The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Driven by the energy consumption concerns, renewable energy harvesting is introduced to reduce the energy demand from the traditional power grid. As a key technology of wireless communications, heterogeneous networks can achieve the spectrum and energy efficiency by deploying various low transmit power base stations, which provide an ideal scenario to utilize the renewable energy harvesting to supply...
Restricted Access Window (RAW) has been introduced to IEEE 802.11ah MAC layer to decrease collision probability. However, the inappropriate application of RAW for different groups of devices would increase uplink energy consumption and decrease data rate. In this paper, we study an energy efficient RAW optimization problem for IEEE 802.11ah based uplink communications. We first present a novel retransmission...
This paper considers power control in energy cooperation enabled heterogeneous networks (HetNets), where each base station (BS) is powered by hybrid energy sources consisting of the conventional power grid and renewable energy sources. Energy can be transferred between BSs with energy loss during the energy transmission process. Transmit power, grid power consumption, and transferred energy are optimized...
Energy efficiency is a crucial challenge in cluster-based capillary networks for Internet of Things (IoT) systems, where the cluster heads (CHs) selection has great impact on the network performance. It is an optimization problem to find the optimum number of CHs as well as which devices are selected as CHs. In this paper, we formulate the clustering problem into the CHs selection procedure with the...
Restricted Access Window (RAW) has been introduced to IEEE 802.11ah MAC layer for application of smart grid networks to decrease collision probability. The number of devices involved and duration affect both transmission energy and overhead information. However, few work has been done on energy efficient RAW. In this paper, we investigate an energy efficient RAW optimization problem for IEEE 802.11ah...
Restricted Access Window (RAW) has been introduced for IEEE 802.11ah MAC layer to decrease collision probability. However, both the number of devices involved and duration of a RAW affect the transmission energy and overhead information. In this paper, we study the energy efficiency of the uplink communications of IEEE 802.11ah networks and propose an access window algorithm using probability theory...
Machine to machine (M2M) communications is one of the key underpinning technologies for Internet of Things (IoT) applications in 5G networks. The large scale of M2M devices imposes challenge on conventional medium access control protocols. In this paper, we propose a reinforcement learning (RL) based duty cycle control for dominant short-range technology IEEE 802.15.4 to provide high performance and...
Base station (BS) sleeping has been proved to be an effective technique for saving energy consumption in cellular networks. However, BSs in sleeping mode might cause coverage holes, which have a negative impact on the connectivity of the network. In order to overcome this problem, we propose a combined coordinated multi-point (CoMP) transmission and BS sleeping scheme under the heterogeneous networks...
Cooperative multiple-input-single-output (CMISO) introduces cooperative nodes (Coops) to reduce the energy consumption of the cluster head (CH) in cluster-based M2M capillary networks. Although CMISO reduces energy consumption of CH, it introduces additional energy overhead to Coops, which contributes to a reduction of network lifetime. In this paper, we propose a joint CH and Coops selection (JCCS)...
IEEE 802.15.4 beacon-enabled mode adopts duty cycle to achieve energy efficiency and provides an optional acknowledgement (ACK) mechanism to ensure the transmission reliability. However, frequently sending ACK introduces additional ACK transmission energy consumption and increases end-to-end delay. In this paper, we focus on a duty cycle optimisation problem with joint consideration on energy efficiency,...
IEEE 802.15.4 defines a duty cycle based medium access control (MAC) protocol to reduce the energy consumption for devices in wireless sensor networks (WSNs). A low duty cycle significantly improves the energy efficiency but reduces the available transmission time, thereby increases end-to-end delay. In this paper, we solve an adaptive duty cycle control problem for beacon-enabled IEEE 802.15.4 networks,...
In wireless sensor networks (WSNs), periodically switching nodes into sleep mode is an effective way to reduce the energy consumption. However, the sleep period introduces additional end-to-end delay into packet delivery. We propose an optimal transmission policy, which assigns the number of packets per node should receive at each active period to minimize the end-to-end delay and the energy consumption...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.