has shown that dynamic guard channel assignment scheme based on channel utilization minimizes call blocking probability better than non-prioritized, prioritized guard channel and prioritized guard channel with queue/buffer. The wireless technology used was Mobile WiMAX with mobile assisted handover (MAHO) and the queueing policy employed was M/M/C/Q with FCFS service discipline

Improving Prioritized Handover Performance for Mobile WiMAX by Dynamic Guard Channel Allocation and RSS Quality Factor

In cellular communication, guard channel has been used to provide priority to ongoing call traffic crossing cell boundaries in handover process but the major concern is that most guard channel allocation scheme are fixed channels. System congestion problems arising from traffic pattern in the real world is another major concern relating to fixed allocation of guard channels let alone the huge traffic that will emanate from user mobility in the envisaged converged traffic of 4G networks. Hence, dynamic guard channel (DGC) allocation based on traffic intensity or channel utilization of each traffic type was used in this research and it reduced the new call blocking probability better than the fixed prioritized guard channel (PGC) and non-prioritized channel allocation scheme. Its performance in terms of call dropping probability reduction is comparable with the PGC and slightly better off at poor signal condition. It was revealed that DGC averaged QoS better than the existing channel assignment schemes. An investigation into the RSS quality factor (QF) proposed also, showed that at high quality RSS the blocking and dropping probability of the traffic were reduced for the Mobile WiMAX wireless technology network with mobile assisted handover

Radio activity and radiological hazards from a kaolinmining field in Ifonyintedo,Nigeria

The concentrations of the radio nuclides in the subsurface formation (soilsandrocks) solely depend on their geological origin, which enables its variation from point to point on the Crust.Construction materials can possess elevated concentrations of radio activity if their by products are mined from contaminated radio nuclide sources.In this article, results of insitu measurements of radio activity concentrations of 40K, 232Th, and 238U as well as gamma doses and radiological hazards from kaolin mining field were presented and evaluated.Eleven stations were randomly occupied in order to cover the upper axis of akaolin mining field in Ifonyintedo.The radio metric survey was achieved using Super-Spec(RS-125), equipment capable of measuring activity concentrations and gamma doses. For each location, measurements were taken four times, while its mean and standard deviation values were estimated for better accuracy. The over all mean activity concentrations(for 40K, 232Th and 238U) and gamma dose were estimated as 93. 9Bqkg�1, 65.1Bqkg�1, 38.2Bqkg�1, and59.6nGyh�1 respectively.The estimated radiological hazards from the measured parameters showed that the overall mean concentrations of Radium Equivalent, External and Internal Hazards,Annual Effective Dose,Gamma and Alpha Indices,and Representative Level index are 138.5Bqkg �1, 0.370.48, 0.29mSvyr�1, 0.48,0.19, and 0.97respectively.By comparing the mean values of the activity concentrations and their radiological risks with the several world standards from the literature, kaolin deposits in Ifonyintedo are highly rich in thorium

Data on the radio metric survey over a kaolinitic terrain in Dahomey Basin,Nigeria

This article consists the insitu data sets of activity concentrations of radio nuclides (K-40,Th-232andU-238) and gamma radiation dose rates measured about 1m above a kaolinitic terrain in Ifo-nyintedo,Dahomey Basin,SW Nigeria.Nineteen(19)data points were randomly occupied at the lower axis of the kaolin field using a hand-held detector known as Super-Spec(RS125).At each data point, the measurements were taken four times,while their averages and standard deviations were estimated in order to ensure accuracy.The radio metric survey was carried out between December,2017andJanuary,2018.The data sets were processed and analyzed via a descriptive statistics. The data can be explored further by estimating the radiological risks to the miners on the field, and to correlate the activity concentrations of the data with the activity concentrations of the tiles that are produced from the kaolin deposits in Ifonyintedo. Furthermore,the data from this article could be compared with other data acquired over a kaoli-nitic terrain across the glob

A Comparative Simulation Study of IP, MPLS, MPLS-TE for Latency and Packet Loss Reduction over a WAN

The need for improved network performance towards providing reliable services in the face of growing demand on enterprise network and internet service across all sectors of the economy has become very paramount. Latency and packet loss as quality of service (QoS) metrics are issues of concern since different multimedia applications, voice and data packets have to be delivered to end systems over long distances. This study investigated the technology behind the delivery of the packets by comparing the performance of each of IP, MPLS and MPLS-TE on the same congested WAN design. The results showed that MPLS-TE had the least latency and barely any packet los

Effect of Increasing Buffer Size on Prioritized Guard Channels with Queue during Call Traffic Congestion

