Prioritization-based adaptive emergency traffic medium access control protocol for wireless body area networks

Wireless Body Area Networks (WBANs) provide continuous monitoring of a patient by using heterogeneous Bio-Medical Sensor Nodes (BMSNs). WBANs pose unique constraints due to contention-based prioritized channel access, sporadic emergency traffic handling and emergency-based traffic adaptivity. In the existing medium access control protocols, the available contention-based prioritized channel access is incomplete due to the repetitions in backoff period ranges. The emergency traffic is considered based on traffic generation rate as well as sporadic emergency traffic that is not handled at multiple BMSNs during contention. In an emergency situation, non-emergency traffic is ignored, traffic is not adjusted dynamically with balanced throughput and energy consumption, and the energy of non-emergency traffic BMSNs is not preserved. In this research, prioritization-based adaptive emergency traffic Medium Access Control (MAC) protocol was designed to consider contention-based prioritized channel access for heterogenous BMSNs along with sporadic emergency traffic handling and dynamic adjustment of traffic in sporadic emergency situation. Firstly, a Traffic Class Prioritization based slotted-CSMA/CA (TCP-CSMA/CA) scheme was developed to provide contention-based prioritized channel access by removing repetitions in backoff period ranges. Secondly, an emergency Traffic Class Provisioning based slotted-CSMA/CA (ETCP-CSMA/CA) scheme was presented to deliver the sporadic emergency traffic instantaneously that occurs either at a single BMSN or multiple BMSNs, with minimum delay and packet loss without ignoring non-emergency traffic. Finally, an emergency-based Traffic Adaptive slotted-CSMA/CA (ETA-CSMA/CA) scheme provided dynamic adjustment of traffic to accommodate the variations in heterogeneous traffic rates along with energy preservation of non-emergency traffic BMSNs, creating a balance between throughput and energy in the sporadic emergency situation. Performance comparison was conducted by simulation using NS-2 and the results revealed that the proposed schemes were better than ATLAS, PLA-MAC, eMC-MAC and PG-MAC protocols. The least improved performances were in terms of packet delivery delay 10%, throughput 14%, packet delivery ratio 21%, packet loss ratio 28% and energy consumption 37%. In conclusion, the prioritization-based adaptive emergency traffic MAC protocol outperformed the existing protocols

Dynamic and Dual Streaming Methods for H.264 Video and Parallel Performance Modeling

Traditional approaches to streaming H.264 video over a network typically rely on a single method of transport (i.e., reliable or unreliable) and/or use static values for parameters that can have a significant negative impact on the perceptual quality of the received video. This dissertation presents a dynamic method for wireless channel selection during video streaming, and explores the latency and QoE improvements yielded by the FDSP dual streaming method. The increased workload that results from these dynamic methods can lead to a counterproductive impairment of streaming performance, and therefore requires efficient use of the multiple cores typically present in both sender and receiver (or server and client). This dissertation therefore presents a performance cost model which can be used to guide the parallelization of specific types of client or server-side streaming components -- specifically, programs containing non-DOALL loops that have inter-iteration data dependences which constrain their parallelism

Acceptance model of SaaS cloud computing at northern Malaysian main campus public universities

Technology advancement has side effects, although it has moved in a fast pace that facilitated life and increased business revenue. To cope with negative aspects while looking for friendly technology, Software as a Service (SaaS) Cloud Computing emerged to preserve natural resources, effectively utilize computing and power consumption, while achieving performance, decreasing cost, and increasing revenue. Yet, there are paucity in empirical studies investigating salient factors affecting the usage, acceptance, or adoption of SaaS services from the individual perspectives specifically in higher education sector. The main objective of this study is to investigate the salient factors with proper model that includes technical, social and control characteristics, as well as user security predisposition. Besides, educational level has also proven to be influential in adopting innovations. Hence, probing its role is another objective. The last objective is to investigate differences between student and lecturer groups in the relationships postulated in the model. A survey with questionnaires was conducted on students and lecturers in four public universities in Northern Malaysia. The scope of the acceptance is to investigate the personal-level use of SaaS services. Decomposed Theory of Planned Behaviour (DTPB) and Diffusion of Innovation Theory (DOI) were applied. Results revealed appropriateness of the model although the role of Trialability and Subjective Norms were not significance. The findings contribute to the body of knowledge and literature in highlighting the role of these factors that SaaS providers could benefit in planning for new services and in promoting SaaS usage to universities