Haleh Khojasteh

Learn More
The paper describes a simple channel scan protocol through which a station can quickly discover and join an existing piconet following a specified channel-hopping MAC protocol piconet in its vicinity. The proposed MAC protocol is simple and does not need a dedicated control channel. Moreover, the cognitive piconet can operate normally throughout the search,(More)
To save energy, physical machines (servers) in cloud data centers are partitioned in different pools, depending on whether they are kept on at all times and/or whether they have virtual machines instantiated. Partitioning (pooling) of servers affects the power consumption of the data center but also the performance and responsiveness to user requests. In(More)
In this paper, we analyze an efficient pool management model for cloud systems that partitions the servers (physical machines) into a hot and cold pool to improve energy efficiency. Servers are moved them from one pool to the other as needed to fulfill the incoming task requests, which are provisioned on virtual machines running on the servers. The model(More)
In this paper, we propose a coexistence scheme that allows radio-frequency identification readers or sinks to collect data from radio-frequency identification tags or sensors that use IEEE 802.15.4 wireless personal area network standard and send it to the access point via an IEEE 802.11 wireless local area network. The proposed scheme uses time scheduling(More)
Spectrum decision – i.e., the selection of a channel for the next hop – is one of the most important factors that affect the performance of a channel-hopping cognitive network. In this paper, we compare the performance of a number of channel selection algorithms through the probability of collisions with primary user transmissions. The results indicate that(More)
In this paper we propose a task admission control scheme in a cloud system. We develop two task admission control algorithms which are based on a random task filtering policy. First, we present a lightweight task admission control algorithm which is appropriate for the cloud systems with smooth changes of task arrival rate. This algorithm is based on(More)
Mash-ups combine several data sources in order to make dynamic content/service/application creation available. Moreover, with the development of mobile internet, mobile mash-up become more important in mobile software as they assemble applications and sources from both internet and mobile network. In this paper, we will review the main components of mobile(More)
We investigate the coexistence of Wi-Fi (WLAN) and RFID/sensor networks that use IEEE 802.15.4 standard in the Industrial, Scientific and Medical (ISM) frequency band. To minimize the interference between the networks, a time scheduling scheme is combined with a sleeping scheme for RFID tags/sensors to further reduce the collision rate and energy(More)