Prioritized guard channel (PGC) assignment with queue was designed to reduce call dropping probability associated with a base station congested with handover call traffic. The Markov chain was used in the analysis of the PGC scheme and queuing discipline was FIFO for a PGC+MAHO scheme. Simulation was carried out using MATLAB. The results showed that increasing buffer size reduces call dropping probability which becomes discontinuous at some value of traffic arrival rate for each buffer size. It was found out that some queuing parameters such as queue product form becomes undefined at an arrival rate for a large buffer size. This limits the extent to which buffer size can be increased. System computational speed was also a contributory facto

Data on the radio metric survey over a kaolinitic terrain in Dahomey Basin,Nigeria

This article consists the insitu data sets of activity concentrations of radio nuclides (K-40,Th-232andU-238) and gamma radiation dose rates measured about 1m above a kaolinitic terrain in Ifo-nyintedo,Dahomey Basin,SW Nigeria.Nineteen(19)data points were randomly occupied at the lower axis of the kaolin field using a hand-held detector known as Super-Spec(RS125).At each data point, the measurements were taken four times,while their averages and standard deviations were estimated in order to ensure accuracy.The radio metric survey was carried out between December,2017andJanuary,2018.The data sets were processed and analyzed via a descriptive statistics. The data can be explored further by estimating the radiological risks to the miners on the field, and to correlate the activity concentrations of the data with the activity concentrations of the tiles that are produced from the kaolin deposits in Ifonyintedo. Furthermore,the data from this article could be compared with other data acquired over a kaoli-nitic terrain across the glob

Performance Evaluation of Dynamic Guard Channels Assignment with Queue and Prioritized Schemes

It has been said that dynamic guard channel (DGC) assignment scheme based on traffic intensities averages QoS and performs better than the prioritized guard channel assignment scheme with queue (QPGC) during traffic congestion. This work has extended the investigation to DGC with queue (QDGC) and carried out its comparison with other call traffic channel assignment schemes. Mathematical analysis of the models was done using Markov chain and simulation was carried out in MATLAB. When traffic arrival rates were symmetric, the QPGC had the lower call blocking probability than the QDGC but became the same when the system was congested. However, the performance of the two queuing schemes was the same when handover call traffic was more than new calls traffic

A Decision Support System for Information Technology Policy Formulation

The implementation of an effective ICT policy requires the development of material and intellectual resources to support good decision making by humans.   In this paper, we examined and analysed Information Technology (IT) policy development process with a view to developing automated system supporting such process.  The data used for this work were obtained through purposeful interview of five professionals and experts who are familiar with IT policy formulation in Nigerian environment.  Some of the experts had earlier participated in policy design and formulation process at national level.     The Hierarchical Input Process Output (HIPO) model was used to analyse various input (contributions of professionals and experts) and output (agreed resolution of the professionals and experts) of the system.  The information obtained from the experts was represented using rule base techniques.  The overall system was designed using the Unified Modelling Language (UML) and implemented using the Visual Prolog version 7.0.  The metrics used for evaluating the system includes: processing time, decision process efficiency and cost effectiveness.   We compared the result of our system with that of the traditional manual system in use.  Our result showed that the DSS for policy formulation process enhances the decision output significantly when compared to the manual process where no DSS is used.  Moreover, the quality of policy produced by our DSS system is more consistent when compared with the manual process.

Background Radiation from 238U, 232Th, and 40K in Bells Area and Canaan City, Ota, Nigeria

Natural radionuclides are present in every constituent of the environment. Monitoring of environmental radionuclides is very vital to avoid exposure above the threshold limit. Due to this, the background radiation from 238U, 232Th, and 40K of Bell University of Technology and Canaan Land City was determined from 20 sample points each in the two areas using RS230 Gamma Spectrometer. The mean activity concentration of 40K, 238U, and 232Th for Bells University of Technology was 442.66 Bq/kg, 41.98 Bq/kg, and 48.35 Bq/Kg, respectively. In Canaan City, mean activity concentration of 40K, 238U, and 232Th was 373.65 Bq/kg, 18.85 Bq/kg, and 67.22 Bq/kg, respectively. The mean absorbed dose rates recorded by the spectrometer directly were 70.03 nGy/h and 66.65 nGy/h, while that estimated from the activity concentration were 67.06 and 64.89 nGy/h for Bells University and Canaan City, respectively. The measured and estimated absorbed dose rates were higher than the safe limit of 57 nGy/h. The mean values of other radiological parameters estimated, except that of the gamma index and excess lifetime cancer risk were lower when compared to the recommended limit. It could be concluded that the possibility of suffering any radiation risk is low in these two areas, but there is possibility of cancer risk for someone that has stayed in the area for 70 years and above