- Title
- Enhanced energy efficiency techniques for packet transmission in IEEE 802.11 networks
- Creator
- W. Muhamad, Wan Norsyafizan
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2017
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- In today’s world, the wireless communication has become an essential part of our daily activities. With the rising demand for wireless communication services the energy consumption has become one of the primary concerns for the ICT industry as it does not only increases the operational costs but also generate negative environmental effects, such as increased greenhouse gas emissions when energy is drawn from fossil fuel energy sources. Higher energy usage also increases the battery charging frequency. Due to these reasons, the demand for energy efficient network design is increasing. In this research, several energy efficient packet transmission techniques for the IEEE802.11 WLAN have been developed to reduce device energy consumptions, while meeting the quality of service (QoS) requirements of the data traffic. The rate and power adaptation algorithms were developed initially based on a single transmission parameter adaptation technique, which adapts the transmission data rate according to the measured network packet delay. Simulation results shows that the energy efficiency of IEEE802.11 networks can be increased up to 16% compared to the previously published works on the optimal low-energy transmission strategy known as the Miser scheme. The energy saving is increased to 26.9% when compared with the standard IEEE 802.11 MAC protocol. At lower traffic loads, the proposed algorithm works reasonably well, offering energy savings while maintaining the QoS performances. However, as the load increases, the algorithm cannot maintain the QoS indicators. The single parameter approach, which is the rate adaptation method based on the measured delay is unable to control higher collision levels when the traffic load started to increase. Uncontrolled collisions would result in higher energy consumption as well as increase the end to end delay. Therefore, to resolve this problem, the work further enhanced the rate and power adaptation algorithm by introducing a new cost function based approach, which is a multi-parameter based optimization technique. The work demonstrated that the proposed cost function algorithm offers significant energy savings of 33% compared to the single parameter approach. The work further explored other dynamic packet transmission techniques using the proposed adaptive contention window length adjustment and the adaptive packet size adjustment techniques to improve the energy efficiency while maintaining the QoS performances. Both approaches were developed to reduce network collision levels by adapting the MAC parameters according to the traffic load conditions. Simulation results for both the CW adaptation and the packet size adjustment techniques show that the proposed algorithms outperforms the non-adaptive algorithms in terms of lower energy consumption as well as improved QoS performances. Finally, to deal with the fading conditions, the rate adaptation algorithm is further enhanced by introducing an effective channel monitoring technique, which tracks the received signal power and adapts the transmission parameters based on varying channel condition as well as with the traffic load conditions. The algorithm adapts the transmission data rate by selecting more robust modulation and coding schemes to combat against low and variable SNR conditions. This reduces the probability of packet loss as well as the technique contributes to lower packet retransmissions. Lower number of retransmissions contributed to 13.9% reduction of energy consumption as compared to the cost function approach. To analyses the performance of proposed energy efficient packet transmission techniques, discrete event simulation models were developed.
- Subject
- energy efficiency; WLAN; QoS; link adaptation; data rate
- Identifier
- http://hdl.handle.net/1959.13/1343185
- Identifier
- uon:29102
- Rights
- Copyright 2017 Wan Norsyafizan W. Muhamad
- Language
- eng
- Full Text
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| Thumbnail | File | Description | Size | Format | |||
|---|---|---|---|---|---|---|---|
| View Details Download | ATTACHMENT01 | Thesis | 2 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 468 KB | Adobe Acrobat PDF | View Details Download |