Author: Watcharachai Kongsiriwattana
Kongsiriwattana, Watcharachai, 2019 Energy and related factors in sustaining mobile telecommunications in disaster contexts, Flinders University, College of Science and Engineering
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Currently, a mobile phone or a smartphone is a device or gadget used for voice, text, video, and data communication. Due to its versatility, the modern mobile phone consumes much more energy or battery life while operating, particularly when turning on Wi-Fi or mobile data. To find out and answer whether a mobile phone battery life can be enhanced to operate for a longer period of time, particularly in disaster or emergency situations, this thesis, thus, investigates the energy and related factors on a mobile phone
in disaster contexts by dividing into four major aspects as follows:
First, mobile phones are useful in disaster response. However, they have limited battery life, and during disaster situations, there may be fewer opportunities to recharge them. A survey of emergency responders and other private citizens shows that there is a clear short-fall in the battery life of mobile phones, which typically operate for only around one day before requiring a recharge, being only approximately half, or 15 hours too short, of the endurance required, depending on the measure applied.
Second, the battery life of most mobile phones is insufficient to enable their effective use throughout a disaster or emergency situation without requiring a recharge. Therefore, this thesis surveys and classifies a number of strategies that can be used for disaster response or for people living beyond the reach of ubiquitous reliable main electricity supply. This thesis presents simple methodology and results for a sample of mobile telephone charging products and techniques to compare and assess our sample of solutions to those currently available, with the intention of making our findings realistic and directly actionable for disaster response practitioners.
Third, through the analysis of eleven years of fine-grained data from the Queensland electricity network from the years 2005 to 2016, it becomes apparent that widespread and long-lasting blackouts are not uncommon in this region. In this thesis, a simple mobile phone battery life prediction model is employed to anticipate the number of mobile phones that would be flat on an hour-by-hour basis over the eleven years. This data clearly demonstrates that it is not feasible to extend mobile phone battery life so as to prevent battery depletion in such events, and that the policy focus should therefore be on ensuring that alternative means of recharging are easily available.
Fourth, in this thesis, it draws on innovations in passive radio sensing, and combine these with a simple Contiki-inspired protocol that can be used with existing Wi-Fi hardware to allow use of ad-hoc Wi-Fi with zero energy consumption when idle, yet allow communications to be established in milliseconds. Feasibility is demonstrated through proof-of-concept hardware, demonstrating that it is possible to provide devices with ad-hoc Wi-Fi communications capabilities with zero impact on stand-by energy consumption. This simple innovation reactivates the possibility of true peerto-peer high-bandwidth, low-latency direct phone-to-phone communications, without any supporting equipment, such as a Serval Mesh Extender, increasing the opportunities for resilient and decentralized mobile communications during a disaster.
The contributions of this research are that a mobile phone in disaster contexts should concern about battery life mostly depleted due to human behaviour and Wi-Fi function on a mobile phone. Therefore, the best way to increase a battery life is recharging a mobile phone as soon as power supply is available using normal or alternative phone recharging strategies. Also, this thesis shows the relationship between mobile phone battery life and people living without electricity during disaster situation, and how this make it practically certain that during disasters that many people will not be able to maintain sufficient charge in their mobile telephones which can cause a flat mobile phone as discussed in chapter 6. A further recommendation for this research is to determine how to improve energy efficiency techniques on disaster communication based on mobile phone ad hoc network by considering valuable information based on proposed technique in this thesis.
Keywords: Mobile phone battery life, Smartphone, Alternative phone charging, Disaster communications, Energy efficiency, Power consumption, Wi-Fi Adhoc network, Power outages
Subject: Computer Science thesis
Thesis type: Doctor of Philosophy
Completed: 2019
School: College of Science and Engineering
Supervisor: Paul Gardner-Stephen