Medium Access Control Protocols for Ad-Hoc Wireless Networks: A Survey

Studies of ad hoc wireless networks are a relatively new field gaining more popularity for various new applications. In these networks, the Medium Access Control (MAC) protocols are responsible for coordinating the access from active nodes. These protocols are of significant importance since the wireless communication channel is inherently prone to errors and unique problems such as the hidden-terminal problem, the exposed-terminal problem, and signal fading effects. Although a lot of research has been conducted on MAC protocols, the various issues involved have mostly been presented in isolation of each other. We therefore make an attempt to present a comprehensive survey of major schemes, integrating various related issues and challenges with a view to providing a big-picture outlook to this vast area. We present a classification of MAC protocols and their brief description, based on their operating principles and underlying features. In conclusion, we present a brief summary of key ideas and a general direction for future work

Promotion of Hospice and Homecare Programs in Thailand: A Framework for the Assessment of Costs and Benefits

Cancer is a leading cause of death in Thailand, yet the Mahavachiralongkorn Thanyaburi Cancer Center is the only facility utilizing hospice and homecare programs to address the needs of terminal cancer patients. Our project developed a Thai-specific patient quality of life survey to assess their program\u27s benefits. Coupled with protocols to record and compile patient data, our project provided the Cancer Center with a framework for proving the value of their services and promoting them to the Thai medical community

Factors influencing palliative care in advanced dementia : A systematic review

© Author(s) (or their employer(s)) 2019. No commercial re-use. See rights and permissions. Published by BMJ.Background: Dementia is a progressive neurodegenerative life-limiting disease. The international literature indicates that patients with advanced dementia can benefit from palliative care (PC) provided during the end-of-life phase. However, evidence indicates that currently many fail to access such provision despite the increased recognition of their palliative needs. Aim: To investigate the factors influencing provision of PC services for people with advanced dementia. Methods: A systematic review of mixed method studies written in English was undertaken. 11 electronic databases including Embase, Medline, PubMed, CINAHL and Scopus from 2008 to 2018 were searched. Narrative synthesis and content analysis were used to analyse and synthesise the data. Key findings: In total, 34 studies were included. 25 studies providing qualitative data, 6 providing quantitative data and 3 mixed methods studies. The findings identified organisational, healthcare professionals and patients-related barriers and facilitators in provision of PC for people with advanced dementia from perspective of stakeholders across different care settings. The most commonly reported barriers are lack of skills and training opportunities of the staff specific to PC in dementia, lack of awareness that dementia is a terminal illness and a palliative condition, pain and symptoms assessment/management difficulties, discontinuity of care for patients with dementia and lack of coordination across care settings, difficulty communicating with the patient and the lack of advance care planning. Conclusions: Even though the provision of PC was empirically recognised as a care step in the management of dementia, there are barriers that hinder access of patients with dementia to appropriate facilities. With dementia prevalence rising and no cure on the horizon, it is crucial that health and social care regulatory bodies integrate a palliative approach into their care using the identified facilitators to achieve optimal and effective PC in this population.Peer reviewe

An efficient scalable scheduling mac protocol for underwater sensor networks

Underwater Sensor Networks (UWSNs) utilise acoustic waves with comparatively lower loss and longer range than those of electromagnetic waves. However, energy remains a challenging issue in addition to long latency, high bit error rate, and limited bandwidth. Thus, collision and retransmission should be efficiently handled at Medium Access Control (MAC) layer in order to reduce the energy cost and also to improve the throughput and fairness across the network. In this paper, we propose a new reservation-based distributed MAC protocol called ED-MAC, which employs a duty cycle mechanism to address the spatial-temporal uncertainty and the hidden node problem to effectively avoid collisions and retransmissions. ED-MAC is a conflict-free protocol, where each sensor schedules itself independently using local information. Hence, ED-MAC can guarantee conflict-free transmissions and receptions of data packets. Compared with other conflict-free MAC protocols, ED-MAC is distributed and more reliable, i.e., it schedules according to the priority of sensor nodes which based on their depth in the network. We then evaluate design choices and protocol performance through extensive simulation to study the load effects and network scalability in each protocol. The results show that ED-MAC outperforms the contention-based MAC protocols and achieves a significant improvement in terms of successful delivery ratio, throughput, energy consumption, and fairness under varying offered traffic and number of nodes